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• TRANSPORT PHENOMENA & FLUID MECHANICS • 上一篇    下一篇

含间隔分置旋流片的缩放管复合强化传热

洪蒙纳; 邓先和; 黄阔; 李志武   

  1. The Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Education Ministry, South China Uni-versity of Technology, Guangzhou 510640, China
  • 收稿日期:2006-11-30 修回日期:1900-01-01 出版日期:2007-12-28 发布日期:2007-12-28
  • 通讯作者: 洪蒙纳

Compound heat transfer enhancement of a converging-diverging tube with evenly spaced twisted-tapes

HONG Mengna; DENG Xianhe; HUANG Kuo; LI Zhiwu   

  1. The Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Education Ministry, South China Uni-versity of Technology, Guangzhou 510640, China
  • Received:2006-11-30 Revised:1900-01-01 Online:2007-12-28 Published:2007-12-28
  • Contact: HONG Mengna

摘要: Pressure drop and compound heat transfer characteristics of a converging-diverging tube with evenly spaced twisted-tapes (CD-T tube) have been investigated experimentally. Swirl was generated by evenly spaced twisted-tape elements which vary in twist ratio and rotation angle. Space ratio also has an important effect on the characteristics. For comparison, experiments in a smooth circular tube and a converging-diverging (CD) tube with-out twisted-tapes were carried out. The results show that the twisted-tape with twist ratio y=4.72 and rotation angle θ=180° has the best performance among the four types of twisted-tapes presented in this paper. At Reynolds num-ber ranging from 3400 to 20000, when space ratio s=48.6, the heat transfer efficiency index, which increases as the Reynolds number increases, is 0.85—1.21 and 1.07—1.15 compared to that of a smooth circular tube and a CD tube without twisted-tape inserts, respectively.

关键词: compound heat transfer;spaced twisted-tape;converging-diverging tube;swirl flow

Abstract: Pressure drop and compound heat transfer characteristics of a converging-diverging tube with evenly spaced twisted-tapes (CD-T tube) have been investigated experimentally. Swirl was generated by evenly spaced twisted-tape elements which vary in twist ratio and rotation angle. Space ratio also has an important effect on the characteristics. For comparison, experiments in a smooth circular tube and a converging-diverging (CD) tube with-out twisted-tapes were carried out. The results show that the twisted-tape with twist ratio y=4.72 and rotation angle θ=180° has the best performance among the four types of twisted-tapes presented in this paper. At Reynolds num-ber ranging from 3400 to 20000, when space ratio s=48.6, the heat transfer efficiency index, which increases as the Reynolds number increases, is 0.85—1.21 and 1.07—1.15 compared to that of a smooth circular tube and a CD tube without twisted-tape inserts, respectively.

Key words: compound heat transfer, spaced twisted-tape, converging-diverging tube, swirl flow