RESEARCH PAPERS: Evaporation, Boiling, and Condensation

A Theoretical Study on Convective Condensation of Water Vapor From Humid Air in Turbulent Flow in a Vertical Duct

[+] Author and Article Information
V. Dharma Rao1

Department of Chemical Engineering, College of Engineering,  Andhra University, Visakhapatnam-53003, Indiav.dharmarao@yahoo.com

V. Murali Krishna

Department of Mechanical Engineering,  G.V.P. College of Engineering, Visakhapatnam-530041, Indiamḵvemula@rediffmail.com

K. V. Sharma

Department of Mechanical Engineering,  JNTU, Kukatpally, Hyderabad-500072, Indiakvsharmajntu@yahoo.com

P. K. Sarma

 GITAM, Rishikonda, Visakhapatnam-530045, Indiasarmapk@yahoo.com


Corresponding author.

J. Heat Transfer 129(12), 1627-1637 (Apr 01, 2007) (11 pages) doi:10.1115/1.2767678 History: Received November 09, 2006; Revised April 01, 2007

The problem of condensation of water vapor from humid air flowing in a duct in turbulent flow is formulated theoretically. Vapor condensing at the dew-point temperature of the vapor-air mixture diffuses to the wall of the duct through an air film. The flow of the condensate is laminar. The condensing vapor releases both convection and latent heats to the wall of the duct. Thus, it is treated as a combined heat and mass transfer problem. The mass, momentum, and energy balance equations for the vapor-air mixture flowing in the duct and the diffusion equation for the vapor species are considered. Ti, the temperature at gas-to-liquid interface, at which condensation takes place, is estimated with the help of the heat balance and mass balance equations at interface. The local and average values of the condensation Nusselt number, condensate Reynolds number, gas-liquid interface temperature, and pressure drop are estimated from the numerical results for different values of the system parameters, such as relative humidity and temperature of air at inlet, gas phase Reynolds number, and total pressure at inlet. The gas phase convection Nusselt and Sherwood numbers are also computed. A comparison of the present work with experimental data, for the case of in-tube condensation of vapor from humid air, shows satisfactory agreement.

Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 1

Physical model and configuration

Grahic Jump Location
Figure 2

Comparison of present work with experimental data

Grahic Jump Location
Figure 3

Effect of Reg,0, T0, RH,0, and P0 on Nul,z and (hgW∕kl)

Grahic Jump Location
Figure 4

Effect of various parameters on local condensate Reynolds number

Grahic Jump Location
Figure 5

Gas-liquid interface temperature (Ti); effect of different parameters

Grahic Jump Location
Figure 6

Effect of Reg,0, T0, and RH,0 on local gas-vapor mixture pressure

Grahic Jump Location
Figure 7

Effect of RH,0 on average condensate Nusselt and condensate Reynolds number

Grahic Jump Location
Figure 8

Effect of RH,0 on average gas-liquid interface temperature and total pressure drop

Grahic Jump Location
Figure 9

Variation of Nul,av, (Shg,avxk+) and (Rel,e) with Reg,0

Grahic Jump Location
Figure 10

Effect of Reg,0 on average interface temperature and total pressure drop

Grahic Jump Location
Figure 11

Effect of P0 on Nul,av and Rel,e



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In