地源热泵U型埋管换热器动态传热特性的数值分析  

Numerical Analysis on Unsteady Heat Transfer of U-tube Under-ground Heat Exchangers of Ground Source Heat Pump

作　　者：王泽生[1] 颜爱斌[1] 

机构地区：[1]天津城市建设学院能源与机械工程系,天津300384

出　　处：《河北工业大学学报》2009年第1期74-79,共6页Journal of Hebei University of Technology

基　　金：天津市高等学校科技发展基金项目(20060822)

摘　　要：针对垂直U型换热器埋管及其周围回填材料和土壤传热过程,建立了将U型管壁的边界换热取为第三类对流换热条件的二维非稳态传热模型,并对处于土壤恒温区某一深度的动态传热特性,尤其是热流规律进行了数值模拟研究.分析结果表明,各处瞬时热流随时间推移存在不规则情况阶段、正常情况阶段以及准稳态阶段.各处进入准稳态阶段的时间主要取决于回填材料和土壤的热扩散系数,而准稳态阶段热流变化规律仅与导热系数有关,这对土壤导热系数现场测试具有重要的理论指导意义.A two dimensional transient heat conduction model is established using the convective boundary conditions according to the heat transfer process in U-tube heat exchanger, soil layer and different backfill materials. Numerical simulation is set up to analysis characteristics of the transient heat conduction, especially the heat flux in initial isothermal soil layer at some certain depth. The result shows that the transient heat flux in different places will experience the irregular process, regular process and quasi-equilibrium state along with time. The time needed to quasi-equilibrium state depends on the heat diffusivity of the soil and backfill material. Heat flux will then only depend on the thermal conductivity after the quasi-equilibrium state is obtained. This will be very important to the in site testing for soil thermal conductivity.

关 键 词：地源热泵 U型管换热器 数值模拟 二维非稳态传热 

分 类 号：TK521[动力工程及工程热物理—热能工程]