岩土竖直温度梯度对地埋管换热器性能的影响  

Influence of Vertical Temperature Gradient of Rock and Soil on Performance of Buried Pipe Heat Exchanger

作　　者：路伟 LU Wei

机构地区：[1]山东建筑大学热能工程学院,山东济南250000

出　　处：《煤气与热力》2020年第10期23-27,42,J0042,J0043,共8页Gas & Heat

摘　　要：在考虑岩土竖直温度梯度(以下简称温度梯度)的前提下,模拟计算单U形地埋管换热器进出水温度、岩土温度、单位钻孔深度换热量的影响因素。钻孔深度一定时,温度梯度越大,地埋管换热器进出水温度整体越高。随着钻孔深度增大,表现更加明显。考虑岩土竖直方向上的温度梯度,对实际工程有利。温度梯度一定时,钻孔深度越大,地埋管换热器进出水温度整体越高。随着温度梯度增大,表现更加明显。增加钻孔深度对实际工程有利,但应结合项目经济性评估结果确定。在钻孔深度150 m、温度梯度0.03℃/m条件下,运行结束时(模拟运行时间为2880 h)钻孔底部的岩土温度最大为16.22℃,这比不考虑温度梯度时高4.37℃。当钻孔深度一定时,单位钻孔深度换热量随温度梯度的增大而增大。Considering the vertical temperature gradient of the rock and soil(hereinafter referred to as the temperature gradient),the influence factors of the inlet and outlet water temperature of the single U-shaped buried pipe heat exchanger,the rock and soil temperature and the heat exchange per unit drilling depth are simulated and calculated.When the drilling depth is constant,the greater the temperature gradient,the higher the overall temperature of the inlet and outlet water of the buried pipe heat exchanger.As the drilling depth increases,the performance becomes more obvious.Considering the temperature gradient in the vertical direction of the rock and soil is beneficial to the actual project.When the temperature gradient is constant,the greater the borehole depth,the higher the overall temperature of the inlet and outlet water of the buried pipe heat exchanger.As the temperature gradient increases,the performance becomes more obvious.Increasing the drilling depth is beneficial to the actual project,but it should be determined according to the economic evaluation results of the project.Under the conditions of a borehole depth of 150 m and a temperature gradient of 0.03℃/m,the maximum rock and soil temperature at the bottom of the borehole at the end of the operation(simulation running time is 2880 h)is 16.22℃,which is 4.37℃higher than when the temperature gradient is not considered.When the drilling depth is constant,the heat exchange per unit drilling depth increases with the increase of the temperature gradient.

关 键 词：U形地埋管换热器 岩土竖直温度梯度 单位钻孔深度换热量 

分 类 号：TU995.7[建筑科学—供热、供燃气、通风及空调工程]