0
RESEARCH PAPERS: Evaporation, Boiling, and Condensation

Flow Boiling Heat Transfer of CO2 at Low Temperatures in a Horizontal Smooth Tube

[+] Author and Article Information
Chang Yong Park

Department of Mechanical and Industrial Engineering,  University of Illinois at Urbana-Champaign, 1206 West Green Street, Urbana, Illinois 61801

Pega S. Hrnjak1

Department of Mechanical and Industrial Engineering,  University of Illinois at Urbana-Champaign, 1206 West Green Street, Urbana, Illinois 61801pega@uiuc.edu

1

Corresponding author.

J. Heat Transfer 127(12), 1305-1312 (Mar 18, 2005) (8 pages) doi:10.1115/1.2098853 History: Received January 06, 2005; Revised March 18, 2005

Flow boiling heat transfer coefficients of CO2 are measured in a horizontal smooth tube with inner diameter 6.1mm. The test tube is heated by a secondary fluid maintaining constant wall temperature conditions. Heat transfer coefficients are measured at evaporation temperatures of 15 and 30°C, mass flux from 100to400kgm2s, and heat flux from 5to15kWm2 for qualities (vapor mass fractions) ranging from 0.1 to 0.8. The characteristics of CO2 flow boiling are explained by CO2 properties and flow patterns. The measured CO2 heat transfer coefficients are compared to other published data. Experiments with R22 were also conducted in the same system and the results show that the heat transfer coefficients for CO2 are 40 to 150% higher than for R22 at 15°C and low mass flux of 200kgm2s mostly due to the characteristics of CO2 nucleate boiling. The presented CO2 heat transfer coefficients indicate the reduction of heat transfer coefficient as mass flux increases at low quality regions and also show that dryout does not occur until the high quality region of 0.8, for mass fluxes of 200 and 400kgm2s. The Gungor and Winterton correlation gives a relatively good agreement with measured data; however it deviates more at lower evaporation temperature and high mass flux conditions.

FIGURES IN THIS ARTICLE
<>
Copyright © 2005 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 7

Counterintuitive effect of a mass flux increase on heat transfer at low quality regions: prediction by Thome and Hajal (6) vs experimental data from this study

Grahic Jump Location
Figure 8

Comparison of the measured and predicted heat transfer coefficients with Thome and Hajal (6) model

Grahic Jump Location
Figure 9

Comparison of the measured and predicted heat transfer coefficients with the Gungor and Winterton (14) correlation

Grahic Jump Location
Figure 6

Flow boiling heat transfer coefficient with respect to mass flux and heat flux at an evaporation temperature of −30°C

Grahic Jump Location
Figure 5

Flow boiling heat transfer coefficient with respect to mass flux and heat flux at an evaporation temperature of −15°C

Grahic Jump Location
Figure 4

Flow boiling heat transfer coefficient comparison for CO2 and R22

Grahic Jump Location
Figure 3

Comparison of the data from this study to Bredesen (7) and Knudsen and Jensen (8)

Grahic Jump Location
Figure 2

Schematic of the test section

Grahic Jump Location
Figure 1

Simplified schematic of the test facility

Tables

Errata

Discussions

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