Dissertations / Theses: 'Combined power plant'

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Rosso, Stefano. "Power Plant Operation Optimization Economic dispatch of combined cycle power plants." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264350.

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As electricity production from renewable sources increases, higher flexibility is required by fossil fuel generation to cope with the inherent fluctuations of solar and wind power. This results in shorter operating cycles and steeper ramps for the turbines, and more uncertainty for the operators. This thesis work applies mathematical optimization and statistical learning to improve the economic dispatch of a combined cycle power plant composed by two separate blocks of two gas turbines and one steam turbine. The goal is to minimize the input fuel to the gas turbines while respecting a series of constraints related to the demand the plant faces, power generation limits etc. This is achieved through the creation of a mathematical model of the plant that regulates how the plant can operate. The model is then optimized to reduce fuel consumption at a minimum. Machine learning techniques have been applied to sensor data from the plant itself to realistically simulate the behavior of the turbines. Input-Output curves have been obtained for power and exhaust heat generation of all the turbines using ordinary least squares on monthly data with a ten minutes sampling rate. The model is cross-validated and proven statistically valid. The optimization problem is formulated through generalized disjunctive programming in the form of a mixed-integer linear problem (MILP) and solved using a branch-and-bound algorithm. The output of the model is a one-week dispatch, in fifteen minutes intervals, carried out for two months in total. Lower fuel consumption is achieved using the optimization model, with a weekly reduction of fuel consumed in the range of 2-4%. A sensitivity analysis and a correlation matrix are used to highlights the demand and the maximum available capacity as critical parameters. Results show that the most efficient machines (alternatively, the ones with highest available capacity) should be operated at maximum load while still striving for an efficient utilization of the exhaust gas.
När elproduktionen från förnybara källor ökar krävs högre flexibilitet av fossil bränsleproduktion för att hantera fluktuationerna från sol- och vindkraft. Detta resulterar i kortare driftscykler och brantare ramper för turbinerna och mer osäkerhet för operatörerna. Detta avhandlingsarbete tillämpar matematisk optimering och statistisk inlärning för att förbättra det ekonomiska utnyttjandet av en kombicykel i ett kraftverk som består av två separata block med två gasturbiner och en ångturbin. Målet är att minimera bränsleförbrukningen hos gasturbinerna samtidigt som man tar hänsyn till en serie av villkor relaterade till efterfrågan som anläggningen står inför, kraftproduktionsbegränsningar etc. Detta uppnås genom skapandet av en matematisk modell för anläggningen som reglerar hur anläggningen kan fungera. Modellen är sedan optimerad för minsta möjliga bränsleförbrukning. Maskinteknik har använts på sensor data från själva anläggningen för att realistiskt simulera turbinernas beteende. In och utdata kurvor har erhållits för kraftproduktion och avgasvärmeproduktion med hjälp av ordinary least squares (OLS) med månads data och med en tio minuters samplingshastighet. Modellen är korsvaliderad och bevisad statistiskt giltig. Optimeringsproblemet formuleras genom en generaliserad disjunktiv programmering i form av ett mixed-integer linear problem (MILP) och löses med hjälp av en Branch-and-Bound algoritm. Resultatet från modellen är en veckas värden, med femton minuters intervall, totalt i två månader. Lägre bränsleförbrukning uppnås med hjälp av optimeringsmodellen, med en vecka minskad bränsleförbrukning i intervallet 2-4%. En känslighetsanalys och en korrelationsmatris används för att visa efterfrågan och den maximala tillgängliga kapaciteten som kritiska parametrar. Resultaten visar att de mest effektiva maskinerna (alternativt de med högsta tillgängliga kapacitet) bör drivas med maximal belastning medan de fortfarande strävar efter ett effektivt utnyttjande av avgaserna.

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2

Bengtsson, Sara. "Modelling of a Power System in a Combined Cycle Power Plant." Thesis, Uppsala universitet, Elektricitetslära, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-149318.

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Simulators for power plants can be used for many different purposes, like training for operators or for adjusting control systems, where the main objective is to perform a realistic behaviour for different operating conditions of the power plant. Due to an increased amount of variable energy sources in the power system, the role of the operators has become more important. It can therefore be very valuable for the operators to try different operating conditions like island operation. The aim of this thesis is to model the power system of a general combined-cycle power plant simulator. The model should contain certain components and have a realistic behaviour but on the same time be simple enough to perform simulations in real time. The main requirements are to simulate cold start, normal operation, trip of generator, a controlled change-over to island operation and then resynchronisation. The modelling and simulations are executed in the modelling software Dymola, version 6.1. The interface for the simulator is built in the program LabView, but that is beyond the scope of this thesis. The results show a reasonable performance of the power system with most of the objectives fulfilled. The simulator is able to perform a start-up, normal load changes, trip of a generator, change-over to island operation as well as resynchronisation of the power plant to the external power grid. However, the results from the changing-over to island operation, as well as large load losses during island operation, show an unreasonable behaviour of the system regarding the voltage magnitude at that point. This is probably due to limitations in calculation capacity of Dymola, and the problem has been left to further improvements due to lack of time. There has also been a problem during the development of a variable speed regulated induction motor and it has not been possible to make it work due to lack of enough knowledge about how Dymola is performing the calculations. Also this problem has been left to further improvements due to lack of time.

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Hassan, Mohamed Elhafiz. "Power Plant Operation Optimization : Unit Commitment of Combined Cycle Power Plants Using Machine Learning and MILP." Thesis, mohamed-ahmed@siemens.com, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-395304.

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In modern days electric power systems, the penetration of renewable resources and the introduction of free market principles have led to new challenges facing the power producers and regulators. Renewable production is intermittent which leads to fluctuations in the grid and requires more control for regulators, and the free market principle raises the challenge for power plant producers to operate their plants in the most profitable way given the fluctuating prices. Those problems are addressed in the literature as the Economic Dispatch, and they have been discussed from both regulator and producer view points. Combined Cycle Power plants have the privileges of being dispatchable very fast and with low cost which put them as a primary solution to power disturbance in grid, this fast dispatch-ability also allows them to exploit price changes very efficiently to maximize their profit, and this sheds the light on the importance of prices forecasting as an input for the profit optimization of power plants. In this project, an integrated solution is introduced to optimize the dispatch of combined cycle power plants that are bidding for electricity markets, the solution is composed of two models, the forecasting model and the optimization model. The forecasting model is flexible enough to forecast electricity and fuel prices for different markets and with different forecasting horizons. Machine learning algorithms were used to build and validate the model, and data from different countries were used to test the model. The optimization model incorporates the forecasting model outputs as inputs parameters, and uses other parameters and constraints from the operating conditions of the power plant as well as the market in which the plant is selling. The power plant in this mode is assumed to satisfy different demands, each of these demands have corresponding electricity price and cost of energy not served. The model decides which units to be dispatched at each time stamp to give out the maximum profit given all these constraints, it also decides whether to satisfy all the demands or not producing part of each of them.

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4

Zheng, J. "Combined pinch and exergy analysis for commercial power plant design." Thesis, University of Manchester, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.532908.

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This thesis addressesth e analysisa nd design of commercial power plants by using the Combined Pinch and Exergy Approach. Current practice in design for commercial power plants heavily relies on experience and computer simulation and lacks systematic design methodologies. On the contrary, Pinch Technology allows systematic and generic approaches to chemical process design in which targets are set prior to design. These approaches can address issues related to process integration and optimisation. This thesis exploits the analogy between power plant design and chemical process design and applies the philosophy of Pinch Technology to the field of power plant design. In this thesis, the "onion" model used to represent the hierarchy of chemical process design is applied to power plant design. This model decomposes the whole design problem into three relatively simple tasks, including turbine system selection, heat exchanger network (HEN) design and fuel supply determination. Complex interactions exist between these individual components. To describe the complex interactions between the different components, a qualitative tool called the Combined Pinch and Exergy Representation (CPER) has been developed. The CPER allows engineers to visualise the overall performance of a power plant and the interactions between components. This diagram can also help engineers to screen design options. A quantitative tool, called the shaftwork targeting approach, has been developed in this thesis to evaluate each possible design option and identify the most promising one ahead of detailed simulation and designA tool called the Exergy Remaining Problem Analysis (ERPA) has been developed to guide HEN design. This allows the design to achieve the shaftwork targets. By evaluating the impact of individual matches on the remaining problem, the ERPA can determine the influence of individual matches on shaftwork generation. By detecting inappropriate matches, the ERPA can ensure that the HEN design meets the shaftwork targets. Based on the "onion" model of power plant, a systematic and generic approach to power plant design has been developed. In this approach, power plant design starts with the turbine system, then moves to the heat exchanger network and the fuel supply. This approach is entirely general which can be applied for design of different power plants. The significance of the new approach is that it enables engineers to screen possible design options with physical understanding and identify the most promising design option ahead of detailed simulation and design. This speeds up the overall design process and ensures that an optimal solution is obtained. vi

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Qur'an, Omar Ali Sammour. "Design criteria and performance of steam turbines in a CPP plant for electrical power generation." Thesis, University of Hertfordshire, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247306.

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6

Bergström, Jarl, and Conny Franzon. "Thermo-economic optimization of a combined heat and power plant in Sweden : A case study at Lidköping power plant." Thesis, Blekinge Tekniska Högskola, Institutionen för industriell ekonomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-20766.

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Energy production in power plants comes with both high costs and turnover whereas variations in the production strategy—that is, which boilers, coolers, or generators that should be running—have big impact on the economic result. This is especially true for a combined heat and power (CHP) plant where the production of district heating and electricity is linked, thus allowing for a higher flexibility in the production strategy and potential of increasing the revenue. Previous research states that thermo-economic optimization can have a great impact on economic result of power plants, but every power plant is operating under a unique set of conditions depending on its location, operating market, load demand, construction, surrounding, and the like, and comparable studies on CHP plants in Sweden are very few. This study aims to fill this research gap by evaluating savings potential of a CHP plant in Lidköping, Sweden by utilizing thermo-economic optimization with the approach of combining actual historical data from the power plant with mass-flow equations and constraints to construct a mathematical MODEST model that is optimized by linear programming. The result demonstrates a clear theoretical potential to improve earnings and the conclusion that the studied CHP would benefit by implementing optimization procedures or software to schedule production. The result was also comparable to previous research but varied over time, which highlights how unique conditions may impact the result.

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Al-Hamdan, Qusai Zuhair Mohammed. "Design criteria and performance of gas turbines in a combined power and power (CPP) plant for electrical power generation." Thesis, University of Hertfordshire, 2002. http://hdl.handle.net/2299/14041.

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The simple gas turbine engine Operates on the basic Joule-Brayton cycle and it is notorious for its poor thermal efficiency. Several modifications have been made to the simple cycle in order to increase its thermal efficiency but, within the thermal and mechanical stress constrains, the efficiency still ranges between 28 and 35%. However, higher values of energy utilisation efficiency have been claimed in recent years by using low grade heat from the engine exhaust either for district heating or for raising low pressure steam for chemical processes. Both applications are not very attractive in hot countries. The concept of using the low grade thermal energy from the gas turbine exhaust to raise steam in order to drive a steam turbine and generate additional electricity, i. e. the combined power and power or CPP plant would be more attractive in hot countries than the CHP plant. It was hypothesized that the operational parameters, hence the performance of the CPP plant, would depend on the allowable gas turbine entry temperature. Hence, the exhaust gas temperature could not be decided arbitrarily. This thesis deals with the performance of the gas turbine engine operating as a part of the combined power and power plant. In a CPP plant, the gas turbine does not only produce power but also the thermal energy that is required to operate the steam turbine plant at achievable thermal efficiency. The combined gas turbine-steam turbine cycles are thermodynamically analysed. A parametric study for different configurations of the combined gas-steam cycles has been carried out to show the influence of the main parameters on the CPP cycle performance. The parametric study was carried out using realistic values in view of the known constraints and taking into account any feasible future developments. The results of the parametric study show that the maximum CPP cycle efficiency would be at a point for which the gas turbine cycle would have neither its maximum efficiency nor its maximum specific work output. It has been shown that supplementary heating or gas turbine reheating would decrease the CPP cycle efficiency; hence, it could only be justified at low gas turbine inlet temperatures. Also it has been shown that although gas turbine intercooling would enhance the performance of the gas turbine cycle, it would have only a slight effect on the CPP cycle performance. A graphical method for studying operational compatibility, i.e. matching, between gas turbine components has been developed for a steady state or equilibrium operation. The author would like to submit that the graphical method offers a novel and easy to understand approach to the complex problem of component matching. It has been shown that matching conditions between the compressor and the turbine could be satisfied by superimposing the turbine performance characteristics on the compressor performance characteristics providing the axes of both were normalised. This technique can serve as a valuable tool to determine the operating range and the engine running line. Furthermore, it would decide whether the gas turbine engine was operating in a region of adequate compressor and turbine efficiencies. A computer program capable of simulating the steady state off-design conditions of the gas turbine engine as part of the CPP plant has been developed. The program was written in Visual Basic. Also, another program was developed to simulate the steady state off-design operation of the steam turbine power plant. A combination of both programs was used to simulate the combined power plant. Finally, it could be claimed that the computer simulation of the CPP plant makes significant contribution to the design of thermal power plants as it would help in investigating the effects of the performance characteristics of the components on the performance of complete engines at the design and off-design conditions. This investigation of the CPP plant performance can be carried out at the design and engineering stages and thus help to reduce the cost of manufacturing and testing the expensive prototype engines.

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8

Bhatt, Dhruv. "Economic Dispatch of the Combined Cycle Power Plant Using Machine Learning." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-266110.

