储能科学与技术 ›› 2019, Vol. 8 ›› Issue (6): 1217-1223.doi: 10.12028/j.issn.2095-4239.2019.0122

• 研究开发 • 上一篇    下一篇

固液相变材料储能过程传热机制的数值模拟

杨智舜, 陈丽华, 夏振华   

  1. 浙江大学航空航天学院, 浙江 杭州 310027
  • 收稿日期:2019-06-07 修回日期:2019-06-23 出版日期:2019-11-01 发布日期:2019-07-31
  • 通讯作者: 陈丽华,副教授,研究方向为多相流理论与数值模拟,E-mail:mecclh@zju.edu.cn。
  • 作者简介:杨智舜(1994-),男,硕士研究生,研究方向为相变传热,E-mail:21724020@zju.edu.cn

Numerical investigation of the thermal mechanism of the solid-liquid phase changing process

YANG Zhishun, CHEN Lihua, XIA Zhenhua   

  1. Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, Zhejiang, China
  • Received:2019-06-07 Revised:2019-06-23 Online:2019-11-01 Published:2019-07-31

摘要: 由于相变换热储能技术可以协调能量在时间和空间尺度的分配,成为了目前研究的热点问题。本工作用焓值法分别对充填低温无机盐相变材料的二维和三维管壳式相变储能换热器模型的储/放热特性进行了模拟研究,采用Boussinesq近似研究了液相区密度变化引起的自然对流的影响。研究表明换热器的入口温度对相变换热效率影响显著;在储热过程中自然对流发挥了重要作用,换热效率与液相区的运动状态直接相关,而放热过程中的热交换主要依靠热传导完成;三维模拟的结果表明换热管出口温度与管壁的平均努赛尔数高度相关,且换热管水平放置的换热效率略低于竖直放置。

关键词: 相变储热, 自然对流, 计算流体力学, 融化, 凝固

Abstract: Latent heat thermal energy storage (LHTES) has been a hot research topic because of the advantage of coordinating the mismatch between energy supply and demand. This paper presents numerical investigation to study the thermal behavior of shell-and-tube LHTES system. The twodimensional physical model was considered to simplify. The three-dimensional physical model was also used to monitor outlet temperature and time needed to accomplish phase change. The enthalpy method was used to solve the energy equation in liquid and solid regions of phase change material (PCM). The natural convection (NC) in liquid PCM was considered by adopted Boussinesq approximation. The numerical model is validated by literature data. The result indicates that the inlet temperature of heat transfer fluid (HTF) has a significant influence during the phase change process. It also confirms that the melting process is significantly influenced by natural convection, vorticity distribution directly affects the heat exchange efficiency; and the thermal conduction plays a dominant role during the solidification process. The three-dimensional simulation shows that outlet temperature of HTF depends on the average Nusselt number at the tube, in the meantime, the horizontal arrangement of heat exchange tube has slightly lower heat transfer efficiency than vertical arrangement.

Key words: latent heat thermal energy storage, natural convection, computational fluid dynamics, melting, solidification

中图分类号: