Review and prospect of rock and soil thermal response tests

The design of ground heat exchanger directly determines the rationality and economic benefits of the ground-source heat pump system. The reasonable design of ground heat exchanger is based on accurate thermophysical properties of rock and soil. The commonly used method for obtaining thermophysical properties of rock and soil is to conduct in-situ thermal response test. Presents the development of thermal response test and the working principle of testing instrument. Reviews several important parameters involved in the thermal response test, including initial average temperature of rock and soil, heating power, circulating working medium velocity and thermal response duration. Summarizes heat transfer models of the thermal response test, including linear heat source model, column heat source model and numerical model. On this basis, puts forward some relevant research suggestions.