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Combined Cycle Power Plant (CCPP)s play a key role in modern powersystem due to their lesser investment cost, lower project executiontime, and higher operational flexibility compared to other conventionalgenerating assets. The nature of generation system is changing withever increasing penetration of the renewable energy resources. Whatwas once a clearly defined generation, transmission, and distributionflow is shifting towards fluctuating distribution generation. Because ofvariation in energy production from the renewable energy resources,CCPP are increasingly required to vary their load levels to keep balancebetween supply and demand within the system. CCPP are facingmore number of start cycles. This induces more stress on the gas turbineand as a result, maintenance intervals are affected.The aim of this master thesis project is to develop a dispatch algorithmfor the short-term operation planning for a combined cyclepower plant which also includes the long-term constraints. The longtermconstraints govern the maintenance interval of the gas turbines.These long-term constraints are defined over number of EquivalentOperating Hours (EOH) and Equivalent Operating Cycles (EOC) forthe Gas Turbine (GT) under consideration. CCPP is operating in theopen electricity market. It consists of two SGT-800 GT and one SST-600 Steam Turbine (ST). The primary goal of this thesis is to maximizethe overall profit of CCPP under consideration. The secondary goal ofthis thesis it to develop the meta models to estimate consumed EOHand EOC during the planning period.Siemens Industrial Turbo-machinery AB (SIT AB) has installed sensorsthat collects the data from the GT. Machine learning techniqueshave been applied to sensor data from the plant to construct Input-Output (I/O) curves to estimate heat input and exhaust heat. Resultsshow potential saving in the fuel consumption for the limit on CumulativeEquivalent Operating Hours (CEOH) and Cumulative EquivalentOperating Cycles (CEOC) for the planning period. However, italso highlighted some crucial areas of improvement before this economicdispatch algorithm can be commercialized.
Kombicykelkraftverk spelar en nyckelroll i det moderna elsystemet pågrund av den låga investeringskostnaden, den korta tiden för att byggaett nytta kraftverk och hög flexibilitet jämfört med andra kraftverk.Elproduktionssystemen förändras i takt med en allt större andel förnybarelproduktion. Det som en gång var ett tydligt definierat flödefrån produktion via transmission till distribution ändrar nu karaktärtill fluktuerande, distribuerad generering. På grund av variationernai elproduktion från förnybara energikällor finns ett ökat behov avatt kombicykelkraftverk varierar sin elproduktion för att upprätthållabalansen mellan produktion och konsumtion i systemet. Kombicykelkraftverkbehöver startas och stoppas oftare. Detta medför mer stresspå gasturbinen och som ett resultat påverkas underhållsintervallerna.Syftet med detta examensarbete är att utveckla en algoritm för korttidsplaneringav ett kombicykelkraftverk där även driften på lång siktbeaktas. Begränsningarna på lång sikt utgår från underhållsintervallenför gasturbinerna. Dessa långsiktiga begränsningar definieras som antaletekvivalenta drifttimmar och ekvivalenta driftcykler för det aktuellakraftverket. Kombikraftverket drivs på den öppna elmarknaden.Det består av två SGT-800 GT och en SST-600 ångturbin. Det främstamålet med examensarbetet är att maximera den totala vinsten förkraftverket. Ett sekundärt mål är att utveckla metamodeller för attskatta använda ekvivalenta drifttimmar och ekvivalenta driftcyklerunder planeringsperioden.Siemens Industrial Turbo-machinery AB (SIT AB) har installeratsensorer som samlar in data från gasturbinerna. Maskininlärningsteknikerhar tillämpats på sensordata för att konstruera kurvor för attuppskatta värmetillförseln och avgasvärme. Resultaten visar en potentiellbesparing i bränsleförbrukningen om de sammanlagda ekvivalentadrifttimmarna och de sammanlagda ekvivalenta driftcyklernabegränsas under planeringsperioden. Det framhålls dock också att detfinns viktiga förbättringar som behövs innan korttidsplaneringsalgoritmenkan kommersialiseras.

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9

Yevalkar, Amol. "Integrated Combined Heat and Power Plant with Borehole Thermal Energy Storage." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-266787.

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Countries like Sweden, that experience temperatures below 0 𝑜C, have a high heating demand during winters. The heating demand in Sweden is satisfied through district heating, electric heating, heat pumps and biofuel boilers. The fossil fuels account for around 5 % of the heating market. Sweden is currently looking for alternative solutions in order to replace the fossil fuels. One of the solutions being studied is to have a Borehole Thermal Energy Storage (BTES) system that can store the excess heat produced from a Combined Heat and Power (CHP) plant during the summer. In previous studies, a dynamic model of BTES system was developed which was limited for a specific case. In order to design the BTES systems for different cases as well, a generic steady-state sizing model was developed. This generic steady-state sizing model is flexible can be used to determine the size of BTES in terms of number of boreholes, borehole depth, etc. as per the requirements of the user. Few key results for different input parameters from the newly developed steady-state sizing model and the existing dynamic model were compared for several simulations in order to validate the new steady-state model. The results for a reference case of 240 m borehole depth and 0.8 kg/s mass flow rate in the borehole loop were presented. Further a sensitivity analysis was done by varying the borehole depth and the mass flow rate in the borehole loop. It showed that the Net Present Value (NPV) of the entire system after 20 years and BTES efficiency were higher for lower borehole depth and higher mass flow rate in the borehole loop.
Länder som Sverige, som upplever temperaturer under 0 𝑜C, har ett högt värmebehov under vintrarna. Värmebehovet i Sverige tillgodoses genom fjärrvärme, elvärme, värmepumpar och pannor eldade med biobränsle. Fossila bränslen står för cirka 5 % av värmemarknaden. Sverige letar för närvarande efter alternativa lösningar för att ersätta de fossila bränslena. En av lösningarna som studeras är att ha värmelagring i borrhål (Borehole Thermal Energy Storage, BTES) som kan lagra överskottsvärmen som produceras från en kraftvärmeanläggning under sommaren. I tidigare studier utvecklades en dynamisk modell av ett BTES-system som var begränsat till ett specifikt fall. För att utforma BTES-system även för andra fall, utvecklades en generisk modell. Denna generiska dimensioneringsmodell för stabiliseringsstatus är flexibel och kan användas för att bestämma storleken på BTES när det gäller antalet borrhål, borrhålsdjup etc. enligt användarens krav. Några nyckelresultat för olika ingångsparametrar från den nyutvecklade statiska dimensioneringsmodellen och den befintliga dynamiska modellen jämfördes för flera simuleringar för att validera den nya statiska modellen. Resultaten för ett referensfall på 240 m borrhålsdjup och 0,8 kg/s massflödeshastighet i borrhålslingan presenterades. Dessutom utfördes en känslighetsanalys genom att variera borrhålens djup och massflödeshastigheten i borrhålslingan. Det visade sig att både nettonuvärdet (net present value, NPV) för hela systemet efter 20 år och BTES-effektiviteten var högre för lägre borrhåldjup och högre massflödeshastighet i borrhålsslingan.

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10

Bouzguenda, Mounir. "Study of the combined cycle power plant as a generation expansion alternative." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/101165.

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Analysis of future alternatives for US utilities is needed as a part of evaluating the impact of combined cycle and phased-construction of integrated coal gasifier power plants on generation expansion. The study encompassed both large and small electric utilities and long-run, least-cost expansion plan for the generating system and studies of the short-run production cost of electrical generation for selected years. The long-run studies were carried out using the Wien Automatic System Planning Package (WASP-II). The optimal combined cycle penetration level was determined for a set of assumptions that involve economics, new technology trends, and feasibility as well as the utility's existing capacity and load forecast. Additional cases were run to account for phased construction and coal gasification. Two electric utilities were selected in this study. These are a U.S. southeastern utility the Bangladesh Electric Utility. The former was chosen as the large utility. The latter was considered a small size utility. WASP-II enhancements enabled us to run cases using IBM-RT and to account for phased construction. The sensitivity studies involved the penetration levels, the fuel supply (oil and natural gas), and economic dispatch of coal gasifiers in particular, and combined cycle power plants in general. Load forecast, and availability of hydroelectric energy were kept uniform. However, adding new power plants and retiring old ones were considered to achieve a more economical and reliable planning strategy while considering issues of technical feasibility.
M.S.

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11

Horkeby, Kristofer. "Simulation of Heat Recovery Steam Generator in a Combined Cycle Power Plant." Thesis, Linköpings universitet, Institutionen för systemteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-75836.

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This thesis covers the modelling of a Heat Recovery Steam Generator (HRSG) in a Combined Cycle Power Plant(CCPP). This kind of power plant has become more and more utilized because of its high efficiency and low emissions. The HRSG plays a central role in the generation of steam using the exhaust heat from the gas turbine. The purpose of the thesis was to develop efficient dynamic models for the physical components in the HRSG using the modelling and simulation software Dymola. The models are then to be used for simulations of a complete CCPP.The main application is to use the complete model to introduce various disturbances and study their consequences inthe different components in the CCPP by analyzing the simulation results. The thesis is a part of an ongoingdevelopment process for the dynamic simulation capabilities offered by the Solution department at SIT AB. First, there is a theoretical explanation of the CCPP components and control system included in the scope of this thesis. Then the development method is described and the top-down approach that was used is explained. The structure and equations used are reported for each of the developed models and a functional description is given. Inorder to ensure that the HRSG model would function in a complete CCPP model, adaptations were made and tuning was performed on the existing surrounding component models in the CCPP. Static verifications of the models are performed by comparison to Siemens in-house software for static calculations. Dynamic verification was partially done, but work remains to guarantee the validity in a wide operating range. As a result of this thesis efficient models for the drum boiler and its control system have been developed. An operational model of a complete CCPP has been built. This was done integrating the developed models during the work with this thesis together with adaptations of already developed models. Steady state for the CCPP model is achieved during simulation and various disturbances can then be introduced and studied. Simulation time for a typical test case is longer than the time limit that has been set, mainly because of the gas turbine model. When using linear functions to approximate the gas turbine start-up curves instead, the simulation finishes within the set simulation time limit of 5 minutes for a typical test case.

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Smith, P. J. "Predicting hot corrosion rates under coal fired combined cycle power plant conditions." Thesis, Cranfield University, 1994. http://dspace.lib.cranfield.ac.uk/handle/1826/10512.

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Type 11 hot corrosion has been identified as a major life limiting factor of gas turbine components in the topping cycle of coal fired combined cycle power plant. Impurities in the coal combustion gases provide the environmental contaminants necessary for type 11 hot corrosion to occur. It is the purpose of the present study to develop corrosion lifting models such that corrosion rates and thus component lives in coal fired combined cycle plant gas turbines may be accurately predicted thus minimising efficiency losses and plant downtime due to corrosion related problems. Type 11 hot corrosion has been shown to follow bi11lodal distributions which cannot be modelled using the well known mathematical models. It has been shown that a probabilistic approach to modelling is appropriate and that the Gumbel Type I extreme value model of maxima can be used to model the maximum extreme corrosion data This is appropriate as it is the maximum extreme corrosion which in life limiting in the plant gas turbine. Basic corrosion data has been generated through a series of laboratory hot corrosion tests designed to simulate the ambient conditions within the plant gas turbine. The variables having most influence on the corrosion process have been identified as ; temperature, thermal cycling, alkali (Na + K) metal sulphate deposition rate, S02 and HCl in the ambient atmosphere. The corrosion models have been developed from this data which accurately predict the type 11 hot corrosion rates observed in the coal fired gas turbine of a combined cycle power plant .

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Yilmaz, Oguz. "Participation Of Combined Cycle Power Plants To Power System Frequency Control: Modeling And Application." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607228/index.pdf.

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This thesis proposes a method and develops a model for the participation of a combined cycle power plant to power system frequency control. Through the period of integration to the UCTE system, (Union for Coordination of Transmission of Electricity in Europe) frequency behavior of Turkey&rsquo
s grid and studies related to its improvement had been a great concern, so is the reason that main subject of my thesis became as &ldquo
Power System Frequency Control&rdquo
. Apart from system-wide global control action (secondary control)
load control loops at power plants, reserve power and its provision even at the minimum capacity generation stage, (primary control) are the fundamental concerns of this subject. The adjustment of proper amount of reserve at the power plants, and correct system response to any kind of disturbance, in the overall, are measured by the quality of the frequency behaviour of the system. A simulator that will simulate a dynamic gas turbine and its control system model, together with a combined cycle power plant load controller is the outcome of this thesis.

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Safyel, Zerrin. "Enhancement Of The Bottoming Cycle In A Gas/steam Combined Cycle Power Plant." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12605896/index.pdf.

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A combined cycle gas/steam power plant combines a gas turbine (topping cycle) with a steam power plant (bottoming cycle) through the use of a heat recovery steam generator. It uses the hot exhaust of the gas turbine to produce steam which is used to generate additional power in the steam power plant. The aim of this study is to establish the different bottoming cycle performances in terms of the main parameters of heat recovery steam generator and steam cycle for a chosen gas turbine cycle. First of all
for a single steam power cycle, effect of main cycle parameters on cycle performance are analyzed based on first law of thermodynamics. Also, case of existence of a reheater section in a steam cycle is evaluated. For a given gas turbine cycle, three different bottoming cycle configurations are chosen and parametric analysis are carried out based on energy analysis to see the effects of main cycle parameters on cycle performance. These are single pressure cycle, single pressure cycle with supplementary firing and dual pressure cycle. Also, effect of adding a single reheat to single pressure HRSG is evaluated. In single pressure cycle, HRSG generates steam at one pressure level. In dual pressure cycle, HRSG generates steam at two different pressure levels. i.e. high pressure and low pressure. In single pressure cycle with supplementary firing excess oxygen in exhaust gas is fired before entering HRSG by additional fuel input. So, temperature of exhaust gas entering the HRSG rises. Second law analysis is performed to able to see exergy distribution throughout the bottoming plant
furthermore second law efficiency values are obtained for single and dual pressure bottoming cycle configurations as well as basic steam power cycle with and without reheat. It is shown that maximum lost work due to irreversibility is in HRSG for a bottoming cycle in a single pressure gas / steam combined power plant and in boiler for a steam cycle alone. Comparing this with the single pressure cycle shows how the dual pressure cycle makes better use of the exhaust gas in the HRSG that dual pressure combined cycle has highest efficiency values and lost work due to irreversibility in -most significant component- HRSG can be lowered. And also it is shown that by extending the idea of reheat the moisture content is reduced and improvement in the performance is possible for high main steam pressures. Another observation is that supplementary firing increases the steam turbine output compared to the cycle without supplementary firing. The efficiency rises slightly for HP steam pressures higher than 14 MPa at HRSG exit, because the increased steam production also results in increased mass flows removing more energy from the exhaust gas.

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Safyel, Zerrin Supervisor :. Yeşin Tülay. "Enhancement of the bottoming cycle in a gas/steam combined cycle power plant." Ankara : METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12605896/index.pd.

