楔形管壳式蓄热罐的传热性能  

Heat transfer performance study of wedge-shaped shell-and-tube heat storage tank

作　　者：毛前军[1] 陈凯莉 MAO Qianjun;CHEN Kaili(School of Urban Construction,University of Science and Technology Wuhan,Wuhan 430065,Hubei,China)

机构地区：[1]武汉科技大学城市建设学院,湖北武汉430065

出　　处：《储能科学与技术》2022年第11期3658-3666,共9页Energy Storage Science and Technology

基　　金：国家自然科学基金资助项目(51876147)。

摘　　要：针对常规矩形管壳式相变蓄热系统中相变材料热响应较慢的问题,实现蓄热系统高效储热结构优化具有重要意义。本工作采用数值模拟对基准管壳式相变储热单元和优化结构单元中相变材料带自然对流的熔化过程进行研究,并进行实验验证。根据不同的增强自然对流技术如楔形化、内流管偏心及倾斜罐体,讨论温度场、储热量、Fo数、平均Nu数及相界面的演化过程,分析不同增强自然对流方式内相变材料的动态热行为,得出改善储热系统传热效率的优化解。研究结果表明:楔形相变储热单元外壳形状可增强自然对流作用,提高储热单元的传热性能。当楔形比X=5时,与基准矩形结构中的相变材料熔化时间相比,其完全熔化时间缩短了28%;偏心距对竖直放置蓄热系统内相变材料的储热量影响不大,但是延长了完全熔化时间,对熔化效率起到反作用;楔形罐体倾斜75°时,在熔化前期自然对流换热效果达到最大值,蓄热效率也随之增长到最大,与垂直放置相比提升了29%。研究结果对节能减排以及双碳目标的实现具有一定的借鉴意义。It is crucial to optimize the efficient thermal storage structure of thermal storage systems to address the problem of slow thermal response of phase change materials(PCMs)in conventional rectangular shell-and-tube phase change thermal storage systems.Numerical simulations were employed to examine the melting process of PCM with natural convection in a baseline shell-and-tube phase change thermal storage unit and an optimized structural unit and to perform experimental verification.According to different improved natural convection approaches,such as wedging,internal flow tube eccentricity,and inclined tanks,discuss the evolution of temperature field,heat storage capacity,Fo number,average Nu number,and phase interface.The dynamic thermal behavior of PCM within different improved natural convection approaches was examined to derive optimized solutions for enhancing the heat transfer efficiency of heat storage systems.The findings reveal that the wedge-shaped phase change heat storage unit shell shape can improve the natural convection effect and enhances the heat transfer performance.The complete melting time was reduced by 28%compared to the melting time of the PCM in the reference rectangular structure when the wedge ratio X=5.Although it prolongs the complete melting time and has an opposite effect on the melting efficiency,the eccentric distance has little effect on the heat storage capacity of the PCM in the vertically placed thermal storage system.The research findings have a certain reference significance for the realization of energy conservation and emission reduction and the realization of the dual carbon goal,where the natural convection heat transfer effect reaches its maximum during the early melting,and the heat storage efficiency increases to its maximum,with a 29%increase compared to vertical placement when the wedge-shaped tank is tilted at 75°.

关 键 词：强化传热 自然对流 相变材料 楔形蓄热系统 

分 类 号：TQ051.5[化学工程]