Dissertations / Theses on the topic 'Cogeneration'
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Velayuthan, Manohar. "Cogeneration power plant." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0012/MQ52488.pdf.
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Psaltas, Michael A. "Hybrid cogeneration desalination process." Thesis, University of Surrey, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576090.
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Supplies of potable water from the conventional resources are descending due to increased industrialization;' extensive irrigation and rapid population growth. In Cyprus, a country without any perennial river, fixed rainy season and depleted natural aquifers faces severe water shortage in future. Desalination along with power cogeneration certainly poses as the most suitable option in the long run to avoid any water scarcity and rationing. This dissertation introduces all the major desalination processes and is focused on the commercially employed desalination processes. The processes have been discussed in relation with their history, principle, capacity, costs, market capitalization, energy consumption, required pre treatments, future growth potential and their environmental effects. The dissertation extensively investigates Cyprus' existing water resources, water scarcity in Cyprus, the need and existing desalination including the overall power generation capacity. This dissertation is unique in the sense of covering all the major desalination processes and investigating the Cyprus water resources as a whole outlining the need for commercially viable desalination and power, cogeneration facilities. The aim of this study is to expand the existing MSF systems to a higher level for potential changes which they will help the industrial desalination in increasing the efficiency and reducing the costs. This is a new three stage distillation system which will be designed and constructed in Cyprus. The plant will be manufactured from local materials by local manpower and requires little maintenance and operating costs. Hence it offers relatively higher efficiency which enables this system to be more cost effective.
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Scholz, Matthew John. "Microbial Cogeneration of Biofuels." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/145446.
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The fields of biodiesel and bioethanol research and development have largely developed independently of one another. Opportunities exist for greater integration of these processes that may result in decreased costs of production for both fuels.To that end, this work addresses the use of the starches and glycerol from processed algal biomass as substrates for fermentation by the yeasts
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Benelmir, Riad. "Second analysis of a cogeneration cycle." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/20000.
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BASTOS, WALTER NOVELLO. "COGENERATION IN AIR SEPARATION CRIOGENIC PLANTS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1999. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=25011@1.
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Diante da crise energética e de mercado a Cogeração se apresenta oportuna tanto para a produção de energias elétrica e térmica quanto para a redução dos custos operacionais de produção de uma empresa.
Um sistema de cogeração integrado e adaptado ao processo de uma Planta Criogênica de Separação de Ar, que tem a energia elétrica como insumo básico, pois o ar não tem custo, pode se mostrar viável, com considerável redução nos custos operacionais da planta.
Um estudo termoeconômico, englobando uma análise da Primeira e Segunda Lei da Termodinâmica, e uma análise Econômica, foi necessário não apenas para demonstrar esta viabilidade, mas também para propor as modificações no processo Criogênico de Separação de Ar, assim como, para definir o melhor sistema de Cogeração a ser integrado à planta típica T-240 NA MPL3.
Os resultados da Análise Termodinâmica das modificações foram bem satisfatórios. As eficiências de Segunda Lei - Exergéticas - dos equipamentos envolvidos nas modificações da planta melhoraram, e o seu consumo de energia elétrica foi reduzido em 12 porcento.
Foram propostos para integrar a planta 4 (Quatro) Sistemas de Cogeração a partir dos Ciclos Clássicos: Rankine, Brayton, Combinado e Otto. Estes Sistemas foram analisados inicialmente pelas Primeira e Segunda Leis da Termodinâmica e finalmente foram analisados economicamente.
Termoeconomicamente, o Sistema de Cogeração a partir do Ciclo Combinado foi o que melhor se apresentou para integrar o processo Criogênico de Separação de Ar da planta. Neste Sistema houve um maior equilíbrio entre as demandas térmica e elétrica, acarretando a eficiência de Segunda Lei - Exergética - mais alta. Este Sistema teve, também, a maior Receita Operacional e embora o seu Investimento Adicional tenha sido um pouco maior, este acréscimo compensou, pois apresentou os menores Tempo e Taxa Interna de Retorno.
Apesar do Sistema de Cogeração a partir do Ciclo Combinado se apresentar viável, os resultados devem ser considerados, apenas, como preliminares, pois são provenientes da primeira interação Termoeconômica. Outras interações devem ser realizadas visando a melhoria deste Sistema, para viabilizar cada vez mais a Cogeração em Plantas Criogênicas de Separação de Ar.The energy shortage and the cogeneration market present a unique opportunity for energy cost reduction of an industry by simultaneously making use of electric and thermal energy generated with the same fuel. This thesis analyzes an integrated cogeneration system adapted to an air separation criogenic plant which has electric energy as a basic input, besides the available and costless air from the atmosphere. It has been shown to be feasible with the big savings inthe operational cost of the plant. A thermal and economic study, carried on by using the first and second Law of thermodynamics demonstrated the economic feasibility of the cogeneration system, and proposed modifications to be done in the studied criogenic plant, a typical T240- NA MPL3 plant. The thermodynamic analysis showed that the second law efficiency of the processes could be improved, together with a 12 percent electric energy consumption reduction. Four cogeneration schemes were analyzed with both the first and second laws of thermodynamics and, then, the economic analysis was performed. Rankine, Brayton, OTTO and combined gas-steam basic cycles were used in this analysis. The combined gas-steam cycle was shown to be more economically feasible than others. Thermal and electric loads were well balanced, resulting in a higher second law efficiency. Although the initial investiment for the modification was higher, the savings resulted to be higher, turning into a high rate of return of the investment. This analysis was judged to be preliminary. More precise results require a deepers analysis with more detailed information.
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Colpan, Can Ozgur. "Exergy Analysis Of Combined Cycle Cogeneration Systems." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605993/index.pdf.
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In this thesis, several configurations of combined cycle cogeneration systems proposed by the author and an existing system, the Bilkent Combined Cycle Cogeneration Plant, are investigated by energy, exergy and thermoeconomic analyses. In each of these configurations, varying steam demand is considered rather than fixed steam demand. Basic thermodynamic properties of the systems are determined by energy analysis utilizing main operation conditions. Exergy destructions within the system and exergy losses to environment are investigated to determine thermodynamic inefficiencies in the system and to assist in guiding future improvements in the plant. Among the different approaches for thermoeconomic analysis in literature, SPECO method is applied. Since the systems have more than one product (process steam and electrical power), systems are divided into several subsystems and cost balances are applied together with the auxiliary equations. Hence, cost of each product is calculated. Comparison of the configurations in terms of performance assessment parameters and costs per unit of exergy are also given in this thesis.
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DeJong, Bretton. "Cogeneration in the new deregulated energy environment." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/17549.
