The Study On The Thermal Response Test And Its Application

Ground-coupled heat pump systems have been developed widely nowadays, due to their characteristics in saving energy and no pollution to the environment. They are widely developed not only in the residential buildings, but also in the commercial and institutional buildings. Comparing to the other systems, ground-coupled heat pump systems are added an underground system which include boreholes and buried pipes. Then the initial costs of ground-coupled heat pump systems will be increased largely. In this paper, we start from raising the veracity of ground thermal conductivity, to find a new way to reduce the initial costs and the ground areas usage.Ground thermal conductivities are not only the thermal performance of the ground. They are named the"effective thermal conductivities"which contain that of buried pipes, grouting materials, ground soils and the movement of underground water. In this paper, existing models of ground heat exchanger are analyzed, especially emphasizing the data analysis. Through comparison, line-source method is considered the best one among the four methods when testing in-situ. Talking above the test equipment, the principle is introduced. Electric heater testing equipments are considered more suitable for in-situ measurement. Automatic control system is also important in the testing equipments. Quality of power input is the difficulty one in control system. It's the parameter which influences the testing result most. Through the in-situ test and data analysis, some important parameters are obtained. Values are recommended about these parameters. According to the influence on test result analysis, some factors such as tube material, tube diameter, tube type, grouting materials, and borehole depth are all compared. At last, error analyses of the thermal response test are made. Then the future of research is suggested.