This diploma thesis with resolution of technical and partially economical project of combustion exchanger of cogeneration unit for application of absorbing cooling. Considered types of exchangers are: combustions/water and combustions/steam. The other capitols include the description of cogeneration, trigeneration and other possible resolutions of intersections among mentioned systems; general overview of plant oils used as a fuel in energetics, particularly in compression engines in technology of combined production of electricity and heat.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-09-25T13:55:05Z No. of bitstreams: 1 arthurgoncalvesgivisiez.pdf: 15097769 bytes, checksum: e434481fde7014f783d8b75137429fba (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-10-01T18:11:02Z (GMT) No. of bitstreams: 1 arthurgoncalvesgivisiez.pdf: 15097769 bytes, checksum: e434481fde7014f783d8b75137429fba (MD5) / Made available in DSpace on 2018-10-01T18:11:02Z (GMT). No. of bitstreams: 1 arthurgoncalvesgivisiez.pdf: 15097769 bytes, checksum: e434481fde7014f783d8b75137429fba (MD5) Previous issue date: 2018-08-29 / O mundo está tentando mudar para um ambiente de energia mais limpa, especialmente no setor de geração de eletricidade, que é responsável por uma grande parcela das emissões de CO2. No Brasil, fontes renováveis são responsáveis por grande parte da geração de eletricidade, mas mudanças atuais no clima brasileiro trouxeram uma necessidade de diversificação na matriz energética. Logo, a geração distribuída é uma boa maneira de diversificar a matriz energética brasileira. Considerando que os sistemas de cogeração se enquadram na geração distribuída, e que os prédios brasileiros necessitam de resfriamento, devido ao clima quente, o uso de cogeração adicionado à um chiler de absorção ou absorção pode ser muito útil. O sistema de trigeração é um processo altamente eficiente, que pode produzir eletricidade, aquecimento e resfriamento a partir da mesma fonte de energia primária. No entanto, existem poucas pesquisas sobre os sistemas de trigeração no Brasil, especialmente em pequena e micro escala. Assim, esta dissertação fará uma avaliação técnica e econômica de sistemas de micro e trigeração para diferentes edifícios sob políticas tarifárias distintas no Brasil. Para tanto, este trabalho otimizará o dimensionamento e o cronograma de despacho mensal dos sistemas de trigeração para cada um dos quatro estudos de caso. Em seguida, avaliará o valor presente líquido máximo (VPL) considerando a variação da taxa de desconto e da taxa de conversão do dólar norte-americano. Na sequência, o índice de dependência da rede (GDI), o payback descontado, o custo nivelado da energia (LCOE) e a razão da energia primária (PER) para os melhores VPLs serão apresentados e analisados. Como resultado, esta dissertação mostrará que as plantas de trigeração podem ser lucrativas e certamente ser uma maneira eficiente de utilização de uma geração distribuída confiável e controlável. Além disso, provará que é possível encontrar situações em que a planta de trigeração possa oferecer uma alta taxa de energia primária (PER), um adequado custo de energia nivelado (LCOE) e, ao mesmo tempo, pode proporcionar economia financeira com tempo de retorno razoável em edifícios brasileiros. / The world is trying to move to a cleaner energy environment, especially on the electricity generation sector, which is responsible for a large share of CO2 emissions. In Brazil,crenewable energy sources are responsible for a great part of the electricity generation, but current changes in the Brazilian climate brought a necessity of diversification on the energy matrix. Then, distributed generation is a good way to diversify the Brazilian power matrix. Considering that cogeneration systems are distributed generation, and Brazilian buildings have need of cooling, due to the warm weather, the use of cogeneration equipped with an absorption or adsorption chiller could be beneficial. The trigeneration system is a highly efficient process, which can produce electricity, heating and cooling from the same primary energy source. However, there are really few researches concerning trigeneration systems in Brazil, especially on small and micro plants. Thus, this thesis will make and provide a technical and economical evaluation of small and micro trigeneration systems to different buildings under distinct tariff policies in Brazil. To do so, this work will optimize the sizing and monthly schedule the dispatch of the trigeneration systems to each one of the four study cases. Then, it will evaluate the maximum net present value (NPV) considering the variation of discount rate and US Dollar conversion rate. In the sequence, the grid dependence index (GDI), the discounted payback, the levelized cost of energy (LCOE) and the primary energy ratio (PER) to the best NPVs will be presented and analysed. As a result, this thesis will show that trigeneration plants can be profitable and can be certainly an efficient way to adopt a reliable and controllable distributed generation. Also, it will prove that it is possible to find situations in which the trigeneration plant can offer a high primary energy ratio, a fair levelized cost of energy, and in the meantime, it can provide financial savings with fair payback time in Brazilian buildings.

