泡沫金属蓄能相变材料的传热数值模拟  

NUMERICAL SIMULATION ON HEAT TRANSFER PROCESS IN PHASE CHANGE ENERGY STORAGE MATERIAL EMBEDDED IN METAL FOAM

作　　者：龚玮[1] 杨震[1] 段远源[1] 

机构地区：[1]清华大学热能工程系,北京100084

出　　处：《太阳能学报》2014年第9期1682-1687,共6页Acta Energiae Solaris Sinica

基　　金：国家重点基础研究发展(973)计划(2011CB706904)

摘　　要：采用双温度模型对泡沫金属基复合相变材料的传热过程进行数值模拟。通过孔隙努赛尔数描述金属骨架与相变材料之间的传热,定义壁面努赛尔数描述整体传热性能。将方程无量纲化分析斯蒂芬数以及粘度对熔化传热过程的影响。结果表明,自然对流使上部熔体熔化更快;增大斯蒂芬数时,熔化界面推进速度加快,壁面努赛尔数减小;粘度主要影响格拉晓夫数,粘度减小,对流换热增强,熔化界面出现明显倾斜,进一步加强上部区域的熔化界面推进;在熔化后期,粘度越小,壁面努赛尔数越大。A two-temperature model is adopted to numerically study the heat transfer process in phase change material embedded in metal foam. In the model, the coupling heat transfer rate between the phase change material and the metal foam is characterized by an interstitial Nusselt number, and the overall heat transfer rate is characterized by a wall Nus- seh number. The study derives the dimensionless equations and analyzes the influence of the Stefan number Ste and the viscosity on melting process. Result shows as the influence of convection, the melting front moves more rapidly in the up- per region than in the bottom region. When the Stefan number increases, the melting front moves faster and the wall Nus- selt number decreases. The viscosity mainly affects the Grashof number. As the viscosity decreases, the convection be- come important and the melting front become more inclined. The melting front in the upper region moves faster. In the lat- er stage of melting process, the wall Nusselt number increases as the viscosity decreases.

关 键 词：相变材料 泡沫金属 双温度模型 熔化传热 斯蒂芬数 粘度 

分 类 号：TK124[动力工程及工程热物理—工程热物理]