Unsteady Simulation of Heat Transfer around a Borehole Heat Exchanger with Groundwater Flow

Abstract

This paper performs a 2D unsteady simulation of heat transfer around a borehole heat exchanger (BHE) with groundwater flow using the computational fluid dynamics (CFD) method. In order to validate the effectiveness of the numerical approach, the dimensionless temperature profile surrounding the heat source wall is compared with the analytical solution. There is a good agreement with the relative error of less than 5%. Then, the upstream and downstream temperature profile around the BHE under different flow velocities are obtained and compared with the situation without groundwater advection. Further, the effects of groundwater flow on the heat injection of the BHE are discussed. The present work can be useful for the design of ground source heat pump (GSHP) systems especially in those regions with abundant groundwater resources.