Research on Environmental Friendly Refrigerant Heat Pump Water Heater Based on Enhanced Vapor Injection

Abstract

This paper studied the substitutability of R417A in enhanced vapor injection air source heat pump, mainly analyzed the feasibility of R417A instead of R22 under the low temperature conditions by experimental performance test. By adjusting the openness of the electronic expansion valve to regulate refrigerant volume, and found out the optimal openness of R22 and R417A system under winter conditions(7℃,6℃) and low temperature conditions(-7℃,-8℃) . The results show that for the direct-heated heating system, the lower ambient temperature, the more feasibility of R417A instead of R22.