地埋管回填材料与地源热泵地下温度场的测试分析

Experimental Investigation on Backfill Material and Soil Temperature Profile for Ground-coupled Heat Pump System

试验研究了两种不同回填材料地埋管换热器的热响应性能、地源热泵运行对地源温度场的作用。热响应测试发现回填材料黄沙＋膨润土的传热能力优于水泥浆＋膨润土，散热能力前者高于后者11％。对某地源热泵的运行测试发现，在地下10m地埋管井壁处土壤最高温度出现在9月初、最低温度出现在3月初，随离井距离的增加，井外测点温度出现最值的时间延后2～3个月。数据显示，一年后井外测点地下温度场有1．9～2．2K不等的温升，升高程度随离井距离的增加而增加。本文对优化地源热泵设计、探讨地源热泵的可持续运行具有参考价值。

Heat transfer performance of different backfill materials and temperature field variation of ground-coupled heat pump system are studied. Two different backfill materials are formed by mixing cement slurry,yellow sand with bentonite separately. By thermal response test, heat transfer performance of the former is better than the latter. For the beat sinking capability, the former is higher 11% than the latter. The highest and the lowest temperature for the borehole edge underground 10m occur at early Sep- tember and March respectively. With the increased distance from borehole, the wave crest and wave trough of soil temperature curve will delay about 2 - 3 months. Soil temperature outside borehole increases from 1.9 to 2.2K after one year. The longer the distance from the borehole is, the higher the temperature rise is. This paper has reference value for optimization design and sustainable operation of ground-coupled heat pump system.