Experimental study on long-term operating characteristics of ground-coupled heat pump system with cross-seasonal soil cold storage
In order to solve the problem of operation efficiency decrease caused by soil heat imbalance under long-term operation conditions,a ground-coupled heat pump(GCHP)system with cross-seasonal soil cold storage was proposed,using the outdoor fan coil to store air cold into the soil in winter or transitional season in response to the characteristics of hot summer and cold winter zone.An experimental bench using a similar model method of the buried pipe heat ex-change system was built,and the GCHP system has been operated and tested for three years under the conditions of cooling,heating and cold storage.The parameters such as the inlet and outlet water temperature of the buried pipe,air temperature,soil temperature,heat exchange of soil and buried pipe,and heat exchange rate per unit buried depth were comprehensively analyzed to study the long-term operating characteristics of the system.The results show that the average soil tem-perature of three years increased by 0.14 ℃,0.22 ℃ and 0.20 ℃,respectively,which were generally small,the lower the outdoor air temperature and the greater the temperature difference between soil and outdoor air,the better the effect of cold storage;the average temperature differ-ence between the inlet and outlet of buried pipe,the average soil temperature change,the heat ex-change of the soil,the heat exchange of the buried pipe and the heat exchange rate per unit buried depth were consistent.The research results indicate that cross-seasonal cold storage maintains the long-term heat balance of the soil,and the long-term operation effect of the system is good.
ground-coupled heat pumpsoil cold storagelong-term experimentwater tem-peraturesoil temperature
万方数据
维普