Un nouveau procédé de trigénération thermo-hydraulique fonctionnant à partir d'énergie thermique basse température (80 à 110 °C) a été étudié pour assurer les différents besoins du secteur résidentiel. Le terme "thermo-hydraulique" se réfère à l'utilisation d'un liquide incompressible qui permet de transférer le travail hydrauliquement entre différents composants ou sous-systèmes, permettant d'améliorer l'efficacité de la chaine de conversion énergétique. Un modèle quasi-statique a été développé pour évaluer les performances énergétiques des différentes variantes du procédé. Ces calculs ont permis de définir parmi un large choix, quels fluides de travail étaient les plus appropriés. Ces calculs ont été complétés par une étude quasi-dynamique et dynamique permettant un meilleur dimensionnement du procédé. Enfin, une étude de fonctionnement annuel a été réalisée à partir du modèle quasi-statique pour évaluer l'évolution des performances ainsi que sa production d'énergie sur une année complète de fonctionnement. Ces études montrent que le couple fluide R1234yf/R1233zd semble le plus approprié à un fonctionnement en climat méditerranéen. L'étude annuelle montre qu'en considérant les données climatiques de la ville de Perpignan, le procédé permet d'amplifier l'énergie solaire collectée d'un facteur de 1,32 en moyenne et permet d'atteindre un COP solaire de 0,24 en mode rafraichissement. Quand les besoins thermiques sont satisfaits, l'intégralité de l'énergie solaire captée est valorisée pour produire de l'électricité avec un rendement moyen annuel de 4,2%. / A new process based on thermal-hydraulic conversion actuated by low-grade thermal energy (80–110 °C) is investigated and aims at providing trigeneration energy features for the residential sector. "Thermo-hydraulic" term refers to a process involving an incompressible fluid used as an intermediate medium to transfer work hydraulically between different thermal operated components or sub-systems allowing to improve the efficiency of the energy conversion chain. A model, assuming steady-state operations, is developed to assess the energy performances of different variants of this thermo-hydraulic process as well as various pairs of working fluids. These calculations were completed by a quasi-dynamic and dynamic models allowing a better sizing of the process. Finally, an annual study was realized from the quasi-static model in order to estimate the evolution of the performances as well as its power production over a complete year of functioning. For instance, in the frame of a single-family home, located in the Mediterranean region, the working fluid pair (R1234yf/R1233zd) is investigated in detail in order to estimate the annual performances. For domestic houses, the process aims at amplifying the solar energy collected by a factor of 1.32 for heating purpose, provides a cold production with a solar COP of 0.24 and generates electricity from the remaining solar energy with an efficiency of 4.2%.

The aim of the Masterâs thesis was to create a computational model for integration of the cogeneration unit into the smart thermal network. For the better use of waste heat from the selected cogeneration unit MOTORGAS MGM250 during the summer period, the absorption circuit was dimensioned and the appropriate trigeneration computational model was formed. In the theoretical part, the function, operation and heat performance of the cogeneration unit as well as the suitability of the connection of the cogeneration unit with the absorption chiller during the summer period were described. In the practical part, the operational data of the Faculty of Mechanical Engineering of the Brno University of Technology and the theoretical performance data from created cogeneration and trigeneration computational models were compared. Based on this comparison, the conclusion about the suitability of use of both computational models was made.

The diploma thesis titled Energy supplies fairgrounds is divided into four parts. The first part is devoted to the theory of sources of froze and heat energy. The next part deals with current condition of energy supplies of fairgrounds. The third part is based on the design of possible adjustment of energetic management for both the whole compound and partial objects. The last part sums up all the adjustments and evaluates all the real variants by closer economic analysis.

