Airsource and groundsource heat pump application to northern regions of China

The annual soil thermal imbalance is a key problem to limit the application of ground coupled heat pump (GCHP) in northern regions. Hybrid GCHP integrating with air source heat compensator (AHC) can fully use the advantages of air and soil to solve the problem essentially and satisfy the demand of space heating, space cooling and domestic hot water (DHW). AHC absorbs heat from high temperature air and operates in four different modes: direct heat compensation, heat compensation coupled with heat pump, space heating coupled with heat pump and DHW coupled with heat pump, to eliminate soil thermal imbalance effectively through increasing soil heat compensation and reducing soil heat extraction. Builds a system model in TRNSYS platform and analyses the longterm system performance and the applicability in different regions (Harbin, Changchun and Shenyang). The results show that this system can maintain the soil thermal balance very well in different regions, heating COP is about 3.26~3.83 with 24%~34% of energy saving compared with coal boiler plus split air conditioner system, and the system has low initial cost in which AHC only accounts for 2%~3%, far cheaper than GCHP system assisted by gasfired boiler and by solar collector. Therefore, the system is economic, reliable, clean and efficient and has the reasonable application potential in northern regions.