Review and improvement on heat transfer model of ground heat exchangers

Reviews the existing calculation theories, numerical heat models and their calculation methods for the design of ground heat exchanger (GHE), and finds that almost all the models are only based on the heat conduction theory without considering the influence of groundwater advection. Illustrates that the groundwater advection has a major influence on the heat transfer of GHE. Establishes the heat transfer model of GHE covering both heat conduction and groundwater advection. Through calculation for single well pipe GHE, finds that groundwater advection enhances the heat transfer.