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Staněk, Štěpán. "Paroplynová turbína pro akumulaci energie." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417553.
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Master thesis discusses the growing need of electric energy storage and its effectivity and capacity. It describes an overview of possible technologies with their advantages and disadvantages. Greater attention is paid to the storage of energy in gas, so-called Power to Gas, which combines the electrolytic production of hydrogen from water and the Sabatier reaction to produce synthetic methane. This technology is introduced in the so-called SIT Brno cycle of Siemens Industrial Turbomachinery company. The main part of the thesis is focused on the description of this cycle and on the calculation of the steam-gas turbine (high-pressure and low pressure module). This thesis describes the methodology of turbine calculation and the composition of the steam gas mixture after combustion of methane. The carbon dioxide formed by combustion in the steam-gas mixture generator was replaced by steam. Part of the diploma thesis are drawings of cross-section of individual turbine modules.
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Landelle, Arnaud. "Experimental and numerical study of transcritical Organic Rankine Cycles for low-grade heat conversion into electricity from various sources." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI090/document.
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Le Cycle Organique de Rankine (abrégé ORC de l’anglais Organic Rankine Cycle) est une technologie permettant la conversion de chaleur basse température en électricité. L’ORC transcritique a été identifié comme une solution prometteuse pour la valorisation de la chaleur fatale. Cependant, peu d’installations expérimentales ont permis de confirmer ces performances. Ce travail de thèse présente le fonctionnement et l’optimisation d’ORC sous-critique et transcritique pour la conversion de chaleur basse température en électricité à partir de différentes sources. Premièrement, les contextes thermodynamique et technologique de l’ORC sont présentés. Des critères de performance énergétiques et exergétiques sont définis et appliqués à une base de données d’installations expérimentales afin d’exposer l’état de l’art actuel des ORC. Deuxièmement, les outils numériques et expérimentaux, spécifiquement développés ou utilisé pour ces travaux, sont présentés. Trois installations expérimentales d’ORC transcritique complet ou incomplet fournissent les données expérimentales. Différents modèles numériques sont utilisés : sous l’environnement Matlab pour la modélisation en permanent, l’analyse des données expérimentales et l’analyse énergétique/exergétique ; L’environnement Modelica/Dymola pour l’analyse des transitoires et de la dynamique du système. Dans un troisième temps, ces différents outils sont utilisés pour étudier quatre différentes problématiques : - Le fonctionnement de la pompe de circulation est étudié, d’un point de vue énergétique et volumétrique. Des modèles semi-empiriques et des corrélations de performance sont présentés. - Les transferts thermiques en supercritique sont examinés, en local et en global. Les coefficients de transfert thermique sont comparés avec différentes corrélations de la littérature. - L’influence de la charge de réfrigérant sur les performances et le comportement de l’ORC est analysée. La charge optimale est estimée pour différentes conditions de fonctionnement et des mécanismes de régulation de la charge sont présentés. - Les performances énergétiques et exergétiques de l’ORC sont comparées avec la base de données. Une analyse exergétique du procédé a permis d’identifier des voies d’améliorationThe Organic Rankine Cycle (ORC) is a technology used for low-grade thermal energy conversion into electricity. Transcritical ORC has been identified as a solution for efficient waste heat recovery. However, few experimental tests have been conducted to confirm the interest of transcritical ORC and investigate its operational behaviors. The work presented focuses on the operation and the optimization of subcritical and transcritical Organic Rankine Cycles for low-grade heat conversion into electricity from various heat sources (solar, industrial waste heat). First, the thermodynamic framework of ORC technology is presented. Energetic and exergetic performance criteria, appropriate to each type of input source, are introduced and selected. The criteria are later applied to a database of ORC prototypes, in order to objectively analyze the state-of-the-art. In a second step, the experimental and numerical tools, specifically developed or used in the present thesis, are presented. Three subcritical and transcritical ORC test benches (hosted by CEA and AUA) provided experimental data. Numerical models were developed under different environments: Matlab for steady-state modeling, data processing and energy/exergy analysis. The Modelica/Dymola environment for system dynamics and transient operations. Lastly, the different tools are exploited to investigate four different topics: - The ORC pump operation is investigated, both under an energetic and volumetric standpoint, while semi-empirical models and correlations are exposed. - Supercritical heat transfers are explored. Global and local heat transfer coefficients are estimated and analyzed under supercritical conditions, while literature correlations are introduced for comparison. - Working fluid charge influence over the ORC performance and behavior is investigated. Optimal fluid charge is estimated under various operating conditions and mechanisms for charge active regulation are exposed. - ORC system performances and behavior are discussed. Through both an energetic and exergetic standpoint, performances are compared with the state-of-the-art, while optimization opportunities are identified through an exergetic analysis
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Joska, Jakub. "Charakteristiky ventilátorových chladicích věží." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443198.
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This diploma thesis deals with the problematics of fan cooling towers. The very first part of the text is research, focusing mainly on the theory of cooling and the function of fan cooling towers in general. The following chapter deals with the water resource management of the Dukovany nuclear power plant and the specification of its objects of forced draft cooling towers. The second part describes a computational model created to determine the cooling performance of these towers under the given input conditions. In the following chapters, the results from the computational model are compared with the available data from warranty measurements and with the provided characteristics. The final pages deal with the study of the influence of changes in input parameters on the cooling performance and the research of the behavior of the cooling towers under extreme weather conditions.
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Brandsar, Jo. "Offshore Rankine Cycles." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19069.
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The title of the thesis - "Offshore Rankine Cycles" - is very general and cover a large range of engineering fields, e.g. thermodynamic cycles (Rankine, ORC, Brayton, Kalina, etc.), mechanical equipment (gas/steam turbine, heat exchangers and additional equipment) and safety concerns (flammable and/or toxic fluids, high temperature and pressures), to name the most important.The thesis try to give a brief overview of all critical points and alternatives, concerning employment of a waste heat recovery machine on offshore facilities, although focus has been on three more specified cases, namely:1. Comparison of a steam cycle vs. an organic Rankine cycle for high temperature operating conditions.2. Study of heat exchanger parameters on total cycle performance.3. Investigation of a modular expander setup versus a single expander.To compare a steam cycle to an organic cycle, a choice of working fluid for the organic cycle had to be made. After some investigation, toluene was chosen as it is a "common" fluid with known properties and was found to be a viable option for high temperature heat sources, both for subcritical and supercritical operation. Due to water being constricted to subcritical operation a CO2 cycle was implemented as a comparison to the supercritical toluene cycle. The main focus of the comparison was exergy losses during heat transfer and power output.The heat exchanger parameter study was conducted with a printed circuit heat exchanger as an example. The study of overall cycle performance has close connections to the heat exchanger size, since it is an important parameter concerning offshore employment due to costly "footprint". The cycle's dependency on the heat exchanger is mainly by the heat transfer rate, or heat load, which the heat exchanger applies to the cycle. The heat transfer rate is given by the heat exchanger`s ability to reduce the temperature of the exhaust gases. This ability depends on the two fluids involved and the geometry of the heat exchanger. While the choice in working fluid and pinch points sets the amount of heat transferred, the remaining analysis rest on the overall heat transfer coefficient (UA) to balance the heat load. When fluid properties are determined, the UA - value is again dependent on heat exchanger geometry and further variation of these parameters will in turn reveal the size of the heat exchanger. When imposing a working fluid to the cold side of the heat exchanger an optimization in heat exchanger volume could be found at specified heat load.A VBA macro has been made where expander parameters (rated power and efficiency vs. volumetric flow rate values) could be used as inputs to calculate the power output of two expanders in a modular setup relative to a single expander as reference.
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Igobo, Opubo. "Low-temperature isothermal Rankine cycle for desalination." Thesis, Aston University, 2016. http://publications.aston.ac.uk/28569/.
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In brackish groundwater desalination, high recovery ratio (of fresh water from saline feed) is desired to minimise concentrate reject. To this effect, previous studies have developed a batch reverse osmosis (RO) desalination system, DesaLink, which proposed to expand steam in a reciprocating piston cylinder and transmit the driving force through a linkage crank mechanism to pressurise batches of saline water (recirculating) in a water piston cylinder unto RO membranes. However, steam is largely disadvantaged at operation from low temperature (< 150oC) thermal sources; and organic working fluids are more viable, though, the obtainable thermal cycle efficiencies are generally low with low temperatures. Consequently, this thesis proposed to investigate the use of organic working fluid Rankine cycle (ORC) with isothermal expansion, to drive the DesaLink machine, at improved thermal efficiency from low temperature thermal sources. Following a review of the methods of achieving isothermal expansion, ‘liquid flooded expansion’ and ‘expansion chamber surface heating’ were identified as potential alternative methods. Preliminary experimental comparative analysis of variants of the heated expansion chamber technique of effecting isothermal expansion favoured a heated plain wall technique, and as such was adopted for further optimisation and development. Further, an optimised isothermal ORC engine was built and tested at < 95oC heat source temperature, with R245fa working fluid – which was selected from 16 working fluids that were analysed for isothermal operation. Upon satisfactory performance of the test engine, a larger (10 times) version was built and coupled to drive the DesaLink system. Operating the integrated ORC-RO DesaLink system, gave freshwater (approximately 500 ppm) production of about 12 litres per hour (from 4000 ppm feed water) at a recovery ratio of about 0.7 and specific energy consumption of 0.34 kWh/m3; and at a thermal efficiency of 7.7%. Theoretical models characterising the operation and performance of the integrated system was developed and utilised to access the potential field performance of the system, when powered by two different thermal energy sources – solar and industrial bakery waste heat – as case studies.
