球形容器内石蜡非约束融化特性实验  

Experiment on the unconstrained melting of paraffin in spherical containers

作　　者：高泽世[1] 姚元鹏[1] 吴慧英[1] GAO Zeshi;YAO Yuanpeng;WU Huiying(School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)

机构地区：[1]上海交通大学机械与动力工程学院

出　　处：《化工学报》2019年第7期2480-2487,共8页CIESC Journal

基　　金：国家自然科学基金项目(51820105009,51536005);中国博士后科学基金项目(2018M642012)

摘　　要：通过可视化实验研究了球内受空隙影响的石蜡(RT27)非约束融化过程,探讨了球直径、加热温度、初始温度以及相变材料(PCM)填充率对球内非约束融化特性的影响。通过对PCM固液界面演化、固相运动等融化行为的观察发现,受球内空隙影响,非约束融化过程会出现固相PCM先漂浮后下沉的融化模式。进一步的量化结果表明:增大球直径,固相PCM漂浮时间先增大后减小,总融化时间则持续增大;提升加热温度和初始温度,固相PCM漂浮时间和总融化时间减小;增大PCM填充率,固相漂浮时间和总融化时间先增大后减小。最后,通过对实验数据的无量纲化分析,提出了无量纲总融化时间(受Rayleigh数、Stefan数、PCM填充率、无量纲初始温度影响)关系式。A visualization experiment is conducted to investigate the unconstrained melting process of phase change material (PCM, paraffin RT27) with void in a spherical container. Factors including the spherical container diameter, the heating temperature, the initial temperature and the filling ratio of PCM are discussed. Melting behaviors including the solid-liquid interface evolution and the solid PCM motion are revealed, in which a melting mode of floating melting following by close-contact melting is observed due to the existence of void in the spherical container. The quantitative results show that as the spherical container diameter increases, the floating melting time increase first and then decreases, while the total melting time shows a continually increasing trend. Increasing heating temperature or increasing initial temperature will decrease the floating melting time and total melting time. With the increases of PCM filling ratio, the PCM floating melting time and the total melting time increase first and then decrease. Finally, a dimensionless total melting time correlation in terms of Rayleigh number, Stefan number, filling ratio of PCM and dimensionless initial temperature is proposed.

关 键 词：相变 多相流 传热 热能存储 非约束融化 空隙 球形容器 

分 类 号：TK124[动力工程及工程热物理—工程热物理]