U型管埋地换热器三维传热模型及实验对比分析

THREE-DIMENSIONAL HEAT TRANSFER MODEL AND EXPERIMENTAL ANALYSIS OF U-PIPE HEAT EXCHANGER

针对U型管埋地换热器的传热特点,考虑了两管脚之间的相互影响,建立起非稳态传热模型。采用数值解法对该理论模型进行了求解,并将结果与实验值进行了对比分析,发现两者变化趋势一致,但理论计算结果比实验测试值低,其中的一个重要原因是因为换热器与土壤间的热交换不是纯导热过程,还应该进一步考虑土壤中热湿迁移等因素的影响。

An unsteady heat transfer model was set up and solved by numerical solution for the heat transfer characteristic of U-pipe heat exchanger and the interaction of the two pipe legs of the GSHPs. The theoretic results were compared with the experimental results. Those change trends are similar, but the theoretic results are less than the experimental results. One of the important reasons is that the heat exchange between the heat exchangers and the soil is not pure heat conduction and some factors such as mass transfer in soil should be considered.