Investigation of Heat Extraction and Injection Performance Associated With Utilizing A Novel Dbhe In A Deep Geothermal Well

In this study, a check valve is adopted in a deep borehole heat exchanger (DBHE) system in which the whole section of the well is used for heat extraction in winter during building heating and the upper part of the well is used for heat injection in summer during building cooling. The heat extraction and heat injection performance of deep borehole heat exchanger in deep geothermal wells has been numerically simulated with particular reference to residential heating associated with utilization of a heat pump. The influence of injected water flowrates, water inlet temperatures, depths of the check valve and formation’s thermal conductivities on the performance of the proposed novel DBHE system has been investigated. It is found that heat injection through the upper part of the well in summer can improve the heat extraction rates to a certain extent during the heating season. In summer, the inlet temperature of water has a great influence on the heat injection rates. The increase in the depth of the check valve improves the heat injection rates of the proposed novel DBHE system.