Experiment study of an enhanced vapor injection refrigeration/heat pump system using R32

R32, with an ozone depletion potential (ODP) of zero and a global warming potential (GWP) of 675, may be an acceptable working fluid for refrigeration/heat pump systems to replace HFCs. The performance of an enhanced vapor injection refrigeration/heat pump system (EVI system) was experimentally investigated using R32. The results show that this system reduces the discharge temperatures for both cooling and heating, with the heating capacity of the EVI system using R32 3 – 9% higher than that of the single-stage system. The cooling capacity, cooling EER and heating COP depend on the refrigerant intermediate pressure and the operating conditions so they can be bigger or smaller than for the single-stage system. The best range of relative vapor injection mass is 12 – 16% for the best overall cooling and heating performance. Vapor injection changes the systems operating conditions, and increases both the evaporating and condensing temperatures by 0.8 – 1 °C.

► Evaluate the EVI system performance using R32 and provides useful data for the development of R32 systems.
► Make an analyze of the different effect on heating condition and cooling condition for EVI system.
► Research on the system change when using vapor injection on single-stage system and give out some explanation.