Hot Gas를 이용한 히트펌프 성능개선에 관한 실험적 연구 = An Experimental Study on the Improvement of a Heat Pump Performance using Hot Gas Bypass Method

다국어 초록 (Multilingual Abstract)

Frost formation easily occurs on the fin coils of outdoor heat exchanger under high humidity air below 5 ℃,it results in the decrease of geating capacity of heat pump. Several methods have been studied by far in order to solve this problem, one of the methods is hot gas bypass method. Two cases of experiments were performed, Case 1 is that outdoor fan speed is controlled under the poeration of hot gas bypass, Case 2 is that additional line is constructed so that refrigerant passes through thermal expansion valve and the hot gas bypass line independently. Outdoor fan speed is also controlled. In case 1, the optimal fan speed was 60% of rated fan speed, it showed about 1% decrease of average COPand 21% increase of heating capacity compared to time-controlled reverse cycle defrost. In case 2, the optimal fan speed is also 60% of rated fan speed, and it showed about 2% increase of average COP and 78% increase of heating capacity compared to time-controlled reverse cycle defrost. The reasons are that in Case 2, the defrost on the upper side of fin coilsoccurs rapidly in comparison with Case 1 under the operation of hot gas, it results in the increase of heating capacity and heating time.