含不同结构金属骨架石蜡相变传热数值模拟  

Numerical Simulation of Phase Change Heat Transfer of Paraffin with Different Structural Metal Frameworks

作　　者：常钊 陈宝明[1] 王惠临 罗丹 CHANG Zhao;CHEN Baoming;WANG Huilin;LUO Dan

机构地区：[1]山东建筑大学热能工程学院,山东济南250101

出　　处：《煤气与热力》2022年第1期22-29,共8页Gas & Heat

基　　金：国家自然科学基金项目(5197061221)。

摘　　要：分别将2种三维金属骨架(面中心法金属骨架,圆柱交叉金属骨架)加入纯相变材料(石蜡)制备复合相变材料1,2。采用数值模拟方法,模拟相变传热过程,分析加热过程纯相变材料,复合相变材料的温度变化,液相率变化,速度场分布。容纳石蜡的方腔长×宽×高为5 cm×2 cm×5 cm,方腔左壁面为加热面,温度为65℃,其他壁面绝热。纯相变材料,复合相变材料的初始温度均为25℃。相同加热时间,复合相变材料的平均温度明显高于纯相变材料。对于纯相变材料,热量向方腔右侧壁面传递缓慢,加入金属骨架可加速热量向方腔右侧壁面传递。相同加热时间,复合相变材料的液相率明显高于纯相变材料。在加热初期,复合相变材料1液相率更高,添加面中心法金属骨架更有利于加速相变蓄热。纯相变材料内部传热由导热和自然对流传热共同作用形成。复合相变材料内部的传热也是由导热与自然对流传热共同作用形成。相同加热时间,复合相变材料1的液相区域要大于复合相变材料2,且相变更加均匀。对于纯相变材料,熔化过程中,石蜡的流动主要集中在加热面附近及左上角,角化现象明显。对于复合相变材料,在接近完全熔化及完全熔化状态,固态石蜡基本熔化完成,方腔内液态石蜡温度基本趋于一致,自然对流强度减弱,复合相变材料1,2内石蜡的流动并不明显。与复合相变材料2相比,复合相变材料1的速度场分布更加均匀。面中心法金属骨架的综合性能更优,适合作为相变材料的强化传热金属骨架。Two kinds of three-dimensional metal frameworks(face center method metal framework and cylindrical cross metal framework)are added to the pure phase change material(paraffin)to prepare composite phase change materials 1 and 2.The numerical simulation method is used to simulate the phase change heat transfer process,and analyze the temperature change,liquid phase rate change,and velocity field distribution of pure phase change material and composite phase change material during the heating process.The length×width×height of the square cavity containing paraffin is 5 cm×2 cm×5 cm.The left wall of the square cavity is the heating surface,the temperature is 65℃,and the other walls are insulated.The initial temperatures of pure phase change material and composite phase change material are both 25℃.For the same heating time,the average temperature of the composite phase change material is significantly higher than that of the pure phase change material.For pure phase change material,the heat transfer to the right wall of the square cavity is slow,and the addition of a metal framework can accelerate the heat transfer to the right wall of the square cavity.For the same heating time,the liquid phase rate of the composite phase change material is significantly higher than that of the pure phase change material.In the initial heating stage,the liquid phase ratio of the composite phase change material 1 is higher,and the addition of the face center method metal framework is more conducive to accelerating the phase change heat storage.The internal heat transfer of the pure phase change material is formed by the combined action of heat conduction and natural convection heat transfer.The heat transfer inside the composite phase change material is also formed by the combined action of heat conduction and natural convection heat transfer.For the same heating time,the liquid phase area of the composite phase change material 1 is larger than that of the composite phase change material 2,and the phase change is more uniform.

关 键 词：三维金属骨架 复合相变材料 石蜡液相率 自然对流传热 

分 类 号：TK513.5[动力工程及工程热物理—热能工程]