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16

Wiesner, Emma. "Optimization and energy efficiency measures in modified combined heat and power plant processes : A case study of changed processes in Mälarenergi power plant." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-324389.

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The EU energy efficiency directive is driving the EU member states to set ambitious goals to increase energy efficiency. Mälarenergi AB is one of the Swedish energy companies, affected by the directive, that have taken an active role in order to increase efficiency within their energy production. This study was initiated to perform energy analysis and find energy optimization measures in the systems attached to one of Mälarenergi’s CHP-units, called P5.The operating conditions of the bio fueled combined heat and power plant, P5, recently changed when the connected boiler, P4, was decided to be shut down. The two boilers shared turbine, steam, feed water, condensate and oil systems, and the operating conditions of these systems changed radically when the mass flow decreased as P4 was shut down. The changed operating conditions affects the efficiency and the performance of the plant. The changed mass flow affects the capacity demands, efficiency in components and the technical conditions of the plant.The general approach through this thesis and the used methodology is based on initial analysis of the system changes, review of the necessary functions in the system and identification of the differences between the needed functions and the existing system. Optimization potential were identified where there were large differences and as a final step, technical and economic feasibility of implementing identified optimization measures was analyzed. The results shows that feasible optimization potential is identified in removing pumps without adjustable speed drives from the system, installing adjustable speed drives to the warm condensate pumps, replacing the dilution water pumps and detaching the atomization steam tank for P4. The economic feasibility to invest in a new direct heater, better adjusted to the operating conditions of P5, is small but could be an option to Mälarenergi if the alternative production cost remains high. Without the already installed adjustable speed drives in Mälarenergi’s plant the efficiency of the operations would be much lower than what it is today and the optimization potential essentially larger. The efficiency potential in the plant increases further when the attached turbine, G4, is to be dismantled and the operating conditions changes again. More extensive simplifications and rearrangements of the system can be made to decrease the energy demand for operations with 745 MWh/year.
EU:s energieffektiviserings direktiv ställer hårda krav på företag i medlemsländerna att kartlägga och analysera energiförbrukning för att identifiera åtgärder för att öka effektivitet. Utöver detta så har Sverige ambitiösa mål om ökad energieffektivitet i samtliga sektorer. Att effektivisera energiproduktionsanläggningar för att hitta effektiviseringspotential är därför aktuellt för svenska energiproducenter. Mälarenergi är ett av de energiföretag som arbetar aktivt med att kartlägga och minska sin energiförbrukning. Studien har därför genomförts för att granska panna 5 i Västerås kraftvärmeverk, för att undersöka hur energieffektiviseringsåtgärder kan identifieras i kraftvärmeprocesser där driftförutsättningar och processer har förändrats. Panna 5 har flertalet gemensamma processer med en äldre panna i anläggningen, panna 4, vars drift har upphört och pannan ska läggas ner. Driftförhållandena i de tidigare gemensamma systemen för kondensat, matarvatten, kylning och olja har därför förändrats och massflöden i systemen minskat kraftigt. De förändrade förhållandena och massflödena påverkar kapacitetsbehovet i systemen, effektiviteten i flertalet komponenter samt de tekniska kraven som ställs på panna 5. Den största förändringen i systemet är de minskade massflödena. Flödet i kondensatsystemet har minskat från ca 100 kg/s till 45 kg/s. Samma förändring i matarvattensystemet då panna 4 kopplas bort, är från 160 kg/s till 50 kg/s. Studien visar att det finns energieffektiviseringspotential i att byta ut pumpar vars pumpdrift har påverkats kraftigt, upphöra med drift av pumpar utan frekvensstyrning, installera frekvensstyrning på pumpar där flöden varierar samt förenkla och ta bort överflödiga processer som inte nyttjas vid de nya förhållandena. Processerna kan också optimeras genom att investera i en ny direktvärmare bättre lämpad för panna 5, dock är lönsamhetskalkylen för denna svag och ytterligare bedömning krävs. Resultatet visar även att då turbinen till panna 5 är uttjänt och nedmonteras så kan processerna kring panna 5 förenklas ytterligare och optimeras så pass att 745 MWh el för drift av pannan kan sparas varje år. Generellt kan det konstaterats att även förvärmare, matarvattentank och värmeväxlare är överdimensionerade när flödet i systemet minskar, kostnads-och energibesparingen för att byta ut dessa komponenter är dock negativa, eftersom komponenterna själva inte förbrukar någon energi. Att ha för stora kapaciteter i värmeväxlare bör snarare ses som en möjlighet, att kartlägga kapacitetsbehovet underlättar dock underhållsplanering i systemet. Den generella metoden som användes i studien bygger på modellen att först kartlägga de genomförda förändringarna i systemen, fastställa funktionskraven i det nya systemet och därefter analyserna skillnaderna mellan de fastställda funktionskraven och den befintliga tekniken. Optimeringspotential kan därefter identifieras där dessa två skiljer sig till stor del. Därefter utvärderas optimeringsåtgärden genom kvantitativ analys och investeringskalkylering.

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Carls, Fredrik. "Evaluation of machine learning methods for anomaly detection in combined heat and power plant." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-255006.

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In the hope to increase the detection rate of faults in combined heat and power plant boilers thus lowering unplanned maintenance three machine learning models are constructed and evaluated. The algorithms; k-Nearest Neighbor, One-Class Support Vector Machine, and Auto-encoder have a proven track record in research for anomaly detection, but are relatively unexplored for industrial applications such as this one due to the difficulty in collecting non-artificial labeled data in the field.The baseline versions of the k-Nearest Neighbor and Auto-encoder performed very similarly. Nevertheless, the Auto-encoder was slightly better and reached an area under the precision-recall curve (AUPRC) of 0.966 and 0.615 on the trainingand test period, respectively. However, no sufficiently good results were reached with the One-Class Support Vector Machine. The Auto-encoder was made more sophisticated to see how much performance could be increased. It was found that the AUPRC could be increased to 0.987 and 0.801 on the trainingand test period, respectively. Additionally, the model was able to detect and generate one alarm for each incident period that occurred under the test period.The conclusion is that ML can successfully be utilized to detect faults at an earlier stage and potentially circumvent otherwise costly unplanned maintenance. Nevertheless, there is still a lot of room for improvements in the model and the collection of the data.
I hopp om att öka identifieringsgraden av störningar i kraftvärmepannor och därigenom minska oplanerat underhåll konstrueras och evalueras tre maskininlärningsmodeller.Algoritmerna; k-Nearest Neighbor, One-Class Support Vector Machine, och Autoencoder har bevisad framgång inom forskning av anomalidetektion, men är relativt outforskade för industriella applikationer som denna på grund av svårigheten att samla in icke-artificiell uppmärkt data inom området.Grundversionerna av k-Nearest Neighbor och Auto-encoder presterade nästan likvärdigt. Dock var Auto-encoder-modellen lite bättre och nådde ett AUPRC-värde av 0.966 respektive 0.615 på träningsoch testperioden. Inget tillräckligt bra resultat nåddes med One-Class Support Vector Machine. Auto-encoder-modellen gjordes mer sofistikerad för att se hur mycket prestandan kunde ökas. Det visade sig att AUPRC-värdet kunde ökas till 0.987 respektive 0.801 under träningsoch testperioden. Dessutom lyckades modellen identifiera och generera ett larm vardera för alla incidenter under testperioden. Slutsatsen är att ML framgångsrikt kan användas för att identifiera störningar iett tidigare skede och därigenom potentiellt kringgå i annat fall dyra oplanerade underhåll. Emellertid finns det fortfarande mycket utrymme för förbättringar av modellen samt inom insamlingen av data.

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Wasantakorn, Aran. "Efficient power generation by integrating a MSW incinerator with a combined cycle gas turbine plant." Thesis, University of Sheffield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369938.

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19

García, José Angel. "Development and validation of a combined heat and power plant model for integration in DYESOPT." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264265.

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The liberalization of electricity markets and a growing penetration of renewables has led many countries to feel changes in the operation of their grids. The boundary conditions for the operation of conventional power plants are changing and, as such, an improved understanding of the varying loads and prices on the electricity grid is required to assess the performance of emerging combined cycle gas turbine (CCGT) concepts and to further optimize their design for these new markets in the pursuit of increasing their profitability, especially when considering co-generation of heat and power. A clear consequence of such renewable integration is the need for these plants to be more flexible in terms of tamping-up periods and higher part-load efficiencies. In the pursue of greater power plant dispatch flexibility, new ideas and technologies are being analyzed and tested in new and in already existing installations. Power plant simulations in modeling tools offer the possibility to have first estimates of how profitable it is to implement a new technology, operation scheme or dispatch strategy without having to invest in building the systems or applying any change to the operation of a real power plant. DYESOPT is one of the modeling tools used by researchers and consultants at KTH for simulating and doing techno-economic analyses of thermal energy systems. It has proven to be an accurate and customizable tool for the task. In that sense, the work in this thesis project is to enhance this modeling tool by incorporating a new power plant layout, which will be used in future works for increasing dispatch flexibility of a pilot combined heat and power plant. The power plant modeled consists on a topping Brayton cycle coupled to a bottoming Rankine cycle with three pressure levels, reheat features, and two extractions to feed a district heating system (one extraction from the low-pressure section of the steam turbine, and other from the economizer section of the heat recovery steam generator). The model was built considering the novel ideas to be tested on it and was then validated by comparing its performance against operational data provided by a real power plant during steady state conditions and part load transients. The results show that the validated model is of high relevance for further investigations regarding flexibility increase of CCGT-CHP power plants.

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20

Biliyok, Chechet. "Study of power plant with carbon dioxide capture ability through modelling and simulation." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/12111.

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With an increased urgency for global action towards climate change mitigation, this research was undertaken with the aim of evaluating post-combustion CO2 capture as an emission abatement strategy for gas-fired power plants. A dynamic rate-based model of a capture plant with MEA solvent was built, with imposed chemical equilibrium, and validated at pilot scale under transient conditions. The model predicted plant behaviour under multiple process inputs and disturbances. The validated model was next used to analyse the process and it was found that CO2 absorption is mass transfer limited. The model was then improved by explicitly adding reactions rate in the model continuity, the first such dynamic model to be reported for the capture process. The model is again validated and is observed to provide better predictions than the previous model. Next, high fidelity models of a gas-fired power plant, a scaled-up capture plant and a compression train were built and integrated for 90% CO2 capture. Steam for solvent regeneration is extracted from the power plant IP/LP crossover pipe. Net efficiency drops from 59% to 49%, with increased cooling water demand. A 40% exhaust gas recirculation resulted in a recovery of 1% efficiency, proving that enhanced mass transfer in the capture plant reduces solvent regeneration energy demands. Economic analysis reveals that overnight cost increases by 58% with CO2 capture, and cost of electricity by 30%. While this discourages deployment of capture technology, natural gas prices remain the largest driver for cost of electricity. Other integration approaches – using a dedicated boiler and steam extraction from the LP steam drum – were explored for operational flexibility, and their net efficiencies were found to be 40 and 45% respectively. Supplementary firing of exhaust gas may be a viable option for retrofit, as it is shown to minimise integrated plant output losses at a net efficiency of 43.5%. Areas identified for further study are solvent substitution, integrated plant part load operation, flexible control and use of rotating packed beds for CO2 capture.

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Mantilla, Gutierrez Weimar. "Towards Flexible Power Generation Short-term Optimization of a Combined Cycle Power Plant Integrated with an Inlet Air Conditioning Unit." Thesis, KTH, Energiteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-263904.

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Combined cycle gas turbine power plants (CCGT), as part of the electricity generation fleet, are required to improve their flexibility to help balance the power system under new scenarios with high shares of variable renewable sources. Among the different possibilities to enhance the power plant performance, an inlet air conditioning unit offers the benefit of power augmentation and “minimum environmental load” reduction by controlling the gas turbine intake temperature using cold thermal energy storage and a heat pump. In this thesis, an evaluation of the conditioning unit impact over a power-oriented CCGT under a day-ahead optimized operation strategy is presented. To establish the hourly dispatch of the power plant and the right operation mode of the inlet condition unit bringing the desired benefits, a mixed-integer linear optimization was formulated aiming to maximize the operational profit of the plant within a 24 hours horizon. To assess the impact of the proposed unit operating under this control strategy, annual simulations of a reference power plant were developed with and without the unit, allowing to a comparison of their performance by means of technical and economic indicators. Furthermore, a case study changing equipment sizes was performed in order to identify trends of the power plant performance related to such parameters; and lastly, a sensitivity analysis on market conditions to test the control strategy response was included. The results indicate that the inlet conditioning unit together with the dispatch optimization increase the power plant operational profit trough the gain of power variation over peak and off-peak periods. For the specific case study in northern Italy, it is shown that a power plant integrated with the conditioning unit is more profitable in terms of net present value based on the undertaken investment figures. Related to the technical performance, it also shows that the unit reduces by 1,34% the minimal environmental load when part-load operations are required and that it can increase the net power output by 0.17% annually. All in all, this study presents the benefits of a dispatch optimization strategy when couple to a novel solution to increase CCGT flexibility.
Elproducerande kombikraftverk (CCGT) förväntas förbättra sin flexibilitet för att kunna bidra till stabilisering av elnätet i framtida scenarier med ökande andel variabla, förnybara energikällor. Av de diverse metoder som finns att tillgå för att förbättra ett kraftverks prestanda, erbjuder en inluftsbehandlingsenhet både fördelar med kraftförbättring samt minskning av “minimun environmental load”; genom att med hjälp av kall termisk energilagring och en värmepump kontrollera gasens inluftstemperatur till gasturbinen. I den här uppsatsen undersöks hur en sådan inluftsbehandlingsenhet påverkar prestandan hos en kraftproduktionsfokuserad CCGT när en optimerad driftsstrategi introduceras. För att bestämma kraftverkets elproduktion vid varje timme och det korrekta driftläget för luftbehandlingsenheten (för att uppnå tidigare nämnda eftersökta fördelar) formulerades ett linjärt optimeringsproblem med syfte att maximera kraftverkets driftsförtjänst under ett 24-timmars tidsspann. För att bedöma den föreslagna inluftsbehandlingsenhetens inverkan under den optimerade driftsstrategin genomfördes simuleringar av ett referenskraftverk med och utan nämnda enhet, varpå en jämförelse med avseende på teknisk prestanda och ekonomi genomfördes. Vidare genomfördes en fallstudie där storlek på diverse utrustning varierades för att kunna identifiera trender i kraftverksprestanda baserat på dessa parametrar; slutligen genomfördes en känslighetsanalys rörande hur luftbehandlingsenheten och kontrollstrategin reagerar vid olika marknader.. Resultaten indikerar att en inluftsbehandlingsenhet tillsammans med en optimerad driftsstrategi ökar kraftverkets driftsvinning genom en ökad variation i kraftuttag över peak och off-peak timmar. För fallstudien i norra Italien fanns att ett kraftverk med integrerad luftbehandlingsenhet är mer lönsamt sett till nuvärdesanalys. Gällande teknisk prestanda visade resultaten att enheten minskar den minsta miljöbelastningen med 1,34 % när delbelastningsdrift fordras, och att det kan öka nettokraftuttag med 0,17% årligen. Sammanfattningsvis presenterar denna studie fördelarna med ett driftsoptimerat kraftverk kopplat till en ny lösning för att öka flexibilitet hos CCGT:er.

