• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2015, Vol. 51 ›› Issue (10): 152-159.doi: 10.3901/JME.2015.10.152

• 可再生能源与工程热物理 • 上一篇    下一篇

螺旋折流板换热器局部流场和温度场的数值研究

许伟峰, 王珂, 靳遵龙, 刘敏珊   

  1. 郑州大学河南省过程传热与节能重点实验室 郑州 450002
  • 出版日期:2015-05-15 发布日期:2015-05-15
  • 基金资助:
    国家自然科学基金(51476147)和中国博士后科学基金(201104400)资助项目

From Field Synergy to Thermodynamics Coupling:Thermodynamics Mechanism for Convective Heat Transfer Enhancement

XU Weifeng, WANG Ke, JIN Zunlong, LIU Minshan   

  1. Key Laboratory of Process Heat Transfer Energy Saving of Henan Province, Zhengzhou University, Zhengzhou 450002
  • Online:2015-05-15 Published:2015-05-15

摘要: 建立连续螺旋折流板换热器和四分螺旋折流板换热器模型,采用大型CFD分析软件FLUENT借助数值模拟的方法,研究螺旋折流板换热器局部流场和温度场的分布规律,并采用 耗散原理对两种折流板结构下换热器的综合性能进行对比研究。结果表明,以 耗散分析为指标的评价标准同以换热器综合性能为指标的评价标准具有一致性。相同的壳程流量下,同四分螺旋折流板换热器相比,连续螺旋折流板换热器 耗散值较小。两种折流板类型的换热器局部流场和温度场分布均呈现出相同的规律,壳程中心部位,换热管壁面传热系数最高,沿壳体径向,流体螺旋流动状态和换热管壁面传热系数均呈现先减小后增加的现象。同连续折流板相比,折流板的不连续性在小流量下能够促进壳程中心部位的局部传热,当流量增大到一定程度则表现为减弱壳程中心部位的局部传热。计算结果为改进螺旋折流板结构形式提供了理论依据。

关键词: 耗散, 换热器, 局部特性, 螺旋折流板, 数值模拟

Abstract: Models of continuous helical baffles and quarter helical baffles heat exchangers are established. With large CFD analysis software FLUENT, the distribution characteristics of local flow field and temperature field of helical baffles heat exchangers are investigated through numerical simulation. And comprehensive performances of both heat exchangers are compared and studied with entransy dissipation. The results show:In the research of heat exchanger, the evaluation standard of entransy dissipation is consistent with that of comprehensive performances. When the flow of shell side is the same, the entransy dissipation value of continuous helical baffles heat exchanger is less than that of quarter helical baffles heat exchanger. The distribution characteristics of local flow field and temperature field of both heat exchangers present the same rules, in the central part of shell side, heat transfer coefficient of tubes is the highest. Along the radial direction, both helical flow and heat transfer coefficient of tubes first increase then decrease. Compared to continuous baffles, the discontinuity of baffles could enhance local heat transfer. Yet, when flow increases to an extent, the local heat transfer in the center will be weakened. The results provide theoretical basis for the improvement of structure forms of helical baffles.

Key words: entransy dissipation, heat exchangers, helical baffles, local characteristic, numerical simulation

中图分类号: