scholarly journals Closure to “Discussion of ‘A General Heat Transfer Correlation for Annular Flow Condensation’” (1968, ASME J. Heat Transfer, 90, p. 274)

1968 ◽  
Vol 90 (2) ◽  
pp. 274-276 ◽  
Author(s):  
M. Soliman ◽  
J. R. Schuster ◽  
P. J. Berenson
Keyword(s):  
Heat Transfer ◽  
Annular Flow ◽  
Heat Transfer Correlation ◽  
Flow Condensation

A General Heat Transfer Correlation for Annular Flow Condensation

1968 ◽  
Vol 90 (2) ◽  
pp. 267-274 ◽  
Author(s):  
M. Soliman ◽  
J. R. Schuster ◽  
P. J. Berenson
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Annular Flow ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Heat Transfer Process ◽  
Heat Transfer Correlation ◽  
Wide Range ◽  
Prandtl Numbers ◽  
Flow Condensation

The interaction between friction, momentum, and gravity, as they affect the heat transfer process during annular flow condensation inside tubes, is studied. Analytical forms for each of these forces are derived and incorporated in a correlation that predicts the local heat transfer coefficient. The predictions agree well with the available experimental data over a wide range of vapor velocities and over a range of Prandtl numbers from 1 to 10. The analysis also yields a means for predicting the onset of liquid run-back in the presence of an adverse gravitational field.

scholarly journals Comparative study of flow condensation in conventional and small diameter tubes

2012 ◽  
Vol 33 (2) ◽  
pp. 67-83 ◽  
Author(s):  
Dariusz Mikielewicz ◽  
Rafał Andrzejczyk
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flow Structure ◽  
Annular Flow ◽  
Flow Boiling ◽  
Small Diameter ◽  
Bubble Generation ◽  
Flow Condensation ◽  
The Heat Transfer Coefficient

Abstract Flow boiling and flow condensation are often regarded as two opposite or symmetrical phenomena. Their description however with a single correlation has yet to be suggested. In the case of flow boiling in minichannels there is mostly encountered the annular flow structure, where the bubble generation is not present. Similar picture holds for the case of inside tube condensation, where annular flow structure predominates. In such case the heat transfer coefficient is primarily dependent on the convective mechanism. In the paper a method developed earlier by the first author is applied to calculations of heat transfer coefficient for inside tube condensation. The method has been verified using experimental data from literature on several fluids in different microchannels and compared to three well established correlations for calculations of heat transfer coefficient in flow condensation. It clearly stems from the results presented here that the flow condensation can be modeled in terms of appropriately devised pressure drop.

Phase-Change Heat Transfer in Microsystems

2006 ◽  
Vol 129 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Ping Cheng ◽  
Hui-Ying Wu ◽  
Fang-Jun Hong
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Mass Flux ◽  
Annular Flow ◽  
Pulse Heating ◽  
Flow Boiling ◽  
Mist Flow ◽  
Flow Condensation ◽  
Phase Change Heat Transfer ◽  
Condensation Flow

Recent work on miscroscale phase-change heat transfer, including flow boiling and flow condensation in microchannnels (with applications to microchannel heat sinks and microheat exchangers) as well as bubble growth and collapse on microheaters under pulse heating (with applications to micropumps and thermal inkjet printerheads), is reviewed. It has been found that isolated bubbles, confined elongated bubbles, annular flow, and mist flow can exist in microchannels during flow boiling. Stable and unstable flow boiling modes may occur in microchannels, depending on the heat to mass flux ratio and inlet subcooling of the liquid. Heat transfer and pressure drop data in flow boiling in microchannels are shown to deviate greatly from correlations for flow boiling in macrochannels. For flow condensation in microchannels, mist flow, annular flow, injection flow, plug-slug flow, and bubbly flows can exist in the microchannels, depending on mass flux and quality. Effects of the dimensionless condensation heat flux and the Reynolds number of saturated steam on transition from annular two-phase flow to slug/plug flow during condensation in microchannels are discussed. Heat transfer and pressured drop data in condensation flow in microchannels, at low mass flux are shown to be higher and lower than those predicted by correlations for condensation flow in macrochannels, respectively. Effects of pulse heating width and heater size on microbubble growth and collapse and its nucleation temperature on a microheater under pulse heating are summarized.

scholarly journals Heat Transfer during Annular Flow Condensation of Steam inside Tubes

1977 ◽  
Vol 20 (147) ◽  
pp. 1174-1181 ◽  
Author(s):  
Tatsuhiro UEDA ◽  
Mitsuru INOUE
Keyword(s):  
Heat Transfer ◽  
Annular Flow ◽  
Flow Condensation

scholarly journals Comparative study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels

2014 ◽  
Vol 35 (3) ◽  
pp. 17-37 ◽  
Author(s):  
Dariusz Mikielewicz ◽  
Rafał Andrzejczyk ◽  
Blanka Jakubowska ◽  
Jarosław Mikielewicz
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Shear Stress ◽  
Pressure Drop ◽  
Flow Structure ◽  
Annular Flow ◽  
Flow Boiling ◽  
Bubble Nucleation ◽  
Shear Stresses ◽  
Flow Condensation

Abstract In the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation of the so called blowing parameter. The shear stress between vapor phase and liquid phase is generally a function of nonisothermal effects. The mechanism of modification of shear stresses at the vapor-liquid interface has been presented in detail. In case of annular flow it contributes to thickening and thinning of the liquid film, which corresponds to condensation and boiling respectively. There is also a different influence of heat flux on the modification of shear stress in the bubbly flow structure, where it affects bubble nucleation. In that case the effect of applied heat flux is considered. As a result a modified form of the two-phase flow multiplier is obtained, in which the nonadiabatic effect is clearly pronounced.

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