| The traditional CO2 heat pump uses a throttle valve to reduce pressure during the process which causes inevidable loss of energy. Many scientists found that an ejector which can eject low pressure fluid in the evaporater by using high pressure fuild in the transcritical CO2 cycle can reduce the throttling losses of the swelling process. In this paper, in order to study the cycle performance of the CO2 heat pump water heater with an ejector, the ejector, the gas-liquid separator and other equipment required has been designed and processed, and the existing equipment is reformed for the conduction of experimental study.Determining the size of the ejector, gas-liquid separator and so on which are the new processing equipment by detailed calculating. And the drawings have been done which are used to prosess.The thermodynamic models of a traditional circulation system and a system with an ejector are set up, and the analysis and comparison between these models are conducted through Matlab programming. The effect of the evaporation temperature and the compressor exhaust pressure on heating coefficient is mainly researched. The results show that the exhaust temperature of the compressor decreases significantly and COP is improved when adding an ejector to the traditional heat pump cycle system.The effects of the amount of refrigerant charge, the volume flow of water, the inlet temperature of water, the cooling pressure and so on on COP and the outlet temperature of water are studied through sysmatic experiments. Then the results are compared with those of experiments conducted on the traditional device. The results show that when the cooling pressure is higher than 8MPa, efficiency is more obvious adding an ejector to the traditional heat pump system. The highest increase of COP is 7.9%. |
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