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JUNIOR, CARLOS THOMAZ GUIMARAES LOPES. "THERMODYNAMIC COMPARISON BETWEEN A TRADITIONAL RANKINE CYCLE WITH AN INNOVATIVE RANKINE CYCLE USING RESIDUAL GASES FROM THE SIDERURGIC PROCESS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=11329@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROO presente trabalho realiza uma comparação entre o ciclo Rankine tradicional e uma nova proposta de ciclo Rankine para uma planta de cogeração na indústria siderúrgica. O ciclo inovador é caracterizado por um sistema de regeneração por injeção direta de vapor seguida de bombeamento bifásico substituindo o uso de pré-aquecedores como no ciclo tradicional. Para a simulação dos ciclos de potência é empregado o Software Gate Cycle. São simuladas e estudadas diversas alternativas de configuração para a aplicação da nova tecnologia. A melhor alternativa de configuração do ciclo inovador é então comparada com o ciclo tradicional por meio da aplicação das análises de Primeira e Segunda Leis da Termodinâmica. Observou-se, entretanto, pouca diferença no desempenho do ciclo tradicional e do ciclo modificado.
In the present work, a comparison between a traditional Rankine cycle and a proposed innovative Rankine cycle, for a cogeneration plant in the steel industry, is carried out. The innovative cycle is characterized by a regeneration system with direct steam injection followed by two-phase pumping, instead of the water pre-heaters used in the traditional cycle. Different configuration alternatives for the technology application were simulated and studied. The best alternative was then selected and compared with the traditional cycle using First and Second Laws of Thermodynamics analyses. Little difference was observed, however, between the traditional and the modified cycle performances.
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Dahlqvist, Johan. "Impulse Turbine Efficiency Calculation Methods with Organic Rankine Cycle." Thesis, KTH, Kraft- och värmeteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104174.
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A turbine was investigated by various methods of calculating its efficiency. The project was based on an existing impulse turbine, a one-stage turbine set in an organic Rankine cycle with the working fluid being R245fa. Various methods of loss calculation were explored in the search for a method sufficiently accurate to make valid assumptions regarding the turbine performance, while simple enough to be time efficient for use in industrial research and development. The calculations were primarily made in an isentropic manner, only taking into account losses due to the residual velocity present in the exit flow. Later, an incidence loss was incorporated in the isentropic calculations, resulting in additional losses at off-design conditions. Leaving the isentropic calculations, the work by Tournier, “Axial flow, multi-stage turbine and compressor models” was used. The work presents a method of calculating turbine losses separated into four components: profile, trailing edge, tip clearance and secondary losses. The losses applicable to the case were implemented into the model. Since the flow conditions of the present turbine are extreme, the results were not expected to coincide with the results of Tournier. In order to remedy this problem, the results were compared to results obtained through computational fluid dynamics (CFD) of the turbine. The equations purposed by Tournier were correlated in order to better match the present case. Despite that the equations by Tournier were correlated in order to adjust to the current conditions, the results of the losses calculated through the equations did not obtain results comparable to the ones of the available CFD simulations. More research within the subject is necessary, preferably using other software tools.
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Somayaji, Chandramohan 1980. "First and second law analysis of Organic Rankine Cycle." Diss., Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-03102008-143144.
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Collings, Peter. "Theoretical and experimental analysis of an organic Rankine Cycle." Thesis, University of Glasgow, 2018. http://theses.gla.ac.uk/30642/.
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In order to reduce emissions of carbon dioxide from the energy and transportation sectors, while still providing a reliable and affordable service, innovation in the fields of power generation and energy efficiency is needed. There exists a wide variety of low-temperature heat sources, such as waste heat from industry and transportation, solar thermal, biomass and geothermal, which contain large amounts of energy, but do not have sufficient temperature to be economically viable using traditional power generation techniques. Several technologies have been proposed to utilise these promising resources, of which the Organic Rankine Cycle is widely considered to be the technology with the most potential for large-scale commercial deployment. However, the low driving temperature differential available to Organic Rankine Cycles using these heat sources means that they face several technological challenges, some of which are addressed in this thesis. Firstly, they experience low efficiencies, which means that small absolute changes in efficiency and cost can be proportionally very significant, this makes cycle optimisation to achieve marginal gains a worthwhile exercise. Secondly, there is a lack of suitable working fluids for the Organic Rankine Cycle, meaning that they often have to operate with a fluid that is not tailored for the specific application. Producing tailor-made working fluids to a given heat source and sink temperature could represent a significant field for optimising the performance of ORCs. Thirdly, there is a lack of experimental validation of many theoretical aspects of the Organic Rankine Cycle, particularly for low heat source temperatures and power outputs. This thesis aims to contribute to the body of research on ORC technology by developing an analytical model to design an experimental rig. This rig is used to validate several theoretical predictions, which are then expanded upon to develop a novel method of cycle optimisation in an application with variable heat sink temperatures. Firstly, a thermodynamic model was developed in MATLAB to analyse a small-scale Organic Rankine Cycle. This model builds on well-established analytical modelling principles that frequently appear in the literature. This basic model was used as a tool to design a lab-scale experimental Organic Rankine Cycle rig, capable of addressing several gaps in the current literature, most notably the lack of research on the impact of a regenerator on the performance of an Organic Rankine Cycle, and the lack of experimental research on the performance of an Organic Rankine Cycle using a working fluid composed of a mixture of two working fluids, in this case r245fa and r134a. The model, its results and the design of the experimental rig are described in detail. The results from this experimental rig showed an increase in cycle efficiency and cycle output power with increasing heat source temperature and increasing cycle pressure ratio. The use of a regenerative cycle resulted in an increased cycle efficiency, but the extra flow resistance caused by the additional heat exchanger caused the mass flow rate of the cycle to drop, reducing the output power at the same time as reducing the evaporator heat demand and thereby increasing cycle efficiency. The addition of more r134a, which has a lower boiling point, to the working fluid mixture, increased the condenser pressure and thereby reduced the cycle pressure ratio, reducing output power and efficiency. The maximum efficiency achieved was 11.3%, for a regenerative cycle with a heat source temperature of 95°C and a pressure ratio of 4.56:1. Using the results from the experimental rig, and the model that they validate, the concept for the Dynamic Organic Rankine Cycle is presented. The Dynamic Organic Rankine Cycle was conceived as a solution to a problem identified in the literature, namely that an Organic Rankine Cycle using ambient air as the heat sink cannot fully utilise the driving temperature differential available to it during times of colder ambient temperature, as it must be designed to still function on the hottest day of the year. In order to address this, the Dynamic ORC Concept uses a variable working fluid composition, capable of shifting the composition between one working fluid component and the other by batch distillation in order to change the fluid’s bubble and dew points to match the heat sink temperature. The use of working fluid mixtures is in contrast to most current research, which has focused primarily on pure, single-component working fluids. A theoretical analysis of this cycle in MATLAB was carried out, and it was found that the cycle results in substantial increase in year-round power generation from the cycle, of the order of 8-10% for a heat source temperature of 150°C, increasing to 23% and higher for heat source temperatures of 100°C and below, while operating in a continental climate, such as that of Beijing, China. When operating in a climate with less temperature variation, the gains are lower, but still significant. Structurally, this paper presents a review of the relevant literature to the Organic Rankine Cycle, identifying the knowledge gaps that justify the work carried out. It then reviews the theory of the ORC, and how this was used both to build a computer model for analysis of the dynamic ORC and design the 1kW experimental rig. The experimental results from the rig are then presented and discussed. Finally, the results of the theoretical analysis of the dynamic ORC are presented, and analysed with the aid of the REFPROP fluid properties program to explain the trends observed in the data. Finally, suggestions for further work are made.
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Chandrasekaran, Vetrivel. "Virtual Modeling and Optimization of an Organic Rankine Cycle." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408456065.
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Хамза, Хамза Алі Адел. "Вибір та обґрунтування параметрів дизель-електричної станції з системою утилізації теплоти." Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/31934.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.05.03 – двигуни та енергетичні установки. – Національний технічний університет "Харківський політехнічний інститут". – Харків, 2017. Дисертація присвячена вибору і обґрунтуванню параметрів дизель-електричної станції з системою утилізації вторинної теплоти дизеля з використанням циклу Ренкіна, що використовує теплоту відпрацьованих газів та системи охолодження. В результаті аналізу особливостей перспективної енергетичної установки з двигуном Hyundai 25/33 для виробництва електричної енергії на заводі в Іраку розроблена технологічна схема комплексної системи утилізації вторинної теплоти дизель-електричної станції з додатковим отриманням електроенергії, теплоти для підігріву важкого палива, конденсації технічної води з відпрацьованих газів двигуна. Для утилізації вторинної теплоти двигуна Hyundai H25/33 запропоновано утилізаційний контур установки, який працює за органічним циклом Ренкіна (ОЦР). В якості робочого тіла в циклі Ренкіна доцільно використовувати воду системи охолодження двигуна. З використанням розробленої математичної моделі утилізаційного контуру дизель-електростанції виконане розрахунково-експериментальне дослідження впливу температури навколишнього середовища на показники ефективності утилізаційного контуру. При зміні температури навколишнього середовища від 0 ° С до 40 ° С кількість електроенергії, виробленої за циклом Ренкіна для двигуна Hyundai H25/33 збільшується до 10%. При роботі однієї когенераційної установки з двигуном Hyundai H25/33 та розробленим утилізаційним комплексом можна отримати на добу до 2300 кг конденсату водяної пари, що є дуже цінною в Іраку. На основі результатів дослідження було розроблено два варіанта технологічної схеми (проекти "А" та "Б") модернізації дизельних електростанцій компанії Hyundai Heavy Industries. Виконана техніко-економічна оцінка проектів за метод NPV показала, що після того, як обладнання утилізаційного контуру в повному обсязі буде введено у експлуатацію, максимально досяжний прибуток складе близько 1 406 219 дол. США/рік.Dissertation for the degree of candidate of technical sciences in specialty 05.05.03 – engines and power plants. – National Technical University "Kharkiv Polytechnic Institute". – Kharkiv, 2017. The dissertation is devoted to the choice and substantiation of parameters of a diesel power plant with heat recovery system of recycling the secondary heat from diesel engine using the Rankin cycle, which uses the heat of exhaust gases and cooling water systems. As a result of the analysis of the features of a promising power plant with a Hyundai 25/33 engine for the production of electric power at a plant in Iraq, a technological scheme of a comprehensive system for recycling diesel fuel from an electric power station with the additional generation of electricity, heat for heating heavy fuel, condensing technical water from exhaust gases. As a working fluid in the Rankin cycle, it is advisable to use the hot water from the engine cooling system. Using the developed mathematical model of the distillation circuit of the diesel power plant, the design-experimental study of the influence of the ambient temperature on the indicators of the efficiency of heat recovery was performed. When the ambient temperature changes from 0 ° C to 40 ° C, the amount of electric energy generated by the Rankin cycle for the Hyundai H25 / 33 engine increases to 10%. With a single cogeneration unit with a Hyundai H25 / 33 engine and a recycling complex developed, it is possible to get up to 2300 kg of water vapor condensate per day, which is very valuable in Iraq. Based on the results of the study, two variants of the technological scheme (projects A and B) were developed for the modernization of Hyundai diesel power plants. The feasibility study for the NPV method has shown that after the full recovery equipment is put into operation, the maximum achievable profit will be about 1 406 219 $ /year.
