In order to study the heat transfer performance of coaxial and U-type buried pipe heat exchangers in middle-deep layers,a numerical model is established using Fluent based on the actual conditions of a sports training base venue.The effects of intermittent operation mode,rock-soil thermal conductivity and geothermal gradient on the heat trans-fer capacity of these two types of buried pipe heat exchangers are simulated for a 10-year operating period.The results show that the heat transfer capacities of both types of heat exchangers decline significantly in the first five years,with a decrease of about 6.6％,and then gradually stabilize.When the rock-soil physical parameters are consistent,the heat transfer capacities of the two heat exchangers show little difference in ten years.Under four kinds of intermittent operating conditions,the heat transfer performance of U-type buried pipe heat exchanger behaves slightly better than the coaxial buried pipe heat ex-changer.Under conditions of high rock-soil thermal conductivity and high geothermal gra-dient,the heat transfer performance of U-type buried pipe heat exchanger is greater than that of coaxial buried pipe heat exchanger after ten years of operation.
关键词
地源热泵/地埋管换热器/同轴式/U形/换热量
Key words
ground source heat pump/buried pipe heat exchanger/coaxial/U-type/heat transfer capacity
万方数据