이산화탄소 급탕 열펌프의 운전조건에 따른 성능 특성에 관한 실험적 연구

Abstract

In this study, the steady state performance of a CO_2 heat pump water heater was measured with a variation of operating conditions such as refrigerant charge amount, compressor frequency, EEV opening, and water mass flow rate. Transient state performance tests were also conducted to investigate major system effects associated with the interaction between the CO_2 heat pump water heater and the water tank. Optimum refrigerant charge amount for the system was 1600 g. At compressor frequencies of 50 Hz and 60 Hz, water mass flow rates of 95 kg/h and 105 kg/h, and EEV opening of 8% and 16%, the water heating temperatures were 65℃ and 68℃ and COPs were 3.0 and 2.8, respectively. In the transient condition, the instantaneous COP decreased with an increase in the inlet water temperature.