Numerically simulating the thermal behaviors in groundwater wells of groundwater heat pump

Abstract

In the geothermal energy utilization of a closed loop groundwater system of a GWHP (groundwater heat pump) and an ATES (aquifer thermal energy storage), thermal breakthrough is a very important aspect in the design of these systems. It can cause a gradual variation in the temperature of the pumping water and impact the efficiency of the GWHP. For pumping and injecting well groups, the influence of groundwater flow on the heat transfer is particularly important, especially for the aquifers with high porosity and hydraulic conductivity, the direction and velocity of groundwater directly affects the underground temperature field evolution. In this research, heat-water transfer numerical simulation and experiment has been conducted to study the evolution rule between aquifer temperature field and groundwater flow field. Simulation results were compared with the experimental results, and the validity of the simulation model was confirmed. Furthermore, the effects of groundwater flow on pumping average temperature and thermal breakthrough have been estimated by the numerical analysis, which will serve as a basis for the engineering design and further study of GWHP system.