摘要
通过与建筑负荷和热泵机组运行参数的耦合,建立了U型地埋管换热器内对流换热及与其周围土壤换热的三维数学模型。计算得到了夏热冬冷地区地源热泵运行20年的土壤温度场和沿地埋管的热流分布,分析了地源热泵长期运行对土壤热平衡的影响。研究结果表明,土壤平均温度逐年上升并趋于稳定;随着运行时间的增加,地埋管附近的土壤等温线由水平分布变为倒锥形(供冷季)或锥形(供热季)分布,并在第5年后接近竖直分布;沿进水管的热流密度在供热季逐年上升,在供冷季则逐年降低,且变化幅度逐年减小,最大值出现在4～7 m深处;在靠近地面处存在逆向传热段,在供热季逆向传热段最大深度达1.76 m。该研究对夏热冬冷地区地源热泵的应用与推广具有指导意义。
A three-dimensional mathematical model of convection heat transfer in U-tube ground heat exchanger and heat transfer between U-tube ground heat exchanger and its surrounding soil is estab- lished by coupling the calculations of building load and operating parameters of ground-source heat pump. The soil temperature distribution and heat flux distribution along ground heat exchanger in oper- ation for 20 years are obtained and heat balance of surrounding soil under long-term operation is ana- lyzed. It is found that average soil temperature rises and tends to be stable with its contour changing from the horizon to inverted cone in cooling season and cone in heating season, respectively, and turn- ing to upright after 5 years. The heat flux along the inlet pipe increases in heating season and decreases in cooling season which, however, reaches stable in a long-term operation. The heat flux along the in- let pipe reaches the maximum in the depth of 4-7 m. The reverse heat transfer exists between the outlet pipe and soil near the ground surface which is more obvious in heating season with a maximum depth of about 1.76 m. The results are of significance for GSHP application and generalization in hot summer and cold winter region.
出处
《可再生能源》
CAS
北大核心
2013年第10期74-79,85,共7页
Renewable Energy Resources
基金
中央高校基本科研业务费专项资金资助项目(2010QZZD0105)
关键词
地源热泵
夏热冬冷地区
热平衡
传热
数值模拟
ground-source heat pump
hot summer and cold winter region
heat balance
heattransfer
numerical simulation