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22

Gonzalez, Diaz Abigail. "Sequential supplementary firing in natural gas combined cycle plants with carbon capture for enhanced oil recovery." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/20483.

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The rapid electrification through natural gas in Mexico; the interest of the country to mitigate the effects of climate change; and the opportunity for rolling out Enhanced Oil Recovery at national level requires an important R&D effort to develop nationally relevant CCS technology in natural gas combined cycle power plants. Post-combustion carbon dioxide capture at gas-fired power plants is identified and proposed as an effective way to reduce CO2 emissions generated by the electricity sector in Mexico. In particular, gas-fired power plants with carbon dioxide capture and the sequential combustion of supplementary natural gas in the heat recovery steam generator can favourably increase the production of carbon dioxide, compared to a conventional configuration. This could be attractive in places with favourable conditions for enhanced oil recovery and where affordable natural gas prices will continue to exist, such as Mexico and North America. Sequential combustion makes use of the excess oxygen in gas turbine exhaust gas to generate additional CO2, but, unlike in conventional supplementary firing, allows keeping gas temperatures in the heat recovery steam generator below 820°C, avoiding a step change in capital costs. It marginally decreases relative energy requirements for solvent regeneration and amine degradation. Power plant models integrated with capture and compression process models of Sequential Supplementary Firing Combined Cycle (SSFCC) gas-fired units show that the efficiency penalty is 8.2% points LHV compared to a conventional natural gas combined cycle power plant with capture. The marginal thermal efficiency of natural gas firing in the heat recovery steam generator can increase with supercritical steam generation to reduce the efficiency penalty to 5.7% points LHV. Although the efficiency is lower than the conventional configuration, the increment in the power output of the combined steam cycle leads a reduction of the number of gas turbines, at a similar power output to that of a conventional natural gas combined cycle. This has a positive impact on the number of absorbers and the capital costs of the post-combustion capture plant by reducing the total volume of flue gas by half on a normalised basis. The relative reduction of overall capital costs is, respectively, 9.1% and 15.3% for the supercritical and the subcritical combined cycle configurations with capture compared to a conventional configuration. The total revenue requirement, a metric combining levelised cost of electricity and revenue from EOR, shows that, at gas prices of 2$/MMBTU and for CO2 selling price from 0 to 50 $/tonneCO2, subcritical and supercritical sequential supplementary firing presents favourably at 47.3-26 $/MWh and 44.6-25 $/MWh, respectively, compared with a conventional NGCC at 49.5-31.7 $/MWh. When operated at part-load, these configurations show greater operational flexibility by utilising the additional degree of freedom associated with the combustion of natural gas in the HRSG to change power output according to electricity demand and to ensure continuity of CO2 supply when exposed to variation in electricity prices. The optimisation of steady state part-load performance shows that reducing output by adjusting supplementary fuel keeps the gas turbine operating at full load and maximum efficiency when the net power plant output is reduced from 100% to 50%. For both subcritical and supercritical combined cycles, the thermal efficiency at part-load is optimised, in terms of efficiency, with sliding pressure operation of the heat recovery steam generator. Fixed pressure operation is proposed as an alternative for supercritical combined cycles to minimise capital costs and provide fast response rates with acceptable performance levels.

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Jayasinghe, Prabodha. "Development of a tool for simulating performance of sub systems of a combined cycle power plant." Thesis, KTH, Energiteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99164.

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Abstract In Sri Lanka, around 50% of the electrical energy generation is done using thermal energy, and hence maintaining generation efficiencies of thermal power plants at an acceptable level is very important from a socio-economic perspective for the economic development of the country. Efficiency monitoring also plays a vital role as it lays the foundation for maintaining and improving of generation efficiency. Heat rate, which is the reciprocal of the efficiency, is used to measure the performance of thermal power plants. In combined cycle power plants, heat rate depends on ambient conditions and efficiencies of subsystems such as the gas turbine, Heat Recovery Steam Generator (HRSG), steam turbine, condenser, cooling tower etc. The heat rate provides only a macroscopic picture of the power plant, and hence it is required to analyse the efficiency of each subsystem in order to get a microscopic picture. Computer modelling is an efficient method which can be used to analyse the each subsystem of a combined cycle power plant. Objective of this research is to develop a computer based tool which simulates the performance of subsystems of a combined cycle power plant in Sri Lanka. At the inception of the research, only heat rate was measured, and performances of subsystem were unknown. During the analysis, plant is divided into main systems, in order to study them macroscopically. Then, these main systems are divided into subsystems in order to have a microscopic view. Engineering equation solver (EES) was used to develop the tool, and the final computer model was linked with Microsoft excel package for data handling. Final computer model is executed using both present and past operating data in order to compare present and past performance of the power plant. In combined cycle power plants steam is injected into the gas turbine to reduce the NOx generation and this steam flow is known as NOx flow. According to the result it was evident that turbine efficiency drops by 0.1% and power output increase by 1MW when NOx flow increases from 4.8 to 6.2kg/s. Further it was possible to conclude that gas turbine efficiency drop by 0.1% when ambient temperature increased by 3 C; and gas turbine power output decrease by 2MW when ambient temperature increases from 27 to 31 degrees. Regarding the steam cycle efficiency it was found that steam turbine power output drops by 0.5MW when ambient temperature increases from 27 to 31 degrees; and steam cycle efficiency increases by 1% when NOx flow increases from 4.8 to 6.2kg/s. Further, steam turbine power output decreases by 0.25MW When NOx flow increases from 4.8 to 6.2kg/s Heat rate, which is the most important performance index of the power plant, increases by 10units (kJ/kWh) when ambient temperature increases by 3 C. Heat rate also increases with raising NOx flow which was 6.2kg/s in 2007 and 4.2kg/s in 2011. Hence, heat rate of the power plant has improved (decreased) by 10units (kJ/kWh) from 2007 to 2011. Other than above, following conclusions were also revealed during the study. 1) HRSG efficiency has not change during past 4 years 2) Significant waste heat recovery potential exists in the gas turbine ventilation system in the form of thermal energy

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Bellingham, Christopher Grant. "The clean development mechanism potential of a combined heat and power plant in Stellenbosch, South Africa." Master's thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/5556.

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Lin, TsungPo. "An adaptive modeling and simulation environment for combined-cycle data reconciliation and degradation estimation." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24819.

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Thesis (Ph.D.)--Aerospace Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Dimitri Mavris; Committee Member: Erwing Calleros; Committee Member: Hongmei Chen; Committee Member: Mark Waters; Committee Member: Vitali Volovoi.

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Agha, Mujtaba Hassan. "Integrated management of energy and production : scheduling of batch process and Combined Heat & Power (CHP) plant." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT050G/document.

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Dans un contexte de développement durable, la question énergétique constitue un des problèmes majeurs des décennies à venir. Bien que la solution pour faire face à la raréfaction de certaines ressources, l'augmentation globale de la demande l'augmentation des émissions de CO2, réside dans le développement des énergies renouvelables, il est clair que ces nouvelles technologies ne seront matures que dans plusieurs décennies. A court terme, les énergies fossiles demeureront la source principale d'énergie primaire. Il est donc essentiel de promouvoir de nouvelles méthodologies permettant une utilisation plus rationnelle de l'énergie. Dans le secteur industriel, le développement de centrales de production d'utilités sur le site industriel (en général des centrales de cogénération) contribue grandement à l'amélioration de l'efficacité énergétique des procédés. Traditionnellement, la gestion de ce type de système repose sur une approche séquentielle : ordonnancement de l'atelier de production, calcul des besoins énergétiques et planification de la centrale de cogénération. Toutefois, dans ce type d'approche, l'accent est mis avant tout sur l'atelier de production, la centrale de cogénération étant considérée comme une unité esclave. Pour améliorer le processus de décision, cette thèse développe une approche intégrée pour l'ordonnancement simultanée et cohérent des ateliers de production et des centrales de production d'utilités. La méthodologie proposée repose sur une formulation MILP à temps discret. Par ailleurs, une extension du formalisme RTN a été développée : les ERTN ("Extended Resource Task Network"). Celui-ci permet d'une part, de décrire de manière systématique les recettes et d'autre part, permet une modélisation explicite et générique des différents types de systèmes dont notamment les centrales d'utilités. Les résultats montrent que l'approche intégrée permet d'obtenir une réduction notable du coût énergétique grâce une meilleure coordination des activités de production et de fabrication d'utilités. En effet, les tâches de production sont ordonnancées de manière à consommer sur les mêmes périodes les utilités générées simultanément par la centrale de cogénération, conduisant ainsi à une réduction significative du rapport quantité de biens fabriqués / quantité de carburant consommé et des émissions de gaz à effet de serre
The issue of energy has emerged as one of the greatest challenges facing the mankind. The search is on for finding alternative sources of energy that will replace fossil fuels as the primary source of energy. However, for the foreseeable future, fossil fuels will remain the main source of energy. Therefore, it is of paramount importance to devise methodologies for more rational use of energy in all walks of human life. In the industrial perspective, the deployment of site utility system (generally CHP plants) provides a great potential source for energy savings. However, the management of such type of industrial units is traditionally carried out using sequential three step approach: scheduling of the production plant, estimation of the utility needs of production plant and finally scheduling of the site utility system. In this kind of approach, all the focus is placed on the production plant and the utility system is treated as its subsidiary. To improve the decision-making process, this thesis proposes an integrated approach which addresses this imbalance by carrying out simultaneous and coherent scheduling of batch production plant and site utility system. The proposed methodology relies on discrete time modeling and uses Mixed Integer Linear Programming (MILP). Moreover, to permit an efficient and generic formulation of various kinds of industrial problems, a new scheduling framework called Extended Resource Task Network (ERTN) has been developed. The ERTN framework (an extension of existing RTN framework) allows for accurate representation and scheduling of any type of production plant and any type of site utility system. The results show that the integrated approach leads to better synchronization between production plant and site utility system. Thereby, the integrated approach leads to significant reduction in energy costs and decrease in harmful gas emissions

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27

Nuutinen, Antti, and Giovanni Graziano. "Towards Flexible Cogeneration: Techno-economic Optimization of Advanced Combined Cycle Combined Heat and Power Plants integrated with Heat Pumps and Thermal Energy Storage." Thesis, KTH, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235820.

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The liberalization of electricity markets and a growing penetration of renewables is changing operation of electrical grids. The boundary conditions for the operation of conventional power plants are changing and, as such, an improved understanding of the varying loads and prices on the electricity grid is required to assess the performance of emerging combined cycle gas turbine (CCGT) concepts and to further optimize their design for these new markets in the pursuit of increasing their profitability, especially when considering combined heat and power (CHP). To increase the flexibility of CCGT-CHP plants, three new plant layouts have been investigated by integrating different storage concepts and heat pumps in key sections of the traditional plant layout. The present study analyses the influence that market has on determining the optimum CCGT-CHP plant layout that maximizes profits (in terms of plant configuration, sizing and operation strategies) for a given location nearby Turin, Italy, for which hourly electricity and heat prices, as well as meteorological data, have been gathered. A multi-parameter approach for design and operation was followed using KTH’s and EPS’ techno-economic modeling tool DYESOPT. Results are shown by means of a comparative analysis between optimal plants found for each layout and the state-of-the art CCGT-CHP. It is shown that a plant configuration in which a cold storage unit is integrated together with a heat pump at the inlet of the gas turbine unit increases the net present value of the plant by approximately 0.3% when compared against conventional plant layouts. Using the same concept with a heat pump alone can improve lifetime profitability by 1.6%. A layout where district heating supply water is preheated with a combination of a heat pump with hot thermal tank increases plant profitability by up to 0.5%. This work has been performed as part of the PUMP-HEAT project, an EU Horizon 2020 research project in which KTH collaborates with other 13 stakeholders including industry and research institutions. The results will directly influence future work of the project.

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Bydén, William, and David Fridlund. "Carbon Negative Heat and Power with Biochar Production : An Economic Analysis of a Combined Pyrolysis and CHP plant." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279608.

