Research Of Heat Transfer And Recovery Of Tube Banks In Pile Foundational Ground-Coupled Heat Pump

Pile foundational ground-coupled heat pump system, as a new type of ground-coupled heat pump system, remits the traditional ground-coupled heat pump system's high original investment problem that caused by the process of boring holes. The research for this system will conduce to the application of pile foundational ground-coupled heat pump system in practical engineering.This thesis makes an academic research for the heat transfer mechanism of the vertical U type underground heat exchanger, establishes a mathematic and physical model of the vertical U type underground heat exchanger; makes a numerical simulation for three types of underground heat exchanger with the finite element analysis software ANSYS, and then makes a conclusion that the heat transfer performance among three types of underground heat exchanger in the same ground original temperature: normal underground heat exchanger, underground heat exchanger with backfilling, pile foundational underground heat exchanger.The long time operation of ground-coupled heat pump system will affect the ground temperature which directly relates to the application of this system in practical engineering. Therefore, this thesis makes a numerical simulation for the heat transfer of the tube banks in pile foundational ground-coupled heat pump system. In the condition of different original ground temperature, different heat exchange quantity, different distance between tubes, simulates the effect of tube banks in pile foundational ground-coupled heat pump for one year's operation. So makes a recommendation of the important parameters such as: the optical distance between tubes, heat exchange quantity, and so on. It also directly educes the ground temperature hoist, so confirms the recovery time of the tube banks in pile foundational ground-coupled heat pump.In the finality, the problems requiring further studies are discussed.