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VAL, LUIZ GUSTAVO DO. "CRITICAL ANALYSIS OF THE COGENERATION PLANT PERFORMANCE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2001. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26481@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICONo presente trabalho, foi desenvolvido uma metodologia teórico-experimental para a avaliação de plantas de cogeração, incluindo o confronto com os dados dos fabricantes dos equipamentos, a análise de incerteza de medição dos principais parâmetros e a análise termoeconômica. Como resultado, o trabalho visa apresentar critérios mais otimizados para especificação e operação de sistemas de cogeração. Para o seu desenvolvimento, foram analisadas a planta da Companhia Cervejaria Brahma, localizada em Campo Grande, RJ, que é constituída de três turbinas a gás de 4,90 MW acopladas a três caldeiras de recuperação que utilizam Pós-Queima, com capacidade nominal de até 36000 kg/h, cada uma, e a planta do Parque Gráfico do InfoGlobo, localizada na rodovia Washington Luis, Duque de Caxias, RJ, que é constituída de dois motores alternativos de combustão interna de 2,90 MW, duas caldeiras de recuperação e um chiller de absorção de 800 TR s. Para a Companhia Cervejaria Brahma, foi utilizado a metodologia do balanço de massa das reações químicas, usando as medições das emissões e da composição do gás natural na planta, para obtenção da vazão mássica do ar admitido pela turbina e, consequentemente, a vazão mássica dos gases de exaustão. Essa metodologia foi empregada devido a não existência de um medidor de vazão de ar nas turbinas, que é um parâmetro essencial para avaliação do desempenho da planta. Esta metodologia também foi empregada, para a avaliação das caldeiras de recuperação que utilizam queima adicional de combustível. Foi realizada, também, a análise de incertezas dos resultado de desempenho obtidos na planta, de modo a identificar problemas operacionais como, o economizador sujo da caldeira de recuperação. Também, pode-se ver verificar, que o aproveitamento global do combustível utilizado, para geração de energia elétrica e térmica pelo lado da água foi inferior ao aproveitamento deste, para geração de energia elétrica e térmica pelo lado dos gases. A menor diferença encontrada destes valores na escala percentual, foi de 6 porcento. Como esta diferença não é desprezível, chega-se à conclusão que a medida do desempenho da planta de cogeração deve ser feito com base na energia térmica transferida para a água, e não a que é transferida dos gases, como normalmente é feito, sem levar em consideração as perdas térmicas. Por fim, foi realizado uma análise técnico-econômica da utilização dos equipamento empregados na planta, com a finalidade de determinação de custo-benefício. Para o Parque Gráfico do InfoGlobo, foi realizada uma simulação do desempenho dos equipamentos utilizados nesta planta, devido a impossibilidade de se obter dados experimentais em determinados pontos da planta. Para isto, foram utilizados dados de projeto dos equipamentos, admitindo que estes pouco variam com as condições ambientais. Desta forma, não foram realizadas as análises de incertezas dos resultados encontrados. Com a metodologia empregada, pôde-se identificar problemas operacionais como o fato de que a bomba da água de alimentação de caldeira, estar fora doe seu ponto de projeto. De um modo geral, o percentual de aproveitamento da energia do combustível varia muito durante o dia, indicando um acoplamento insatisfatório entre a demanda e oferta de energia. Foi desenvolvido um modelo computacional, para a simulação da turbina a gás de eixo duplo THM 1203 Hispano Suiza, modo a obter todos os parâmetros essenciais que possam ser utilizados para o projeto de sistemas de cogeração. É previsto neste modelo a operação em cargas parciais com a variação das condições ambientais.
A theoretical-experimental methodology was developped in this work for evaluating the performance of cogeneration plants, including the data comparison with manufacturer specifications, uncertainty analysis of main parameters and thermoeconomic analysis. As a result, this work aims the establishment of an optimized criteriumfor especifying and operating cogeneration systems. Two existing cogeneration plants were analyzed in this work, (a) Companhia Cervejaria Brahma, located in Campo Grande, RJ, consisting of three 4,90 MW gas turbine generators, three heat recovery boilers, including after burners, with a nominal capacity of 36000 kg/h of steam, each one, and (b) Parque Gráfico do InfoGlobo, located in the Wshington Luis Highway, Duque de Caxias, RJ, consisting of two 2,90 MW reciprocating engine gas generators, two heat recovery boilers and 800 TR absorption chiller. A chemical reaction mass balance methodologywas used in the BRAHMA plant.It uses the measurement of pollutant emissions and natural gas compositionfor estimating the turbine inlet air and exhaust gas flow rates, which are important for evaluating the plant performance. Thei methodology was preferred due to the fact that no air and exhaust gas flow rate measurement instrument was installed in the plant, which is usually the case. This methodology was also used for evaluating the performance of heat recovery boilers with after burners. An uncertainty analysis procedure was developed and used to identify operational problems like fouling, reducing the effectiveness of the heat recovery economizer. One of the main results of this work was the fact that as least a 6 percentual point difference between the gas and the steam sides was measured for the overall fuel chemical energy usage, demonstrating the need of a more careful analysis of component performance for designing and specifying a cogeneration plant, which takes into account the heat losses. Thus, one suggests that the heat transfer to the water be specified, rather than the one from the hot gases. A technical-economic analysis of the plant was carried on, and its cost-benefit determined. Due to difficuties in obtaining experimental data, a simulation procedure had to be used for analyzing the performance of the InfoGlobo plant. Design data for several equipments were used in the calculations, supposing that they do not vary too much with ambient conditions. Thus, the uncertainty analysis was not carried on. The used methodology identified the fact that the boiler feedwater pump was not operating in the design point. In a general way, it was observed that the overall fuel chemical energy usage varies too much along the day, indicating a mismatching between load and energy supply. Finally, as a tool for the plant analysis, a computational model was developped for estimating the cogeneration plant component parameters, to be used for design purposes. Partial load operation of the turbines is contemplated in this model, as a function of ambient conditions.
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Monge, Zaratiegui Iñigo. "Profitability of cogeneration in a chemical industry." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-24251.
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A high demand of both electricity and heat exists in Arizona Chemical (a chemical plant dedicated to the distillation of Crude Tall Oil) for production processes. Due to the rising cost of resources and electricity, more and more companies are trying to decrease the energy expenses to increase their competitiveness in a global market, thus increasing their profit. Some companies look at their energy consumption in order to diminish it or to explore the opportunity to generate their own and cheaper energy. In companies where the production of steam already takes place, cogeneration can be a good solution to palliate the cost of the energy used. This study addresses this issue through three actions such as the characterization of the boiler, a better steam flow measurement grid and the generation of electricity. The first one addresses the state of one of the key parts of steam production, the boiler, through the calculation of its efficiency with two different methods (direct and indirect calculation). These methods require some measurements which were provided afterwards by the company supervisor. This will allow the company to identify the weaknesses of the boiler to be able to improve it in the future. The second one aims to improve the knowledge about the steam system. New flow measurement points were suggested after doing an analysis of the current controlled flows to have a better overview outline of the steam use.The third one studies the generation of electricity with a Rankine cycle. The limitations in the characteristics of the steam were identified and different configurations are proposed in accordance to the restrictions identified. An efficiency of 93% is obtained for the boiler with the direct method and 82.3 % for the indirect one. The difference between them can be explained by the use of datafrom different time frames for both methods. The main contributors to the losses are the ones related to the dry flue gas and the hydrogen in the fuel. In the current status only 40% of the steam flows are identified, a number which is expected to raise with the new measurement points. It was not possible to estimate the effect of the new points due to the desire of the company to not disturb the current production. Due to the fuel price the production of steam for only electricity was not profitable and instead the generation of both electricity and heat from the same steam is proposed. This integrated system is now possible to implement due to its low payback time (2.3 years). This solution can generate 758 kW of electricity and provide the company with 6437 MWh of electricity each year. Then, the effect of the variation of different variables over the performance of the cycle were studied: different electricity prices, steam rate production, fuel cost and the state of the condensate recovery were discussed. The variation of both the condensate recovery and fuel cost did not affect the payback time due to their costs being neutralised by the revenues obtained from them. The variation of the electricity prices and steam production affects the payback but due to the high revenue that is expected it does not hamper the good nature of the investment. The generation of electricity is recommended due to the low payback time obtained. The different variations studied in the system did not change the payback time notably and showed that the investment is highly profitable in all the scenarios considered. The use of two smaller turbines instead of the one chosen (with a maximum rated power of 6 MW while only 758 kW is generated with the proposed solution) should be studied since the turbines would work closer to their maximum efficiency.
