CO2 급탕 열펌프의 성능 특성에 관한 실험적 연구

Abstract

The performance of a CO2 heat pump water heater was measured with a variation of operating conditions such as refrigerant charge amount, outdoor temperature, compressor frequency, EEV opening, and water mass flow rate. The optimum refrigerant charge amount of the CO2 system was 1800g. At water mass flow rates of 75, 85, and 95kg/h, the water heating temperatures were 74, 67, and 62℃ and COPs were 2.6, 2.8, and 3.0, respectively. Besides, the compressor frequency and water mass flow rate were adjusted to maintain the water heating temperature at 60℃ with the decrease of outdoor temperature. As the outdoor temperature decreased by 5℃, the compressor frequency increased beyond 60Hz and the water mass flow rate decreased by 16.7%.