| Title |
The Performance of a Simultaneous Heat and Cooling Heat Pump at Various Charging Conditions |
| Authors |
송인식(In Sik Song) ; 최종민(Jong Min Choi) ; 주영주(Young Ju Joo) ; 정현준(Hyun Joon Chung) ; 강훈(Hoon Kang) ; 김용찬(Yongchan Kim) |
| Keywords |
충전량 ; 열펌프 ; 성능계수 ; 난방모드 ; 냉방모드 ; 동시냉난방모드 Charge ; Heat pump ; COP ; Heating mode ; Cooling mode ; Heat recovery mode ; |
| Abstract |
The cooling load in winter is significant in many commercial buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. The development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the performance of a multi-heat pump with 3-piping system was investigated as a function of refrigerant charge and its performance was analyzed in cooling mode, heating mode, and heat recovery mode. COP in the heating or cooling mode showed little dependence on refrigerant charge at overcharge conditions, while those were strongly dependent on refrigerant charge at undercharge conditions and outdoor inlet temperature. In the heat recovery mode, the performance of the system was very sensitive to charge amount at all conditions. Optimum charge amount in the heat recovery mode was 14% lower than that in the cooling mode at the standard condition because the refrigerant only passed the indoor units. It is required to store the excessive refrigerant charge in a storage tank to optimize the system performance at operating modes. |