天然冷源对地下水源热泵的影响规律

东北某些地区长期存在着一定规模的地下冻土，在地下水源热泵的运行中可视为天然冷源。天然冷源对地下水源热泵的利用产生一定的影响。为了提高地下水源热泵运行效率，运用室内外实验和数值模拟方法探寻冷源对地下水源热泵影响规律。对加格达奇地区的冷源场地进行了室内热物性试验和现场岩土热响应试验。研究表明：该地区砂、砾的热物性参数（比热容、导热系数）随深度增加呈现离散现象，砂岩、花岗岩热物性参数变化不大；岩土体导热系数花岗岩最大，砾、砂最小，砂岩居中；比热容受深度影响波动较大，特别是不同深度的砾、砂层比热容差别较大。依据该场地的地质条件，构建数值模型，开展模拟研究，对多井抽灌系统下热突破现象以及影响范围进行模拟分析，模拟结果显示冷源对该场地地下水源热泵的影响范围在150 m以内，而且在小于75 m的范围内对地下水源热泵的影响最为显著，为未来该地区地下水源热泵的设计、选址提供理论基础和参考依据。

Influence of Nature Cold Source on Groundwater Heat Source Pump

A certain scale underground permafrost is chronically existing in northeast certain regions, it can form a nature cold source and has a great influence on the application of groundwater source heat pump. In order to improve operational efficiency of groundwater source heat pump, the authors use laboratory and field tests and numerical simulatiion method to study influence rule of cold source on groundwater heat source pump. Thermal physical experiments and field thermal response tests of the cold source site for Jiagedaqi region are carried on. It has been shown that thermal physical parameters of sand and gravel such as specific heat capacity and thermal conductivity present discrete phenomenon with the depth in the region; thermal physical parameters of sandstone and granite have a little change; thermal conductivity of granite is the largest and sand and gravel is the smallest and sandstone is in the middle in these samples; specific heat capacity is obvious fluctuated with the depth, specially for sand and gravel layers. Based on geological conditions, a numerical model is constructed and numerical simulation of heat breakthrough and influence radius of pumping and injecting system of multiple well are studied. The results show that influence range of cold source is within 150 m and cold source has the greatest effect on water source heat pump within the range of not more than 75 m. The results will provide theoretical basis and reference for groundwater source heat pump designing and site selection.