Development of Universal Two-Phase Heat Transfer Correlations for Cryogenic Transfer Line Chilldown

Author(s):  
Jason W. Hartwig ◽  
Samuel R. Darr ◽  
Jacob Chung
Author(s):  
Avram Bar-Cohen ◽  
Ilai Sher ◽  
Emil Rahim

The present study is aimed at evaluating the ability of conventional “macro-pipe” correlations and regime transitions to predict the two-phase thermofluid characteristics of mini-channel cold plates. Use is made of the Taitel-Dukler flow regime maps, seven classical heat transfer coefficient correlations and two dryout predictions. The vast majority of the mini-channel two-phase heat-transfer data, taken from the literature, is predicted to fall in the annular regime, in agreement with the reported observations. A characteristic heat transfer coefficient locus has been identified, with a positive slope following the transition from Intermittent to Annular flow and a negative slope following the onset of partial dryout at higher qualities. While the classical two-phase heat transfer correlations are generally capable of providing good agreement with the low-quality annular flow data the quality at which partial dryout occurs and the ensuing heat transfer rates are not predictable by the available macro-pipe correlations.


2000 ◽  
Author(s):  
Dongwoo Kim ◽  
Jae-yong Kim ◽  
Afshin J. Ghajar ◽  
Ronald L. Dougherty

Abstract New heat transfer correlations were developed for two-phase heat transfer in a horizontal pipe for different flow patterns. Flow patterns were observed in a transparent circular pipe (2.54 cm I.D. and L/D = 96) using an air/water mixture. Visual identification of the flow patterns was supplemented with photographic data, and the results were plotted on the flow regime map proposed by Taitel and Dukler and agreed quite well with each other. A two-phase heat transfer experimental setup was built for this study and a total of 150 two-phase heat transfer data with different flow patterns were obtained under a uniform wall heat flux boundary condition. For these data, the superficial Reynolds number ranged from 640 to 35,500 for the liquid and from 540 to 21,200 for the gas. Our previously developed robust two-phase heat transfer correlation for a vertical with modified constants predicted the horizontal pipe air-water heat transfer experimental data with good accuracy. Overall the proposed correlations predicted the data with a mean deviation of 1.0% and an rms deviation of 12%.


Equipment ◽  
2006 ◽  
Author(s):  
Leonid L. Vasiliev ◽  
A. Zhuravlyov ◽  
A. Shapovalov ◽  
L. L. Vasiliev, Jr

Author(s):  
Bryan E. Burk ◽  
Torben P. Grumstrup ◽  
Taylor A. Bevis ◽  
Jack Kotovsky ◽  
Todd M. Bandhauer

2005 ◽  
Vol 127 (10) ◽  
pp. 1106-1114 ◽  
Author(s):  
Ali Koşar ◽  
Chih-Jung Kuo ◽  
Yoav Peles

Boiling flow of deionized water through 227μm hydraulic diameter microchannels with 7.5μm wide interconnected reentrant cavities at 47 kPa exit pressure has been investigated. Average two-phase heat transfer coefficients have been obtained over effective heat fluxes ranging from 28 to 445W∕cm2 and mass fluxes from 41 to 302kg∕m2s. A map is developed that divides the data into two regions where the heat transfer mechanisms are nucleation or convective boiling dominant. The map is compared to similar atmospheric exit pressure data developed in a previous study. A boiling mechanism transition criterion based on the Reynolds number and the Kandlikar k1 number is proposed.


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