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Refrigerating System By Rank-Hilsch Tubes With Supply of Compressed Air Tank to Power With PV Source / Sistema de refrigeraÃÃo por tubos de Ranque-Hilsch com abastecimento de instalaÃÃo de ar comprimido para alimentaÃÃo com fonte solar fotovoltaicaOseas Carlos da Silva 28 August 2014 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A busca por novos sistemas de refrigeraÃÃo vem se tornando o alvo de estudo de diversos pesquisadores, com o objetivo de diminuir impactos ambientais referentes à destruiÃÃo da camada de ozÃnio e efeito estufa que trazem consigo diversos malefÃcios à vida no planeta.
Sistemas de refrigeraÃÃo convencionais respondem por boa parte do consumo de energia elÃtrica de uma residÃncia ou uma empresa (de 20 ou atà 25%), e sÃo normalmente ligados durante o dia , quando a demanda à maior e as tarifas mais caras. Dispositivos de refrigeraÃÃo
sÃo indispensÃveis nas atividades humanas, como conservaÃÃo de alimentos, medicamentos, etc. Sistemas fotovoltaicos sÃo fontes de energia elÃtrica confiÃveis e independentes. Por essas razÃes, atualmente, hà um aumento no uso de sistemas de refrigeraÃÃo acionados por energia solar fotovoltaica nas zonas rurais. Tubos de Ranque-Hilsch ou tubos de vÃrtice sÃo geralmente utilizados para refrigeraÃÃo local de baixo custo, onde hà a disponibilidade de ar
comprimido. Nesse trabalho, um tubo de vÃrtice foi concebido, testado e otimizado para operaÃÃo em pressÃes inferiores Ãs convencionais, de modo a ser alimentado por um compressor acionado por mÃdulos fotovoltaicos, suprindo as necessidades de esfriamento em
localidades desprovidas de energia elÃtrica. Nas mediÃÃes experimentais, foram obtidas temperaturas abaixo do ponto de congelamento da Ãgua por meio da combinaÃÃo de certos parÃmetros, possibilitando a esse sistema de climatizaÃÃo ser utilizado de maneira eficiente e racional em localidades remotas, podendo contribuir para a soluÃÃo da questÃo energÃtica e ambiental da sociedade. / The search for new refrigeration systems has become the target of various researchers. Their goal is to reduce the environment impacts resulting from the destruction of the ozone layer and the greenhouse effects that harm life in the planet Earth. Vapor-compression refrigeration
systems represent a big fraction of the world energy consumption in houses and commercial stores (between 20 to 25%) and these systems usually run during the day, when the energy demand and the prices are higher. Refrigeration systems are necessary to todayâs human
activities, such as food and medicament conservation, air conditioning, etc. Photovoltaic systems are reliable energy sources and they can operate separately from the distribution energy grid. For these reasons, there is an increase in the use of refrigeration systems powered
by solar photovoltaic panels in rural areas. Ranque-Hilsch tubes or vorticity tubes are commonly used for low cost local refrigeration, where compressed air is available. In this study, a vortex tube was designed, tested, and optimized to operate at pressure levels lower
than the conventional values. The purpose is to allow its operation by a compressor system powered by solar photovoltaic panels and, therefore, its installation in locations where there is no electrical grid. In the experimental measurements, temperatures below the water freezing point were reached due to the combination of a number of tube parameters. These low temperature values support the use of the vortex tube in air cooling applications in a more efficient and rational energy use, particularly in remote locations, and can contribute to the solution of the energy demand and environmental problems.
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An Alternative Refrigeration System For Automotive ApplicationsMcLaughlin, Shannon 06 August 2005 (has links)
The air conditioning systems currently utilized in automobiles are the vapor compression systems. This type of system has many disadvantages: the refrigerant used is not environmentally friendly, the compressor is in competition with the engine coolant system, and the compressor uses a significant portion of the engine power. A waste heat driven absorption refrigeration system is one alternative to the current systems that could address these problems. The absorption refrigeration system uses solutions for the absorbent-refrigerant pair that do not harm the environment. This investigation includes a theoretical analysis of the feasibility of absorption air conditioning system in automotive applications. Also, a comparison of the power requirements of the proposed system and the vapor compression system is performed.
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