基岩地区地埋管换热器传热特性的测试研究

Test study of heat transfer performance of borehole heat exchangers in bedrock areas

在山东省威海市环翠区测试了4组基岩地层条件下不同类型地埋管换热器的换热特性,获得了单位井深换热量的变化规律及其影响因素.结果表明,基岩地层条件下地埋管换热器的传热性能明显优于常见的第四系钻孔换热器.地下水流动不明显时,双U形DN25地埋管换热器的单位井深换热量与单U形相比平均偏高约33%.当地下水流动强烈时,单位井深换热量会出现较大程度的增加,同时地埋管换热器周围地区的地下水开采状况也会影响地下水流动的强化换热效应.

In-situ tests were performed to obtain the thermal performance of four ground borehole exchangers（BHEs） in bedrock areas at Huancui District of Weihai,China.The heat transfer rates of BHEs per depth and their influence factors were analyzed.Test results show that the thermal performance of BHEs in bedrocks is better than that in the Quaternary strata.When groundwater flow is very weak,the heat transfer rate of double U-shaped DN25 BHEs is higher by 33% averagely,compared with single U-shaped BHEs.When groundwater flow is strong,the heat transfer rate of BHEs improves greatly.The status of exploitation of groundwater in the areas surrounding the BHEs can also affect the enhanced effect on the thermal performance of BHEs.