摘要
为研究分层岩土各层各异的热物性对管群区域整体换热效率的影响,基于有限长线热源理论,考虑岩土分层现象和管群条件,建立并验证管群分层传热解析模型,同时引入区域热效率(Ei)这一无量纲数作为管群换热特性评价指标。与管群均质模型的区域热效率、进出口温差进行对比分析,结果表明:运行2000 h后,管群分层模型的Ei比均质模型低10.3%,且Ei的下降速度相差近6倍,而Ei的下降导致进出口温差最高减少13%。对管群整体进行逐层换热分析发现:在固定4 m间距下,热扩散系数最大的土层其每延米换热量减少37.4%,而热扩散系数最小层其换热量提高0.32%。对置于热物性区别明显的岩土层中的地埋管管群换热器而言,有针对性的逐层分析可更加准确的实现地源热泵系统高效换热。
To study and analyze the influence of thermophysical properties of each layer of rock on the overall heat exchange efficiency of tube bank area,a layered heat transfer analytical model of tube banks was built and verified,and regional thermal efficiency(Ei)was put in as the evaluation index of heat transfer property of tube banks based on the finite long-line heat source theory,consideration of soil layer and conditions of tube banks.Comparisons were made with a homogeneous model of tube banks in respect of regional heat efficiency and temperature difference between inlet and outlet,and the results show that after operation for 2000 hours,Ei of the layered model was lower than that of the homogeneous model by 10.3%,and the decrease speed difference of Ei between the two models is approximately 6 times.Ei decrease results the reduction in temperature difference between inlet and outlet by 13%at most.Heat transfer analysis layer by layer of tube banks suggesteis that,with a fixed distance of 4 m,the heat exchange amount each linear meter of the soil layer with the largest thermal diffusion coefficient is reduced by 37.4%,while that of the layer with the smallest thermal diffusion coefficient increased by 0.32%.This shows that if heat exchanger of underground tube banks is to be set in layered soil with great difference in physical property parameters(especially thermal diffusion coefficient),stratified analysis is needed so as to figure out the overall regional thermal efficiency of tube banks accurately.
作者
金光
李政
张凯
赵文秀
吴晅
郭少朋
Jin Guang;Li Zheng;Zhang Kai;Zhao Wenxiu;Wu Xuan;Guo Shaopeng(School of Energy&Environment,Inner Mongolia University of Science&Technology,Baotou 014010,China)
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2021年第6期487-492,共6页
Acta Energiae Solaris Sinica
基金
内蒙古自治区自然科学基金(2019MS05045)
内蒙古自治区科技创新引导奖励资金项目(2017CXYD-1)
内蒙古自治区科技成果转化项目(CGZH2018150)。
关键词
地源热泵
分层
换热器
区域热效率
热相互作用
ground source heat pump
laysered
heat exchanger
regional thermal efficiency
thermal interaction