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Hwang, Michael Yichun. "Cogeneration Heat Sink for a Photovoltaic System." Thesis, The University of Arizona, 2010. http://hdl.handle.net/10150/146053.
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The University of Arizona is heavily invested in transforming itself into a leader in sustainable practices. Among these efforts are the establishments of the “Practice School of Sustainability” and the SAGE Fund, both housed at the University of Arizona College of Engineering. This design report is an exhaustive analysis of designing and constructing a lowcost solar cogeneration system. Cogeneration refers to two-tiered energy output in the form of electricity and hot water. Benefits of capturing and utilizing waste heat from the photovoltaic panels are a more efficient electricity production capacity in combination to hot water generation. The aim of these efforts is to have a direct impact on campus utility costs, and to serve as a template for implementing future systems on a larger scale. The selected building to install the pilot system is the Optical Sciences West building because it has a high constant hot water demand for proper air handling. The design coconsists of 16 photovoltaic panels with a heat sink attached to the back of each panel, with a water and propylene glycol mixture flowing in a closed loop throughout each heat sink. If installation is approvedand the system performs as predicted, there will be an average output of 89.19 kWh per day in thermal energy. At a flowrate of 600 gallons of water per day, hot water will exit the system at 58.8 ?C. This translates to a savings of $1,391 per year in natural gas costs. The cogeneration system is also expected to have an electrical output of 33 kWh per day, translating to a $762 savings per year. Combined, the Cogeneration Heat Sink for Photovoltaic Panels 2 system is expected to save $2,153 per year and offset CO2 emissions by 10,938 kg per year. With a system cost of $18,490, the payback period for this pilot system is a mere 4.8 years. For scaling purposes in future installations, the design in its current form costs $2.35 per watt. Based on these favorable economic and environmental benefits, combined with minimal risks to safety or cost mitigation capability, it is highly recommended that more heat sinks be manufactured to facilitate this installation in the near future. If the system performs as predicted, future installations should take place on other campus buildings that use a variable air volume air handling system with terminal reheat.
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PICINARDI, Alberto. "Cogeneration of cooling energy and fresh water." Doctoral thesis, Università degli studi di Bergamo, 2011. http://hdl.handle.net/10446/883.
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A design simulation of the cogeneration system allowed to chose the best HD unit configuration, while a TRNSYS off-design simulation revealed the main design variables on which to focus the optimization. The optimization study on the design variables was performed by GenOpt, a generic optimization program which minimizes an objective function with respect to multiple variables. This study has been carried out on different objective functions and reveals that maximizing the production of cooling energy means damaging the fresh water production. A compromise solution has been chosen to balance the contrast between cooling energy and fresh water production.
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PICINARDI, Alberto. "Cogeneration of cooling energy and fresh water." Doctoral thesis, Università degli studi di Bergamo, 2011. http://hdl.handle.net/10446/222125.
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A design simulation of the cogeneration system allowed to chose the best HD unit configuration, while a TRNSYS off-design simulation revealed the main design variables on which to focus the optimization. The optimization study on the design variables was performed by GenOpt, a generic optimization program which minimizes an objective function with respect to multiple variables. This study has been carried out on different objective functions and reveals that maximizing the production of cooling energy means damaging the fresh water production. A compromise solution has been chosen to balance the contrast between cooling energy and fresh water production.
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Niap, Damian Tien Foo, and e58018@ems rmit edu au. "Environmental Management Accounting for an Australian Cogeneration Company." RMIT University. Accounting and Law, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080102.102723.
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This research explores whether Environmental Management Accounting can be applied to assist an Australian cogeneration company in improving both its financial performance as well as its environmental performance. Cogeneration or 'combined heat and power', in this particular case, involves the simultaneous production of heat and electricity using a single fuel, that is, natural gas. The heat generated is then used to produce steam to meet the customers' requirements as well as boost the production of electricity. Therefore, cogeneration provides greater efficiencies compared to traditional electricity generation methods because it utilizes heat that would otherwise be wasted. In addition, greenhouse gases emissions can be reduced substantially. The approach taken in this research is to assess whether an improvement in the energy efficiency of the cogeneration plant can lead to a reduction in greenhouse gases emissions. An improvement in energy efficiency means that either: less gas is consumed, thus leading to cost savings; or more electricity is generated for the same quantity of gas consumed, which leads to an increase in income and consequently profit. Therefore, an improvement in energy efficiency means an improvement in the financial performance. In addition, a reduction in the quantity of gas consumed or generating as much electricity as possible from a given quantity of gas can lead to a reduction in greenhouse gases emissions which means an improvement in the company's environmental performance. A case study method, which involves an Australian cogeneration company, is adopted because this would provide valuable in-depth practical insight into the operations and mechanisms of a company that is involved in combined heat and power generation. A review of the literature and the evidence collected indicated that a cogeneration plant's efficiency can be improved at least back to near the plant's designed efficiency. And, further improvements may be achieved by utilizing the latest technology although this involves capital investment. It is also established that an improvement in plant efficiency can reduce greenhouse gases emissions. This research then concludes that Environmental Management Accounting can help the case study company improve its financial and environmental performances. An Environmental Management Accounting system can provide the physical information that is not available in the existing management accounting system. Physical information such as the physical quantities of gas consumed, electricity and steam produced, and greenhouse gases emitted, can help the company in decision-making relating to improving plant efficiency as well as reducing greenhouse gases emissions.
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Zheng, Xiaofeng. "Exploration and development of domestic thermoelectric cogeneration system." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/29922/.