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Mička, Radek. "Design průmyslového kotle s možností kogenerace." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-319495.
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The diploma thesis deals with the design of the industrial boiler for biomass, Which deals with the issue of the energy future of combustion of fuels using current power generation - microcogeneration, designed for larger houses or smaller com- panies. The shape of the device is the interconnection of individual functional and technological parts of the boiler, a view of a new product that re ects its function. It uses modern and timeless materials, color and control technology to achieve overall comfort and time savings and service.
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Hamza, Hamza Ali Adel. "Selection and justification the parameters of diesel power plant with heat recovery system." Thesis, NTU "KhPI", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/31664.
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Dissertation for the degree of candidate of technical sciences in specialty 05.05.03 – engines and power plants. – National Technical University "Kharkiv Polytechnic Institute". – Kharkiv, 2017. The dissertation is devoted to the choice and substantiation of parameters of a diesel power plant with heat recovery system of recycling the secondary heat from diesel engine using the Rankin cycle, which uses the heat of exhaust gases and cooling water systems. As a result of the analysis of the features of a promising power plant with a Hyundai 25/33 engine for the production of electric power at a plant in Iraq, a technological scheme of a comprehensive system for recycling diesel fuel from an electric power station with the additional generation of electricity, heat for heating heavy fuel, condensing technical water from exhaust gases. As a working fluid in the Rankin cycle, it is advisable to use the hot water from the engine cooling system. Using the developed mathematical model of the distillation circuit of the diesel power plant, the design-experimental study of the influence of the ambient temperature on the indicators of the efficiency of heat recovery was performed. When the ambient temperature changes from 0 ° C to 40 ° C, the amount of electric energy generated by the Rankin cycle for the Hyundai H25 / 33 engine increases to 10%. With a single cogeneration unit with a Hyundai H25 / 33 engine and a recycling complex developed, it is possible to get up to 2300 kg of water vapor condensate per day, which is very valuable in Iraq. Based on the results of the study, two variants of the technological scheme (projects A and B) were developed for the modernization of Hyundai diesel power plants. The feasibility study for the NPV method has shown that after the full recovery equipment is put into operation, the maximum achievable profit will be about 1 406 219 $ /year.Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.05.03 – двигуни та енергетичні установки. – Національний технічний університет "Харківський політехнічний інститут". – Харків, 2017. Дисертація присвячена вибору і обґрунтуванню параметрів дизель-електричної станції з системою утилізації вторинної теплоти дизеля з використанням циклу Ренкіна, що використовує теплоту відпрацьованих газів та системи охолодження. В результаті аналізу особливостей перспективної енергетичної установки з двигуном Hyundai 25/33 для виробництва електричної енергії на заводі в Іраку розроблена технологічна схема комплексної системи утилізації вторинної теплоти дизель-електричної станції з додатковим отриманням електроенергії, теплоти для підігріву важкого палива, конденсації технічної води з відпрацьованих газів двигуна. Для утилізації вторинної теплоти двигуна Hyundai H25/33 запропоновано утилізаційний контур установки, який працює за органічним циклом Ренкіна (ОЦР). В якості робочого тіла в циклі Ренкіна доцільно використовувати воду системи охолодження двигуна. З використанням розробленої математичної моделі утилізаційного контуру дизель-електростанції виконане розрахунково-експериментальне дослідження впливу температури навколишнього середовища на показники ефективності утилізаційного контуру. При зміні температури навколишнього середовища від 0 ° С до 40 ° С кількість електроенергії, виробленої за циклом Ренкіна для двигуна Hyundai H25/33 збільшується до 10%. При роботі однієї когенераційної установки з двигуном Hyundai H25/33 та розробленим утилізаційним комплексом можна отримати на добу до 2300 кг конденсату водяної пари, що є дуже цінною в Іраку. На основі результатів дослідження було розроблено два варіанта технологічної схеми (проекти "А" та "Б") модернізації дизельних електростанцій компанії Hyundai Heavy Industries. Виконана техніко-економічна оцінка проектів за метод NPV показала, що після того, як обладнання утилізаційного контуру в повному обсязі буде введено у експлуатацію, максимально досяжний прибуток складе близько 1 406 219 дол. США/рік.
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Хамза, Хамза Алі Адел. "Вибір та обґрунтування параметрів дизель-електричної станції з системою утилізації теплоти." Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/31663.
Full textAbstract:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.05.03 – двигуни та енергетичні установки. – Національний технічний університет "Харківський політехнічний інститут". – Харків, 2017. Дисертація присвячена вибору і обґрунтуванню параметрів дизель-електричної станції з системою утилізації вторинної теплоти дизеля з використанням циклу Ренкіна, що використовує теплоту відпрацьованих газів та системи охолодження. В результаті аналізу особливостей перспективної енергетичної установки з двигуном Hyundai 25/33 для виробництва електричної енергії на заводі в Іраку розроблена технологічна схема комплексної системи утилізації вторинної теплоти дизель-електричної станції з додатковим отриманням електроенергії, теплоти для підігріву важкого палива, конденсації технічної води з відпрацьованих газів двигуна. Для утилізації вторинної теплоти двигуна Hyundai H25/33 запропоновано утилізаційний контур установки, який працює за органічним циклом Ренкіна (ОЦР). В якості робочого тіла в циклі Ренкіна доцільно використовувати воду системи охолодження двигуна. З використанням розробленої математичної моделі утилізаційного контуру дизель-електростанції виконане розрахунково-експериментальне дослідження впливу температури навколишнього середовища на показники ефективності утилізаційного контуру. При зміні температури навколишнього середовища від 0 ° С до 40 ° С кількість електроенергії, виробленої за циклом Ренкіна для двигуна Hyundai H25/33 збільшується до 10%. При роботі однієї когенераційної установки з двигуном Hyundai H25/33 та розробленим утилізаційним комплексом можна отримати на добу до 2300 кг конденсату водяної пари, що є дуже цінною в Іраку. На основі результатів дослідження було розроблено два варіанта технологічної схеми (проекти "А" та "Б") модернізації дизельних електростанцій компанії Hyundai Heavy Industries. Виконана техніко-економічна оцінка проектів за метод NPV показала, що після того, як обладнання утилізаційного контуру в повному обсязі буде введено у експлуатацію, максимально досяжний прибуток складе близько 1 406 219 дол. США/рік.Dissertation for the degree of candidate of technical sciences in specialty 05.05.03 – engines and power plants. – National Technical University "Kharkiv Polytechnic Institute". – Kharkiv, 2017. The dissertation is devoted to the choice and substantiation of parameters of a diesel power plant with heat recovery system of recycling the secondary heat from diesel engine using the Rankin cycle, which uses the heat of exhaust gases and cooling water systems. As a result of the analysis of the features of a promising power plant with a Hyundai 25/33 engine for the production of electric power at a plant in Iraq, a technological scheme of a comprehensive system for recycling diesel fuel from an electric power station with the additional generation of electricity, heat for heating heavy fuel, condensing technical water from exhaust gases. As a working fluid in the Rankin cycle, it is advisable to use the hot water from the engine cooling system. Using the developed mathematical model of the distillation circuit of the diesel power plant, the design-experimental study of the influence of the ambient temperature on the indicators of the efficiency of heat recovery was performed. When the ambient temperature changes from 0 ° C to 40 ° C, the amount of electric energy generated by the Rankin cycle for the Hyundai H25 / 33 engine increases to 10%. With a single cogeneration unit with a Hyundai H25 / 33 engine and a recycling complex developed, it is possible to get up to 2300 kg of water vapor condensate per day, which is very valuable in Iraq. Based on the results of the study, two variants of the technological scheme (projects A and B) were developed for the modernization of Hyundai diesel power plants. The feasibility study for the NPV method has shown that after the full recovery equipment is put into operation, the maximum achievable profit will be about 1 406 219 $ /year.
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Drescher, Ulli. "Optimierungspotenzial des Organic Rankine Cycle für biomassebefeuerte und geothermische Wärmequellen /." Berlin : Logos-Verl, 2008. http://deposit.d-nb.de/cgi-bin/dokserv?id=3126519&prov=M&dok_var=1&dok_ext=htm.
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Daminabo, Ferdinand Frank Oko. "A novel 2kWe biomass-organic rankine cycle micro cogeneration system." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/10985/.
