Prediction of two phase flow condensation of pure and refrigerant mixtures on enhanced surface tubing

1992 ◽  
Vol 19 (2) ◽  
pp. 191-202 ◽  
Author(s):  
S.M. Sami ◽  
J. Schnotale
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Refrigerant Mixtures ◽  
Flow Condensation ◽  
Enhanced Surface

Analysis of Heat Transfer and Fluid Flow in Two-Phase Thermosyphon Loop with Minichannels

2016 ◽  
Vol 831 ◽  
pp. 92-103 ◽  
Author(s):  
Henryk Bieliński ◽  
Jaroslaw Mikielewicz
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
General Model ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Phase Flow ◽  
Two Phase ◽  
Considerable Impact ◽  
Flow Condensation ◽  
Computer Processor

The present paper offers an analysis of heat transfer and fluid flow in two phase thermosyphon loop with minichannels. A one-dimensional model of two-phase flow and heat transfer in a closed thermosyphon loop with minichannels was examined. The created general model is based on mass, momentum, and energy balances in the evaporators, rising tube, condensers and the falling tube. The separate two-phase flow model is used in calculations. The numerical results obtained for the selected heater and cooler using the general model of thermosyphon loop indicate that the mass flux increases with increasing length of the heated section and decreases with increasing length of the cooled section of the loop. It was found that the heat transfer coefficient for flow boiling and flow condensation in the steady state increases with increasing heat flux in the heater and cooler with minichannels, respectively. The design and configuration of heaters and coolers has a considerable impact on the efficiency of thermosyphon loop. These factors make it possible to optimize the computer processor cooling.

Study of Pressure Drop of Refrigerant Mixtures Inside Enhanced Surface Tubing

2001 ◽  
Author(s):  
S. M. Sami ◽  
J. Grell
Keyword(s):  
Pressure Drop ◽  
Reynolds Numbers ◽  
The Other ◽  
Phase Flow ◽  
Specific Pressure ◽  
Two Phase ◽  
Transfer Rates ◽  
Refrigerant Mixtures ◽  
Flow Pressure ◽  
Enhanced Surface

Abstract Two phase flow pressure drop characteristics observed during condensation and boiling of azeotropic refrigerant mixtures R-404A (R125/R134a/R143a:44/4/52), R-407B (R32/R125/ R134a:10/70/20), R407C (R32/R125/R134a:23/25/52) and R408A (R22/R125/R143a:46/7/47) are presented in this paper. Experiments showed that for liquid Reynolds numbers higher than 3.00 E06, R-408A appears to have greater heat transfer rates than the other blends under investigation. Furthermore, it is quite evident from this data that R-407C has the highest specific pressure drop among the refrigerants under investigation.

Sign in / Sign up

Export Citation Format

Share Document