넷-제로에너지주택의 공기열원 히트펌프시스템 동적거동 및 에너지성능 분석

Abstract

Air-source heat pumps (ASHPs) have somewhat lower operating performance than ground- source heat pumps (GSHPs), but they have been reported to have low initial investment costs and a great energy-cost-saving effect due to the implementation of net-zero-energy houses. In this study, we analyzed the dynamic behavior and energy performance of equivalent ASHPs in existing low-energy houses installed with GSHPs of 9 kW using TRNSYS dynamic simulation. The house with a total floor area of 194 m2 was an all-electric house and domestic hot water, space heating, and cooling energy were supplied by the ASHP. To summarize the main results, first, the annual space heating and cooling energy supply of the ASHPs was 7,698 kWh and 2,226 kWh, respectively, and the annual heating COP and cooling EER were 3.4 and 3.1, respectively. Second, the total annual power consumption of the proposed model with ASHPs was 8,218 kWh and the annual power generation of the 6 kWp PV system was 8,682 kWh, which generated a surplus of 464 kWh, achieving net-zero energy. Third, the total annual electricity charge was 249,000 generated by ASHPs (proposal model) connected to the “residential service” grid of KEPCO, which was reduced by approximately 66% compared to the 736,000 generated by the GSHPs (existing model) linked to a “general service” grid.