摘要
中深层地热资源丰富,具有清洁环保、稳定可靠等特点,利用中深层地热向地面建筑物供热越来越受到人们重视.文中在考虑岩土层分层的前提下,建立中深层套管式地埋管换热器传热模型,基于有限差分法将其离散求解,并将求解的结果与某实际项目的实测数据进行比对,在此基础上对中深层套管式地埋管换热器的传热特性做了进一步模拟研究.研究结果表明:特定工况下,在系统连续运行整个采暖季后对钻井周围岩土层温度场的影响半径为7.7 m;系统取热量随着套管式换热器外径的增大而增加;当工质循环流量由35 m^(3)/h增加到42 m^(3)/h,管道底部温度仅变化2.2%;延米换热功率不宜大于150 W;当回填材料导热系数由2 W/(m·K)增加到2.5 W/(m·K)时,管底温度上升比例仅为1.9%,即回填材料导热系数达到一定值时再增大导热系数对进出水温度影响不大.
There are abundant geothermal resources in the middle and deep layers,which are clean,environment-friendly,stable and reliable.In this paper,considering the stratification of rock and soil layer,the heat transfer model of the Medium-deep borehole exchanger is established.Based on the Finite Difference Method(FDM),the solution is discretized,and the results are compared with the measured data of an actual project.On this basis,the heat transfer characteristics of the middle deep buried tube heat exchanger are further simulated.The results show that:under specific conditions,the influence radius of the system on the temperature field of rock and soil around the drilling well is 7.7 m;the heat extraction of the system increases with the increase of the outer diameter of the casing heat exchanger;when the circulating flow rate of the working medium increases from 35 m^(3)/h to 42 m^(3)/h,the temperature at the bottom of the pipe only changes by 2.2%;the heat transfer power per meter should not be greater than 150W;when the thermal conductivity increases from 2 W/(m·K)to 2.5 W/(m·K),the temperature rise ratio of pipe bottom is only 1.9%,that is,when the thermal conductivity of backfill material reaches a certain value,then increasing the thermal conductivity has little effect on the inlet and outlet water temperature.
作者
黄帅
董建锴
姜建中
李骥
姜益强
Shuai Huang;Jiankai Dong;Jianzhong Jiang;Ji Li;Yiqiang Jiang(School of Architecture,Harbin Institute of Technology,key laboratory of Cold Region Urban and Rural Human Settlement Environment Science and Technology of Ministry of Industry and Information Technology,Harbin Heilongjiang 150090;Academy of National Defense Engineering,Academy of Military Sciences,Beijing 100850;China Academy of Building Research,Beijing 100101)
出处
《东北电力大学学报》
2021年第4期16-23,共8页
Journal of Northeast Electric Power University
基金
黑龙江省自然科学基金优秀青年项目(YQ2019E024)。
关键词
地源热泵
中深层地热
套管式地埋管换热器
数值模拟
取热特性
Ground source heat pump
Medium and deep geothermal energy
Deep borehole heat exchanger
Numerical simulation
Heat extraction performance
