Simulation And Experiment On The Character Of R290 Applied In Air Source Heat Pump Water Heater

In response to the urgency of the substitution of HCFCs and HFCs refrigerant and meet the market need for air source heat pump water heater, this paper presented the R290 air source heat pump water heater for the hot summer and cold winter zone which used green refrigerant propane (R290). Considering the inflammable and explosive of R290, plate condenser and micro-channel evaporator were adopted in the design of the unit for reducing the amount of refrigerant charge, which effectively ensured the safety of the application of R290 units. At the same time, the drainage of the evaporator and defrost were optimized to improve the applicability of wide temperature range.In order to study the operation characteristics of the system, the experimental prototype was successfully developed through detailed design and selection and set up the experimental platform. According to the experimental plan, the experimental prototype is tested by multi-conditions. Firstly, under the same conditions, the operating characteristics of R290 and R22 are compared to determine the advantages of R290 as a refrigerant. Secondly, under nominal operating conditions, the heating performance of R290 heat pump water heater was tested. The experimental results showed that the heating performance of the unit had reached the national standard GB 29541-2013 third level with good heating performance. Finally, research on frosting problem on the machine and put forward the corresponding strategy of defrosting to instruct the performance test of the unit under various conditions. The effect of removing frost according with anticipate proved that the viability of the strategy of defrosting.Secondly, the dynamic variation of parameters of R290 pump, such as discharge temperature, condensing pressure, evaporation pressure, power consumption and COP, are simulated in process of water heating model. The comparison of simulation results with the measured data showed that the average deviation of the simulation results was less than 10%, which was of good accuracy. This paper studies the air volume and the refrigerant distribution uniformity by the the simulation model.The results showed that the more uniform air flow and refrigerant distribution, the more favorable to the performance of the unit.