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Energy is potentially at the hub of modern civilization and right from Industrial Revolution, technology has refined and redefined the way we use energy; but technological advancement in all spheres will continue to depend and use energy to progress. However, fossil fuels (coal, gas, oil) have remained the dominant energy resource accounting for a larger proportion of world energy consumption when compared to nuclear energy and renewable energy resources. There are mounting fears of both the climate and our environment reaching a characteristic tipping point due to global warming. This is associated with the relentless use of fossil fuels and uncontrolled emissions of greenhouse gases. The persistent trend has triggered the need for alternative and renewable energy options which are now being considered and pursued globally to avert the possibility of climate change attaining a state of irreversibility. This research describes the development of a novel 2kWe biomass fired Organic Rankine Cycle (ORC) system intended for remote off-grid locations, employing a multi-vane expander as the prime mover. The expander is a four vane model 6AM-FRV-5A 3kW Gast Air motor manufactured by Gast Manufacturing Inc. The prime mover will harness power produced by high pressure vapour to generate torque and rotational motion on the shaft and the mechanical energy generated is converted to electricity by means of an automotive alternator. The conversion of low and medium temperature heat from biomass to electricity by using low cost, lightweight and low maintenance expander as well organic substances or hydrofluoroether, HFE 7100 and HFE 7000 is the subject ofthis research. In order to assess and predict the performance of the system an EES simulation of a basic cycle is carried out in order to compare the the outcome with the actual cycle. A preliminary air test of the system was also carried out to have a perspective on actual performance using compressed air. However, the organic substance, hydrofluoroether (HFE) to be used in further tests is selected because of its thermodynamic properties of having a lower specific volume and higher molecular weight than steam allowing for smaller, less complex, less costly energy applications like expanders and smaller diameter tubes to be employed for low temperature micro system. This is achieved through a phase change transformation in a Rankine cycle process between specified temperature limits when compared to turbines which operate at higher temperature and pressure. An experimental study and initial testing is carried out using a Chromalox- Model CES-12, 9 kW boiler providing temperatures between 100oC and 115oC and test measurements collated and analysed to predict performance and assess outputs and possibly fluctuations in the system. A test involving the use of the biomass boiler is carried out later and analysed results compared with that of the electric boiler. The process will involve the supply of heat from the biomass boiler and the high pressured vapour generated in the ORC cycle is expanded through the prime mover with a fall in temperature and pressure at the exhaust and exiting as saturated vapour or a mixture of vapour and liquid. The energy stored in the working fluid in the vapour state is converted to electricity by work on the shaft while the exhaust heat can be tapped for domestic uses as thevapour is expanded down to low pressure in the condenser and the saturated liquid is pumped to a high pressure in the evaporator to resume the cycle.
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Taylor, Leighton John. "Development of a low temperature geothermal organic rankine cycle standard." Thesis, University of Canterbury. Mechanical, 2015. http://hdl.handle.net/10092/10427.
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The growth in renewable electricity generation is forecast to continue as fossil fuel levels decrease and carbon dioxide emissions are penalized. The growth in geothermal is becoming constrained as conventional high-temperature sources are fully exploited. Geothermal can be a cost competitive base load power source. Governments and utilities are looking at the potential of electricity generation from low temperature geothermal resources for future development. This technology, unlike the high and medium temperature, is not mature and there are a number of companies looking at entering the Organic Rankine Cycle (ORC) market.
This thesis aims to provide a necessary step for reliable commercial develop this technology by developing the first draft of a low temperature geothermal ORC standard. The standard outlines the
critical stages of a geothermal ORC project as the Prospecting stage; Pre-Feasibility stage, Feasibility stage, and the Detailed Design stage. The standard is unlike other standards that are used to design one
component; this standard guides the engineers though the various critical steps of the ORC design to correctly assess the geothermal resource and to inform design and investment decisions.
The standard provides particular guidance on critical factors in ORC design, primarily the working fluid selection and component selection limitations. Experienced industry engineers have provided advice and
insight regarding the critical design points and processes. The draft standard was reviewed by a number of geothermal industry engineers who have worked with large scale, conventional ORCs. They each
commented on the standard from their prospective in the industry and gave general feedback was that it is a technically relevant standard that can be used as a potential start point to develop a new standard for
the low temperature binary ORC industry. The final draft standard has been submitted to the ISO for consideration.
This thesis first sets out the general background on the state of the art and the industry for lowtemperature binary ORC power plants, and provides the review assessment of the standard draft.
However, the bulk of the thesis is the standard itself. The standard represents a substantial contribution to
the mechanical and thermal systems engineering field.
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Pižorn, Žiga. "Implementation of an Organic Rankine cycle on a Stepping furnace." Thesis, KTH, Kraft- och värmeteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-147933.
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In this master thesis an implementation of an Organic Rankine Cycle (ORC) on a stepping furnace in a steel mill is modeled and proposed. The study is a case study at the company Štore&STEEL d.o.o. with intentions of realization. In a steel mill a stepping furnace is used to preheat the steel billets for later forging. The stepping furnace is gas fired and already has recuperation of the inlet air implemented. Still there is high temperature of the stack after recuperation, which makes application of an ORC worth of researching and modeling.First the flue gas over one year of furnace operation is analyzed in terms of temperature and volumetric flow. Mass flow and heat capacity are calculated. A layout of an ORC is proposed and modeled in IPSEpro for different temperatures of the flue gas resulting in different output powers and efficiencies. For each temperature an economic viability calculation with the method of reference cost of electric energy is done.The results are presented and the best design and conditions are proposed. The results of the thesis proved that further detailed measurements and calculation are worthwhile , as the flue gas from the stepping furnace has satisfactory conditions to make an application of an Organic Rankine cycle viable. Also the least ammount of state support to fulfill the companies conditions on return of investment is calculated and presented. Finally there are additional measurements and calculations suggested.
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Drescher, Ulli. "Optimierungspotenzial des organic rankine cycle für biomassebefeuerte und geothermische Wärmequellen." Berlin Logos-Verl, 2007. http://d-nb.info/989242536/04.
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HERRERIA, ERNESTO JAVIER RUANO. "SIMULATION OF AN ORGANIC RANKINE CYCLE POWERED BY SOLAR ENERGY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2012. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=21796@1.
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FUNDAÇÃO DE APOIO À PESQUISA DO ESTADO DO RIO DE JANEIROEsta simulação considera um ciclo Rankine que utiliza um fluido de trabalho orgânico, com a particularidade que a fonte de energia de entrada ao sistema será solar. Esta energia renovável que provem do potencial do Sol é aproveitada com a utilização de coletores concentradores lineares parabólicos. Estes dois circuitos: do ciclo Rankine orgânico e do conjunto de coletores interatuam termicamente mediante um trocador de calor chamado de gerador de vapor. Adicionalmente, existe um sistema de armazenamento térmico que permite acumular parte da energia solar coletada para ser utilizada em períodos sem radiação solar ou com níveis baixos da mesma. A primeira parte deste trabalho mostra os aspectos teóricos introdutórios e as considerações para trabalhar com um ciclo Rankine de tipo orgânico, o tipo de coletores escolhido e a utilização de armazenamento térmico. O segundo capítulo mostra o modelo matemático apropriado para simular um sistema de geração de potência de baixa capacidade (50 kW) e os componentes de cada circuito: ciclo (bomba, expansor, condensador, recuperador, gerador de vapor), coletores (cobertura, refletor, absorvedor, etc.) e armazenamento (tanques, etc.). A simulação foi desenvolvida no software EES. O terceiro analisa os parâmetros do modelo, seus possíveis valores físicos, a sensibilidade da sua variação e sua seleção adequada com o objetivo de efetuar uma simulação bastante similar à realidade e as incertezas presentes. No capítulo final se apresentam os resultados em base as condições de desenho consideradas.
This simulation considers a Rankine cycle that works with an organic fluid, but has the particularity of using solar power as the font of input energy. This renewable energy that comes from the sun’s potential is taken with the use of parabolic trough collectors. These two circuits: that of the organic Rankine cycle (ORC) and the other of collector’s ensemble interact termically in a heat exchanger called as vapor generator. Adicionally there’s a thermal storage system that allows accumulating part of the collected solar energy to be used for periods of time when there’s no solar radiation or with very low levels of it. The first part of this work shows the introductory theoretical aspects and the considerations to work with an organic Rankine cycle (ORC), the type of chosen collector and the use of heat storage. The second chapter shows the appropriate mathematic model to simulate a system of power generation of low capacity (50 kW) and the components of each circuit: ORC (pump, expander, condenser, recuperator, vapor generator), collectors (glass cover, reflector mirror, absorber tube, etc.) and thermal storage (storage tanks, etc.). The simulation was developed using EES software. The third chapter analyzes the parameters of the model, specially its values and possible variations to approach the simulation to the reality. In the final chapter, some results are presented based on some considered design conditions.
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Ranade, Vishakhdutt. "Dynamic Modeling of Rankine Cycle using Arbitrary Lagrangian Eulerian Method." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491562460235764.
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Badr, O. M. "Development of a low-grade energy engine with a multi-vane expander as the prime mover." Thesis, Cranfield University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.482949.
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Cox, Jennifer Marie. "Analysis of a tubular solid oxide fuel cell topping cycle with a modified rankine bottoming cycle." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17531.
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Rowshanzadeh, Reza. "Performance and cost evaluation of Organic Rankine Cycle at different technologies." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32385.
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Santoso, Moeljadi Christensen Richard Neils. "An alternative configuration of Rankine cycle engine-driven heat pump system /." Connect to resource, 1989. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1144698627.
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Santoso, Moeljadi. "An alternative configuration of Rankine cycle engine-driven heat pump system." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1144698627.
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Oelofse, Stephanus Phillipus. "An investigation into the performance of a Rankine-heat pump combined cycle / Stephanus Phillipus Oelofse." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9185.
Full textAbstract:
The global growth in electricity consumption and the shortcomings of renewable electricity generation technologies are some of the reasons why it is still relevant to evaluate the performance of power conversion technologies that are used in fossil fuel power stations.
The power conversion technology that is widely used in fossil fuel power stations is the Rankine cycle. The goal of this study was to determine if the efficiency of a typical Rankine cycle can be improved by adding a heat pump as a bottoming cycle. Three simulation models were developed to perform this evaluation.
The first is a simulation model of a Rankine cycle. A quite detailed Rankine cycle configuration was evaluated. The simulation model was used to determine the heating requirements of the heat pump cycle as well as its operating temperature ranges. The efficiency of this Rankine cycle was calculated as 43.05 %.