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On the fourth of November 2016, The Paris Agreement entered into force, stating that nations worldwide should pursue efforts to limit the global temperature increase to 1,5 °C. Since then, the Intergovernmental Panel on Climate Change has specified that carbon dioxide removal, such as biochar sequestration, is necessary to achieve this goal. Biochar is a solid and porous material, rich in carbon, produced when biomass undergoes a process called pyrolysis and can, if buried in soil, sequester carbon for hundreds or even thousands of years while at the same time acting as a soil amendment. When biomass is pyrolyzed to produce biochar, a pyrolysis gas is also produced, which can be used to generate both heat and electricity. This thesis investigates if constructing and operating a plant, called a combined pyrolysis and CHP plant, which combines biochar production with heat and electricity generation, could be economically feasible and thus be an effective method for carbon dioxide removal. The findings show that constructing and operating a combined pyrolysis and CHP plant can be economically feasible. However, the economic feasibility is greatly affected by the price of biochar as a soil amendment product. The biochar market is also an undeveloped market, making price estimates of biochar far from accurate. Another factor that could significantly affect the economic feasibility of the plant is the fraction of carbon in biochar, which can be accounted for as sequestered. A higher fraction means that significantly more governmental support can be given to provide financing of the plant as well as potential revenue from carbon credits could increase. The capital cost of constructing the plant is also a factor with high uncertainty, which has a substantial effect on the economic feasibility. From this thesis, it is concluded that more research regarding the biochar market, as well as the capital costs of constructing the plant, is needed. More research could further ascertain whether or not the plant could be economically feasible and thus, an effective method for carbon dioxide removal.
Den fjärde november 2016 trädde Parisavtalet i kraft vilket uppgav att länder över hela världen ska sträva efter att begränsa den globala temperaturökningen till 1,5 grader Celsius. I enlighet med detta mål har FN:s mellanstatliga klimatpanel, IPCC, specificerat att koldioxidavlägsnande åtgärder, såsom kolinlagring genom produktion av biokol, är nödvändigt. Biokol är ett fast och poröst material, rikt på kol, som produceras när biomassa genomgår en process som kallas pyrolys. Om biokol blandas ner i jord kan det binda kol i hundratals eller tusentals år samtidigt som det fungerar som jordförbättrare. När biomassa pyrolyseras produceras också en pyrolysgas som kan användas för att generera värme och elektricitet. Det här examensarbetet undersöker om det kan vara ekonomiskt genomförbart att bygga och driva en anläggning, benämnd en kombinerad pyrolys- och kraftvärmeanläggning, som kombinerar biokolsproduktion med värme- och elproduktion för att avlägsna koldioxid från atmosfären. Resultaten från arbetet visar att det kan vara ekonomiskt genomförbart att bygga och driva en kombinerad pyrolys- och kraftvärmeanläggning. Den ekonomiska genomförbarheten påverkas dock i hög grad av priset på biokol som jordförbättringsprodukt. Marknaden för biokol är dessutom outvecklad vilket gör att priset för biokol osäkert. En annan faktor som i hög grad skulle kunna påverka den ekonomiska genomförbarheten för anläggningen är andelen kol i biokol som kan anses vara lagrad. En högre andel innebär att betydligt mer statligt stöd kan ges för att finansiera anläggningen samt att potentiella intäkter från kolkrediter kan öka. Kapitalkostnaderna för att bygga anläggningen är också en faktor med hög osäkerhet som har stor effekt på den ekonomiska genomförbarheten. Från detta examensarbete dras slutsatsen att mer forskning kring biokolsmarknaden samt kring kapitalkostnaderna för att bygga anläggningen behövs. Detta behövs för att ytterligare fastställa den ekonomiska genomförbarheten hos en sådan anläggning för att avlägsna koldioxid från atmosfären.

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29

Malmberg, Malin. "Transient modeling of a high temperature borehole thermal energy storage coupled with a combined heat and power plant." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-226160.

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Coupling High-Temperature Borehole Thermal Energy Storages (HT-BTES) with existing Combined Heat and Power (CHP) systems is a promising approach to increase energy efficiency of district energy systems through recovery of otherwise wasted heat. This solution is currently being discussed in Sweden by the company Tekniska Verken in Linköping AB, for storing waste heat from their CHP operation in summer in a HT-BTES and to utilize it during peaks in winter. This would increase the flexibility between energy supply and demand in one of their plants. The available supply temperature during charge of the BTES is around 95C. There is, though, still limited experience of HT-BTES operation with just a few installations throughout the world. The aim of this Master´s thesis has been to evaluate a potential system design configuration for effective extraction and storage of waste heat from the Gärstadverket CHP-plants in connection to a HT-BTES. Data from previous operation of the CHP-plants and an existing TRNSYS model, developed at KTH and Bengt Dahlgren AB based on the well-known DST approach (Duct Ground Heat Storage Model), was used as a starting point to the development of a new, more complete model that includes a heat pump. The heat pump model was developed from manufacturer’s data for a non-standard 50 MW heat pump system using R717 as refrigerant. As an additional objective, design and operational experience of already existing HT-BTES installations has been compiled and analyzed. The BTES design were simulated with varied number of boreholes and borehole depth. The system was furthermore simulated with two different borehole heat exchangers (BHEs): double U-pipes and coaxial. Based on the results three optimized designs were found: 1 400 boreholes with double U-pipes and a borehole depth of 300 m, 1 300 boreholes with coaxial BHEs and a borehole depth of 300 m, and a design with 1 500 boreholes and 275 m borehole depth – all three designs with a borehole spacing of 5 m and with loops of 3 boreholes connected in series. The three BTES designs showed similar results with a potential to store around 107 GWh/year and to extract around 93 GWh/year with the use of a GSHP. The resulting discharge temperature from the BTES ranges between 40-60C, and up to 70C in the initial discharge period in the tenth simulation year. Further investigation is though needed regarding if there are any coaxial BHE available on the market that can work with the high temperatures in the BTES. Coupling High-Temperature Borehole Thermal Energy Storages (HT-BTES) with existing Combined Heat and Power (CHP) systems is a promising approach to increase energy efficiency of district energy systems through recovery of otherwise wasted heat. This solution is currently being discussed in Sweden by the company Tekniska Verken in Linköping AB, for storing waste heat from their CHP operation in summer in a HT-BTES and to utilize it during peaks in winter. This would increase the flexibility between energy supply and demand in one of their plants. The available supply temperature during charge of the BTES is around 95C. There is, though, still limited experience of HT-BTES operation with just a few installations throughout the world. The aim of this Master´s thesis has been to evaluate a potential system design configuration for effective extraction and storage of waste heat from the Gärstadverket CHP-plants in connection to a HT-BTES. Data from previous operation of the CHP-plants and an existing TRNSYS model, developed at KTH and Bengt Dahlgren AB based on the well-known DST approach (Duct Ground Heat Storage Model), was used as a starting point to the development of a new, more complete model that includes a heat pump. The heat pump model was developed from manufacturer’s data for a non-standard 50 MW heat pump system using R717 as refrigerant. As an additional objective, design and operational experience of already existing HT-BTES installations has been compiled and analyzed. The BTES design were simulated with varied number of boreholes and borehole depth. The system was furthermore simulated with two different borehole heat exchangers (BHEs): double U-pipes and coaxial. Based on the results three optimized designs were found: 1 400 boreholes with double U-pipes and a borehole depth of 300 m, 1 300 boreholes with coaxial BHEs and a borehole depth of 300 m, and a design with 1 500 boreholes and 275 m borehole depth – all three designs with a borehole spacing of 5 m and with loops of 3 boreholes connected in series. The three BTES designs showed similar results with a potential to store around 107 GWh/year and to extract around 93 GWh/year with the use of a GSHP. The resulting discharge temperature from the BTES ranges between 40-60C, and up to 70C in the initial discharge period in the tenth simulation year. Further investigation is though needed regarding if there are any coaxial BHE available on the market that can work with the high temperatures in the BTES.
Koppling av högtemperatur-borrhålslager (HT-BTES) med befintliga kraftvärmeverk (CHP) är ett lovande tillvägagångssätt för att öka energieffektiviteten i fjärrvärmesystem genom återvinning spillvärme. Denna lösning diskuteras för närvarande i Sverige av Tekniska Verken i Linköping AB, för att lagra spillvärme från kraftvärmeproduktion sommartid i en HT-BTES och utnyttja denna under effekttoppar på vintern. Detta skulle öka flexibiliteten mellan energiförsörjning och efterfrågan i en av deras anläggningar, Gärstadverket. Den tillgängliga framledningstemperaturen under laddning av borrhålslagret är ca 95 ℃. Det finns dock fortfarande begränsad erfarenhet av HT-BTES med bara några få installationer i drift över hela världen. Syftet med detta masterexamensarbete har varit att utvärdera en potentiell systemkonfigurationskonfiguration för effektiv utvinning och lagring av spillvärme från Gärstadverkets kraftvärmeverk kopplat till ett HT-BTES. Data från tidigare drift av kraftvärmeverket och en befintlig TRNSYS-modell, utvecklad hos KTH och Bengt Dahlgren AB baserat på den välkända DST-metoden (Duct Ground Heat Storage Model), användes som utgångspunkt för utvecklingen av en ny, mer komplett modell som inkluderar en värmepumpsmodell. Värmepumpsmodellen utvecklades utifrån data från en värmepumpstillverkare för ett icke-standardiserat 50 MW värmepumpsystem, med R717 som kylmedium. Som ett ytterligare mål har designparametrar och erfarenheter från drift av redan befintliga HT-BTES installationer sammanställts och analyserats. BTES-designen varierades genom simuleringar med olika antal borrhål och borrhålsdjup. Systemet simulerades fortsatt med två olika borrhålsvärmeväxlare (BHE): dubbla U-rör och koaxiala BHE. Baserat på resultaten hittades tre optimerade BTES-geometrier: 1 400 borrhål med dubbla U-rörs BHE och 300 m borrhålsdjup, 1 300 borrhål med koaxiala BHE och 300 m borrhålsdjup samt en design med 1 500 borrhål med dubbla U-rör och ett borrhålsdjup på 275 m – alla tre konfigurationer med ett borrhålsavstånd på 5 m och borrhålsloopar med tre borrhål kopplade i serie. De tre BTES-geometrierna visade liknande resultat med potential att lagra cirka 107 GWh / år och att extrahera runt 93 GWh / år med användning av en värmepump. Den resulterande urladdningstemperaturen från borrhålslagret varierar mellan 40-60 °C och upp till 70 °C i början av urladdningsperioden under det tionde simuleringsåret. Vidare studie krävs dock för att undersöka tillgängligheten av koaxiala BHE på marknaden som kan fungera med de höga temperaturerna i borrhålslagret.

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Luo, Xiaobo. "Process modelling, simulation and optimisation of natural gas combined cycle power plant integrated with carbon capture, compression and transport." Thesis, University of Hull, 2016. http://hydra.hull.ac.uk/resources/hull:14005.

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Reducing CO₂ emissions from fossil fuel-fired power plants is a significant challenge, technically and economically. Post-combustion carbon capture (PCC) using amine solvents is widely regarded as the most promising technology that can be commercially deployed for carbon capture from fossil fuel-fired power plants. However, for its application at full commercial scale, the main barrier is high cost increment of the electricity due to high capital costs and significant energy penalty. This thesis presents the studies on optimal design and operation of Monoethanolamine (MEA)-based PCC process and the integrated system with natural gas combined cycle (NGCC) power plant through modelling, simulation and optimisation, with the aim to reduce the cost of PCC commercial deployment for NGCC power plants. The accuracy of optimisation depends on good predictions of both process model and economic model. For the process modelling, the philosophy with its framework was analysed for this reactive absorption (RA) process. Then the model was developed and validated at three stages. In the first stage, the predictions of thermodynamic modelling were compared with experimental data of CO₂ solubility in aqueous MEA solutions. The results show the combination of correlations used in this study has higher accuracy than other three key published contributions. Then key physical properties of MEA-H₂O-CO₂ system were also validated with experimental data from different publications. Lastly, a steady state process model was developed in Aspen Plus® with rate-based mass transfer and kinetic-controlled reactions. The process model was validated against comprehensive pilot plant experiment data, in terms of absorption efficiency and thermal performance of the integrated system. The cost model was developed based on the major equipment costs provided by vendors after detailed engineering design in a benchmark report. The uncertainty of this method could be in the range of from −15% to 20%, instead of other empirical methods with uncertainty of from −30% to 50%. The cost model was integrated into the process model by coding Fortran subroutine in Aspen Plus®. Using this integrated model, the optimisation studies were carried out for the PCC process only. The impact of key variables variation was also analysed. Subsequently, the scope of this study was extended to cover different sections of the integrated system including a 453MWe NGCC power plant, PCC process, CO₂ compression trains and CO₂ transport pipeline network. For the integration of NGCC power plant with PCC process and CO₂ compression, exhaust gas recirculation (EGR) technology was investigated and showed significant economic benefit. A specific supersonic shock wave compressor was adopted for the CO₂ compression and its heat integration options with power plant and PCC process were studied. For the study on the CO₂ transport pipeline network planned in the Humber region of the UK, a steady state process model was developed using Aspen HYSYS®. The process model was integrated with Aspen Process Economic Analyzer® (APEA), to carry out techno-economic evaluations for different options of the CO₂ compression trains and the trunk onshore\offshore pipelines respectively. The results show the optimal case has an annual saving of 22.7 M€ compared with the base case. In the end, optimal operations of NGCC power plant integrated with whole carbon capture and storage (CCS) chain under different market conditions were studied. Levelised cost of electricity (LCOE) is formulated as the objective function. The optimal operations were investigated for different carbon capture level under different carbon price, fuel price and CO₂ transport and storage (T&S) price. The results show that carbon price needs to be over €100/ton CO₂ to justify the total cost of carbon capture from the NGCC power plant and needs to be €120/ton CO₂ to drive carbon capture level at 90%. The results outline the economic profile of operating an NGCC power plant integrated with CCS chain. It could help power plants operators and relevant government organizations for decision makings on the commercial deployment of solvent-based PCC process for power plans.

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31

Han, Song. "Retrofitting CHP Plant and Optimization of Regional Energy System." Licentiate thesis, Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-13185.

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The use of biomass-based combined heat and power (CHP) plants is considered by the EU administration to be an effective way to increase the use of renewables in the energy system, to reduce greenhouse gas emissions and to alleviate the dependency on imported fossil fuels. At present in Sweden, most of the CHP plants are operated in part-load mode because of variations in heat demand. Further use of the potential heat capacity from CHP plants is an opportunity for integration with other heat-demanding processes. Retrofitting the conventional CHP plants by integration with bioethanol and pellet production processes is considered a feasible and efficient way to improve the plants’ performances. Modeling and simulation of the CHP plant integrated with feedstock upgrading, bioethanol production and pellet production is performed to analyze the technical and economic feasibility. When integrating with bioethanol production, the exhaust flue gas from the CHP plant is used to dry the hydrolysis solid residues (HSR) instead of direct condensation in the flue gas condenser (FGC). This drying process not only increases the overall energy efficiency (OEE) of the CHP plant but also increases the power output relative to the system using only a FGC. Furthermore, if steam is extracted from the turbine of the CHP plant and if it is used to dry the HSR together with the exhaust flue gas, pellets can be produced and the bioethanol production costs can be reduced by 30% compared with ethanol cogeneration plants. Three optional pellet production processes integrated with an existing biomass-based CHP plant using different raw materials are studied to determine their annual performance. The option of pellet production integrated with the existing CHP plant using exhaust flue gas and superheated steam for drying allows for a low specific pellet production cost, short payback time and significant CO2 reduction. A common advantage of the three options is a dramatic increase in the total annual power production and a significant CO2 reduction, in spite of a decrease in power efficiency. The retrofitted biomass-based CHP plants play a crucial role in the present and future regional energy system. The total costs are minimized for the studied energy system by using wastes as energy sources. Analyses of scenarios for the coming decades are performed to describe how to achieve a regional fossil fuel-free energy system. It is possible to achieve the target by upgrading and retrofitting the present energy plants and constructing new ones. The conditions and obstacles have also been presented and discussed through optimizing the locations for proposed new energy plants and planting energy crops.
REMOWE, CSC

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32

Bughazem, Mohamed. "Performance enhancement of the single shaft combined cycle gas turbine power plant by intake air cooling using an absorption chiller." Thesis, University of Newcastle Upon Tyne, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613447.

