Case study on determination of rock-soil thermal conductivity for ground-source heat pump systems

Taking three ground-source heat pump projects for example, compares average thermal conductivity of rock-soil body determined by look-up table method with that determined by thermal response test. The results show that the relative difference of thermal conductivities determined by two ways is less than 10%. Suggests that for small vertical buried pipe projects, average thermal conductivity of rock-soil body in the pipe depth range can be determined by look-up table method, while for large or medium sized projects, the boreholes for thermal response test should be drilled with the core drilling method, and then thermal conductivities measured by thermal response test are verified by look-up table method.