A basic vapour compression cycle configuration was selected as the heat pump of the combined cycle. A simulation model of the vapour compression cycle and the interfaces with the Rankine cycle was developed as the second simulation model.
Working fluids that are typically used in vapour compression cycles cannot be used for this application, due to temperature limitations. The vapour compression cycle’s simulation model was therefore also used to calculate the coefficient of performance (COP) for various working fluids in order to select a suitable working fluid. The best cycle COP (3.015 heating) was obtained with ethanol as working fluid.
These simulation models were combined to form the simulation model of the Rankine-heat pump combined cycle. This model was used to evaluate the performance of the combined cycle for two different compressor power sources.
This study showed that the concept of using steam turbine or electrical power to drive a compressor driven vapour compression cycle in the configuration proposed here does not improve the overall efficiency of the cycle.
The reasons for this were discovered and warrant future investigation.Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013.
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Liamini, Mokhtar. "Conception d'une microturbine cycle Rankine microfabriquée pour le fonctionnement à haute température." Thèse, Université de Sherbrooke, 2014. http://hdl.handle.net/11143/5425.
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Le projet présenté ici consiste en la conception et l’étude de faisabilité d’une microturbopompe de type Rankine destinée à être opérée à haute température. Une étude préliminaire est d’abord effectuée pour déterminer la configuration globale ainsi que les matériaux possibles pour l’isolation thermique du dispositif. Il en découle la nécessité d’utiliser des matériaux isolants pour le rotor et la structure statique. Les matériaux retenus sont le quartz et le Pyrex et la surface de la structure statique doit être réduite tout en s’assurant de la solidité du dispositif. Le domaine d’application retenu est la récupération de la chaleur de gaz d’échappements automobiles pour la génération d’énergie électrique. Dans cette application, l’utilisation de panneaux de microturbines pourrait permettre d’économiser jusqu’à 2.7% du carburant consommé. Après que la configuration globale soit définie, les composants rotodynamiques sont conçus en utilisant les modèles physiques les plus actuels. La conception finale comporte la pompe centripète, la turbine à un étage, deux paliers axiaux, un palier radial anisotropique comportant quatre réservoirs ainsi que trois joints d’étanchéité (un joint d’étanchéité spiral à viscosité et deux joints d’étanchéité annulaires) permettant de découpler les écoulements des différents composants.
Par la suite, une séquence de procédés est définie ainsi que le concept détaillé incluant les aménagements permettant l’instrumentation et l’opération dans un banc d’essai de la microturbopompe de démonstration. La conception des dix-huit photomasques de fabrication découle de cet exercice. Finalement, des tests de microfabrication sont effectués pour évaluer la faisabilité des principales étapes définies dans la séquence de procédés de fabrication. Les étapes de photolithographie, de gravure du silicium, de collage anodique et par fusion sont démontrées tandis que les défis inhérents à la gravure du Pyrex et du quartz sont explorés. Une approche pour compléter la fabrication d’un dispositif de démonstration est proposée à la fin de ces travaux.
Cette étude définit pour la première fois la configuration détaillée d’une microturbopompe à vapeur opérant à haute température, confirmant la faisabilité de ce concept. Les jalons sont posés pour la fabrication d’un prototype de démonstration et la validation des modèles présentés ici.
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Kloppers, Cornelius Petrus. "Thermodynamic cycle design of a Brayton–Rankine combined cycle for a pebble bed modular reactor / Cornelius Petrus Kloppers." Thesis, North-West University, 2011. http://hdl.handle.net/10394/7623.
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The rapid development in nuclear technology worldwide has created the need for an efficient power conversion unit to extract the energy from the new generation IV reactors. The generation IV reactor currently under investigation in South Africa is the PBMR–DPP (Pebble Bed Modular Reactor Demonstration Power Plant) based on the High temperature Reactor Modul. This reactor produces 200 MW of thermal energy at inlet/outlet temperatures of 250oC/700oC. Due to the reactor layout and accompanying thermal fluid path design outlet temperatures in the order of 900oC would be possible. This dissertation is aimed at the design and optimisation of a Brayton–Rankine combined cycle for use with a PBMR–DPP. The combination of these two cycles improves the thermal efficiency due to the large difference between the maximum and minimum temperatures. The Brayton and Rankine cycles will be developed independently and optimised to ensure that the best possible efficiency is gained from the combined cycle. The heat energy available in the reactor is the input parameter for the Brayton cycle, After the Brayton cycle's pressure ratio has been optimised the heat rejected to the Rankine cycle will be known. The aim of the design is to determine if 50% combined cycle thermal efficiency is achievable. The initial sizing calculation of the cycle parameters has been done in a software package that has been developed for use in the thermo–hydraulics field. Engineering Equation Solver (EES) makes use of an iterative process to simultaneously solve the set of equations. The results obtained from EES were verified by Microsoft Excel with a specialised macro installed for thermo–hydraulics.
A very specific methodology was used to solve the Brayton cycle. Traditionally the Brayton cycle is optimised for maximum cycle efficiency to ultimately obtain the best combined cycle efficiency. Very complex cycles such as reheat and multi–shaft Brayton cycles were used. The solution methodology used in this dissertation is to optimise the simple Brayton cycle for the maximum specific work produced in the cycle. The large amount of heat at the turbine outlet is then transferred to the Rankine cycle. The results obtained from the calculations preformed were that a combined cycle efficiency of 52.914% has been achieved at optimum operating conditions. The combined cycle has been shown to operate above 50% efficiency in a wide variety of load–following conditions.Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2011.
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Schuster, Andreas M. [Verfasser]. "Nutzung von Niedertemperaturwärme mit Organic-Rankine-Cycle-Anlagen kleiner Leistung / Andreas Schuster." München : Verlag Dr. Hut, 2011. http://d-nb.info/1015605532/34.
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Pumaneratkul, Chayadit. "Basic characteristics of Rankine cycle with functional elements, using supercritical carbon dioxide." Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13097320/?lang=0, 2018. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13097320/?lang=0.
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Siviter, Jonathan Peter. "Increasing the efficiency of the Rankine cycle using a thermoelectric heat pump." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5802/.
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Thermal plants operating on the Rankine cycle are by far the most common method of global electrical power generation. The Rankine cycle, first developed in the late 19th century, continues to this day to be one of the most important practical implementations of a heat engine. Innovation and enhancement of the cycle continues and today's emphasis is directed towards reduced carbon emissions from the combustion of fossil fuel as well as improvement of the absolute efficiency. This thesis presents an increase in the Rankine cycle efficiency through reducing the waste heat rejected from the process by the use of a thermoelectric heat pump. A thermoelectric heat pump converts a flow of electrical charge carriers to a flow of thermal energy via phonon transport through a semiconductor lattice, described by the Peltier effect. The heat flux through the device can be modulated by varying the electrical voltage and current applied to the semiconductor. Unlike a conventional heat pump, however, the direction of heat transport is determined by the direction of migration of the charge carriers. The efficiency with which the device operates is determined by complex relationship amongst the differential temperature across the device, the geometry of the semiconductor pellets forming the device and the electrical current flow. Peltier effect devices are typically used in small-scale refrigerators, on high-power lasers to aid cooling and to maintain the wavelength stability of optical communications networks. In this thesis the application of a heat pump to recover a portion of the waste thermal energy normally rejected from the Rankine cycle process after the re-condensation of feedwater in the condenser of a steam turbine is considered. Firstly, a theoretical statement of the required Coefficient of Performance for economic operation of such a system is derived. This is followed by an experimental investigation to determine if the calculated performance is available using today's thermoelectric technology point. The thesis then presents a rigourous analysis of novel experimental apparatus used to characterise the impact of redirecting enthalpy normally rejected from the process to instead reducing the fuel load to the plant and concludes with an assessment of the economic benefits such a heat pump system would bring.
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Webster, Jack Ryan. "Suitability of the Kalina Cycle for Power Conversion from Pressurized Water Reactors." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6882.
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The primary objective of this work is to determine the Kalina cycle's suitability for thermal power conversion from a pressurized water reactor. Several previous papers have examined this application, but these either lack proof of concept or make unfeasible assumptions. This work expands current knowledge by simulating the Kalina cycle and comparing it to current pressurized water reactor Rankine cycles in order to identify which is more efficient. Prerequisite to the modeling is a simulation tool capable of modeling the thermodynamics of ammonia/water mixtures. Instead of using an existing program, a new one called Clearwater is used. This tool is based on a preexisting Gibbs free energy "super" equation of state. Algorithms for vapor-liquid equilibrium calculations and phase identification are presented. Clearwater will be distributed online as open-source code to aid future developers of ammonia/water power and refrigeration cycles. A comparison of single-stage Kalina and Rankine cycles driven by heat from PWR core coolant suggests that the Kalina cycle is not well suited to the application. Any benefit from the Kalina cycle's ability to match temperature profiles in the boiling region of the steam generator is outweighed by other drawbacks. These include the cycle's 1) increased turbine exhaust pressure and 2) lower average heat absorption temperature caused by its working fluid's relatively high liquid heat capacity, both of which lower efficiency. Having concluded this, an attempt is made to quantify the conditions under which the Kalina cycle produces more power than the Rankine cycle. Both cycles are optimized for a range of heat source inlet and outlet temperatures between 350 ℃ and 525 ℃. When both cycles absorb the same amount of heat from the source"”i.e., when source outlet temperature is constrained"” the Kalina cycle is less effective for small source temperature drops. When outlet temperature is unconstrained, the Kalina cycle outperforms the Rankine cycle for all but the lowest inlet temperature. This is due to the Kalina cycle's non-isothermal boiling profile, which allows it to absorb low temperature heat at relatively high pressure. Because of its isothermal boiling profile, the Rankine cycle cannot capture low temperature heat as effectively, so it performs worse over large, unconstrained source temperature drops.
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Holmgren, Magnus. "Utveckling av dataanalysprogram för Opcon Powerbox." Thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-121736.
