螺旋型埋管能源桩传热模型的适用性及其试验验证

传热模型的精确性直接关系到能源桩换热效率的计算精度,进而影响能源桩设计。以螺旋型埋管能源桩为研究对象,在信阳地区开展了一项现场原位试验,实测获得了螺旋型埋管能源桩换热过程中的桩周温度场数据,并分别与圆柱面热源模型和线圈热源模型的计算成果进行了对比分析。研究成果显示有限长热源模型较无限长热源模型具有更高的计算精度,有限长线圈热源模型较有限长圆柱面热源模型具有更高的计算精度,采用有限长线圈热源模型计算的桩壁温度误差<1.5%,桩周温度场计算误差<2.5%,地埋管进出口水温计算误差<2.2%,故将其推荐为螺旋型埋管能源桩桩周温度场的计算模型。最后,探索了不同传热模型针对螺旋型埋管能源桩的适用性,为指导螺旋型埋管能源桩设计提供了科学依据。

Applicability of Heat Transfer Model of Energy Pile with Buried Spiral Pipe and Its Experimental Verification

Accuracy of heat transfer model is directly related to the computational accuracy of heat transfer efficiency of energy pile,which influences the design of energy piles.Taken energy pile with buried spiral pipe as the research object,an in-situ test was conducted in Xinyang area,Henan province.Then,measured data such as temperature field around the pile was acquired,and calculation results of the cylindrical heat source model and the coil heat source model are respectively compared with measured data.Research results show that the computational accuracy of heat source model with finite length is higher than that of heat source model with infinite length.Coil heat source model with finite length is more accurate than cylindrical surface heat source model with finite length.The calculation error of tube wall temperature in coil heat source model with finite length is less than 1.5％,the calculation error of temperature field around the pile is less than 2.5％,and the water temperature at inlet and outlet of buried pipe less than 2.2％,respectively.In view of this,coil heat source model with finite length is recommended for calculating temperature field in energy pile with spiral buried tube.The applicability of different heat transfer models for the spiral pipe pile was explored,and can be taken as reference for the design of energy pile with buried spiral tube.