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33

Karkulahti, Linnéa, and Monika Mizgalewicz. "Optimization of a Combined Heat and Power Plant for the Future Electricity Market : A case study conducted at Söderenergi AB." Thesis, KTH, Energiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-271708.

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The Swedish energy system is changing and two major events that are taking place are the phase out of nuclear power and the increase of wind power. The associated changes affect the electricity market and the electricity producers, including combined heat and power plants. This thesis evaluates the Swedish energy system of 2025 with focus on electricity spot prices. It also investigates how a combined heat and power plant might perform in the future, given certain changes in the electricity price. Six different scenarios are developed where the electricity price is modified according to findings with regards to the influence of wind- and nuclear power. A model of a combined heat and power plant and a district heating network is created in BoFiT. The scenarios are applied to the model and results are analyzed in terms of heat production, choice of operational mode, merit order and economical performance. Major findings show a more volatile electricity price in 2025. Low price hours (<100SEK/MWh) occur throughout the year, while high price hours (>640SEK/MWh) take place mostly during winter - the season during which the heat demand is at its peak. Results show that the developed electricity prices require much more regulation from the modelled power plant and that the power plant is more adapted to handling high price hours than low price hours. The district heating network is also affected by the volatile electricity prices, and more frequent and greater variations are observed in the merit order. This suggests that in the future, the electricity prices will need to be followed more actively, and that a strategy will need to be developed, allowing for quick adaptation to the prices - communication and cooperation between the different actors in the network will be needed.
Sveriges energisystem är i förändring där avvecklingen av kärnkraft och ökad implementering av vindkraft är i fokus. Konsekvenserna av dessa förändringar kommer påverka elmarknaden och därmed elproducenterna, bland dem kraftvärmeverk. Detta examensarbete utvärderar energisystemet i Sverige 2025 med fokus på elmarknaden. Arbetet undersöker också hur ett kraftvärmeverk kan prestera i framtiden baserat på förändringar i elpriset. Sex olika scenarios har utvecklats där elpriset har modifierats baserat på analysen av vind- och kärnkraftsutvecklingen i Sverige och dess påverkan på elpriset. Ytterligare skapas en modell av ett kraftvärmeverk och ett fjärrvärmenät i BoFiT. Scenarierna implementeras i modellen och resultat extraheras och analyseras baserat på värmeproduktion, val av driftläge, körordning i systemet samt ekonomisk prestanda. Resultaten visar främst att volatiliteten i elpriset ökar till 2025. Låga elpristimmar (<100SEK/MWh) visar sig inträffa under hela året medan höga elpristimmar(>640 SEK/MWh) dominerar under vintern - säsongen där efterfrågan på värme är som högst. Resultaten visar att det förväntade elpriset kräver högre reglering av det modellerade kraftvärmeverket och att anläggningen idag är anpassad för att hantera framförallt höga elpriser men inte låga elpriser. Även fjärrvärmenätet i sig påverkas av volatilitet i elpriserna och mer frekventa och större variationer observeras i körordningen. Detta antyder att elpriserna i framtiden måste följas mer aktivt och att en strategi, som möjliggör snabb reglering för anpassning av elpriserna, måste utvecklas. Kommunikation och samarbete mellan parterna i fjärrvärmesystemet kommer därmed vara av hög betydelse.

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Krüger, Jan. "Models for the location decision for a combined cycle power plant : basic principles for solving the decision problem of the choice of location for a feasibility study of gas-fired power plants." Doctoral thesis, Universitat Politècnica de Catalunya, 2015. http://hdl.handle.net/10803/326467.

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The present thesis deals with the foundations for solving the decision problem of site selection for a feasibility study of gas-fired power plants, based on realistic and practical statements, under a business approach. The analysis of different theories and the investigation of site-relevant decision criteria has illustrated the broad range of site-specific factors and criteria that are to be taken into account. On the basis of existing projects, in which site theories were analysed for various industries, the present research project thus lays a new foundation for an extended specific approach in the area of electricity generation in gas-fired power plants. For gas-fired power plants, IEA anticipates a major increase, but otherwise notes that renewables and nuclear power account for more than half of all the new capacity added worldwide until 2040. Due to the low investment costs per KW of installed capacity, the high efficiency factor, the low CO2-emissions and the relatively short construction times, a large number of gas and steam power plants are planned or are already under construction in Europe. A lot of countries have been focussing on liquefaction of natural gas (LNG) for several years. The physical properties of LNG facilitate its transport on tankers to the ports of destination and / or power plants, where the natural gas is returned to its gaseous state. Thus, LNG offers a practical alternative to the gas transport by pipelines and a possibility to put the procurement structure on a broader basis. This, in turn, will lead to new alternatives for the choice of sites. Projects like the Baltic pipeline or the Nabuko project offer the prospect of a greater security of supply. The study considers the impact of measures to secure supply as decentralised generation and the use of renewable energies for power generation. The expansion targets of the EU 15 countries of 2004 and the values in each EU member country resulted in an indicative target value of around 20% of the share of renewable energies in the gross electricity consumption for the EU 25 in 2010. The political implementation in the individual EU 25 countries is one of the criteria for the choice of sites for power plant projects within Europe. The importance of the international electricity trade for the liberalised electricity market in Europe is stressed. It may include the promotion of the Europe-wide competition in the generation of electricity, increasing the efficient use of the existing capacities in the power plant fleet, and expansion of the cross-border power transfer capacities between the individual European states. It is also essential good cooperation of all participants on the energy market, for the development of an efficient power plant fleet in Europe and finally, for the success of each individual company.The survey method used in the self-designed empirical questionnaire has proven successful in the present study. The extension of the quantitative investment calculation by a refined qualitative evaluation and decision process and the introduction of a modified utility analysis rightly seem to claim their place in such a paradigm. On the basis of empirical material, a detailed characterization of the weighting of site criteria was performed. As a result of this it was found that the criteria weighting for a site decision is a multipersonal process, in which the behaviour of the subjective or restricted rationality of the players involved does not allow for a definite conclusion, but only provides a conclusion on tendencies. However, it could be proved that the subjective component is moderated by a multipersonal process and thus, by forming collective judgements instead of individual judgements. Over time, restrictions change, new energy concepts and technologies are developed, decision criteria and parameters vary. This induces permanent adaptation and further optimization of the present approach.
La presente tesis trata sobre las bases para la solución del problema de decisión de la selección del emplazamiento para un estudio de viabilidad de las plantas eléctricas de gas, basado en declaraciones realistas y prácticas, bajo un enfoque de negocio. El análisis de las diferentes teorías y la investigación de criterios de decisión relevantes ha ilustrado la amplia gama de factores específicos del lugar y los criterios que han de ser tenidos en cuenta. Sobre la base de los proyectos existentes, en los que se analizaron las teorías de selección de sitio para diversas industrias, el presente proyecto de investigación establece una nueva base para un enfoque específico en el área de generación de electricidad en centrales eléctricas de gas. Para las plantas eléctricas a gas, la AIE prevé un aumento importante de capacidades, y señala que las energías renovables y la energía nuclear cuenta con más de la mitad de toda la nueva capacidad añadida en todo el mundo hasta el año 2040. Debido a los bajos costos de inversión por kW de potencia instalada, el alto factor de eficiencia, las bajas emisiones de CO2 y los tiempos de construcción relativamente cortos, un gran número de plantas usando gas ya están en construcción en Europa. Una gran cantidad de países se han centrando en la licuefacción del gas natural (GNL) desde hace varios años. Las propiedades físicas de GNL facilitar su transporte en barcos a los puertos de destino, donde el gas natural se evapora a su estado gaseoso. El GNL ofrece una alternativa práctica para el transporte de gas a través de gasoductos y una posibilidad de poner la estructura de adquisición sobre una base más amplia. Esto, a su vez, dará lugar a nuevas alternativas para la elección de los sitios. Proyectos como el oleoducto del Báltico o el proyecto Nabuko ofrecen la perspectiva de una mayor seguridad del suministro. El estudio considera el impacto de las medidas para garantizar el suministro como la generación descentralizada y el uso de energías renovables para la generación de energía. Las metas de expansión de la UE de 15 países de 2004 y los valores de cada país miembro de la UE dio lugar a un valor objetivo indicativo de alrededor del 20% de la cuota de las energías renovables en el consumo bruto de electricidad de la UE-25 en 2010. La puesta en práctica política individuales en cada uno de 25 países de la UE, es uno de los criterios para la selección de sitios para proyectos de plantas de energía en Europa. La importancia del comercio internacional de electricidad para el mercado eléctrico liberalizado en Europa se destaca en el trabajo, además de la promoción de la competencia a escala europea en la generación de electricidad, el aumento de la utilización eficiente de las capacidades existentes en la flota de la planta de energía, y la expansión de las capacidades de transferencia de energía transfronterizos entre los estados europeos. Una buena cooperación de todos los participantes es esencial en el mercado de la energía, para el desarrollo de una flota de plantas de energía eficiente en Europa y, por último, para el éxito de cada empresa en particular. El método de encuesta utilizada, de diseño propio ha demostrado su eficacia en el presente estudio. La extensión del cálculo de la inversión cuantitativa por un proceso de evaluación y decisión cualitativa refinada y la introducción de un análisis de la utilidad modificado con razón tiene su lugar en este paradigma. Sobre la base del material empírico, se realizó una caracterización detallada de la ponderación de los criterios del sitio. Como resultado de esto se encontró que la decisión del sitio es un proceso multipersonal, en el que el comportamiento de la racionalidad subjetiva o restringida de los jugadores implicados no permite una conclusión definitiva, pero sólo proporciona una conclusión de tendencias, planteando la solución como juicios colectivos en lugar de individuales. Cambios futuros, pueden obligar a optimizar el trabajo.

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ÖHMAN, AXEL. "Green hydrogen production at Igelsta CHP plant : A techno-economic assessment conducted at Söderenergi AB." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299434.

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The energy transition taking place in various parts of the world will have many effects on the current energy systems as an increasing amount of intermittent power supply gets installed every year. In Sweden, just as many other countries, this will cause both challenges and opportunities for today´s energy producers. Challenges that may arise along with an increasingly fluctuating electricity production include both power deficits at certain times and regions but also hours of over-production which can cause electricity prices to drop significantly. Such challenges will have to be met by both dispatchable power generation and dynamic consumption. Conversely, actors prepared to adapt to the new climate by implementing new technologies or innovative business models could benefit from the transition towards a fully renewable energy system. This thesis evaluates the techno-economic potential of green hydrogen production at a combined heat and power plant with the objective to provide decision support to a district heat and electricity producer in Sweden. It was in the company’s interest to investigate how hydrogen production could help reduce the production cost of district heat as well as contribute to the reduction of greenhouse gases. In the project, two separate business models: Power-to-gas and Power-to-power were evaluated on the basis of technical and economic performance and environmental impact. To do this, a mathematical model of the CHP plant and the hydrogen systems was developed in Python which optimizes the operation based on costs. The business models were then simulated for two different years with each year representing a distinctly different electricity market situation. The main conclusions of the study show that Power-to-gas could already be profitable at a hydrogen retail price of 40 SEK per kg, which is the projected retail price for the transportation sector. The demand today is however limited but is expected to grow fast in the near future, especially within heavy transportation. Another limiting factor for hydrogen production showed to be the availability of storage space, as hydrogen gas even at pressures up to 200 bar require large volumes. Power-to-power for frequency regulation was found to not be economically justifiable as the revenue for providing grid services could not outweigh the high investment costs for any of the simulated years. This resulted in a high levelized cost of energy at over 3000 SEK per MWh which was mostly due to the low capacity factor of the power-to-power system. Finally, green hydrogen has the potential of replacing fossil fuels in sectors that is difficult to reach with electricity, for example long-haul road transport or the shipping industry. Therefore, green hydrogen production in large scale could help decarbonize many of society’s fossil-heavy segments. By also serving as a grid-balancer, hydrogen production in a power-to-gas process has the potential of becoming an important part of a renewable energy system.
Energiomställningen som äger rum i olika delar av världen kommer att ha många effekter på de nuvarande energisystemen eftersom en ökande mängd väderberoende kraftproduktion installeras varje år. I Sverige, precis som många andra länder, kommer detta att medföra både utmaningar och möjligheter för dagens energiproducenter. Utmaningar som kan uppstå tillsammans med en alltmer fluktuerande elproduktion inkluderar både kraftunderskott vid vissa tider och regioner men också timmar av överproduktion som kan få elpriserna att sjunka avsevärt. Sådana utmaningar måste mötas av både planerbar kraftproduktion och dynamisk konsumtion. Omvänt kan aktörer som är beredda att anpassa sig till det nya klimatet genom att implementera ny teknik eller innovativa affärsmodeller dra nytta av övergången till ett helt förnybart energisystem. Denna rapport utvärderar den tekno-ekonomiska potentialen för produktion av grön vätgas vid ett kraftvärmeverk med målet att ge beslutsstöd till en fjärrvärme- och elproducent i Sverige. Det var i företagets intresse att undersöka hur vätgasproduktion kan bidra till att sänka produktionskostnaden för fjärrvärme samt bidra till att minska växthusgaser. I projektet utvärderades två separata affärsmodeller: Power-to-gas och Power-to-power baserat på teknisk och ekonomisk prestanda samt miljöpåverkan. För att kunna göra detta utvecklades en matematisk modell i Python av kraftvärmeverket och vätgassystemen som optimerar driften baserat på kostnader. Affärsmodellerna simulerades sedan för två olika års elpriser för att undersöka modellens prestanda i olika typer av elmarknader. De viktigaste slutsatserna i studien visar att Power-to-gas redan kan vara lönsamt till ett vätgaspris på 40 SEK per kg, vilket är det förväntade marknadspriset på grön vätgas for transportsektorn. Efterfrågan är idag begränsad men förväntas växa snabbt inom en snar framtid, särskilt inom tung transport. En annan begränsande faktor för vätgasproduktion visade sig vara tillgången på lagringsutrymme, eftersom vätgas även vid tryck upp till 200 bar kräver stora volymer. Power-to-power för frekvensreglering visade sig inte vara ekonomiskt försvarbart, eftersom intäkterna för att tillhandahålla nättjänster inte kunde uppväga de höga investeringskostnaderna under några av de simulerade åren. Detta resulterade i en hög LCOE på över 3000 SEK per MWh, vilket främst berodde på Power-to-power-systemets låga utnyttjandegrad. Slutligen kan det sägas att grön vätgas har stor potential att ersätta fossila bränslen i sektorer som är svåra att elektrifiera, exempelvis tunga vägtransporter eller sjöfart. Därför kan storskalig grön vätgasproduktion hjälpa till att dekarbonisera många av samhällets fossiltunga segment. Genom att dessutom fungera som balansering har väteproduktion i en Power-to-gas-process potential att bli en viktig del av ett system med stor andel förnybar energi.