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Opcon Powerbox is a product developed by Opcon together with the underlying company SRM (Svenska Rotor Maskiner) where surplus heat from the industry is used through an Organic Rankine Cycle (ORC)–process to produce electricity. An ORC-process is a thermodynamic circle process in which a refrigerant is used as the working fluid. The refrigerant makes it possible for the circle process to operate at lower temperatures than the conventional Rankine process. In this master’s thesis a data analysis software for the Opcon Powerbox has been developed in which measurement data is retrieved and handled from the Opcon Powerbox. The software performs calculations and analysis on the data with which the system can be evaluated. This thesis has been carried out with SRM.
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Gabrielli, Paolo. "Design and optimization of turbo-expanders for organic rankine cycles." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6829/.
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In a world focused on the need to produce energy for a growing population, while reducing atmospheric emissions of carbon dioxide, organic Rankine cycles represent a solution to fulfil this goal. This study focuses on the design and optimization of axial-flow turbines for organic Rankine cycles. From the turbine designer point of view, most of this fluids exhibit some peculiar characteristics, such as small enthalpy drop, low speed of sound, large expansion ratio. A computational model for the prediction of axial-flow turbine performance is developed and validated against experimental data. The model allows to calculate turbine performance within a range of accuracy of ±3%. The design procedure is coupled with an optimization process, performed using a genetic algorithm where the turbine total-to-static efficiency represents the objective function. The computational model is integrated in a wider analysis of thermodynamic cycle units, by providing the turbine optimal design. First, the calculation routine is applied in the context of the Draugen offshore platform, where three heat recovery systems are compared. The turbine performance is investigated for three competing bottoming cycles: organic Rankine cycle (operating cyclopentane), steam Rankine cycle and air bottoming cycle. Findings indicate the air turbine as the most efficient solution (total-to-static efficiency = 0.89), while the cyclopentane turbine results as the most flexible and compact technology (2.45 ton/MW and 0.63 m3/MW). Furthermore, the study shows that, for organic and steam Rankine cycles, the optimal design configurations for the expanders do not coincide with those of the thermodynamic cycles. This suggests the possibility to obtain a more accurate analysis by including the computational model in the simulations of the thermodynamic cycles. Afterwards, the performance analysis is carried out by comparing three organic fluids: cyclopentane, MDM and R245fa. Results suggest MDM as the most effective fluid from the turbine performance viewpoint (total-to-total efficiency = 0.89). On the other hand, cyclopentane guarantees a greater net power output of the organic Rankine cycle (P = 5.35 MW), while R245fa represents the most compact solution (1.63 ton/MW and 0.20 m3/MW).
Finally, the influence of the composition of an isopentane/isobutane mixture on both the thermodynamic cycle performance and the expander isentropic efficiency is investigated. Findings show how the mixture composition affects the turbine efficiency and so the cycle performance. Moreover, the analysis demonstrates that the use of binary mixtures leads to an enhancement of the thermodynamic cycle performance.
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El, Chammas Rody. "Cycle Rankine adapté à un véhicule hybride : simulation et conception d'un premier démonstrateur." Paris, ENMP, 2005. http://www.theses.fr/2005ENMP1317.
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Ebhuomhan, Sarah. "Effectiveness of using Organic Rankine cycle engine in small-scale district heating systems." Thesis, Linnéuniversitetet, Institutionen för byggd miljö och energiteknik (BET), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-105294.
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Co-production of electricity and heat using biomass is important in providing sustainable energy for the future. District heating systems, which are well established in Sweden, provide a great opportunity to co-produce electricity simultaneously. With small-scale district heating comprising majority of the district heating systems in Sweden, there is great potential for electricity production. The overall efficiency of the primary energy use of the cogeneration system of electricity and heat from district heating systems shows its sustainability advantage and energy benefits. The cost effectiveness of such systems gives an idea as to how profitable, market-competitive, and feasible the implementation of such systems might be. This thesis analyses the effectiveness of co-producing electricity in small-scale district heating systems, using Organic Rankine cycle (ORC) engines from an overall energy system viewpoint. A small-scale district heating system in Ingelstad Sweden with an annual heat capacity of 6.0 GWh, was used as a case study. The additional fuel use and the amount of electricity that could be produced if an ORC turbine was integrated into the system as well as its production cost were estimated. Results show that a net electricity production of 219 MWh could be yielded annually at a production cost of 102.0 €/MWh, but an additional primary energy of 239.9 MWh could be consumed. Consequently, the system yielded about double the quantity of electricity when compared to the case of producing in standalone power plants. Considering the situation where the co-produced electricity is used to replace that from different fossil-based standalone power plants, a carbon abatement cost of 90.4 - 158.4 €/ton CO2 is accounted. Sensitivity analysis done on this integrated system showed that increased heat demand would serve to improve the energy efficiency of the system, if applied, while lower discount rates and elongation of the equipment lifetime would serve to improve the cost-effectiveness of the system. The positive results from the study reveal that, the integration of ORC engines into small-scale district heating systems is promising from an overall energy system viewpoint.
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Johnston, Jon R. Jr. "Evaluation of expanders for use in a solar-powered Rankine Cycle Heat Engine." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1298561887.
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Supak, Kevin Robert. "Reduced gravity Rankine cycle system design and optimization study with passive vortex phase separation." Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-2094.
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Liquid-metal Rankine power conversion systems (PCS) coupled with a fission reactor
remain an attractive option for space power applications because system specific power
and efficiency is very favorable for plant designs of 100 kW(e) or higher. Potential
drawbacks to the technology in a reduced gravity environment include two-phase fluid
management processes such as liquid-vapor phase separation. The most critical location
for phase separation is at the boiler exit where only vapor must be sent to the turbine
because blade erosion occurs from high velocity liquid droplets entrained by vapor flow.
Previous studies have proposed that rotary separators be used to separate the liquid and
vapor from a two phase mixture. However these devices have complex turbo machinery,
require kilowatts of power and are untested for high vapor flow conditions. The
Interphase Transport Phenomena (ITP) laboratory has developed a low-power, passive
microgravity vortex phase separator (MVS) which has already proven to be an essential
component of two-phase systems operating in low gravity environments.
This thesis presents results from flight experiments where a Rankine cycle was operated
in a reduced gravity environment for the first time by utilizing the MVS for liquid and
vapor phase separation. The MVS was able to operate under saturated conditions and
adjust to system transients as it would in the Rankine cycle by controlling the amount of
liquid and vapor within the device. A new model is developed for the MVS to predict
separation performance at high vapor flow conditions for sizing the separator at the boiler, condenser, and turbine locations within the cycle by using a volume limiting
method. This model factors in the following separator characteristics: mass, pumping
power, and available buffer volume for system transients. The study is concluded with
overall Rankine efficiency and performance changes due to adding vortex phase
separation and a schematic of the Rankine cycle with the integration of the MVS is
presented. The results from this thesis indicate the thermal to electric efficiency and
specific mass of the cycle can be improved by using the MVS to separate the two phases
instead of a rotary separator.
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Marin, Andreea. "Optimizarea exergoeconimică a unei centrale solare termice." Thesis, Paris 10, 2014. http://www.theses.fr/2014PA100054.
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Dans le contexte économique et énergétique actuel, la mise en œuvre de technologies à l'aide de l'énergie renouvelable comme source de chauffage offre un double avantage: la réduction de la pollution et des coûts de carburant. Il y a un besoin de promouvoir les sources renouvelables d'énergie comme les sources significatives de production d'énergie pour les systèmes décentralisés. Une première étude bibliographique a été fait sur les technologies existantes pour la production d'énergie électrique à partir du solaire. Cette étude consiste dans la recherche d’une nouvelle solution de conversion de l’énergie solaire pour la production d’électricité de faible puissance. L'un des objectifs de cette thèse a été la construction d'un moteur Stirling de type gamma fonctionnant à basse différence de température, adapté à un circuit solaire (capteur plan). Le moteur Stirling a été testé en vue de comparer les résultats expérimentales avec les résultats d’un model Schmidt, fait dans le logiciel, Matlab. Un autre cycle thermodynamique étais étudie dans cette travail, le Cycle Organique Rankine (ORC). Un modèle mathématique a été développé et vérifie dans les logiciels, Thermoptim et EES (Engineering Equation Solver) avec les résultats expérimentaux pour étudier les performances d'installation avec des différentes températures de fonctionnement. La méthode exergétique et la méthode du Pincement sont utilisée pour évaluer les performances du système comme irréversibilité, destruction d’exergie et phénomènes qui se produisent dans toutes les composantes du système ORC pour améliorer son fonctionnementIn the current economic and energy context, implementation of technologies using renewable energy as heat source has two advantages: reducing pollution and fuel costs. There is a need to promote renewable energy sources such as significant sources of power generation for decentralized systems. In the first part, it was made a literature review on existing technologies for the production of electricity with solar energy. One of the objectives of this thesis was to build a Stirling engine gamma type suitable to use solar energy (flat plate collator). The Stirling engine was tested to compare the experimental results with the results of Schmidt model, realized in the software, Matlab. Another thermodynamic cycle was studied in this work, the Organic Rankine Cycle (ORC). A mathematical model was developed and verified in software, Thermoptim and EES (Engineering Equation Solver) with experimental results to study the installation performance function of different operating temperatures. The entire system and each subsystem are analyzed according to the first and the second law of thermodynamics. The exergy method and Pinch analysis are used to evaluate the performance of the system like irreversibility and exergy destruction, phenomenon that occurs in all components of the ORC system. This analysis is to improve the operation
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Shao, Yingjuan. "Development and evaluation of a biomass-fired micro-scale CHP with organic rankine cycle." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/13597/.
