Experimental study of the characteristics of solidification of stearic acid in an annulus and its thermal conductivity enhancement
Experimental study of the characteristics of solidification of stearic acid in an annulus and its thermal conductivity enhancement
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DOI：
10.1016/j.enconman.2004.05.011
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发表时间：
2005-04
影响因子：
10.4
通讯作者：
Zhongliang Liu;Xuan Sun;Chong-fang Ma
中科院分区：
文献类型：
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作者：
Zhongliang Liu;Xuan Sun;Chong-fang Ma
在垂直环形储能系统中，实验研究了硬脂酸在凝固过程中的传热和换热特性。得到了冻结过程中不同径向位置的温度分布和温度随时间的变化情况。研究了硬脂酸的热特性，包括固液界面沿径向的运动，以及雷诺数对传热参数的影响。用一个简单的近似模型估算了热流密度。为了提高硬脂酸的导热性能，设计了一种新型的铜翅片，并将其固定在电热棒上。结果表明，新型翅片能同时强化相变材料的导热和自然对流换热，其凝固强化系数可达250%。实验还考察了翅片宽度对强化效果的影响，发现翅片越细，强化效果越好。
The thermal and heat transfer characteristics of stearic acid during the solidification processes were investigated experimentally in a vertical annulus energy storage system. The temperature distribution and temperature variations with time at different radial positions during the freezing processes were obtained. The thermal characteristics of the stearic acid, including movement of the solid–liquid interface in the radial direction, and the effects of Reynolds number on the heat transfer parameters were studied. The heat flux was estimated by using a simple approximate model. A new copper fin was designed and fixed to the electrical heating rod to enhance the thermal conductivity of the stearic acid. The results show that the new fin can enhance both the conduction and the natural convection heat transfer of the PCM, and the enhancement factor during solidification is estimated to be as high as 250%. The effect of the fin width on the enhancement was also examined experimentally, and it is found that the fine fin usually produce more effective enhancement.