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Due to quiet operation, no moving parts, long lifespan and compact structure, the thermoelectric application has become a potential green technology which has been used in different areas in the efforts of contributing to achieve simplified and compact system structures and environmental friendliness. Its applications cover a wide range from the earliest application on kerosene lamp to aerospace applications, transportation tools, industrial utilities, medical services, electronic devices and temperature detecting & measuring facilities. Its disadvantage lies in the low conversion efficiency which only converts small amount (for Bi2Te3, up to 5%) of harvested energy to electrical power. It makes the use of the TEG system far from being economically feasible due to long cost recovery period. Consequently, its use is limited to specialised area where it is unnecessary to consider the cost of the thermal energy input and system cost recovery. This research aims to explore a way of widening the application range of thermoelectric generation based on introducing a potential direction of improving energy utilisation efficiency to a higher level by adopting thermoelectric cogeneration concept in residential house. It focuses on investigating the practicality of using thermoelectric applications in domestic sectors where the large amount of heat is exhausted to environment without being used and developing thermoelectric cogeneration system to generate electricity and produce pre-heated water for domestic use by recovering the waste heat from the domestic boiler and utilising the on-site solar energy. With the conversion efficiency given by the current commercially available thermoelectric modules, the optimised heat exchanging regimes and systems for thermoelectric applications have been comprehensively studied from the aspects of system design, integration, experimental study, numerical simulation and modification. The importance and necessity of effective heat exchanging methods have been emphasised by the experimental and numerical proofs for the development of a domestic thermoelectric cogeneration system with higher thermal efficiency. The impacts of this domestic energy solution have been evaluated from the aspects of the improvement for outdoor environment and indoor energy profile, as well as economic benefit. For the flue gas heat exchanger, the model with sudden expansion and gradual constriction has been identified gives in terms of overall performance. The model with sudden expansion, gradual constriction and staggered pipe layout and the one with sudden expansion, gradual constriction and inline pipe layout show better overall performance than other models. Among these two models, the one with staggered pipe layout shows better performance than the one with inline pipe layout in the velocity range of 3.6m/s-5m/s, whilst the one with inline pipe layout shows better performance between 0-3.6m/s. For the cold side heat exchanger, the one with four ø5mm branch channel angled at 90 against the main channel delivers the best overall performance out of 9 cooling plates built according to three variables. Experimental studies show the one-stage TCS produces more power than the two-stage TCS does when the heat input is supplied at 47W and 60W. As the heat input increases, the power output of two-stage TCS gets closer to that of one-stage TCS. In the system construction and assembly, uneven assembly can lead to a 20% drop in conversion efficiency. The pressure load at 18lpsi gives the highest power output out of five load values, which are 136psi, 159psi, 181psi, 204psi and 227psi, respectively. In comparison with individual assembly, module thickness difference in whole assembly degrades the system conversion efficiency. The cost recovery period of deploying this system in a residential house installed with a 24kW boiler and a 1 m2 solar collector has been evaluated. Based on the conversion efficiency and thermal efficiency that is 4% and 67% at 130C temperature difference. the house can produce 98W electricity and 1640W useable heat when the boiler is running and the contribution from the solar energy is included. It takes less than 4.2 years to recover the system cost.
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Lu, Yiji. "A resorption cogeneration cycle for power and refrigeration." Thesis, University of Newcastle upon Tyne, 2016. http://hdl.handle.net/10443/3515.
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Heat-driven energy system attracts ever increasing attentions to improve the efficiency of overall energy utilisation by recovering the heat energy such as solar thermal energy, wasted heat from industry and geothermal energy. Adsorption technology is recognised as one of the promising solutions to convert low-grade heat to refrigeration or be used as heat pump. Based on the working principle of this technology, it can promisingly be developed into combined refrigeration and power generation system by integrating an expander in to the system. However, due to the limited research efforts on the system investigation, refrigeration generation by adsorption technology is still immature. The investigation on the working conditions of the system, the selection of proper expansion machine for power generation part of the cogeneration and overall system evaluation are important to be conducted. This study aims to explore the feasibility of integration the adsorption technology with expansion machine for refrigeration and power generation. The proposed cogeneration combines resorption system, which has potentially twice of the cooling capacity compared with conventional adsorption system, integrated with expansion machine to continuously produce refrigeration and power. The design and optimisation methods of the proposed system were studied in order to select the proper resorption working pairs under different heat source conditions. Furthermore, the system performance with and without the optimisation methods were evaluated by the first and second law analysis. Results indicated attractive performance and MnCl2-SrCl2 was stood out as the optimal resorption working pair for the purpose of high refrigeration generation under low grade heat source, when ammonia is the working fluid in the system. Scroll expander was selected as the expander to be explored in this study because of its highest average isentropic efficiency, low cost, low vibration noise, high availability and easy modification from compressor to expander for our special application demand. A lab scale scroll expander test rig was designed, constructed and tested to obtain the performance such as isentropic efficiency and electrical efficiency of a selected scroll machine under various working conditions. An assessment of a case study of the resorption cogeneration system was conducted to evaluate the variation of the power and refrigeration performance with the time. Results indicated that a resorption cogeneration with 25.2 kg MnCl2 and 18.9 kg SrCl2 could potentially produce 1 kW power and 2.5 kW cooling capacity when the cycle time is around 25 minutes.
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Rwezuva, Onekai Adeliade. "Solar Augmentation of Process Steam Boilers for Cogeneration." Master's thesis, Faculty of Engineering and the Built Environment, 2021. http://hdl.handle.net/11427/33898.
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In this study, the techno-economic feasibility of converting an existing process steam plant into a combined heat and power plant, using an external solar thermal field as the additional heat source was studied. Technical feasibility entailed designing a suitable heat exchanger, which uses hot oil from the solar field to raise the steam conditions from dry saturated to superheated. The solar field was sized to heat a selected heat transfer fluid to its maximum attainable temperature. A suitable turbine-alternator was chosen which can meet the required plant power demand. For this to be a success, the processes which require process steam were analysed and a MathCAD model was created to design the heat exchanger and check turbine output using the equations adapted from various thermodynamics and power plant engineering texts, together with the Standards for the Tubular Exchanger Manufacturer's Association. The U.S. National Renewable Energy Laboratory system advisor model was used to size the suitable solar field. A financial model was developed in Excel to check the economic feasibility of the project, using discounted payback period as the economic indicator. It was found out that amongst loan interest rates, variation of system output and the electricity output, the profitability of the project was largely influenced by the electricity tariff. An optimum size for the heat exchanger of 30ft was established from the sensitivity analysis and it was concluded that the project is currently not economically viable on an independent investor financing model, unless either the electricity tariff improves or the solar thermal energy and turbine technology costs decrease.
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Dogan, Osman Tufan. "A Stochastic Approach For Load Scheduling Of Cogeneration Plants." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/2/12611698/index.pdf.
