Numerical simulation on influence of groundwater seepage on heat exchange performance of single-borehole ground heat exchangers

Establishes a numerical calculation model for the heat exchange performance of ground heat exchanger in two-dimensional groundwater seepage condition, and simulates the temperature field of soil around single-borehole ground heat exchangers.In order to validate the effectiveness of the numerical method,compares the simulation result with the analytical solution based on moving linear heat source theory in groundwater seepage condition. The result shows that the relative error is 0.72% and 5.42% When R is 0.5 and 2.5 respectively, so there is a good agreement with the analytical solution. The simulation results show that when Pe is less than 6, namely, the groundwater seepage velocity is less than 3×10^-7 m/s（9.46 m/a）, the influence of the convention heat transfer caused by groundwater seepage can be ignored.