This thesis deals with electricity, heat and cold production and describes ways of their simultaneous production – trigeneration. The main intention is to describe the ways of cooling the A1 building which is used by The Faculty of Mechanical Engineering. There is a Vapor compression cycle, a One stage absorption cycle and a Two stage compression cycle designed for cooling A1 building. This thesis includes suggestion for suitable commercial units for the purpose of cooling and a comparison of their running costs. An economic analysis is also included. Another part of the thesis is the design of a one stage absorption cycle connected to cogeneration units placed in The Faculty of Mechanical Engineering campus. The condenser of this cycle is also designed.

Esta dissertação analisa a viabilidade técnico-econômica de pequenas centrais de cogeração a gás natural no setor terciário do estado de São Paulo, os estudos de cogeração foram baseados em casos reais de estabelecimentos comerciais dos principais segmentos do setor terciário com demanda elétrica e térmica compatível ao balanço energético para a configuração de cogeração. A análise dos resultados inclui o fator de utilização de energia (FUE), investimentos iniciais, economia operacional (fluxo de caixa), retorno dos investimentos (Payback), taxa interna de retorno (TIR) e valor presente líquido (VPL). As tecnologias empregadas nos estudos foram gerador do tipo Motor a Combustão Interna (MCI) e Microturbina (TG), resfriador de líquido por absorção (ABS) e resfriador de líquido elétrico convencional. Foi realizada análise do potencial de mercado para aplicação de cogeração através do mapeamento dos principais segmentos do setor terciário e realizado o levantamento do estado da arte. Foram estudadas as legislações brasileiras tanto no que se refere à cogeração qualificada como geração distribuída, realizado análise de emissões com destaque ao comparativo entre emissão de CO2 das centrais de cogeração e a emissão de CO2 das termelétricas a gás natural. Foi realizado estudo do cenário energético brasileiro do ponto de vista geração e distribuição de energia elétrica, cenário da oferta de gás natural no Brasil e a sua estrutura de distribuição no estado de São Paulo e, por fim, foram destacados os benefícios e barreiras da cogeração no Brasil. Os resultados alcançados apontam para um revés na viabilidade financeira da cogeração devido aos consecutivos aumentos no preço da tarifa de gás natural, apesar de bastante racional e com benefícios diretos ao meio ambiente e ao país, fazem-se necessários incentivos específicos relacionados à tarifa do gás natural para o crescimento da aplicação de cogeração no setor terciário do estado de São Paulo. / This dissertation examines the technical and economic feasibility of small cogeneration plants powered by natural gas in the tertiary sector of the state of São Paulo. Cogeneration studies were based on real cases of commercial facilities of the main segments of the tertiary sector with electrical and thermal demands compatible for energy usage in cogeneration configuration. The analysis results include energy utilization factor (EUF), initial investments, operational savings (cash flow), return on investment (payback), internal rate of return (IRR) and net present value (NPV). The technologies investigated in the study were Internal Combustion Engine (ICE) and Microturbine (TG) generator, absorption chiller (ABS) and conventional electrical chiller. It was carried out an analysis of the potential market for application of cogeneration by mapping the main segments of the tertiary sector and conducted a survey of the state of the art. Brazilian laws were studied both with regard to qualified cogeneration and distributed generation, performed emissions analysis with emphasis on the comparative between CO2 emission from cogeneration plant and CO2 emission from power plants by natural gas. It was made a study of Brazilian energy scenario from the viewpoint of generating and distributing of electricity, scenario of supply of natural gas in Brazil and its distribution structure in the São Paulo state and, finally, it was appointed the benefits and barriers of cogeneration in Brazil. The results indicate a setback on the financial viability of cogeneration due to consecutive increases in the price of natural gas, although quite rational and with direct benefits to the environment and the country, it\'s necessary specific incentives related to the natural gas price for the growth of the application of cogeneration in the tertiary sector of the state of São Paulo.

