Experimental Study on Ground Source Heat Pump in Karst Area under Heating Condition

The operation experiment of ground source heat pump system in winter heating condi- tion was carried out by means of thermal and wet migration experiment platform, which was de- veloped by authors. Besides, the changes of heat exchange performance and temperature field a- round the soil were discussed and analyzed. The results of test indicate that the heat transfer per-formance of the vertical pipe is obviously better than that of the horizontal pipe, which is more favorable to the development and utilization of geothermal energy. The surface temperature with- in 3. 0m is still influenced by the atmosphere, where the soil temperature is changed by the ground heat exchanger and the heat exchange between the soil, the surrounding climate and envi- ronmental changes under the impact of the interaction. The decrease of soil temperature near the horizontal buried pipe is related to the distance and direction of the buried pipe, and the tempera- ture decreases with the increase of the distance, and the heat conduction in the soil has the char- acteristics of anisotropy.