Operation Characteristic Analysis For Air-Source Heat Pump Water Heater In Hot Summer And Cold Winter Zone

Air source heat pump water heater, as a high-efficiency and energy-saving hot water production device, is of increasingly extensive development and application. However, operation efficiency of air source heat pump is influenced by parameters of outdoor environment, especially by its seasonality performance. The operation stability and efficiency have become major problems constraining popularization of air source heat pump water heater.The characteristic analysis and performance test scheme regarding air source heat pump water heater are provided in this paper. Performance test has been conducted on an air source heat pump water heater produced by certain company, which measured operation parameters including inlet/outlet water temperature of condenser, instant power dissipation and exhaust gas temperature of compressor of such 5.0HP air source heat pump water heater under the typical environment. Based on the measured data, changes of main performance parameters of the heat pump water heater under different environmental parameters have been analyzed, thus figuring out the influence of those environmental parameters on main performance indexes of the air source heat pump water heater. Besides, the thermodynamical analysis has been also conducted for the air source heat pump water heater. The results showed that, the exergy efficiency of the system is 43.7%. As for exergy loss coefficient, compressor has the largest exergy loss coefficient, which is 26.12%; and exergy loss coefficient of expansion valve, condenser and evaporator are 14.15%, 9.82% and 6.21%, respectively; Finally, the method to reduce exergy loss of the system has been discussed based on such analysis and it suggest that putting both electronic expansion valve and inverter compressor under the control would be effective.A system model of the air source heat pump water heater has been established by the aid of TRNSYS software, which figured out the relation among time and changes of COP, power dissipation and heating capacity of the system. Performance curves of operation of the air source heat pump water heater all through the year, which can serve as referential information for consumer, are also obtained. In addition, effect of water tank volume and the set water temperature on system performance is also analyzed in this paper, the results showed that in the process of water volume from 300 L to 800 L, the system COP is on the rise with a different pace, and the growth of annual average COP appears first quick back slow trend; The higher set water temperature is, the lower annual average COP of system would be, and 50℃ would be the perfect temperature for the system. Moreover, based on the existing model, a system optimizing operation scheme has been proposed to provide a reference for improving the climate adaptability of the system.