Heat exchange performance of ground source heat pump that use direct expansion method

The cooling performance of ground source heat pump (GSHP) that use direct expansion method were obtained by an experiment. An underground heat exchanger with a three-branch copper tube was used in the GSHP. The GSHP also adopted a pouring water system into the borehole during high-load continuous operation. The output power of the heat pump is 6.8 kW in cooling operation. The depth of a borehole and the length of the three-branch copper tube was 30 m. The casing pipe were inserted into the borehole. Then, the U-shaped underground heat exchanger was inserted into the casing pipe filled with water. The average value of the obtained output power, power consumption, and System Coefficient of Performance during the cooling operation period was 10.0 kW, 1.3 kW, and 7.45, respectively.