方腔内正十八烷相变材料凝固放热特性试验研究  

Experimental Study on Heat Release Properties of N-octadecane Phase Change Materials During Solidification in Square Cavity

作　　者：曹世豪 赵锡佳 王方全 喻贤磊 杨荣山[3] CAO Shihao;ZHAO Xijia;WANG Fangquan;YU Xianlei;YANG Rongshan(College of Civil Engineering,Henan University of Technology,Zhengzhou 450001,China;Henan Key Laboratory of Grain and Oil Storage Facility and Safety,HAUT,Zhengzhou 450001,China;MOE Key Laboratory of High-speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]河南工业大学土木工程学院,郑州450001 [2]河南省粮油仓储建筑与安全重点实验室,郑州450001 [3]西南交通大学高速铁路线路工程教育部重点实验室,成都610031

出　　处：《材料导报》2025年第9期259-263,F0003,共6页Materials Reports

基　　金：国家自然科学基金(52272442,51908197);河南省科技攻关项目(242102240026);河南省粮油仓储建筑与安全重点实验室开放课题(2024KF08)。

摘　　要：针对方腔内正十八烷相变材料的凝固放热特性问题开展研究。首先测试液相密度、动力黏度等与温度的关系,完善热物理参数。随后设计出正十八烷的凝固放热性能综合试验,测得温度时空分布特征以及凝固边界演化规律。建立流-固-热三场耦合计算模型,分析液相自然对流的影响。结果表明,液相密度与温度呈线性减小关系,动力黏度与温度呈二次多项式减小关系,而热膨胀系数介于9.03×10^(-4)~9.55×10^(-4)℃^(-1)。在低温环境下,方腔内正十八烷的凝固边界呈现对称状向中心点蔓延,整个凝固放热过程可分为四个阶段,其中前两个阶段储能释放量占比达到97.1%,而液相自然对流传热仅对第一阶段有微弱的影响。此外,正十八烷的凝固放热效率与冷却温度呈四次多项式关系,其中15℃为最优冷却温度。In this work,the solidification heat release characteristics of n-octadecane phase change materials in square cavity was studied.Firstly,in order to improve the thermophysical parameters,the relation curves of liquid density,dynamic viscosity and temperature were measured.Then a comprehensive test of the solidification heat release of n-octadecane was designed,the temporal and spatial distribution characteristics of temperature were measured,as well as the evolution of solidification boundary.The results show that,the liquid density decreases linearly with temperature,the dynamic viscosity has a quadratic polynomial decreasing relationship with temperature,and the thermal expansion coefficient ranges from 9.03×10^(-4)℃-1 to 9.55×10^(-4)℃^(-1).In low temperature environment,the solidification boundary of n-octadecane in the square cavity spreads symmetrically towards the center point.The whole solidification heat release process can be divided into four stages,the energy storage release in the first two stages accounts for 97.1%,while the liquid phase natural convection heat transfer only has a weak influence on the first stage.In addition,there is a quartic polynomial relationship between the freezing efficiency and the cooling temperature,in which 15℃is the optimal cooling temperature.

关 键 词：相变材料 正十八烷 凝固边界 温度 自然对流 

分 类 号：TB34[一般工业技术—材料科学与工程]