The Numerical Simulation and Experiment Study on the Coupled Thermal Conduction and Groundwater Advection Heat Transfer Process under the Intermittent Operation of the Ground-Coupled Heat Pump System

The three-dimension coupled thermal conduction and groundwater advection unsteady state heat transfer model in this paper is developed according to the heat-transfer process between the vertical U tube underground and its ambient soil. The feasibility of this model is verified by intermittent experiment of ground source heat pump in winter. In the model, boundary layer is replaced by velocity equation in inlet boundary condition based on the saturated soil and groundwater in order to be more close to the actual. The the soil recovery temperature influenced by the thermal conductivity and environmental element (the temperature of the air, solar radiation energy, velocity of wind) in the intermittent operation is studied in this paper. The result has guiding significance to the intermittent operation of the ground source heat pump.