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Errey, Olivia Claire. "Variable capture levels of carbon dioxide from natural gas combined cycle power plant with integrated post-combustion capture in low carbon electricity markets." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/33240.

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This work considers the value of flexible power provision from natural gas-fired combined cycle (NGCC) power plants operating post-combustion carbon dioxide (CO2) capture in low carbon electricity markets. Specifically, the work assesses the value of the flexibility gained by varying CO2 capture levels, thus the specific energy penalty of capture and the resultant power plant net electricity export. The potential value of this flexible operation is quantified under different electricity market scenarios, given the corresponding variations in electricity export and CO2 emissions. A quantified assessment of natural gas-fired power plant integrated with amine-based post-combustion capture and compression is attempted through the development of an Aspen Plus simulation. To enable evaluation of flexible operation, the simulation was developed with the facility to model off-design behaviour in the steam cycle, amine capture unit and CO2 compression train. The simulation is ultimately used to determine relationships between CO2 capture level and the total specific electricity output penalty (EOP) of capture for different plant configurations. Based on this relationship, a novel methodology for maximising net plant income by optimising the operating capture level is proposed and evaluated. This methodology provides an optimisation approach for power plant operators given electricity market stimuli, namely electricity prices, fuel prices, and carbon reduction incentives. The techno-economic implications of capture level optimisation are considered in three different low carbon electricity market case studies; 1) a CO2 price operating in parallel to wholesale electricity selling prices, 2) a proportional subsidy for low carbon electricity considered to be the fraction of plant electrical output equal to the capture level, and 3) a subsidy for low carbon electricity based upon a counterfactual for net plant CO2 emissions (similar to typical approaches for implementing an Emissions Performance Standard). The incentives for variable capture levels are assessed in each market study, with the value of optimum capture level operation quantified for both plant operators and to the wider electricity market. All market case studies indicate that variable capture is likely to increase plant revenue throughout the range of market prices considered. Different market approaches, however, lead to different valuation of flexible power provision and therefore different operating outcomes.

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von, Hepperger Florian. "Implementation of water electrolysis in Växjö´s combined heat and power plant and the use of excess heat : A techno-economic analysis." Thesis, Linnéuniversitetet, Institutionen för byggd miljö och energiteknik (BET), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-105276.

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Renewable energies are fluctuating and the bigger its share on the Swedish energy market, the more fluctuating are the prices. Therefore, CHP plant operators as VEAB in Växjö, are more and more struggling to be competitive. There is, hence, a need of alternative options for the use of produced electricity, rather than being dependent on such a volatile and unclear market. Hydrogen production through water electrolysis could therefore be an alternative to be decoupled from the electricity business and instead being part of a promising, future hydrogen economy. Since state-of-the-art electrolysers have efficiencies between 51% and 75%, it was assessed that some of the efficiency losses could be recuperated by implementing the excess heat in an existing District heating (DH) grid. Calculations of the base scenario electrolyser with a power input of 870 kW showed, that an increase of the overall temperatures of the returning mass flow of the DH grid from 0,05°C to 0,23°C should be achievable. The economic analysis showed, that for this size of hydrogen production unit, the minimum hydrogen selling price (MHSP) would be 6,64 €/kg, which is not competitive on today’s market. However, the sensitivity analysis showed, that by a decreased investment cost, lower electricity prices and especially by scaling up the base scenario, the MHSP could be lowered significantly. Assuming a reduction of investment costs of 20% and scaling up the electrolyser by 1000% to 8700 kW, the MHSP resulted in 1,9 €/kg, a competitive price on the market. This study revealed that hydrogen production could be part of the future business model of CHP plant operators and provides a guideline on the feasibility of such a project.

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Lindström, Viktor. "Undersökning och riskbedömning av lågtemperaturkorrosion i ett kraftvärmeverk : Investigation and risk assessment of low temperature corrosion in a combined heat and power plant." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-121629.

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Janošťák, František. "Modely toků v síti pro odpadové hospodářství." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254439.

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This thesis is devoted to the construction of new waste-to-energy plants in a territory where is already another fossil-fuel power station in operation. The aim is to create a mathematical model and prove that those two devices are able to cooperate effectively using same technology. Exactly assembled model under real operating have characteristics of a mixed integer nonlinear programming. The optimization software GAMS is used for its calculation. The complexity of the model, however, is at a level that solutions in bad initial conditions ends in local optima, or not found at all. This thesis is devoted to the elimination of non-linearity using binary variables and heuristic so the task was solved with acceptable time limits to guarantee an optimal solution.

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Fogdal, Hanna, and Adrian Baars. "Utilization of Forest Residue through Combined Heat and Power or Biorefinery for Applications in the Swedish Transportation Sector : a comparison in efficiency, emissions, economics and end usage." Thesis, KTH, Kraft- och värmeteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215767.

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Sweden has the goal of reaching a fossil independent transportation sector by 2030. Two ways to reach the goal is to increase the use of electric vehicles or produce more biofuels. Both alternatives could be powered by forest residue, which is an underutilized resource in the country. Electricity could be produced in a biomass fired Combined Heat and Power (CHP) plant, and biofuel could be produced in a biorefinery through gasification of biomass and Fischer-Tropsch process. When located in Stockholm County, both system can also distribute heat to the district heating system. It is however important to use the biomass in an energy-efficient way. The scope of this work has been to analyze the efficiency together with environmental and economic aspects of the two systems. To assess the efficiency and environmental impact of the two systems a forest to wheel study was made of the systems where the product was studied from harvesting of forest residue to driving the vehicle. The studied functional units were: kilometers driven by vehicle, kWh of district heating, CO2-equivalents of greenhouse gases and MWh of forest residue. The system using CHP technology and electric vehicles outperformed the biorefinery system on the two first functional units. Using the same amount of forest residue more than twice as much district heating and almost twice as many driven kilometers were produced in this system. The study also showed that both systems avoids significant greenhouse gas emissions and can be part of the solution to decrease emissions from road transportation. The profitability of investing in a CHP plant or a biorefinery was calculated through the net present value method. It showed that the expected energy prices are too low for the investments to be profitable. The CHP plant investment has a net present value of -1.6 billion SEK and the biorefinery investment has a net present value of -4.6 billion SEK. Furthermore, the biorefinery investment entails higher risk due to the high investment cost and uncommercialized technology. Both systems face barriers for implementation, these barriers have been studied qualitatively.
Sverige har som mål att skapa en fossiloberoende fordonsflotta till år 2030. Två vägar som pekats ut för att nå målet är att öka användningen av eldrivna fordon eller att producera mer biobränsle. Båda alternativen kan drivas av skogsavfall, en råvara som det finns gott om i Sverige. Elektricitet kan produceras av skogsavfallet i ett kraftvärmeverk, och biobränsle i ett bioraffinaderi genom användning av förgasning och Fischer-Tropschmetoden. I Stockholms län skulle båda systemen dessutom kunna producera värme till Stockholms fjärrvärmesystem. Det är dock viktigt att använda skogsavfallet på ett resurseffektivt sätt. Därför undersöker detta arbete effektiviteten av de två olika systemen tillsammans med en analys av växthusgasutsläpp och ekonomiska förutsättningar. För att kunna utvärdera effektiviteten och klimatpåverkan av de två olika systemen utfördes en ”skog-till-hjul”-analys där produkten undersöktes från ursprunget, till drivandet av ett fordon. För att utföra studien definierades fyra funktionella enheter. De funktionella enheterna var: körsträcka med bil mätt i kilometer, kWh fjärrvärmeproduktion, CO2 ekvivalenter av växthusgasutsläpp och MWh skogsavfall. Studien visade att systemet där skogsavfallet används i ett kraftvärmeverk för att producera elektricitet och ladda elbilar hade bättre resultat i de två första funktionella enheterna. Systemet producerade nästan dubbelt så lång körsträcka och mer än dubbelt så mycket fjärrvärme som systemet där skogsavfallet används i ett bioraffinaderi och biobränslet används i dieselbilar. Studien visade även att båda system kan bidra till att sänka växthusgasutsläppen från transportsektorn. Lönsamheten att investera i ett kraftvärmeverk eller bioraffinaderi beräknades med nuvärdesmetoden. Studien visade att de förväntade framtida energipriserna är för låga för att investeringarna ska bli lönsamma. Kraftvärmeanläggningen hade ett nuvärde på -1.6 miljarder kronor, och bioraffinaderiet ett nuvärde på -4.6 miljarder kronor. Dessutom ansågs investeringen i ett bioraffinaderi vara en hög risk på grund av den höga investeringskostnaden och att tekniken idag inte är kommersialiserad. Det finns även en rad andra barriär för att genomföra de två olika systemen, dessa barriärer har studerats kvalitativt i arbetet.

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Wellmann, Johannes [Verfasser], Frank [Akademischer Betreuer] Behrendt, Frank [Gutachter] Behrendt, and Christoph [Gutachter] Nytsch-Geusen. "Conceptual design of a concentrating solar power plant for a combined electricity and water supply of the city El Gouna / Johannes Wellmann ; Gutachter: Frank Behrendt, Christoph Nytsch-Geusen ; Betreuer: Frank Behrendt." Berlin : Technische Universität Berlin, 2015. http://d-nb.info/1156177367/34.

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Dlouhá, Kristýna. "Návrh HRSG kotle." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-401508.

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This master’s thesis deals with the design of a heat recovery steam generator. The introductory part of the thesis is dedicated to waste heat boilers, their division and their utilization in combined cycles gas turbine. In the following chapter, an analysis of the existing combined heat and power plant operation is performed. In the next part of the thesis, the conceptual layout of the new source is designed. Subsequently, the thermal calculation of the boiler is carried out as well as the design of individual heat exchanging surfaces. The sixth chapter deals with the strength calculation of the boiler and the outer piping, chambers and drum are designed here. At the end of the thesis there are described off-design states of the new combined cycle gas turbine.

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Dembinskas, Donatas. "Kogeneracinės jėgainės elektrotechninė dalis." Bachelor's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110804_093038-46733.

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Kogeneracija – techniškai pažangus šilumos ir elektros energijos gamybos būdas. Elektros energija gaunama iš generatoriaus, o šilumos energija gaunama variklio aušinimo metu. Kadangi Lietuvoje elektros ir šilumos gamyba iš atsinaujinančių energijos šaltinių yra labai aktualu, darbo tikslas: suprojektuoti kogeneracinės jėainės vidaus elektros tinklą, parinkti kogeneratorių.
Cogeneration technologically advanced of heat and electricity production. It is particularly relevant for Lithuania, because there exists a strong need for heat production, the restructuring of heat and electricity networks, is changing its legal framework, the development of market relations. Undergraduate work is designed combined heat and power plant. Cogeneration plant will be used for alternative fuel: biogas which derived from the landfill. However, in order to improve the efficiency of cogeneration landfill gas is mixed with natural gas in certain proportion. Combined heat and power plant is designed according to the Republic of Lithuania laws and regulations. Heat comes from cogeneration emissions into the atmosphere in summer. It was found that in order to increase the heat recovery efficiency, not only in winter but in summer, for example to be equipped with heated vegetable production complexes.

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Магєра, Арина Юріївна. "Система газоочищення енергетичного блоку Дарницької ТЕЦ-4 у м. Київ." Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/41710.