Esta dissertação analisa a viabilidade técnico-econômica de pequenas centrais de cogeração a gás natural no setor terciário do estado de São Paulo, os estudos de cogeração foram baseados em casos reais de estabelecimentos comerciais dos principais segmentos do setor terciário com demanda elétrica e térmica compatível ao balanço energético para a configuração de cogeração. A análise dos resultados inclui o fator de utilização de energia (FUE), investimentos iniciais, economia operacional (fluxo de caixa), retorno dos investimentos (Payback), taxa interna de retorno (TIR) e valor presente líquido (VPL). As tecnologias empregadas nos estudos foram gerador do tipo Motor a Combustão Interna (MCI) e Microturbina (TG), resfriador de líquido por absorção (ABS) e resfriador de líquido elétrico convencional. Foi realizada análise do potencial de mercado para aplicação de cogeração através do mapeamento dos principais segmentos do setor terciário e realizado o levantamento do estado da arte. Foram estudadas as legislações brasileiras tanto no que se refere à cogeração qualificada como geração distribuída, realizado análise de emissões com destaque ao comparativo entre emissão de CO2 das centrais de cogeração e a emissão de CO2 das termelétricas a gás natural. Foi realizado estudo do cenário energético brasileiro do ponto de vista geração e distribuição de energia elétrica, cenário da oferta de gás natural no Brasil e a sua estrutura de distribuição no estado de São Paulo e, por fim, foram destacados os benefícios e barreiras da cogeração no Brasil. Os resultados alcançados apontam para um revés na viabilidade financeira da cogeração devido aos consecutivos aumentos no preço da tarifa de gás natural, apesar de bastante racional e com benefícios diretos ao meio ambiente e ao país, fazem-se necessários incentivos específicos relacionados à tarifa do gás natural para o crescimento da aplicação de cogeração no setor terciário do estado de São Paulo. / This dissertation examines the technical and economic feasibility of small cogeneration plants powered by natural gas in the tertiary sector of the state of São Paulo. Cogeneration studies were based on real cases of commercial facilities of the main segments of the tertiary sector with electrical and thermal demands compatible for energy usage in cogeneration configuration. The analysis results include energy utilization factor (EUF), initial investments, operational savings (cash flow), return on investment (payback), internal rate of return (IRR) and net present value (NPV). The technologies investigated in the study were Internal Combustion Engine (ICE) and Microturbine (TG) generator, absorption chiller (ABS) and conventional electrical chiller. It was carried out an analysis of the potential market for application of cogeneration by mapping the main segments of the tertiary sector and conducted a survey of the state of the art. Brazilian laws were studied both with regard to qualified cogeneration and distributed generation, performed emissions analysis with emphasis on the comparative between CO2 emission from cogeneration plant and CO2 emission from power plants by natural gas. It was made a study of Brazilian energy scenario from the viewpoint of generating and distributing of electricity, scenario of supply of natural gas in Brazil and its distribution structure in the São Paulo state and, finally, it was appointed the benefits and barriers of cogeneration in Brazil. The results indicate a setback on the financial viability of cogeneration due to consecutive increases in the price of natural gas, although quite rational and with direct benefits to the environment and the country, it\'s necessary specific incentives related to the natural gas price for the growth of the application of cogeneration in the tertiary sector of the state of São Paulo.

Master thesis deals with usage issues of autonomous, self-sufficient and decentralized systems. In the first part convectional and experimental sources for autonomous systems are disclosed. Second chapter deals with accumulation of electrical and thermal energy and possibilities of applications. 3rd part is focused on pilot project realized for autonomous and smart systems, which were built in last years. In the 4th chapter electrical and thermal energy consumption curves are made on daily and monthly basis for 4 type objects. In the fifth part issue of autonomy is explained, and for type buildings solutions are made with additional return on investment. The last chapter is focused on calculation of thermal accumulator and briefly discloses small district heating.

