Chinese Journal of Chemical Engineering ›› 2020, Vol. 28 ›› Issue (1): 23-32.doi: 10.1016/j.cjche.2019.07.021

• Fluid Dynamics and Transport Phenomena • Previous Articles     Next Articles

Numerical study on falling film flowing characteristics of R113 inside vertical tube under different structural conditions

Weishu Wang, Yihan Liao, Youzhi Yan, Bingchao Zhao, Tao Wang, Shanshan Shangguan   

  1. North China University of Water Resources and Electric Power, Zhengzhou 450045, China
  • Received:2019-04-29 Revised:2019-07-04 Online:2020-01-28 Published:2020-03-31
  • Contact: Bingchao Zhao
  • Supported by:
    Supported by Program for Innovation Research Team (in Science and Technology) in the University of Henan Province (16IRTSTHN017) and plan for Scientific Innovation Talent of Henan Province (154100510011).

Abstract: To develop an appropriate falling film evaporation device for organic fluid cogeneration, a numerical study on the gas-liquid two-phase counter-current flow characteristics of R113 inside a vertical tube under different structural conditions was conducted using the Fluent software. The effects of the tube length, tube diameter, and annular gap on the falling film flow characteristics were determined, respectively. The results indicated that under a certain spray density, the falling film thickness in the region of the steady section was almost constant with different structural parameters for the tube diameter, tube length, and annular gap. In addition, a smaller tube diameter resulted in a steadier film flow. When the tube diameter decreased to a specific value, the film thickness showed a uniform distribution along the wall surface. This indicated that a best falling tube diameter exists. Meanwhile, the film fluctuation was enhanced with an increase in the tube length. When the tube length was greater than 1.2 m, the falling film splashed and could not completely wet the wall surface. The film fluctuation was enhanced by decreasing the annular gap, and the film could not be formed when the annular gap was smaller than 1.2 mm.

Key words: Falling film, Numerical simulation, R113