Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-01-15T21:40:49Z No. of bitstreams: 1 SilasFerreiraTavaresMartinsMiranda_DISSERT.pdf: 1710495 bytes, checksum: dadeb6081ade516cd49048b5696dec5a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-01-17T15:27:19Z (GMT) No. of bitstreams: 1 SilasFerreiraTavaresMartinsMiranda_DISSERT.pdf: 1710495 bytes, checksum: dadeb6081ade516cd49048b5696dec5a (MD5) / Made available in DSpace on 2018-01-17T15:27:19Z (GMT). No. of bitstreams: 1 SilasFerreiraTavaresMartinsMiranda_DISSERT.pdf: 1710495 bytes, checksum: dadeb6081ade516cd49048b5696dec5a (MD5) Previous issue date: 2017-07-28 / O presente trabalho tem como objetivo avaliar o desempenho de um sistema de refrigera??o por compress?o de vapor utilizando diferentes fluidos refrigerantes sint?ticos. Depois do sucesso na aplica??o do Protocolo de Montreal, que culminou na elimina??o dos CFCs (clorofluorcarbonetos) que tinha alto potencial de destrui??o da camada de oz?nio, nos ?ltimos anos foi constatado que os HCFCs que surgiram com excelente alternativa aos CFCs tamb?m prejudicam o meio ambiente, sua libera??o para atmosfera contribui para o efeito estufa causando o aquecimento global. Por isso o governo brasileiro elaborou um Programa de Elimina??o dos HCFCs (hidroclorofluorcarbonos), este programa est? voltado principalmente para elimina??o do consumo do HCFC-22 (R22), que ? um dos fluidos refrigerantes mais utilizado nos sistemas de refrigera??o e ar condicionado. Neste contexto, o presente trabalho pretende fazer estudo termodin?mico comparativo entre dois fluidos refrigerantes sint?ticos o R-22 e o R437a. O refrigerador funcionando com R437 foi submetido a testes abaixamento de temperatura conforme norma ABNT para diferentes cargas t?rmicas no evaporador. Os resultados obtidos foram comparados com o refrigerador funcionando com R22 para as mesmas cargas t?rmicas e revelam que a performance do refrigerador com o R22 ? superior ao R437a. / The objective of this work is to evaluate the performance of a steam compression refrigeration system using different synthetic refrigerant fluids. Following the successful implementation of the Montreal Protocol, which culminated in the elimination of CFCs (chlorofluorocarbons) which had a high potential for destruction of the ozone layer, it has been found in recent years that the HCFCs that have emerged as an excellent alternative to CFCs also harm the environment , its release into the atmosphere contributes to the greenhouse effect causing global warming. For this reason, the Brazilian government has developed a Program for the Elimination of HCFCs (hydrochlorofluorocarbons). This program is mainly aimed at eliminating the consumption of HCFC-22 (R22), which is one of the refrigerants used in refrigeration and air conditioning systems. In this context, the present work intends to make a comparative thermodynamic study between two synthetic refrigerant fluids R-22 and R437a. The refrigerator running on R437 was subjected to temperature lowering tests according to ABNT standard for different thermal loads on the evaporator. The results obtained were compared with the refrigerator running on R22 for the same thermal loads and show that the performance of the refrigerator with R22 is higher than R437a.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-03T23:57:09Z No. of bitstreams: 1 BrunoDanielAlvesDoNascimento_DISSERT.pdf: 2697025 bytes, checksum: 8a93610daedd22a97964b68f4766a99b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-07T20:32:39Z (GMT) No. of bitstreams: 1 BrunoDanielAlvesDoNascimento_DISSERT.pdf: 2697025 bytes, checksum: 8a93610daedd22a97964b68f4766a99b (MD5) / Made available in DSpace on 2016-06-07T20:32:39Z (GMT). No. of bitstreams: 1 BrunoDanielAlvesDoNascimento_DISSERT.pdf: 2697025 bytes, checksum: 8a93610daedd22a97964b68f4766a99b (MD5) Previous issue date: 2015-06-19 / A redu??o no consumo de energia ? o principal requisito a ser satisfeito em sistemas de refrigera??o e condicionamento de ar por compress?o mec?nica de vapor. Em sistemas automotivos essa realidade n?o ? diferente. A an?lise t?rmica nesses sistemas ? de fundamental import?ncia para um bom desempenho do ar-condicionado veicular. Este trabalho tem o objetivo de avaliar as condi??es de utiliza??o do g?s refrigerante R134a (utilizado em ve?culos automotivos), variando a velocidade no eletroventilador do evaporador, comparando a performance do mesmo com o g?s R437a, submetido as mesmas condi??es. Todos os testes foram realizados na unidade de climatiza??o automotiva ATR600, que simula as condi??es t?rmicas do sistema e do habit?culo do ve?culo. O equipamento est? instrumentado para aquisi??o dos dados de temperatura, press?es de alta e baixa e pot?ncia el?trica consumida, para determina??o do coeficiente de performance do ciclo. O sistema foi ensaiado nas rota??es de 800, 1600 e 2400 RPM com carga constante de R134a / R437a, recomendada pelo fabricante. Os resultados mostram que a melhor performance do sistema ocorre na rota??o de 800 RPM para ambos os refrigerantes. / The reduction in energy consumption is the main requirement to be satisfied in refrigeration and air conditioning by mechanical vapor compression system. In automotive system isn?t different. Thermal analyses in these systems are crucial for a better performance in automotive air conditioner. This work aims to evaluate the conditions of use of R134A refrigerant (used in vehicles) and compare with R437A (alternative refrigerant), varying the speed of the electric fan in the evaporator. All tests were performed in automotive air conditioning unit ATR600, simulating the thermal conditions of the system. The equipment is instrumented for data acquisition temperature, condensation and evaporation pressures and electrical power consumed to determine the coefficient of performance of the cycle. The system was tested under rotations of 800, 1600 and 2400 rpm with constant load of R- 134a. It occurred with the same conditions with R437A. Both recommended by the manufacturer. The results show that the best system performance occurs in the rotation of 800 RPM for both refrigerants.