Numerical method and model for calculating thermal storage time for an annular tube with phase change material  

作　　者：刘泛函 徐建新 王辉涛 王华 

机构地区：[1]State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,Kunming University of Science and Technology,Kunming 650093,China [2]Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China [3]Quality Development Institure,Kunming University of Science and Technology,Kunming 650093,China

出　　处：《Journal of Central South University》2017年第1期217-226,共10页中南大学学报（英文版）

基　　金：Projects(51666006,51406071,51174105,51366005)supported by the National Natural Science Foundation of China;Project(2014CB460605)supported by the National Basic Research Program of China

摘　　要：For calculating the thermal storage time for an annular tube with phase change material （PCM）, a novel method is proposed. The method is suitable for either low-temperature PCM or high-temperature PCM whose initial temperature is near the melting point. The deviation fit is smaller than 8% when the time is below 2x104 s. Comparison between the predictions and the reported experimental data of thermal storage time at same conditions is investigated and good agreements have been got. Based on this method, the performance of the thermal storage unit and the role of natural convection are also investigated. Results show a linear relation between the maximum amount of stored heat and thermal storage time, and their ratio increases with the height of the thermal storage unit. As the thickness of the cavity increases, natural convection plays an increasingly important role in promoting the melting behavior of paraffin. When the thickness of the cavity is small, natural convection restrains the melting behavior of paraffin.For calculating the thermal storage time tor an annular tube with phase change material(PCM),a novel method is proposed.The method is suitable for either low-temperature PCM or high-temperature PCM whose initial temperature is near the melting point.The deviation fit is smaller than 8%when the time is below 2×10~4 s.Comparison between the predictions and the reported experimental data of thermal storage time at same conditions is investigated and good agreements have been got.Based on this method,the performance of the thermal storage unit and the role of natural convection are also investigated.Results show a linear relation between the maximum amount of stored heat and thermal storage time,and their ratio increases with the height of the thermal storage unit.As the thickness of the cavity increases,natural convection plays an increasingly important role in promoting the melting behavior of paraffin.When the thickness of the cavity is small,natural convection restrains the melting behavior of paraffin.

关 键 词：natural convection energy storage modeling heat transfer mass transfer 

分 类 号：TK11[动力工程及工程热物理—热能工程]