摘要
为了探讨相变对PCM回填地埋管换热器热响应特性的影响,建立了PCM回填地埋管换热器相变传热数学模型,并利用FLUENT软件对其进行了数值求解,分析了相变过程及PCM物性参数对地埋管换热器周围土壤温度扩散与恢复机理的影响,结果表明:采用PCM回填可有效缓解钻孔外土壤温度变化幅度,提高土壤温度恢复率,减小土壤热影响半径;PCM导热系数越高,温度上升/下降幅度越大,热影响范围也越大,恢复也变慢。从缓解土壤温度变化幅度的角度,夏冬季应分别采用相变温度低与高、且相变潜热大的PCM,但就提高土壤温度恢复率而言,夏冬季均应采用相变温度低、且相变潜热小的PCM。试验验证表明:所建模型可以用来模拟PCM回填地埋管换热器的换热过程,其预测最大相对误差在10%以内。
In order to investigate the influence of phase change on the thermal response characteristics of ground heat exchanger with PCM backfill,a mathematical model of PCM backfill ground heat exchanger with phase change heat transfer was established,and numerical simulation was carried out based on the model using the FLUENT software,and the effects of phase change process and physical parameters of PCM on the temperature diffusion and restoration mechanism of soil around the ground heat exchanger were analyzed.The research results indicate that use of PCM backfill can effectively mitigate the amplitude of temperature change of the soil outside the borehole,improve temperature restoration rate of soil and reduce thermal impact radius of soil;the higher the PCM thermal conductivity,the greater the soil temperature rise/fall,the bigger the heat impact range,and the slower the temperature recovery. In order to mitigate the variation amplitude of soil temperature,the PCM with low phase change temperature in summer and high phase change temperature in winter and high latent heat should be adopted,respectively,but the PCM with low phase change temperature and low latent heat should be used in summer and winter to improve the restoration rate of soil temperature. The experimental validation shows that the model developed in this paper can be used to simulate the heat transfer process of PCM backfill ground heat exchanger,and its predicted maximum relative error is less than 10%.
作者
杨卫波
徐瑞
杨晶晶
陈世坤
Yang Weibo;Xu Rui;Yang Jingjing;Chen Shikun(School of Electrical & Energy Power Engineering,Yangzhou University,Yangzhou 225127,China;Key Laboratory of Thermo-fluid Science and Engineering (Xi'an Jiaotong University),Ministry of Education,Xi'an 710049,China;Jiangsu Qicai Building environment Co.,Ltd.,Yangzhou 225009,China)
出处
《流体机械》
CSCD
北大核心
2019年第7期72-79,60,共9页
Fluid Machinery
基金
国家级星火计划项目(2015GA690240)
江苏省自然科学基金资助项目(BK20141278)
扬州市重点研发计划(社会发展)项目(YZ2018052)
扬州市-扬州大学合作基金项目(YZ2016248)
热流科学与工程教育部重点实验室(西安交通大学)开放基金资助项目(KLTFSE2016KF05)
深部岩土力学与地下工程国家重点实验室开放基金项目(SKLGDUEK1711)
广西建筑新能源与节能重点实验室(桂林理工大学)开放基金项目(桂林能15-J-22-3)
关键词
地源热泵
相变材料
地埋管换热器
热响应特性
数值模拟
试验验证
ground source heat pump
PCM
ground heat exchanger
thermal response characteristics
numerical simulation
experimental validation