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Дипломний проєкт першого (бакалаврського) рівня вищої освіти на тему « Система газоочищення енергетичного блоку Дарницької ТЕЦ-4 у м. Київ»: пояснювальна записка на 74 с., 11 рис., 13 табл., 16 бібліографічних найменувань; 2 дод.; креслень – 4 арк. Ф. А1. Мета проекту – реконструкція системи газоочищення ТЕЦ із заміною існуючих мокрих золовловлювачей з трубою Вентурі на високоефективні електрофільтри. Проведено аналіз екологічних показників експлуатації об’єкту. Наведені особливості експлуатації енергооб’єкту та позитивні характеристики після реконструкції. Наведені та описані методи очищення димових газів від сірки, та розглянуто декілька варіантів очищення димових газів від шкідливих компонентів і особливо від оксидів азоту NOx. Використовуючи нормативні матеріали, проектну документацію та паспортні дані енергетичного парового котла ТП-15, наведено розрахунки технологічних характеристик електрофільтру для різних видів вугілля, що спалюється у котлі. За результатами розрахунків виконано порівняння характеристик очищення димових газів електрофільтром для різних видів вугілля з проектним паливом. Розроблено основні заходи та засоби щодо організаційно-технічного забезпечення охорони праці. На кресленнях наведено розрізи газоочисної установки (електрофільтр) та монтажно-технологічні схеми системи золовидалення котла.
Graduation project of first (Bachelor) level of higher education on the theme: «Gas-cleaning system of Darnytskd CHP-4 power units in the Kyiv»: explanatory note for 74 p., 11 figures, 13 tables, 16 bibliographic names; 2 add,; drawings – 4 arcs. f. A1. The purpose of the project is to reconstruct the CHP gas cleaning system with the replacement of existing wet ash traps with a Venturi pipe with high-efficiency electrostatic precipitators. The analysis of ecological indicators of operation of the object is carried out. Features of operation of the energy facility and positive characteristics after reconstruction are given. Methods for cleaning flue gases from sulfur are presented and described, and several options for cleaning flue gases from harmful components and especially from nitrogen oxides NOx are considered. Using regulatory materials, design documentation and passport data of the TP-15 power steam boiler, calculations of technological characteristics of the electrostatic precipitator for different types of coal burned in the boiler are given. According to the results of calculations, a comparison of the characteristics of flue gas cleaning with an electrostatic precipitator for different types of coal with design fuel was performed. The main measures and tools for organizational and technical support of labor protection have been developed. The drawings show sections of the gas cleaning unit (electrostatic precipitator) and the assembly and technological schemes of the boiler ash removal system.
Дипломный проект первого (бакалаврского) уровня высшего образования на тему: «Система газоочистки энергетического блоку Дарницкой ТЕЦ-4 в г. Киев»: пояснительная записка на 74 с., 11 рис., 13 табл., 16 библиографических наименований; 2 прилож.; чертежей – 4 л. ф. А1. Цель проекта – реконструкция системы газоочистки ТЕЦ с заменой существующих мокрых золоуловителей с трубой Вентури на высокоэффективные электрофильтры. Проведен анализ экологических показателей эксплуатации объекта. Приведенные особенности эксплуатации энергообъекта и положительные характеристики после реконструкции. Приведенные и описаны методы очистки дымовых газов от серы, и рассмотрены несколько вариантов очистки дымовых газов от вредных компонентов и особенно от оксидов азота NOx. Используя нормативные материалы, проектную документацию и паспортные данные энергетического парового котла ТП-15, приведены расчеты технологических характеристик электрофильтра для различных видов угля, сжигаемого в котле. По результатам расчетов выполнено сравнение характеристик очистки дымовых газов электрофильтром для различных видов угля с проектным топливом. Разработаны основные мероприятия и средства по организационно-техническому обеспечению охраны труда. На чертежах приведены газоочистительная установка (электрофильтр) и монтажно-технологическая схема системы золоудаления котла.

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Öström, Daniel. "Styrning av värmepanna med PLC : Från relästyrning till digital styrning." Thesis, Mittuniversitetet, Avdelningen för elektronikkonstruktion, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-31091.

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På det kommunalägda energiföretaget Sala Heby Energi AB pågår arbetet med att konvertera styrningen av en värmepanna från relästyrning och analog övervakning till digital styrning med PLC. Inom ramarna för detta examensarbete studeras tre specifika delar av denna konvertering: en teoretisk studie med syfte att kartlägga fördelar och nackdelar med konverteringen, en undersökning huruvida det finns möjlighet att förbättra en-skilda styrfunktioner i samband med konverteringen och upprättande av ett principschema eller översiktsbild över värmepannan som ska fungera som underlag till dess implementering i kraftvärmeverkets SCADA-system. En fördel med relästyrningen är att den kan vara kostnadseffektiv för att klara enskilda enkla styruppgifter. Dock, överlag och i synnerhet för styrning av större mer komplexa processer talar det mesta till den digitala styrningens fördel. Detta i form av kostnadseffektivitet för större system, möjligheter till mer effektiv larmhantering och möjligheten till loggning av driftdata. Två enskilda funktioner studeras: reglering av värmepannans siktskärm i förhållande till ångdomstrycket och styrning för bränslehanteringen. För reglering av siktskärmens höjd jämförs två alter-nativ med hjälp av simuleringar i Simulink. Konventionell PID-reglering jämförs mot en egenkonstruerad fuzzy-regulator. Mycket på grund av en bristfälligt underbyggd modellering av processen går inte fuzzy-regulatorns eventuella fördelar mot PID-regulatorn att fastställa. Framtida studier av fuzzy-regulatorn skulle potentiellt kunna ändra på detta förhållande. Vidare diskuteras styrningen av funktioner i bränslehantering och då främst autentisering av chaufförer som ska bränslefylla. För att de ska få tillgång till bränslehanteringens funktioner när kraftvärmeverket är obemannat föreslås det en lösning med nyckelbrytare för att aktivera aktuella styrfunktioner. Slutligen tas en ny digital översiktsbild fram över systemet för värmepannan. Denna innehåller mindre uppdateringar och anpassningar jämfört med två översiktsbilder som finns uppritade på de gamla styrskåpen.
At the municipality-owned energy company Sala Heby Energi AB work is underway to convert the control of a heating-pan from relay control and analog monitoring to digital control with PLC. Within the framework of this degree project, three specific parts of this conversion are studied: a theoretical study aimed at mapping the pros and cons of the conversion, an examination of the possibility of improving individual control functions in conjunction with the conversion and the establishment of a schematic diagram or overview of the heat boiler that will serve as a basis for its implementation in the SCADA-system of the combined power and heating plant. An advantage of relay control is that it can be cost-effective to handle individual simple control tasks. However, overall and in particular for controlling major more complex processes the benefits of digital control is large. This in terms of cost-effectiveness for larger systems, possibilities for more efficient alarm management and the ability to log operational data. Two individual functions are studied: control of the heating pans damper in relation to the steam pressure and fuel management control. To adjust the height of the damper, two control options are compared using Simulink simulations. Conventional PID control is com-pared to a self-configured fuzzy controller. Much due to a poorly substantiated modelling of the process, the fuzzy regulator's possible benefits to the PID regulator can not be determined. Future studies of the fuzzy regulator could potentially change this circumstance. Furthermore, the control of functions for the fuel management are discussed, mainly authorship of drivers who will fill fuel to the fuel storage. In order for them to have access to the fuel management functions when the combined power and heating plant is unmanned, a key switch solution is proposed to activate the control functions. Finally, a new digital overview picture is produced for the system of the heating pan. This contains minor up-dates and adjustments compared to two overview images depicted on the old control cabinets.

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Třináctý, Jiří. "Parní turbína pro fosilní elektrárnu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231811.

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This thesis deals with design is condensing steam turbines burning fossil fuels with nominal capacity of the generator of 250 MW with steam reheating and regenerative eight uncontrolled extraction points. The turbine consists of two bodies: a combined high-intermediate pressure section and low pressure parts with dual way outlet down into the water-cooled condenser. Work includes calculating thermal scheme for 100% and 75% capacity, specific heat consumption calculation and design of the flow HP-MP body. Further strength control and basic engineering design of high-medium- work completed by longitudinal section. Achievements are at the end of work compared with work 3a and the conclusion summarizes the advantages and disadvantages of the concept.

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Dogan, Osman Tufan. "Performance Of Combined Cycle Power Plants With External Combustion." Thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1223288/index.pdf.

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Rajasekeran, Sangeetha. "Enabling Grid Integration of Combined Heat and Power Plants." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/99730.

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In a world where calls for climate action grow louder by the day, the role of renewable energy and energy efficient generation sources has become extremely important. One such energy efficient resource that can increase the penetration of renewable energy into the grid is the Combined Heat and Power technology. Combined Heat and Power (CHP) plants produce useful thermal and electrical power output from a single input fuel source and are widely used in the industrial and commercial sectors for reliable on-site power production. However, several unfavorable policies combined with inconsistent regulations have discouraged investments in this technology and reduced participation of such facilities in grid operations. The potential benefits that could be offered by this technology are numerous - improving grid resiliency during emergencies, deferring transmission system updates and reducing toxic emissions, to name a few. With increased share of renewable energy sources in the generation mix, there is a pressing need for reliable base generation that can meet the grid requirements without contributing negatively to the environment. Since CHP units are good candidates to help achieve this two-fold requirement, it is important to understand the present barriers to their deployment and grid involvement. In this thesis work, we explore some of these challenges and propose suitable grid integration technology as well as market participation approaches for better involvement of distributed CHP units in the industrial and commercial sectors.
Master of Science
Combined Heat and Power is a generation technology which uses a single fuel source to produce two useful outputs - electric power and thermal energy - by capturing and reusing the exhaust steam by-product. These generating units have much higher efficiencies than conventional power plants, lower fuel emissions and have been a popular choice among several industries and commercial buildings with a need for uninterrupted heat and power. With increasing calls for climate action and large scale deployment of renewable based energy generation sources, there is a higher need for reliable base-line generation which can handle the fluctuations and uncertainty of such renewables. This need can be met by CHP units owing to their geographic distribution and their high operating duration. CHPs also provide a myriad of other benefits for the grid operators and environmental benefits, compared to the conventional generators. However, unfavorable and inconsistent regulatory procedures have discouraged these facility owners from actively engaging in providing grid services. Therefore, it is imperative to look into some of the existing policies and understand where the changes and incentives need to be made. In this work, we look into methods that can ease CHP integration from a technological and an economic point of view, with the aim of encouraging grid operators and CHP owners to be more active participants.

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Kandamby, Naminda Harisinghe. "Mathematical modelling of gasifier fuelled gas turbine combustors." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267305.

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Olofsson, Emelie. "Lokal provtagning och analys på rökgaskondensat för driftövervakning av tungmetallrening med jonbytarmassor." Thesis, Uppsala universitet, Luft-, vatten- och landskapslära, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-414340.

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I värme- och kraftvärmeverk förbränns olika typer av bränslen för produktion av el och fjärrvärme. Vid förbränningen bildas rökgaser som innehåller föroreningar, till exempel tungmetaller, från bränslet. Anläggningarna har ofta krav på utsläpp både via rökgaserna och avloppsvatten. Rökgaserna renas därmed genom olika tekniker var av en vanlig teknik är rökgaskondensering. Vid rökgaskondenseringen bildas en vätska, kallad rökgaskondensat, som delvis innehåller tungmetaller från bränslet. Rökgaskondensatet måste renas innan det kan lämna anläggningen och det görs bland annat med tungmetalljonbytare. Jonbytarmassan i tungmetalljonbytarkolonnerna behöver bytas ungefär två gånger per driftsäsong då den inte längre kan binda mer tungmetaller. Detta är en kostnad för värme- och kraftvärmeverken som de vill minimera. I denna studie undersöktes om lokal provtagning och analys på ett kraftvärmeverk av ett antal utvalda tungmetaller i rökgaskondensat är en bra metod för att optimering av reningssteget med tungmetalljonbytare. Samt om detta kan säkerställa att miljökraven för tungmetaller i det renade rökgaskondensatet uppfylls. Med optimering avses att jonbytarmassornas fulla kapacitet utnyttjas, d.v.s. att byten av jonbytarmassor kan reduceras utan att riskera otillåtna halter av tungmetaller i de renade rökgaskondensatet till följd av att jonbytarmassorna använts för länge. Även tiden som behöver avsättas för lokal provtagning och analys dokumenterades. I dagsläget sker analyser hos ackrediterade laboratorium där det tar drygt två veckor att få resultatet och under väntetiden kan mycket på anläggningen förändras. En verifiering av resultaten från studien gjordes mot resultat från ett sådant. I denna studie undersöktes lokal provtagning och analys med mätinstrumentet FREEDD som bygger på tekniken kvartskristall mikrobalans (QCM-teknik). Andra alternativ för lokal analys har inte undersökts här. Resultatet visade att det i dagsläget är svårt att med lokal provtagning optimera reningssteget med jonbytarmassor samt kontrollera utsläppen av tungmetaller via det renade rökgaskondensatet. Korrigeringar hos mätinstrumentet och provpunkterna behöver göras för att få pålitligt resultat. Tiden som behöver avsättas för provtagning och analys beror på vilken metall som ska analyseras då tiden för preparering av prov varierar. Men om det kan möjliggöra att anläggningarna kan använda jonbytarmassorna längre samt får kontroll på utsläppen via det renade rökgaskondensatet kan det vara lönsamt att avvara den tiden.
In heating and combined heat and power plants, different types of fuels are burned to produce electricity and district heating. During the combustion flue gases containing pollutants, such as heavy metals, are formed from the flue. The plants have requirements for low emissions, both from the flue gases and the wastewater. The flue gases are purified by various techniques and a common technique is flue gas condensation. During the flue gas condensation, a liquid called flue gas condensate, is formed, which partly contains heavy metals from the flue. The flue gas condensate must be cleaned before it can leave the plant. A step in the purification of the flue gas condensate is usually heavy metal ion-exchanger. The ion-exchange mass in the heavy metal ion-exchange columns needs to be changed approximately twice per operating season as it no longer has room to bind more heavy metals. This is an expensive cost for the heating and combined heat and power plants that they want to minimize. This study investigated whether local sampling and analysis at a cogeneration plant of a number selected heavy metals in flue gas condensate is a good method for optimizing the purifications step with heavy metal ion-exchangers. And if this can ensure that the environmental requirements for the heavy metals in the purified flue gas condensate are met. Optimization means that the full capacity of the ion-exchange masses is utilized, i.e. that the exchange of ion-exchange masses can be reduced without risking unauthorized levels of heavy metals in the purified flue gas condensate as a result of the ion exchange masses being used for too long. The time needed for local sampling and analysis was also documented. At present, analyzes are done at accredited laboratories where it takes over two weeks to get the result and during that time much can be changes at the plant. A verification of the result of the study was also made against the result of an accredited laboratory. In this study, local analysis was made with the measuring instrument FREEDD which is based on quartz crystal microbalance (QCM-technology). Other options for local sampling and analysis have not been investigated. The result showed that, in the present, it is difficult to optimize the purification step with ion-exchange masses and check emissions of heavy metals with the purified flue gas condensate. To obtain reliable result, corrections to the measuring instrument and test points need to be made. The time that needs to be set aside for sampling and analysis depends on the metal, as the time for sample preparation varies. But if it can enable the plants to use the ion-exchange masses longer and gain control of the emissions of heavy metals with the purified flue gas condensate, it can be profitable to save that time.

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Dissertations / Theses on the topic 'Combined power plant'

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