Experimental analysis of the influence of operating conditions on the performance (COP and ejector efficiency) of R744 heat pump with one-phase ejector

摘要

Ejector is increasingly utilized for expansion recovery of low grade heatrnto produce additional cooling effect. The R744 heat pump with one-phase ejectorrnapplies pump which requires quite insignificant work input, instead of compressor.rnExperimental investigations of the optimum operating conditions were performed.rnDifferent operating conditions, including the inlet temperature and pressure of thernejector (high-side temperature and pressure) were examined respectively. Based onrnthe experimental results over a wide range of temperatures and pressures, therninfluences of high-side temperature and pressure on the mass entrainment ratio,rnoverall COP, actual COP and ejector efficiency were obtained. The bestrnperformance was attained with the temperature of around 75 ℃ and pressure ofrnaround 85 bar under certain ejector geometry and fixed evaporator of 51 bar andrncondensing pressure of 58 bar.