Experimental and simulation studies of geothermal single well for building heating

The hydrothermal geothermal heating depends heavily on the existence of hot water reservoir and the shallow ground source heat pump occupies large area. Here a single well geothermal heating (SWGH) technology is shown, which does not depend on the existence of hot water reservoir. An experimental research on SWGH is carried out and a mathematical model describing the heat transfer through surrounding rock to well tube as well as inside the geothermal well is developed. The mathematical model validated by experimental data is then used to predict the performance of SWGH. It is found that the average extracted thermal output is respectively 448.49 and 413.63 kW in the first and tenth heating seasons. By changing the injection water temperature and velocity, SWGH system can meet the requirement of building heating load varying with the outdoor air temperature and adjust the imbalance of the extracted thermal output among different heating seasons. Understanding these will enable us to better apply SWGH technology. (C) 2019 Elsevier Ltd. All rights reserved.