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In this thesis, load scheduling problem for cogeneration plants is interpreted in the context of stochastic programming. Cogeneration (CHP) is an important technology in energy supply of many countries. Cogeneration plants are designed and operated to cover the requested time varying demands in heat and power. Load scheduling of cogeneration plants represents a multidimensional optimization problem, where heat and electricity demands, operational parameters and associated costs exhibit uncertain behavior. Cogeneration plants are characterized by their &lsquoheat to power ratio&rsquo
. This ratio determines the operating conditions of the plant. However, this ratio may vary in order to adapt to the physical and economical changes in power and to the meteorological conditions. Employing reliable optimization models to enhance short term scheduling capabilities for cogeneration systems is an important research area. The optimal load plan is targeted by achieving maximum revenue for cogeneration plants. Revenue is defined for the purpose of the study as the sales revenues minus total cost associated with the plant operation. The optimization problem, which aims to maximize the revenue, is modeled by thermodynamic analyses. In this context, the study introduces two objective functions: energy based optimization, exergy-costing based optimization. A new method of stochastic programming is developed. This method combines dynamic programming and genetic algorithm techniques in order to improve computational efficiency. Probability density function estimation method is introduced to determine probability density functions of heat demand and electricity price for each time interval in the planning horizon. A neural network model is developed for this purpose to obtain the probabilistic data for effective representation of the random variables. In this study, thermal design optimization for cogeneration plants is also investigated with particular focus on the heat storage volume.
18
Lagas, P. K. "Performance of a microturbine cogeneration unit with water-injection." Thesis, University of Sussex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413889.
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Betelmal, Entesar Hassan. "Thermo-economic study of gas turbine-absorption cogeneration cycle." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417545.
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Ehsani, Shoa-Ollah 1967. "Enhanced geothermal energy and cogeneration : design, technology and economics." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/46689.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003.Includes bibliographical references (p. 114-116).
The search for and the development of new sources of energy continue to gather importance into the 2 1st century. One of the options at hand is mining heat from the earth's crust. The U.S. Department of Energy has supported research into Enhanced Geothermal Systems in Hot Dry Rock (HDR) since the mid seventies. Advances in drilling technology, reservoir management and power conversion cycles have all contributed to the further development of HDR geothermal energy schemes. Apart from outlining and reviewing some of the specific characteristics of Enhanced Geothermal Energy Systems, this thesis investigates the possibility of using HDR technology for commercial scale combined heat and electric power applications. This is carried out through cogenerative design of current HDR electric power plant options with direct process heat capacity required in industrial production today. The MIT EGS Simulator was modified to accommodate cogeneration to assess the success of such designs in three separate, industrial case studies. Overall system busbar cost for electricity produced and various thermodynamic efficiency measures will be used as metrics to access the effectiveness of cogeneration design in HDR power generation. Lastly, this research is used to qualitatively evaluate the performance of other low-temperature electric-power and direct use cogeneration designs; one of the important aspects in a move towards increased global energy efficiency.
by Shoa-Ollah Eshani.
S.M.
21
Biffi, C. "COGENERATION OF THERMAL AND ELECTRIC POWER FROM RENEWABLE SOURCES." Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/168365.
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This project deals with a different use of ethanol deriving from biomass. The aim is to produce hydrogen starting from 2nd generation bioethanol as raw material. H2 is then purified and fed to a PEM fuel-cell. The latter co-generates electrical and thermal energy with a 5kWelectric+ 5kWthermal power size, suitable for de-localized energy production. The goals of this work are different: efficient H2 production by bioethanol steam reforming (SR), H2 purification by high and low temperature water gas shift (HTWGS+LTWGS) and methanation of residue CO (<20ppmv), check of the overall plant efficiency and performance under widely different operating and load conditions.
This project is divided in two steps. The former consists in efficiency tests on the above mentioned semi-commercial device (GH2-5000 Energy System provided by Helbio S.A) composed by a PEM fuel-cell integrated in a steam reforming + H2 purification system. The latter step focuses on catalytic tests on new materials in order to find innovative catalysts for the SR of bioethanol. In particular, we aim at finding catalysts active at lowest reaction temperature, to promote the WGS reaction even in the SR step and to lower the energy input of the endothermic SR reaction, due to the exothermicity of the WGS one.
A series of Ni catalyst, differently supported, were synthesised and characterised. Three different series of Ni-based catalysts for the steam reforming reaction were synthesised by two different procedures. Al2O3, TiO2 and La2O3 were chosen as supports and the Ni loading was 5-10-15 wt% for each set of samples. Ni supported on Al2O3 was chosen at first, because it is the most common SR catalyst commercially available and it was assumed as reference material. The biggest problem when using alumina as support was coke formation during the SR reaction, depressing selectivity and deactivating the catalyst. For this reason binary supports, such as Al2O3/La2O3, are used to decrease support acidity . In the present work catalysts directly supported on pure La2O3 were also prepared. At last TiO2 - supported samples, rather new for this application, were prepared to achieve lower acidity than alumina, coupled with interesting redox properties of the support, which could enhance surface cleaning. The selected supports were prepared in nano-powder form by flame spray pyrolysis (FP,) and then Ni was added in proper amount by impregnation from a Ni(NO3)2 · 6H2O aqueous solution. A parallel, completely new, preparation procedure was developed by directly adding Ni during the FP synthesis.
Some of the catalysts prepared were included in a project financed by Regione Lombardia in collaboration with the Universities of Venice (UniVE) and Genoa (UniGE). This project was focused on catalytic materials for both ethanol (ESR) and glycerol (GSR) steam reforming. Catalysts with different active phases (Ni, Co, Cu) and different supports (TiO2, SiO2, ZrO2) were synthesised. Different strategies have been adopted for the preparation of the samples (UniMI-UniVe), namely flame pyrolysis and metal impregnation over traditionally prepared supports. All the catalysts were characterised by atomic absorption, XPS, XRD, O2-chemisorption, FT-IR,TPR-TPO (UniVE, UniGE, UniMI).
Finally, some tests were carried out on the integrated 5 kW plant to set up the analytical procedure. The first tests revealed a number of electrical and set up problems, which were partly solved. Preliminary experiments allowed to monitor the trend of CO concentration , confirming the H2 purity level required to feed the PEMFC (10 ppmv in the reformate). Currently the system was returned to the supplier to allow interfacing with a new type of HT-PEMFC that operates at 160° C and is therefore able to withstand a level of CO equal to 2 vol%.
22
Horák, Jiří. "Mikrokogenerační jednotka na biomasu na bázi lopatkového stroje." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230906.
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This Master´s thesis deals with a theoretical micro cogeneration unit design contains hot air microturbine using energy from biomass. In the first part of the thesis there are model examples of energy consumption in typical family or apartment houses. In the next part there is the overview of micro cogeneration commercial units which can be used in model examples of a family or apartment housing. According to the assignment of this thesis and based on the analysis of model examples a new cogeneration system is designed. The last part of the thesis deals with the economic evaluation of the new cogeneration system compared with commercial systems.
23
Сотник, Ірина Миколаївна, Ирина Николаевна Сотник, Iryna Mykolaivna Sotnyk, and V. Mandryka. "Economic and ecological advantages of cogeneration use in power industry." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/40862.
Full textAbstract:
In the developed countries, the main source of the environmental
contamination is industry. There is a set of plants, factories and other
industrial facilities, which pollute environment in various ways. One of the
key industrial sources of environmental pollution is the energy sector. At
extraction, processing and combustion of fuel, pollutants and redundant
heat are released into the air and contaminate water and land resources.
