Study On The Performance Of R134a Heat Pump System

As a new way of energy utilization,the high efficiency and energy saving of heat pump have reached a consensus in the whole industry.Therefore,the research on heat pump application is being deeper and deeper.R134 a refrigerant is being widely used because of its safety,innocuity and environmental protection.It is widely used in building heating,water for living,automobile air conditioning and other aspects.Based on the thermodynamic analysis method,the thermal efficiency and exergy loss models of R134 a heat pump throttle valve system and expander system were established respectively through reasonable simplified assumptions.The effects of exhaust pressure,evaporation temperature,condensation temperature,superheat temperature,compressor efficiency and expander efficiency on COP,heat exchange and system power consumption were studied respectively.The influences of exhaust pressure,evaporation temperature and condensation temperature on the exergy loss of compressor,condenser,throttle valve,expander and evaporator were analyzed.The results can provide guidance for the selection of operating conditions and the optimization of system performance.Based on R134 a heat pump system,according to the given area,combined with the design parameters of heat pump and air conditioner in winter and summer,calculated the corresponding cooling and heating loads,and then determined the basic data of R134 a heat pump.The R134 a heat pump system was studied by using the fuzzy comprehensive evaluation method and a specific example.According to the results of fuzzy comprehensive evaluation,the deficiencies in the evaluation factors of R134 a heat pump system were found,which can provide the basis for the performance optimization and safety management of R134 a heat pump system.The performance of R134 a heat pump system was tested,and the key parameters affecting the system performance,such as exhaust pressure,condenser outlet temperature,evaporation temperature,cooling water flow and chilled water flow,were studied.The error analysis shows that the performance test and theoretical analysis reach the error expectation,and provides the basis for the reasonable selection of heat pump operating parameters and the optimization of heat pump performance.Figure47;Table19;Reference 43...