Temperature change of underground in the long running of vertical ground-coupled heat pump

The underground heat transfer of vertical ground coupled heat pump is complex, so the model is difficult to take into account all factors. Thus examples of survey on the project and lesson learned are also an important part for research. In the design of vertical ground heat exchanger , it should consider the temperature change of rock and soil caused by heat imbalance after a long run, and the change has a major impact for operating life of heat pump. In the paper, it is to predict the future of temperature varying, based on the comparison of the simulation and measured data.