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过程工程学报 ›› 2018, Vol. 18 ›› Issue (5): 951-956.DOI: 10.12034/j.issn.1009-606X.217395

• 流动与传递 • 上一篇    下一篇

细小槽道换热器内相变微胶囊悬浮液对流传热DPM模拟

鲁进利*， 吕勇军， 韩亚芳， 钱付平   

  1. 安徽工业大学建筑工程学院，安徽 马鞍山 243032
  • 收稿日期:2017-11-15 修回日期:2018-03-06 出版日期:2018-10-22 发布日期:2018-10-12
  • 通讯作者: 鲁进利 lujinli@sina.cn
  • 基金资助:
    安徽省自然科学基金项目;国家自然科学基金

Simulation on convective heat transfer of MPCMS in minichannel heat exchanger based on DPM model

Jinli LU*, Yongjun LÜ, Yafang HAN, Fuping QIAN   

  1. School of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan, Anhui 243032, China
  • Received:2017-11-15 Revised:2018-03-06 Online:2018-10-22 Published:2018-10-12
  • Contact: LU Jin-li lujinli@sina.cn

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摘要： 基于离散相模型，采用颗粒比热容随温度变化分段函数描述颗粒的相变过程，模拟了相变微胶囊悬浮液在细小槽道换热器内的对流传热特性，考察了不同入口流量时换热器进出口压差及温差的变化规律，并与纯水进行比较，分析了换热器内部及加热面温度分布，研究了换热器典型通道修正的局部努赛尔数Nux*沿流动方向的变化规律. 结果表明，相变微胶囊悬浮液在换热器内的压损随流量变化规律与纯水一致，较纯水有所增大；引入相变微胶囊颗粒减缓了加热面和流体温度升高的速率，使换热器出口及加热面的温度比纯水低；受进出口位置影响，换热器内温度呈现中间通道低、向两侧逐渐升高的分布规律. 不同通道的Nux*沿流动方向的变化规律存在一定差异，部分通道内相变材料完全融化，而部分通道内相变材料尚未完全融化就流出换热器. 需改进换热器进出口位置或对换热器内部结构进行优化设计以获得较好的流量分配特性，从而改善换热效果.

关键词: 相变微胶囊, 强化传热, 对流传热特性, 离散相模型

Abstract: With the advantage of high apparent specific heat capacity, high energy storage density, and better comprehensive heat transfer performance, the microencapsulated phase change material suspension (MPCMS) has wide application prospect in the field of energy storage and transport. In this paper, the discrete phase model (DPM) was employed to simulate the pressure drop and heat transfer characteristics of microencapsulated phase change material suspension flow in heat exchanger consisting of a series of parallel minichannel. The piecewise function that representation microencapsulated phase change material particle specific heat capacity varies with temperature was used to describe the phase change process. The inlet and outlet pressure drop and temperature difference of heat exchanger under different flow rates were discussed and compared with pure water. Meanwhile, the temperature distribution of microencapsulated phase change material suspension and heat surface were also concerned. The modified local Nusselt number in three representative channel of heat exchanger were calculated simultaneously. The results showed that the pressure drop of microencapsulated phase change material suspension in heat exchanger was consistent with that of pure water, but the value was bigger than pure water. With introducing the microencapsulated phase change material particle, the temperature increasing rate of outlet and heat surface was reduced slightly. Therefore, the outlet and heat surface of heat exchanger present low temperature compared to pure water. Because of the influence of inlet/outlet location, the temperature in heat exchanger present the distribution law as middle channel low and two sides channel high. So, there was a difference of the local Nusselt number along the flow direction in different channels. The phase change materials were melted in two sides channels of heat exchanger. However, in middle channel of heat exchanger, the phase change material was melting partly. Therefore, the location of inlet/outlet should be changed or interior structure of heat exchanger should be optimized so that to receive better flow distribution and heat transfer performance.

Key words: microencapsulated phase change material, enhanced heat transfer, convective heat transfer characteristic, discrete phase model