For utilizing heat exchangers buried in the ground to transfer heat with the soil and upgrade the tenor of the renewable geothermal energy in shallow layer, a ground source heat pump (GSHP) system is known as one of air conditioning techniques which have the greatest developmental future in the 21th century. It is a matter of common observation that the development of GSHP technique is restricted by a lot of factors, in which the heat transfer of a ground heat exchanger (GHE) is the key of research o...