According to the expert estimations, Ukrainian energy sector provides
about 30% of all environmental pollution volumes in the country. The
world average for this figure is 20% [1].
24
Joyce, James Alexander. "Pressurised entrained flow gasification of sugar cane wastes for cogeneration /." [St. Lucia, Qld.], 2006. http://adt.library.uq.edu.au/public/adt-QU20060713.095935/index.html.
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Jones, Sophia Christina Acle. "Micro-cogeneration optimal design for service hot water thermal loads." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/16016.
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Streckienė, Giedrė. "Research of Heat Storage Tank Operation Modes in Cogeneration Plant." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110621_170138-31454.
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The dissertation investigates typical operation modes of the heat storage tank in the small-scale cogeneration (CHP) plant, analyses formation of thermal stratifi-cation in such storage tank and presents the simulation of the stratification. The main aim of the dissertation is to investigate peculiarities of operation modes of heat storage tank in small-scale CHP plant, develop an algorithm allowing to choose the storage tank volume and present a model allowing determination of thermal stratification in the storage tank at any time of its operation.Disertacijoje nagrinėjami būdingi šilumos akumuliacinės talpos veikimo režimai, susiformuojantys nedidelės galios kogeneracinėje jėgainėje, tiriamas šiluminės stratifikacijos susidarymas tokioje talpoje ir atliekamas jos modeliavimas. Pagrindinis disertacijos tikslas – ištirti nedidelės galios kogeneracinės jėgainės šilumos akumuliacinės talpos veikimo režimų ypatumus, sudaryti algoritmą, padedantį parinkti tokios talpos tūrį ir pateikti modelį, leidžiantį nustatyti šiluminę stratifikaciją akumuliacinėje talpoje bet kuriuo jos veikimo metu.
27
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.
28
Alanis, Francisco J. "Thermodynamic optimisation of industrial cogeneration systems and conventional power plant." Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292578.
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RAMOS, EDUARDO FERREIRA. "PERFORMANCE ANALYSIS OF A GAS FIRED MICROTURBINE BASED COGENERATION SYSTEM." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10387@1.
Full textAbstract:
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORNesta dissertação foi feita uma simulação do desempenho de um sistema de cogeração, a partir de dados experimentais obtidos com uma microturbina a gás natural com 30 kW de potência nominal, operada no horário de ponta, e acoplada com uma unidade recuperadora de calor e um reservatório térmico para fornecimento de água quente de consumo nos chuveiros do Ginásio da PUC-Rio. Inicialmente, o desempenho do sistema de cogeração foi medido para várias condições de operação, mostrando que a eficiência de geração de energia elétrica é inferior à que o fabricante declara (16,6%). O aproveitamento da energia térmica dos gases de exaustão é de 29,1% para plena carga e 46,3% para 25% de carga. Nesta dissertação foi desenvolvida uma metodologia para calcular a efetividade da unidade recuperadora de calor. A simulação realizada teve como objetivos o melhor conhecimento do comportamento do sistema de cogeração para diferentes vazões de água de consumo e da sua temperatura de armazenamento determinando-se o maior valor da vazão para que uma temperatura de 40ºC nos chuveiros fosse mantida. A equação da energia em relação ao tempo foi resolvida numericamente, modelando-se o desempenho de cada componente, para estimar a temperatura da água do reservatório de armazenamento em função do tempo, para diferentes cargas elétrica e térmica. Os resultados indicaram as condições para o melhor aproveitamento de energia térmica e sua viabilidade econômica, inclusive quanto à relação entre o horário de geração e o consumo da energia térmica armazenada.
In this dissertation the performance of a cogeneration system was simulated using data obtained in tests of a natural gas fired 30 kW microturbine, operated during peak hours, and coupled to a heat recovery unit to generate hot water to be consumed in the showers of the PUC-Rio Gymnasium, together with a thermal reservoir to match the demand. Initially, the performance of the cogeneration system was measured at different operating conditions, showing that the electric energy generation efficiency is smaller than what is declared by the manufacturer (16,6%). The heat recovery from the exhaust gases was measured as 29,1% for full load operation and 46,3% for 25% load operation. In this dissertation a methodology was developed for calculating the effectiveness of the heat recovery unit. The performance simulation was aimed to better understand the behaviour of the cogeneration system for different water consumption rates and its storage temperature, determining the maximum allowed value so that the shower water temperature be at least 40ºC. The timewise energy equation was numerically solved, using the modelled performance of each component, to estimate the storage reservoir water temperature as a function of time, for different electric and thermal energy loads. The results indicated the conditions for better thermal energy usage and its economic feasibility, including the relationship between generation hours and the stored thermal energy consumption.
30
Le, Corre Olivier. "Optimisation de la conduite et du dimensionnement d'installations de cogeneration." Paris, ENMP, 1995. http://www.theses.fr/1995ENMP0564.
Full textAbstract:
Les systemes de cogeneration permettent la production simultanee d'energie electrique et thermique, a partir d'une meme source d'energie. Dans le but d'optimiser le dimensionnement et la conduite de ces installations, on peut s'appuyer sur les methodes statiques (programmation lineaire iterative, programmation quadratique iterative, gradient reduit generalise, lagrangien augmente), les methodes dynamiques (principe du maximum de pontryaguine, programmation dynamique), et les methodes de decomposition/coordination. Si le mode de resolution le plus frequemment rencontre, pour les systemes de cogeneration, est aujourd'hui la pli, d'autres methodes plus performantes semblent pouvoir etre utilisees. C'est au travers de deux exemples: la cogeneration dans les usines d'incineration d'ordures menageres et la cogeneration climatique par moteur alternatif, que de nombreuses methodes sont etudiees et testees. Les principaux resultats conduisent d'une part a proposer d'autres methodes que la pli, et d'autre part a un gain economique de 3 a 7% par rapport a une approche classique de dimensionnement
31
Dingle, Jonathan Paul. "Investigation into the potential of industrial cogeneration in South Africa." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/4992.
Full textAbstract:
Includes abstract.Includes bibliographical references.
Cogeneration is a promising technological option for SA and the world at large. This technologypermits the combined production of two forms of energy from a single fuel source. This possibility isadvantageous in industry where electricity and process heat can be produced with outstanding efficiency. It has been shown to offer sizable energy savings and cost advantages in a wide variety ofindustries around the world. Despite these attractive benefits SA‘s use of cogeneration remainslimited. In addition the true potential for cogeneration in SA has not been properly quantified. This represents a significant shortfall in our understanding of the future of the SA energy system. The integrated resource plan for electricity (2012) presents findings that 2GW of cogeneration capacity can be realised by 2020. This figure is unconfirmed and the sources of this proposed cogenerationdevelopment have not been scrutinized. These research gaps must be explored if SA is to realise itscogeneration potential. This research seeks to investigate the potential for cogeneration in SA. A research method was developed specifically to determine what cogeneration currently exists in SA and how much capacity could be developed into the future.