Most energy solutions in developing countries focus primarily on solving domestic energy demands of their growing populations without due consideration of sustainable development. On the other hand, in most of these countries, a segment of energy users that has not received enough attention from governments and institutions regarding appropriate energy solutions is the productive sector. This sector is mainly composed by small and medium-sized industries and ventures that greatly contribute to the countries’ economy, as in the case of Bolivia. However, the low investment capacity, the lack of knowledge, training and insufficient support from local and national governments do not allow these solutions to arrive as expected. Although many of these sectors have the potential to apply energy solutions utilizing alternative energy sources, as the waste generated by the activity, this work has not materialized. This is the case of the dairy farmers in central Bolivia, who do not have an adequate management of farm waste. This problem contributes negatively to the contamination of the local and global environment.  This study explores solutions of combined energy systems applied to the dairy sector of Bolivia. The two cases under investigation consider the utilization of waste from farms to produce biogas, which drives the proposed systems. The first solution focuses on a polygeneration system featuring either an internal combustion engine or internally fired microturbine for the simultaneous provision of biogas for cooking, electricity, refrigeration, and fertilizer. The second system involves trigeneration i.e. absorption chiller integrated to an externally fired microturbine for supplying electricity, refrigeration and hot water. Analysis methods include determination of levelized cost of services, payback period, primary energy rates and energy saving rates.  The techno-economic assessment for the polygeneration system shows that the costs of the supplied services are still attractive when compared to subsidized prices of fossil fuel-based services in the market if the investment capital of this system is partially subsidized. The biogas cost from the system is lower than the cost of conventional gas used for cooking. The use of the internal combustion engine results in a lower electricity cost than using the microturbine. The refrigeration cost is slightly higher than conventional refrigeration for both cases. A sensitivity analysis shows that the cost for feedstock (cow dung) can be increased while maintaining an attractive price of biogas, and that subsidies on investment capital cause a reduction in the services costs. In the case of energy performance evaluation of the trigeneration system it was found to be more efficient in terms of energy utilization than conventional fossil fuel-based solutions, and this leads to energy savings.  Finally, it is shown that combined energy systems applied to the Bolivian dairy sector are competitive in terms of their economic feasibility and energy performance. / De flesta energilösningar i utvecklingsländer fokuserar på att lösa inhemska energibehov för sina växande populationer utan att ta hänsyn till hållbar utveckling. Å andra sidan är ett segment av energianvändare den produktiva sektorn, som inte fått tillräckligt med uppmärksamhet från regeringar och institutioner när det gäller lämpliga energilösningar. Denna sektor består huvudsakligen av små och medelstora industrier och företag som i hög grad bidrar till ländernas ekonomi, vilket är fallet med Bolivia. Låg investeringskapacitet, brist på kunskap, utbildning och otillräckligt stöd från lokala och nationella regeringar tillåter dock inte att dessa lösningar kommer fram som förväntat. Även om många av dessa sektorer har potential att tillämpa energilösningar som använder alternativa energikällor, som det avfall som genereras av verksamheten, har detta inte exploaterats i nämnvärd grad. Detta gäller bland annat mjölkbönderna i centrala Bolivia, som inte har en adekvat hantering av jordbruksavfal, vilket bidrar negativt till föroreningar av den lokala och globala miljön. Denna studie undersöker lösningar med kombinerade energisystem för mjölkhantering i Bolivia. De två fall som undersöks gäller användningen av avfall från gårdar för att producera biogas, som driver de föreslagna systemen. Den första lösningen fokuserar på ett polygenerationssystem som innehåller antingen en förbränningsmotor eller mikroturbin med klassisk intern förbränning. Systemet möjliggör samtidig försörjning av biogas för matlagning och elgenerering, bl.a. för kylning samt ger gödningsmedel som restprodukt. Det andra systemet innefattar tri-gereration, dvs en absorptionskylare integrerad med en externt driven mikroturbin för att leverera el, kylning och varmt vatten. Analysmetoder innefattar bestämning av driftkostnader för de olika energitjänsterna, återbetalningsperiod, förbrukad primärenergi och relativ energibesparing. En teknisk-ekonomisk analys av polygenerationssystemet visar att kostnaderna för de tillhandahållna tjänsterna är attraktiva i förhållande till de subventionerade priserna på tjänster på marknaden om subventioner tillämpas på investeringskapitalet. Kostnaden för biogas från systemet är lägre än kostnaden för konventionell gas som används för matlagning. Användning av en förbränningsmotor resulterar i en lägre elkostnad än att använda en mikroturbin. Kylkostnaden är något högre än med konventionell kylning för båda fallen. En känslighetsanalys visar att kostnaden för råvaror (kogödsel) kan tillåtas öka, samtidigt som ett attraktivt biogaspris bibehålls, och att subventioner på investeringskapital leder till en minskning av kostnaderna för energitjänsterna. När det gäller utvärdering av energiprestanda för tri-gererationssystemet visade sig det vara mer effektivt när det gäller energianvändning än konventionella lösningar baserade på fossila bränslen, vilket leder till energibesparingar. Slutligen visas att kombinerade energisystem som tillämpas på mjölkhanteringssektorn är konkurrenskraftiga när det gäller den ekonomiska genomförbarheten och energiprestanda.