The Research Of Cooling Tower Auxiliary Ground Source Heat Pump System

Soil source heat pump system has been widely applied due to its advantages of high efficiency and energy saving.But it still exists problems such as geographic limitations and economy during the use of this system.There is a summer heat than winter heat problem in ground source heat pump system in predominantly summer air conditioning area.There exists a problem that the heat taken from the soil in winter is greater than the heat in summer in cold region.The soil to exothermic imbalance will lead the soil temperature of this system significantly to deviate from the initial temperature after long-term running.And the efficiency of the system will drop after a long-term running.The underground thermal balance problem is an urgent problem for the soil source heat pump system.It is good to keep the heat balance to use cooling tower auxiliary ground source heat pump system.It has a important significance to research the operation strategy of the cooling tower to improve the system efficiency and keep thermal balance adjustment.Based on the cylindrical source model of underground soil,the heat transfer between buried pipe and soil was simulated in this paper.And the results were verified according to the experimental platform of simulation.Then a long-term operation could be simulated in this system.And we can study the operation of the ground source heat pump to the influence of the underground thermal balance and the thermal recovery ability of the soil.According to the simulation results,it can lead to the phenomenon of underground heat accumulation for long-term running soil source heat pump system.The temperature of the soil has a recovery trend in the transition period.In order to adjust the underground thermal balance,we can only run the cooling tower in the eraly and late of the cooling season.On the other hand,we can cascade the cooling tower and the buried tube heat exchanger directly in the transition season.Four kinds of operation strategy of the hybrid system were studied in this paper.The results show that running the hybrid system on the basis of the temperature difference between the export of buried pipe heat exchanger local fluid wet bulb temperature is the best operation strategy in Wuhan.