32
Carlson, Amy L. "Applying fuel cells to data centers for power and cogeneration." Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1366.
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33
Kučera, Michal. "Začlenění lokálního zdroje – kogenerační jednotky do průmyslové sítě." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220162.
Full textAbstract:
This master's thesis deals with the integration of a mine gas burning cogeneration unit into industrial power system. The aim of the thesis is to design and evaluate different possibilities of integration the cogeneration unit into industrial power system. The first, theoretical part of the thesis discuss about cogeneration (combined heat and power). The technologies used for cogeneration are summed up as well as the possibilities of usage. The next part deals with the mine gas as the fuel for the cogeneration units. The lasts chapters of the theoretical part talks about terms for installation power source into industrial power system and about the possibilities of overflow of the electricity into distribution power system. The practical part deals with the installation of the 600 kW cogeneration unit into particular industrial power system. Four possibilities of operation mode of the cogeneration unit are design. At the end of the thesis the brief economical evaluation is accomplished.
34
Palacios, Gabriel Napoleón Pesantez. "High efficient cogeneration potential." Master's thesis, 2017. http://hdl.handle.net/10400.8/2860.
Full textAbstract:
Due to the current problems that arise in the environmental, energy and economic areas, an increase of the efficiency of the use of fossil fuels is absolutely needed to reduce the dependence on hydrocarbons and improve tue quality of life. Cogeneration is a supply option that aims to achieve this goal, cogeneration by using the exhaust gases, and thermal energy from cooling systems from thermal equipment to supply useful thermal energy to other processes, producing two useful energy streams combined, usually mechanical or electric and thermal energy at the same time.
The principal objective of this work is to evaluate the potential of cogeneration in the industrial sector of Ecuador. In this framework, a short introduction about the development of cogeneration over the last decades is presented, and a classification of cogeneration according to the sequence of production of electricity and heat, and according to the prime mover type is also presented. The concept of trigeneration is analyzed briefly. A summary of the studies used as a source for the present work as well as the current situation of the electricity market in Ecuador is also shown, being also analyzed the energy consumption data published by the INEC in 2011.
Using the factors presented in the consulted bibliography, the cogeneration potential was calculated, considering the current electricity market structure of Ecuador, and using the electrical needs of industries as a base-line. An economic analysis was carried out using as four types of equipment and considering the effects of altitude above sea level as an important parameter. Finally, two specific facilities, representing the paper and the food industry were used as case studies to evaluate the implementation of cogeneration.
35
Murray, PAUL. "Microturbine for Micro-Cogeneration Application." Thesis, 2009. http://hdl.handle.net/1974/5237.
Full textAbstract:
A micro-cogeneration system based on an ArtesJet KJ-66 hobby microturbine may be able to provide a single family dwelling with required heat and power, increasing total efficiency due to utilization of waste heat. The feasibility of such a system was investigated. An engine model based on the similar JG-100 engine was developed, written in Microsoft Excel™ and Visual Basic™. The predicted running characteristics of the KJ-66 were simulated, and a prediction of how these characteristics would be shifted if a diffuser was attached to the engine was made.
An experimental test program was carried out on the KJ-66 engine to determine if this prediction was correct, and to more accurately characterize the performance of the engine. Two diffusers were constructed to use with the testing, along with the nozzle that was supplied with the engine. Having the diffusers on the engine reduced the fuel air ratio by approximately 20% as predicted.
A hypothetical micro-cogeneration system was simulated building on the earlier engine model, with modified turbomachinery maps and combustor performance based on the experimental data. An 85% effective recuperator was included in the model, as well as a recovery heat exchanger. The simulation showed an electrical output of 8.9 kW, a heat output of 30.9 kW, an electrical efficiency of 15.5%, and a total efficiency of 69.0%. While these efficiencies are low, improvements could be made by modifying the turbomachinery and by using a condensing recovery heat exchanger to give a better overall efficiency for the micro-cogeneration system.Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2009-09-26 22:03:57.11
36
Jang, Jinn Jyi, and 鄭進吉. "Economic Analysis of Cogeneration System." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/20298241431486206424.
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Jiuun, Wang Hwa, and 王華駿. "Reseach on Cogeneration Purchase Price." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/23352808785736545867.
Full textAbstract:
碩士國立臺灣科技大學
電機工程研究所
84
With the liberation of utility regulation by government, cogeneration system has played a more important role than before. Instead of studying on the electrical operation, the purchase price is taken into account in this paper. According to regulation, a justified pricing system should consider both capacity avoided cost and energy avoided cost in the same time. These two subjects are elaborated so that price of electricity can be helpful for cogeneration enterprises. The capacity avoided cost is calculated by using the thermal power plant construction data of Taiwan Power Company and cogeneration plant. And energy avoided cost is estimated by calculating the incremental cost of Taiwan Power Company based on the economic dispatching. Finally, a comparison of the result and the existing purchase price has found that the existing purchase price appears higher. This pricing system should be improved in the future so as to meet the requirement of fair market competition.
38
CAI, HUA-WEN, and 蔡華文. "Size selection of cogeneration unit." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/08237180378526084831.
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Van, Holde David J. "Assessing cogeneration feasibility in institutional facilities." Thesis, 1994. http://hdl.handle.net/1957/35601.
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Yang, Shun-Chieh, and 楊順傑. "Pulverized Coal Combustion in Cogeneration Plant." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/62292314726976221933.
Full textAbstract:
碩士國立成功大學
造船工程學系
85
The major components of coal has a great influence on boiler operation.Take mill for example , the capability of mill depends on the fineness ofpulverized coal , the moisture of coal , and grinding . Therefore , while coalis burning , we should carefully choose coal property to avoid mill being deficient in capability and thus results in the generator de-load . Thus , thepurpose of this experimented is to use the ways which the documents have offered and the experimented formulas provided by the manufactures to work out the evaluation formula and , hence , use such a formula to evaluate the characteristicsof coal property and its influences on boiler operation and emission .
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Chen, Wen-Liang, and 陳文良. "Stability analysis of a cogeneration system." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/57023689417744001529.
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Zheng, Yu Yao, and 鄭宇堯. "Power System Analysis of Cogeneration Plant." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/37447897136032786559.
Full textAbstract:
碩士長庚大學
電機工程學系
98
This thesis focuses on the power system analysis of an actual cogeneration plant. The analysis includes power flow calculation, short-circuit current analysis, transient stability evaluation, and voltage sag analysis. First, the system structure of the plant including synchronous generators, induction motors, and transformers are built. The power flow analysis ensures that all equipments are operated under their rated capacities in all possible situations. The short circuit analysis identifies that the fault currents on each bus are within their momentary and interrupting withstanding levels. The transient stability analysis evaluates that the cogeneration plant can recovery from utility faults and possible grid-disconnection behaviors. The voltage sag analysis ensures that sensitive loads in the plant won’t trip because of faults. The above analysis results can provide field personnel with useful information to enhance the overall operation reliability of the plant.
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LIU, SHAO-HENG, and 劉韶恆. "Cogeneration plant programming and economic evaluation." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/66133793165817800392.
