化工学报 ›› 2020, Vol. 71 ›› Issue (4): 1491-1501.DOI: 10.11949/0438-1157.20190964

• 流体力学与传递现象 • 上一篇    下一篇

基于离散相模型的相变微胶囊流体传热特性数值模拟

吴兴辉1(),杨震1,陈颖2,段远源1()   

  1. 1. 清华大学热科学与动力工程教育部重点实验室,北京市二氧化碳利用与减排技术重点实验室,北京 100084
    2. 广东工业大学广东省功能软凝聚态物质重点实验室,广东 广州 510006
  • 收稿日期:2019-08-22 修回日期:2020-01-14 出版日期:2020-04-05 发布日期:2020-04-05
  • 通讯作者: 段远源
  • 作者简介:吴兴辉(1994—),男,博士研究生,wuxh16@mails.tsinghua.edu.cn
  • 基金资助:
    国家自然科学基金项目(51876045)

Simulation studies on heat transfer characteristics of PCM micro-encapsulated fluids based on discrete phase model

Xinghui WU1(),Zhen YANG1,Ying CHEN2,Yuanyuan DUAN1()   

  1. 1. Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Beijing Key Laboratory for CO2 Utilization and Reduction Technology, Tsinghua University, Beijing 100084, China
    2. Guangdong Province Key Laboratory of Functional Soft Condensate Matter, Guangdong University of Technology, Guangzhou 510006, Guangdong, China
  • Received:2019-08-22 Revised:2020-01-14 Online:2020-04-05 Published:2020-04-05
  • Contact: Yuanyuan DUAN

摘要:

相变材料微胶囊悬浮液是将相变微胶囊颗粒添加至单相流体中形成的一种新型传热介质,由于传热系数高、传热储能一体化等优势,具备很大的发展潜力。采用离散相两相流模型,对恒热流水平圆管中相变微胶囊流体的传热特性进行了模拟计算,通过对比实验数据验证了模型的可靠性,进而定量分析了颗粒尺寸、质量分数、相变潜热,特别是颗粒分布对传热的影响。结果表明随着微胶囊颗粒质量分数增加,颗粒粒径减小,相变潜热增大,壁面传热效果越好,且相变潜热大小对壁温控制和壁面传热的影响大于颗粒质量分数和颗粒尺寸的影响。比较了离散相模型与常用的单相流模型的计算结果,发现质量分数越高,颗粒集聚程度越高,单相流模型计算的偏差越大。

关键词: 计算流体力学, 相变, 微胶囊, 粒度分布, 对流, 传热

Abstract:

Micro-encapsulated phase change material slurry is a new type of heat transfer media which consists of microencapsulated phase change particles and a single-phase heat fluid. Due to the advantages of high coefficient of heat transfer, integration of heat transfer and energy storage, the new media has great development potential. In this paper, we used discrete phase model to numerically analyze the heat transfer characteristics of micro-encapsulated slurry in horizontal circular tube under constant heat flux. The model is verified by comparing with the experimental results. The effects of particle size, mass fraction, phase change latent heat, especially particle distribution on heat transfer were quantitatively analyzed. The results show that as the mass fraction of microcapsules increases, particle size decreases, latent heat of phase change increases, the heat transfer at wall is better. Moreover, the effect of latent heat on wall temperature control and heat transfer is greater than that of particle mass fraction and particle size. The calculation results of the discrete phase model and the commonly used single-phase flow model are compared. It is found that the higher the mass fraction, the higher the degree of particle aggregation, and the greater the deviation of the single-phase flow model.

Key words: CFD, phase change, microcapsule, particle size distribution, convective, heat transfer

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