Experimental investigation on a combined solar and ground source heat pump system for a single-family house: Energy flow analysis and performance assessment

Abstract

This paper presents experimental investigations on a combined solar and ground source heat pump (SGHP) system for a single-family house. The SGHP system was installed at the Lyngby campus of Technical University of Denmark with horizontal ground heat exchanger (HGHE). Detailed experiments were carried out on the system in 2019 under real weather conditions and the heating demand for domestic hot water (DHW) and space heating (SH). The focuses of the investigation are energy flow analysis and performance assessment on the SGHP system. The results showed that the yearly system seasonal performance factor of the SGHP system (SPFSHP) was 2.8, and the maximum monthly SPFSHP was up to 5.7 in April with the highest solar radiation. Directly utilized solar energy for the combi-storage was 500 kWh lower than the annual solar heat for charging the ground, and it accounted for 36.6% of annual heat input of the combi-storage, the rest of the heat was supplied by the heat pump system that consumed 84% of total electricity energy. Different from the large fluctuations of monthly solar fraction due to solar radiation, the monthly renewable heat fraction was within the range from 57% to 83%, and the yearly value was 65%.