Design and heat transfer characteristics of buried heat exchange tube group with vertical inlet and flat outlet

Abstract

In order to improve the heat transfer efficiency of ground source heat pump, a vertical inlet and flat outlet type buried tube group enhanced heat transfer system is designed by integrating the advantages of horizontal and vertical buried tube heat exchanger structures, and a shallow geothermal utilization system model is established in a laboratory in Chengdu as an example to study its heat transfer performance under load conditions, and three water circulation heat balance buried tube enhanced heat transfer structures are designed to study its enhanced heat transfer performance.The results show that: compared with the traditional buried tube structure, the heat transfer performance of the vertical inlet and flat outlet buried tube group can be improved by more than 65%; for the heat pump system, the heat transfer of rocky soil stratum is the largest, followed by sandy soil and the smallest clay; compared with the heat exchanger without reinforced structure, the cooling performance of the three water circulation heat balance buried tube heat exchangers are improved by 28.3%, 25.3%, 10.7%, and the heating performance are improved by 27.3% , 21.8%, 10.9%, and better stability.