不同形式和管径的地埋管换热器换热性能分析

ANALYSIS ON THERMAL PERFORMANCE OF DIFFERENT TYPE AND DIAMETER GROUND HEAT EXCHANGER

结合岩土热响应试验,对岩土初始平均温度和综合导热系数的不同获取方法进行对比分析,结果表明无功循环平均温度及现场热响应试验得出导热系数值作为系统设计参数更为接近实际工况。分析对比不同埋管形式、不同管径的地埋管换热器换热性能,换热器采用单U形式时,DN40管较DN32管的换热性能提高约30%;不同换热器形式,DN32双U管换热性能较单U管提高约80%;DN32双U换热器的换热能力较单U40提高近40%。DN32双U换热器的换热能力远远优于其单U换热器和DN40单U换热器,可作为实际工程中优先选用的埋管形式。

Combining with the rock soil thermal response test, the different method to obtain geotechnical initial average temperature and complex thermal conductivity was compared and analyzed, the results showed that the initial average temperature by reactive power cycle and the thermal conductivity by thermal response test are the design parameter of the ground-source heat pump system, and is more closer to the actual working condition than other methods. The ground heat exchanger thermal performance of different buried types and pipe diameters was compare and analyzed, the results showed that the heat exchanger of 40 mm diameter increase by about 30% than that of the heat exchanger of 32 mm diameter with the same single U-type ground heat exchanger; for the different heat exchanger forms, the heat exchanger of the double U-type ground heat exchanger increase by about 80% than that of the single U-type ground heat exchanger with the same 32 mm diameter; for the different heat exchanger forms and pipe diameters, the thermal performance of double U-type 32 mm diameter increases by nearly 40% than that of the single U-type 40 mm diameter. The results showed that the thermal performance of the double U-type 32 mm diameter heat exchanger is far superior to the single Utype 32 mm diameter and 40 mm diameter heat exchanger, it can be used as preferably heat exchanger type in practical engineering pipe.