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Huang, Po-Yuan, and 黃柏元. "Load Reorganization Study for Cogeneration System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/y76dc2.
Full textAbstract:
碩士大同大學
電機工程學系(所)
106
Having reliable and stable power supply is essential to the power generation of cogeneration plants. If a power blackout occurs and cannot be restricted to a local area, the subsequent major power blackout may result in substantial losses. The sample cogeneration plant that had undergone multiple reactive power disturbance events, which increased the system voltage and injected the reactive power into the generators, resulting in generator trip due to loss of field. On June 20, 2012, the sample cogeneration plant caused a major power blackout, reflecting that the power system still possessed various shortcomings. For example, the five tie lines in the ML1, ML2, and HF areas were connected to the same bus, resulting in an overly concentrated load. Loads in these three areas were considered critical loads; hence, during the island mode operation, many critical loads must be shed, leading to substantial production losses. The ML2A area did not contain any generator; hence, the island mode operation of this area required shedding every load. After discussion between units of the plant, improvement measures were proposed according to the aforementioned shortcomings to reconfigure the load feeders. Because the cogeneration plant needs to maintain a continuous production process, a six-phase restructuring plan was proposed to gradually modify the load structure of the power system. Previously, a research team has analyzed the modified system of the sample cogeneration plant of its load flow and transient stability, and completed a power system defense plan in April of 2017. The plan reveals that the modified system still possessed problems concerning reactive power disturbance. Therefore, this study conducted a load flow analysis on the restructuring plan to identify which restructuring stage led to the reactive power problem, and improvement measures were proposed accordingly. In addition, reactive power disturbance were evaluated to determine whether under those circumstances, the generators did not trigger the loss-of-field protection mechanism during a leading power factor operation. These evaluations addressed concerns about service reliability.
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HUANG, MAO-LUNG, and 黃茂龍. "Thermal Efficiency-Economic Analysis of Cogeneration Plants." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/30592323051539999547.
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碩士國立成功大學
造船工程學系
85
The purpose of this research is to study the thermal efficiency-economic analysis of cogeneration plants. The system performance is evaluated on the basis of thermal efficiency which is calculated using an energy balance method for the system. Since in the thermal efficiency, The performance is evaluated the exhaust， inlet state of steam turbine, condensed condition of condenser and steam. The economic analysis is using the Return On Investment (ROI) method. Finally, The optimal model is to establish for the system. As a concluding remark, the results presented here will be a good reference to the operating condition of a practical running (old) cogeneration plants. On the other hand, the simulation model provides a reference to the design work of a new cogeneration plants.
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Chang, Ching-Hsien, and 張靜嫻. "OPTIMAL UNIT COMMITMENT SCHEDULING FOR COGENERATION SYSTEMS." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/97055445160788646563.
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碩士大同大學
電機工程研究所
91
ABSTRACT The main purpose of this thesis is to find the optimal unit commitment schedule in non-summer season for a real cogeneration system with back-pressure and extraction turbines by using “Genetic Algorithms”. This thesis is first to determine at which hour the unit should be shut down and at which hour the unit should be started up during specified period, and then to solve the economic dispatch of units at each hour while considering the time-of-use (TOU) rates and the relative constraints subject to satisfying the process steam demand to reduce production costs and save energy. Genetic algorithms are based on probabilistic transition rules and can adapt to nonlinearities and discontinuities commonly found in power systems, so they are less likely to converge to local optima. In addition, the GAs can manage time-dependent constraints. This thesis also proposes some improved methods to increase the probability of finding the global optima and save the computation time. A real cogeneration system will be used to verify the feasibility of the proposed scheme.
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Chang, Shuan-Shih, and 張栓誌. "Generator Planning and Installation of Cogeneration Systems." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/68tsfu.
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碩士國立高雄應用科技大學
電機工程系博碩士班
103
Taiwan possesses scarce indigenous energy resources and imports most of its necessary energy resources from abroad. Constructing cogeneration equipment is one of the key measures for enabling effective energy use and compensating for insufficient electricity supply. In addition, the government promotes an energy policy of distributed power generation, which includes the use of cogeneration equipment. Therefore, determining a method by which to select suitable generator systems that can maximize the economic benefits of cogeneration systems is crucial. According to domestic environmental policies, this study proposed a plan to establish generator systems in cogeneration plants. This plan was developed on the basis of process expansion and involved determining generator capacity according to the steam and electricity load requirements in the plant. Furthermore, methods of inspection, maintenance, and commissioning were explained. Finally, an operation test was conducted. The results of selected systems were compared and analyzed to verify the efficiency of power generation, thereby acquiring a cogeneration system that fulfills qualification requirements and facilitates effective energy use and cost reduction.
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Chou, Yu-ching, and 邱裕欽. "Neural Network Based Cogeneration Dispatch nder Deregulation." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/17520890155420266718.
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碩士國立中山大學
電機工程學系研究所
93
Co-generation is an efficient energy system that generates steam and electricity simultaneously. In ordinary operation, fuel cost accounts for more than 60% of the operational cost. As a result, the boiler efficiency and optimization level of co-generation are both high. To achieve further energy conservation, objectives of this thesis are to find the Profit-maximizing dispatch and efficiency enhancing strategy of the co-generation systems under deregulation. In a coexistent environment of both Bilateral and Poolco-based power market, there are bid-based spot dispatch, and purchases and sales agreement-based contract dispatch. For profit-maximizing dispatch, the steam of boilers, fuels and generation output will be obtained by using the SQP(Sequential Quadratic Programming ) method. In order to improve the boiler efficiency, this thesis utilizes artificial neural networks(ANN) and evolutionary programming(EP) methods to search for the optimal operating conditions of boilers. A co-generation system (back-pressure type and extraction type) is used to illustrate the effectiveness of the proposed method.
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Chen, Geng-Huei, and 陳耕暉. "Investigation on cogeneration plant design and operation." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/28491557875506658362.
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Hung, Chin Ming, and 洪健明. "Analysis of Performance of a Cogeneration System." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/56508572772630233742.
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碩士國立海洋大學
航運技術研究所
86
The world's population has grown rapidly since industrial revolution. The extension of human activity, which have greatly increased the greenhouse warming potential gas-carbon dioxide, led to damaging effects on living material as well as environment. The greenhouse effect may be reduced by utilized waste heat effectively. A theoretical study of the cogeneration system is thus proposed. In the heating process, the boiler tubes consists of superheated, saturated, and subcooled sections. It is shown that the saturated area of the boiler tube increases with exhaust mass flow rate whereas the superheated region decreases with the mass flow rate of heating gas at a fixed outlet exhaust temperature. No significant change of the subcooled portion is observed. On the other hand, the saturated and subcooled areas, at a fixed mass flow rate of exhaust gas, increase with exhaust temperature. In addition, the power consumption of the working fluid's circulating pump increases as the outlet temperature of the exhaust gas decreases. The more the net turbine work produces, the lower the outlet temperature of working fluid in the condenser for a fixed mass flow rate of exhaust gas.