Analysis on the Soil Heat Accumulation Problem of Ground Source Heat Pump System in High Temperature and High Humidity Areas

The imbalance of cold and heat load is the common problem in Ground Source Heat Pump (GSHP) system. If the problem cannot be solved properly, the temperature of underground soil will gradually rise or decrease inevitably, affecting the GSHP system working in normal condition. Therefore, this paper collects and analyzes the operation data of the GSHP system in high-rise residential district of Jiangsu area in recent three years. The results show: in residential building of high temperature and humidity area, cold load in summer is larger than heat load in winter, which leads to obvious thermal accumulation with a 33% imbalance rate of cold and heat between summer and winter. The soil temperature has an obviously rise about 1.5 °C ∼ 2 °C in past three years time. The outlet water temperature on underground side can be up to above 35 °C, causing the operation of the heat pump unit deviation from designing conditions, low efficiency and the lower cooling load compared with rated value.