하이브리드 지열히트펌프의 최적충전량에 관한 실험적 연구

The objective of this paper is to optimize the refrigerant charge amount for a Hybrid Ground Source Heat Pump(HGSHP) system comprising two refrigerant flow path for two condensing plate heat exchanger(PHEX) in the cooling mode. The HGSHP system was tested by varying refrigerant charge amount from 1800 g to 3000 g with the bypass flow path and no bypass flow path, while maintaining entering water temperature to the indoor heat exchanger and outdoor heat exchanger at 12℃ and 25℃ respectively. This charge test showed that the optimum charge amount was the same value regardless of flow path, but the influence of charge amount variation on the system COP in the case of bypass type flow path was higher than that of no bypass type flow path.