Experimental Research on Bleeding Performance of Single Well Ground-water Heat Pump

Groundwater bleeding is one of the most significant factors in the development of single well groundwater heat pump (SWGWHP), which can be used to improve thermal well performance for a better operation condition. Therefore, a series of tests for bleeding feature have been carried out by a sandbox experimental table, including designing bleeding rate from 0 to 30% in standing column well (SCW) and forced external circulation standing column well (FECSCW). The results of experimental research show that in the heating mode bleeding can improve the outlet water temperature (OWT) and heat absorption quantities (HAQ) of the thermal well, especially the effect on improving the OWT of SCW. However, the role of higher bleeding rate is limited. With the bleeding rate increasing from 5% to 32.1%, the HAQ of FECSCW increases only 7.4%. Moreover, groundwater bleeding reduces the heat influence scope (HIS) of the thermal well. (c) 2017 The Authors. Published by Elsevier Ltd.