竖直地埋管换热器多个钻孔地层热阻计算方法

Multi-boreholeground thermal resistance calculation method for vertical ground heat exchanger

摘要:

为解决国家规范中关于多个钻孔热干扰下的地层热阻计算问题,针对竖直地埋管换热器系统,提出了矩形阵列钻孔布置中不同参考钻孔下的地层热阻数值计算方法,并通过算例模拟分析研究了不同钻孔布置形式以及不同钻孔间距情况下的地层热阻分布.结果表明:规则矩形阵列钻孔布置的中心位置地层热阻最大,且布置形式越趋近正方形,钻孔间距越小,地层热阻越大；而不规则矩形阵列钻孔布置的最大地层热阻位置会根据未布置钻孔点位发生相对偏移,但偏移量可忽略.研究成果可为竖直地埋管换热器设计提供理论参考.

Abstract:

In order to solve the problem of multi-borehole ground thermal resistance calculation concerning thermal interference in the national standard, a numerical method for vertical ground heat exchanger is presented in this paper. And ground thermal resistance distributions of different borehole configurations and different separation space between two neighboring boreholes were studied through a case study. The results show that for regular rectangular-array borehole configuration, the ground thermal resistance in the central position is largest, also, the more the configuration reaches a square, the smaller the separation space is, the larger the total subsurface thermal resistance is; while for irregular rectangular-array borehole configuration, the position where largest subsurface thermal resistance is located will exist at a new negligible offset. The research output can provide theoretical reference for the design of vertical ground heat exchanger.