Thermal characteristics of groundwater heat pump with pumping and recharging in the same well

Pumping and injection of a groundwater heat pump with pumping and recharging in the same well (GWHPPRSW) occurs simultaneously at the same plane spot but at different depth of aquifer, which increases the probability of thermal breakthrough. Thus, it is highly important to analyze its thermal characteristics. A model was first established for groundwater heat transfer in a unitary homogenous confined aquifer by the operation of GWHPPRSW in winter with constant heat pump flow. Based on the model, a numerical simulation was done for a typical fine sand confined aquifer. It was found that the mean pumping temperature was reduced 3.6°C within a whole winter. The thermal effective radius (TER) of GWHPPRSW is far to 74 m because of convection and thermal dispersion. Therefore, GWHPPRSW is feasible to the region where the initial temperature of groundwater is higher than 13°C. Also, a larger TER makes a pumping and recharging well have a large capacity load.