Characterization of size effect of natural convection in melting process of phase change material in square cavity

作     者：Shi-Hao Cao Hui Wang 曹世豪;王辉

作者机构：College of Civil EngineeringHenan University of TechnologyZhengzhou 450001China School of Civil Engineering and ArchitectureHainan UniversityHaikou 570228China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2021年第30卷第10期

页      面：400-409页

核心收录：

学科分类：080702[工学-热能工程] 08[工学] 0807[工学-动力工程及工程热物理] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51908197 and 12072107) the Tackle Key Problems in Science and Technology Project of Henan Province,China(Grant No.202102310262) the Program for Innovative Research Team of Science&Technology of Henan Province,China(Grant No.19IRTSTHN020) the Key Research Project of Higher Education Institutions of Henan Province,China(Grant No.20B580001) 

主　　题：phase change material natural convection size effect equivalent thermal conductivity 

摘      要：The accelerating effect of natural convection on the melting of phase change material(PCM)has been extensively ***,such an influence is directly dependent on the size and shape of domain in which phase change happens,and how to quantitatively describe such an influence is still *** the other hand,the simulation of natural convection process is considerably difficult,involving complex fluid flow in a region changing with time,and is typically not operable in *** overcome these obstacles,the present study aims to quantitatively investigate the size effect of natural convection in the melting process of PCM paraffin filled in a square latent heat storage system through experiment and simulation,and ultimately a correlation equation to represent its contribution is ***,the paraffin melting experiment is conducted to validate the two-dimensional finite element model based on the enthalpy ***,a comprehensive investigation is performed numerically for various domain *** results show that the melting behavior of paraffin is dominated by the thermal *** the melting time exceeds 50 s,a whirlpoor flow caused by natural convection appears in the upper liquid phase region close to the heating wall,and then its influencing range gradually increases to accelerate the melting of ***,its intensity gradually decreases as the distance between the melting front and the heating wall ***,it is found that the correlation between the total melting time and the domain size approximately exhibits a power *** the domain size is less than 2 mm,the accelerating effect of natural convection becomes very weak and can be ignored in ***,in order to simplify the complex calculation of natural convection,the equivalent thermal conductivity concept is proposed to include the contribution of natural convection to the total melting time,and an empirical correlation is given fo