An experimental study of the influence factors of soil freezing surrounding a buried pipe of ground source heat pump in a cold region

In order to examine the influence factors of frozen soil around a buried pipe, a test device of ground source heat pump is established to study the system performance under the condition of thermal imbalance in winter. The impacts of freezing soil around the buried pipe by the inlet fluid temperature, soil moisture content and initial soil temperature are examined experimentally. The results show that the temperature change in the inlet fluid can improve the temperature field and heat exchanger around the buried pipe. With the increasing initial soil temperature, the soil physical parameters reduce and the heat transfer capacity increases. The increase in the soil moisture content can strengthen the heat transfer between the surrounding soil and the buried pipe, which improves the outlet fluid temperature of the buried tube and heat value.