Enhancement technology of underground water flow field in coal mine to improve energy efficiency of heat pump system in geothermal energy development

Abstract

In order to solve the problem that the cold/heat released from the underground pipe of coal mine into the soil layer is difficult to dissipate in a short time, the technology of enhancing the underground flow field of coal mine in geothermal energy development to improve the energy efficiency of the heat pump system is proposed. In this paper, based on the ground source heat pump project located in a coal mine, the energy efficiency enhancement technology of the artificial flow field ground source heat pump system is studied and tested. The test results show that when starting work at about 8:00, due to the increase of heating load, the accumulation of cooling capacity around the buried pipe increases gradually, and the return water temperature at the ground source side decreases gradually. At 14:05, the water was pumped for the operation of the artificial groundwater flow field. It can be seen that the temperature of the return water at the ground source side began to rise gradually, indicating that the accumulation of cold water around the buried pipe was relieved to a certain extent. In conclusion, the artificial groundwater flow field can alleviate the accumulation of cold water around the buried pipe heat exchanger to a certain extent, improve the return water temperature of the buried pipe heat exchanger, and improve the energy efficiency of the ground source heat pump system.