Study on the influence of the identification model on the accuracy of the thermal response test

A 3-D numerical heat transfer model of a ground-source heat pump thermal response test is established in this paper and verified by testing. The numerical model is used to simulate the thermal response test. The soil thermo-physical parameters are estimated based on the cylindrical heat source and the linear heat source theory and contrasted with the values setting in the numerical heat transfer model. The effect of the identification model of the in-situ thermal response on the accuracy of the identification results is studied under different soil thermal properties. The results show that there is an optimal time to identify the soil thermo-physical parameters based on the two models. Identifying the physical parameters at the non-optimal time points will produce a large error. Under the same conditions, the optimal identification time of the cylindrical heat source model is earlier than that of the linear heat source model and is also related to the soil physical properties. Therefore, the test time should be selected to ensure the accuracy of the results. Furthermore, there is no evident influence of the initial soil temperature on the identification accuracy of the two models. This paper offers a reference for improving the thermal response test of ground source heat pumps.