Experimental investigation of thermal performance of ground source heat pump system for summer and monsoon seasons of Himalayan region of India: A case study

In the present experimental research work examines the thermal interactions of borehole heat exchangers on the ground side and psychrometric process involved inside the room during cooling mode operation using a ground source heat pump system (GSHP). An experimental facility of 17.5 kW cooling capacity GSHP system, consisting of five parallelly connected double U-tube borehole heat exchangers fitter with a commercially available heat pump system has been employed. The experiments were performed during peak summer and monsoon (rainy) seasons for space cooling applications for 45 hours of continuous operation in a city located in the Himalayan range of India. Analysis of results obtained indicate that during the summer season the hourly heat rejected to the ground is maximum for peak weather conditions due to high cooling load demand on the user side. On increasing the building load (increase in ambient temperature), there is a slight decrease in COPsys in both the seasons. During heavy rain season, the latent cooling load increases up to 1.5 times of the sensible cooling load. The average value of sensible heat factor is found to be 0.6 for the case of the peak summer season and 0.51 for the rainy season.