中国炼油与石油化工 ›› 2014, Vol. 16 ›› Issue (01): 81-89.

• Simulation and Optimization • 上一篇    下一篇

内插旋流片的缩放管内糖液自然对流的传热研究

张连山,邓先和,刘卫涛,杨志平   

  1. 华南理工大学化学与化工学院
  • 收稿日期:2013-10-28 修回日期:2013-11-28 出版日期:2014-03-30 发布日期:2014-03-30
  • 通讯作者: 张连山 E-mail:lszhang1115@163.com
  • 作者简介:

    张连山(1987-), 男, 博士研究生, 主要从事强化传热与过程节能的研究. E-mail: lszhang1115@163.com

  • 基金资助:
    广东省重大科技专项

Investigation for Natural Convection Heat Transfer of Sucrose Solution using a Converging and Diverging Tube with Regularly-spaced Twisted Tapes

Lian-Shan ZHANG,Xian-He Deng,Wei-Tao Liu,Zhi-Ping Yang   

  1. School of Chemistry and Chemical Engineering, South China University of Technology
  • Received:2013-10-28 Revised:2013-11-28 Online:2014-03-30 Published:2014-03-30
  • Contact: Lian-Shan ZHANG E-mail:lszhang1115@163.com
  • About author:Lian-Shan Zhang (1987-), male, PhD. Student, mainly researching in heat transfer enhancement and energy saving. E-mail: lszhang1115@163.com
  • Supported by:
    Major Science and Technology Projects of Guangdong Province

摘要: 利用实验和仿真模拟的方法对垂直放置的内插旋流片的缩放管内60%的蔗糖溶液的自然对流换热情况进行了研究。通过模拟详细研究了努赛尔数随壁温和内插旋流片个数的变化情况,给出了糖液在管内的速度和温度分布,通过实验研究了流动瑞利数和内插旋流片个数对努赛尔数的影响,并将上述结果与光滑管比较。结果表明,内插2个旋流片能使管内努赛尔数显著增加,更多的旋流片对努赛尔数的提高影响不大,本研究条件下46倍的管径距离下传热效果最优。文中还模拟分析了缩放管及旋流片对糖液自然对流传热的协同强化作用机理,同时指出壁面切向速度的增加是传热得到强化的一个重要原因。

关键词: 自然对流, 旋流片, 仿真模拟, 糖液

Abstract: The natural convection heat transfer of 60% sucrose solution in the vertical converging-diverging tube (CD) with regularly-spaced twisted tapes (RSTT) has been investigated numerically and experimentally. The effects of wall temperature and numbers of RSTT on the Nusselt number are performed in detail. The distributions of velocity and temperature for 60% sucrose solution are studied and the simulated results of CD with RSTT were compared with the smooth tube. The influence of Rayleigh number and RSTT on Nusselt number was conducted experimentally. The results indicate that the Nusselt number of 60% sucrose solution obviously increased with the number of RSTT but increased inconspicuously with 2 twisted tapes and more. The simulation shows that the distance to reach the optimal heat transfer performance is 46 times the diameter of the tube. The mechanism of the natural convection heat transfer enhancement of 60% sucrose solution interrelated by the CD and the RSTT was analyzed, and the change of average tangential velocity with the axial distance was presented to demonstrate that the enhancement of heat transfer was mainly due to the increase of tangential velocity.

Key words: natural convection, regularly-spaced twisted tapes, numerical simulation, sucrose solution