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Combined Heat and Power Generation (CHP) or cogeneration has been considered worldwide as the major alternative to traditional energy systems in terms of signi ticant energy saving and environmental conservation. A renewable energy resource-fuelled CHP would deliver even more environmental benefits than a fossil tuel-driven CHP. Biomass is one of the renewable energy resources that plays an important role to the world primary energy supplies and can be used to fuel CHP systems. Many medium- and large-scale biomass-fired CHP plants have been demonstrated and commercialized in the world. However, biomass-fuelled microscale CHP (1-1 OkW c>) which is suitable tor building applications has yet to be commercialised or demonstrated. The development and evaluation of a micro-CHP system operating on biomass energy has been the focus of this PhD research. It is an integral part of an externally funded research project which aims to develop and evaluate a novel, first-of-its-kind, micro-scale (l - 2 kWe) biomass-tired CHP system suitable for public and large domestic buildings' applications. The specific tasks of the present PhD research arc: To thermodynamically model the micro-scale biomass-fired CHP system with organic Rankine cycle (ORC): different environment-friendly working fluids are to be modelled with the ORC processes. To experimentally evaluate the micro-scale biomass-tired CHP system in terms of power generation and combined heat and power pertormance. To experimentally investigate the combustion performance and NOx emissions of the biomass pellet boiler which is a key component of the micro-scale biomass-fired CHP system. The micro-scale biomass-tired CHP system with ORC developed by the research team of University of Nottingham including the author of this PhD thesis mainly consists of a biomass boiler, an ORC fluid evaporator, an ORC turbine, an alternator, a heat reeouperator and a condenser. The boiler produces hot water which transfers heat to the organic working tluid via the evaporator. The generated organic fluid vapour drives a turbine to rotate an alternator, producing power. The expanded organic fluid vapour leaving the turbine transfers some of its heat to the recouperator and then is condensed by cooling water which can be heated to around 40 - 50 °C for domestic washing and under-floor heating purposes. The main methodologies of the present PhD research are the thermodynamic modelling of the proposed micro-scale biomass-tired CHP system with ORC and the laboratory testing of the assembled micro-scale biomass-fired CHP system and its main components (biomass boiler, ORC turbine, alternator, heat exchangers etc.). Literature review has demonstrated that the biomass-fired micro-CHP systems for buildings present many advantages compared to conventional separate heating and power supply systems (e.g. a dedicated boiler for heating and grid for power supply) as they can present higher primary energy savings and lower CO2 emissions. ORC is a suitable thermodynamic cycle that could be used for micro-CHP systems while operating with waste heat and renewable energy resources which are available at relative low temperatures. Thermodynamical modelling of the proposed micro-scale biomass-fired CHP system with ORC has been carried out and the results have been presented and discussed in the thesis. Three different environment-friendly working fluids, namely HFE7000, HFE7100 and n-pentane, have been modelled with various ORC process configurations. The laboratory testing of the assembled micro-scale biomass-fired CHP system and its main components (biomass boiler, ORC turbine, alternator, heat exchangers etc.) has been carried out initially with a 25kW biomass boiler and then with a 50kW biomass boiler. The main purpose of the laboratory testing has been to evaluate the main energy efficiencies (the electrical efficiency and the total CHP efficiency) of the assembled micro-CHP systems. The combustion performance and NOx emissions of each biomass boiler have also been investigated as the biomass boiler is a key component of the micro-scale biomass-tired CHP system. The experimental findings of these laboratory tests are presented and analysed in the thesis. Finally, the conclusions of the present PhD research have been given. The modelling results have shown that the electrical efficiency of the micro-CHP system depends on not only the modelling conditions but also the ORC fluid. A comparison of the three fluids generally follows the following order: n-pentane > HFE7000 > HFE7100. For the laboratory test, the 25kW biomass boiler-driven micro-CHP system, having an ORC efficiency in the range of 2.20% - 2.85%, can generate electricity of 344.6W and heat of 20.3kW, corresponding to electricity generation efficiency 1.17% and CHP efficiency 86.22%. And the 50kWth biomass boiler-driven micro-CHP system, having an ORC efficiency of 3.48% - 3.89%, can generate electricity of 748.6W and heat of 43.7kW, corresponding to electricity generation efficiency 1.43% and CHP et1iciency 81.06%.
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Choquet, Vincent. "Integrated engine waste heat recovery by combination ofevaporative engine cooling and Rankine bottoming cycle." Thesis, KTH, Maskinkonstruktion (Inst.), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-156866.
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Engine Cooling losses constitutes about 20% of the injected fuel energy in a modern heavy duty truck diesel engine. The objective of this Master Thesis Project is to investigate flow boiling cooling as a thermally efficient method for waste heat recovery as well as a good solution for precision cooling. First, an engine heat transfer model was implemented on GT-suite software in order to estimate heat fluxes within the engine cylinder. Liners being less thermally constrained than the cylinder head, flow boiling cooling was then investigated in the liner’s water jackets. A more adapted heat transfer model taking into account both gas side and cooling side of the liner was thus implemented on Simulink. Unlike commercials software, this simple model allowed to implement the relevant two-phase heat transfer correlations and to study in details the boiling flow behaviors. The hydraulic diameter of the water jackets, the fluid saturated pressure and the surface area of heat transfer are the major parameters and they were studied for various mass flow rate in order to analyze how they influence wall temperature and heat transfer. This study showed good operating conditions for very low mass flow rate (about 1% of the typical mass flow rate for liquid convective cooling). Due to flow control issues, it implied the consideration of other fluids such as refrigerants but showed good prospect for cooling system simplification. This flow boiling model was finally inserted in a complete Rankine loop model using water as a working fluid to study potential efficiency improvements. A Rankine loop using water as a working fluid would thus improve the heat recovery of the considered engine of about 4.8% of the net engine brake power, recovering heat from the liners and the exhaust gases at 1800RPM, full load. Further simulations have also been led with R245fa, which shows a WHR of about 5.5% of the net engine brake power at 1800RPM, full load.Motorns kylförluster utgör ca 20 % av energin som injiceras i dieselmotorn på en modern lastbil. Målet med detta examensarbete är att undersöka om flödes kokande kylning är en termiskt effektiv metod för att återvinna spillvärmes och en effektiv lösning för precisionskyla. Först genomfördes en motorvärmeöverföringsmodell på GT-suite för att beräkna värmeflöden i motorcylindern. Eftersom cylinderfoder är mindre termiskt begränsade än topplockundersöktes flödes kokande kylning i cylinderfoder. En mer anpassad värmeöverföringsmodell med hänsyn till både avgas- och kylmedelsidan på cylinderfoder genomfördes således med Simulink. Till skillnad från kommersiella programvaror, gör denna enkla modell det möjligt att utföra 2-fas värmeöverföringskorrelationer och studera flödes kokande beteendet i detalj. De viktigaste parametrarna (vattenmantelns hydrauliska diameter, vätsketrycket och ytan av värmeöverföringarna) studerades för olika massflöden för att analysera hur de påverkar väggtemperatur och värmeöverföring. Undersökningen visade goda arbetsförhållanden för mycket låga massflöden (ca 1 % av det typiska massflödet för konvektiv vätskekylning). På grund av problem med flödesregleringen, behövde andra vätskor beaktas som köldmedier men hade god potential för att kyla systemet effektivt. För att studera potentiella förbättringar av energieffektiviteten infördes den flödes kokande modellen slutligen i en komplett modell av en Rankine-krets där vatten användes som kylmedel. En Rankine-krets med vatten skulle förbättra värmeåtervinningen på den avsedda motorn med 4,8 % motorns bromskraft, genom att återvinna värme från cylinderfoder och avgaserna vid 1800 RPM, full belastning. Ytterligare simulationer har också hållits med R245fa, som visar en återvinning av spillvärmen med 5,5 % av motorns bromskraft vid 1800 RPM, full belastning.
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Yildiz, Ilhami. "Simulation of greenhouse microclimates and environmental control strategies using a Rankine cycle heat pump /." Connect to resource, 1993. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1145453202.
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Thesis (Ph. D.)--Ohio State University, 1993.Advisor: Dennis P. Stombaugh, Dept. of Agricultural Engineering. Includes bibliographical references (leaves 213-226). Available online via OhioLINK's ETD Center
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Peralez, Johan. "Récupération d'énergie par cycle de Rankine à bord d'un véhicule : commande et gestion énergétique." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10024/document.
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Au moins 30% de l'énergie produite par les moteurs à combustion interne est dissipée sous forme de chaleur dans les gaz d'échappement. L'intérêt des constructeurs pour les systèmes de récupération de chaleur bases sur le cycle thermodynamique de Rankine est justifié par des réductions de consommation espérées entre 5 et 10%. L'ambition de cette thèse est de contribuer à lever les principaux verrous liés à la gestion des procédés Rankine pour des applications ≪ mobiles ≫. Ce manuscrit s'appuie sur trois cas d'étude avec, pour chacun, un procédé pilote destiné à être intégré respectivement sur des véhicules légers à moteur essence, sur des camions poids-lourds et sur des trains à propulsion hybride Diesel électrique. Pour cela, des approches de l'automatique à base de modèle ont été développées. Une nouvelle loi de commande non-linéaire, permettant l'asservissement de la température et de la pression en sortie d'évaporateur, est proposée. Il est montré expérimentalement que le système peut être maintenu dans des conditions permettant la récupération d'énergie sans discontinuer, même sur des cycles routiers très dynamiques. La supervision énergétique du cycle de Rankine à bord d'un véhicule est ensuite abordée. Il s'agit de trouver les consignes pour la commande rapprochée qui permettent de maximiser l'efficacité énergétique d'un véhicule équipé d'un système de récupération d'énergie par cycle de Rankine. Il est montré que le gain énergétique apporté par l'optimisation dynamique temps réel proposée est important, comparé à une stratégie basée sur l'optimisation statique du système habituellement employée dans la littératureMore than 30% of the energy produced by internal combustion engines (ICE) is dissipated as heat through the exhaust gases. The interest of manufacturers in heat recovery systems based on the thermodynamic Rankine cycle is justified by announced reductions in fuel consumption ranging from 5 and 10% depending on the system and the driving cycle. The aim of this thesis is to help remove the main barriers associated with supervising and controlling Rankine processes for ≪ mobile ≫ applications. This dissertation is based on three study cases, each corresponding to a pilot process installed in engine test benches at IFP Energies nouvelles (IFPEN). These are applications to be integrated respectively on board light-duty vehicles with spark-ignition engine, heavy-duty trucks and trains with Diesel-electric propulsion. An original nonlinear (model-based) control law for the temperature and the pressure tracking at the evaporator outlet is proposed. It is shown experimentally that the system can be maintained under conditions allowing continuous energy recovery, even during highly transient road cycles. Then the supervision of Rankine systems is addressed, resulting in the choice of optimal set-points (in term of energy management) for the low-level controller. An optimal control problem is formulated, allowing online implementation via dynamic real-time optimization.The proposed approach is validated on a realistic simulator, showing significant benefits in the amount of energy recovered when compared with the classical (static) approach found in Rankine cycle literature
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Kalua, Tisaye Bertram. "Analysis of factors affecting performance of a low-temperature Organic Rankine Cycle heat engine." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/17844.
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Organic Rankine Cycle (ORC) heat engines convert low-grade heat to other forms of energy such as electrical and mechanical energy. They achieve this by vaporizing and expanding the organic fluid at high pressure, turning the turbine which can be employed to run an alternator or any other mechanism as desired. Conventional Rankine Cycles operate with steam at temperatures above 400 ℃. The broad aspect of the research focussed on the generation of electricity to cater for household needs. Solar energy would be used to heat air which would in turn heat rocks in an insulated vessel. This would act as an energy storage in form of heat from which a heat transfer fluid would collect heat to supply the ORC heat engine for the generation of electricity. The objective of the research was to optimize power output of the ORC heat engine operating at temperatures between 25℃ at the condenser and 90 to 150℃ at the heat source. This was achieved by analysis of thermal energy, mechanical power, electrical power and physical parameters in connection with flow rate of working fluid and heat transfer fluids.
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Di, Cairano Luca. "Etude d'un système réversible climatisation/cycle Rankine organique : application au cas du véhicule terrestre." Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEM066.
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La récupération de chaleur dans les véhicules est une solution prometteuse permettant de réduire la consommation du moteur et de ses émissions. Les fortes contraintes de poids, compacité et coût présentes dans le domaine automobile empêchent l’intégration d’un système de récupération de chaleur dans le véhicule. Une solution proposée dans ce travail consiste en un système de multi-génération appelé ReverCycle. Ce dernier fonctionne avec trois modes: climatisation à compression de vapeur, cycle de Rankine Organique (ORC) et cycle de réfrigération à éjecteur. Le système peut assurer un seul mode de fonctionnement à la fois. Les avantages du système sont sa compacité et son coût réduit étant donné la possibilité d’exploiter les composants du système de climatisation déjà présents dans le véhicule. En effet, le compresseur scroll de la climatisation peut être converti en machine réversible compresseur/turbine et le condenseur peut être mutualisé pour les trois modes de fonctionnement. Une double démarche de modélisation et d’expérimentation a été menée pour évaluer le potentiel de réduction de la consommation de ReverCycle et pour vérifier sa faisabilité technique. Un modèle global du véhicule a été développé pour reproduire les conditions de fonctionnement dynamique du véhicule et pour décrire l’interaction entre ses différents sous-systèmes. Le modèle a ensuite permis de calculer le gain en consommation moyenné sur une année pour différentes régions climatiques. Deux différentes architectures de véhicules ont été étudiées : un véhicule conventionnel et un véhicule hybride série. Pour un véhicule conventionnel, le gain en consommation maximal est obtenu dans un climat océanique (e.g. Paris) avec une valeur de 2,1% avec un démarrage à chaud du moteur et 1,3% avec un démarrage à froid. Le cycle de conduite de référence pour l’évaluation du gain est le cycle WLTC (Worldwide harmonized Light vehicles Test Cycles). Dans le cas du véhicule hybride série, le gain en consommation maximal est obtenu dans un climat continental (e.g. Moscou) avec une valeur de 2,2% avec un démarrage à chaud du moteur et 1,2% avec un démarrage à froid. La réalisation d’une preuve de concept de ReverCycle a permis de valider sa faisabilité technique. Les essais se sont focalisés surtout sur le mode de fonctionnement en ORC. Les résultats des essais ont montré un rendement maximal de récupération pour le cycle de 3,9% sur un point de fonctionnement stabilisé. Le rendement maximal moyenné sur un cycle dynamique, représentatif des conditions opératoires sur un véhicule conventionnel, a été de 3,3%In a light duty vehicle, waste heat recovery is a promising solution for reducing engine fuel consumption and emissions. The strong compactness, weight and cost requirements of the automotive sector are preventing the integration of waste heat recovery systems in vehicles. This work is proposing as a possible solution a multi-generation system called hereafter ReverCycle. ReverCycle is a system with three operating modes: vapor compression air conditioning, Organic Rankine Cycle (ORC) and ejector refrigeration cycle. The system can provide one function at a time. ReverCycle advantages are its compactness and cost since it is possible to exploit the vehicle air conditioning components. This means that the air conditioning scroll compressor is converted into a reversible compressor/expander machine and the condenser is mutualized for the three operating modes. The calculation of the fuel economy and the technical feasibility of the system are investigated combining a modeling approach with experimental activity. A global vehicle model reproduces the vehicle dynamic working conditions and the interaction between the different vehicle sub-systems. The model estimates the annual average fuel economy for different climatic regions. Two different vehicle architectures are investigated: a conventional vehicle and a series hybrid vehicle. For a conventional vehicle the maximum fuel economy is obtained in an oceanic climate ( e.g. Paris) with a 2.1% improvement at a hot start initial condition for the engine and 1.3% improvement at a cold start initial condition. The reference driving cycle for the fuel economy evaluation is the WLTC (Worldwide harmonized Light vehicles Test Cycles). For a series hybrid vehicle the maximum fuel economy is obtained in a continental climate ( e.g. Moscow) with a 2.2% improvement at a hot start initial condition for the engine and 1.2% improvement at a cold start initial condition. The realization of ReverCycle proof of concept has allowed validating its technical feasibility. Experimental tests have mainly focused on the ORC operating mode. The experimental results show that the maximum cycle efficiency is 3.9% for a steady-state point. The average maximum cycle efficiency over a dynamic cycle, equivalent to a typical conventional vehicle operating mode, is 3.3%
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Ruiz, Nathan Daniel. "Increasing Isentropic Efficiency with Hydrostatic Head and Venturi Ejection in a Rankine Power Cycle." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1450.
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This thesis describes the modifications made to the Cal Poly Thermal Science Laboratory’s steam turbine experiment. While the use of superheating or reheating is commonly used to increase efficiency in a Rankine cycle the methods prove unfeasible in a small scale project. For this reason, a mathematical model and proof of concept design using hydrostatic head generated by elevation and venturi ejection for use by the condenser is developed along with the equations needed to predict the changes to the system. These equations were used to create software to predict efficiency as well as lay down the foundation for future improvements of the system.
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Riddle, Derek S. "Model Order Reduction and Control of an Organic Rankine Cycle Waste Heat Recovery System." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu150055199341535.
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Nolan, Cathal. "Application of the organic rankine cycle to improve fuel economy on a hybrid vehicle." Thesis, Queen's University Belfast, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.696154.
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This thesis investigates how current hybrid bus technology can be improved, through the application of a waste heat recovery system capable of operating on a hybrid bus. At present modem internal combustion engines reject the majority of fuel energy consumed as waste heat through the engine coolant and exhaust streams. By employing innovative technology it is proposed that this, otherwise wasted, heat can be captured and converted to power or to provide useful heating or cooling on the hybrid bus. This recaptured heat will therefore allow an improvement in fuel consumption and a reduction in exhaust emissions. The research carried out in this thesis attempts to determine if the fuel economy of a hybrid bus can be improved by using a waste heat recovery system. The work also aims to discover which type of system is the most suitable for installation on such a vehicle. To achieve this, the modeling of system performance, as well as the design and testing of a fully operational waste heat recovery system on a hybrid bus is presented. The result of the system modeling is benchmarked against the actual, installed system, experimental results which were conducted at M ill brook proving ground U. K. A novel model of an expander was also developed during the research. This model was compared to test data obtained during experimental testing of an expander at Queen's University Belfast. The purpose of the model was to gain a greater understanding of expander leakage and performance while operating in a waste heat recovery system.
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Venieri, Giulia. "Development and testing of Model Predictive Controllers for an automotive organic Rankine cycle unit." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022.
Find full textAbstract:
Two-thirds of the energy produced by an internal combustion engine (ICE) is lost into waste heat through the coolant and the exhaust gas; hence, studying Waste Heat Recovery (WHR) systems is of vital importance. The organic Rankine cycle (ORC) is a powerful system to recover low-grade heat and transform it into electrical energy.
This thesis aimed at developing and testing a Model Predictive Control (MPC) system that ensures a safe operation of a system that constitutes an ICE bottomed by an ORC unit. The experimentation was carried out at the DTU Mekanik laboratories and was divided into different campaigns. Firstly, to study the plant behavior, steady-state and dynamic characterizations were accomplished. The latter was useful to obtain transfer function models for the MPCs at different vehicle speeds. Secondly, Proportional-Integral (PI) controllers and MPCs qualities were evaluated thanks to three performance indices while the engine was following a testing cycle. The MPC model was derived at 90km/h. Afterward, a test campaign aimed at optimizing the tuning parameters of the MPC cost function and at evaluating their influence on the plant response. Finally, the controllers that performed best were tested on a World harmonized Light-duty vehicles Testing Cycle (WLTC) to characterize their operation under realistic driving conditions.
The results showed that MPCs were more suitable for the task than PIs due to their better ability to operate the plant in safe conditions, and to their best performance indices when subjected to the testing cycles as well as to the WLTC. Nevertheless, MPCs have to be further optimized to follow the homologation cycle. Future experimentations could be based on be exploiting multi-model systems constituted of two or more MPCs or obtaining the MPC model from other working points.