Heat transfer intensity at forced flow boiling of cryogenic liquids in tubes

Cryogenics ◽  
1982 ◽  
Vol 22 (11) ◽  
pp. 569-576 ◽  
Author(s):  
V.V. Klimenko
Keyword(s):  
Heat Transfer ◽  
Flow Boiling ◽  
Forced Flow ◽  
Cryogenic Liquids

Effect of dissolved gas on bubble formation and boiling heat transfer in forced flow boiling

2020 ◽  
Vol 2020 (0) ◽  
pp. 16B01
Author(s):  
Hiroaki NARAZAKI ◽  
Satoshi MATSUMOTO ◽  
Yutaka ABE ◽  
Akiko KANEKO
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Flow Boiling ◽  
Bubble Formation ◽  
Forced Flow ◽  
Dissolved Gas

Study on Subcooled-Forced Flow Boiling Heat Transfer and Critical Heat Flux of Solid-Water Two-Phase Mixture

1999 ◽  
Author(s):  
Yasuo Koizumi ◽  
Hiroyasu Ohtake ◽  
Manabu Mochizuki
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Liquid Layer ◽  
Boiling Heat Transfer ◽  
Flow Boiling ◽  
Nucleate Boiling ◽  
Forced Flow ◽  
Superheated Liquid ◽  
Flow Boiling Heat Transfer

Abstract The effect of solid particle introduction on subcooled-forced flow boiling heat transfer and a critical heat flux was examined experimentally. In the experiment, glass beads of 0.6 mm diameter were mixed in subcooled water. Experiments were conducted in a range of the subcooling of 40 K, a velocity of 0.17–6.7 m/s, a volumetric particle ratio of 0–17%. When particles were introduced, the growth of a superheated liquid layer near a heat trasnsfer surface seemed to be suppressed and the onset of nucleate boiling was delayed. The particles promoted the condensation of bubbles on the heat transfer surface, which shifted the initiation of a net vapor generation to a high heat flux region. Boiling heat trasnfer was augmented by the particle introduction. The suppression of the growth of the superheated liquid layer and the promotion of bubble condensation and dissipation by the particles seemed to contribute that heat transfer augmentation. The wall superheat at the critical heat flux was elevated by the particle introduction and the critical heat flux itself was also enhanced. However, the degree of the critical heat flux improvement was not drastic.

Flow Boiling Dynamics of Water and Nanofluids in a Single Microchannel at Different Heat Fluxes

2013 ◽  
Author(s):  
Zachary Edel ◽  
Abhijit Mukherjee
Keyword(s):  
Heat Transfer ◽  
Flow Boiling ◽  
Nucleate Boiling ◽  
Bubble Nucleation ◽  
Heat Fluxes ◽  
Forced Flow ◽  
Fluid Temperature ◽  
Nanofluid Flow ◽  
Nanoparticle Suspension ◽  
Nanoparticle Deposition

The preferable cooling solution to the problem of thermal management of modern electronics for increasing power dissipation could be micro heat exchangers based on forced flow boiling. Nanoparticle deposition can affect nucleate boiling heat transfer coefficient via alteration of surface thermal conductivity, roughness, capillary wicking, wettability, and nucleation site density. It can also affect heat transfer by changing bubble departure diameter, bubble departure frequency, and the evaporation of the micro and macrolayer beneath the growing bubbles. In this study, flow boiling was investigated using degassed, deionized water, and 0.001 vol% aluminum oxide nanofluids in a single rectangular brass microchannel for one inlet fluid temperature of 63°C, one flow rate of Re = 100, and two heat fluxes of 130 kW/m2 and 300 kW/m2. High speed images were taken periodically for water and after durations of 25, 75, and 125 minutes of nanofluid flow boiling. The change in regime timing revealed the effect of nanoparticle suspension and nanoparticle deposition on the Onset of Nucelate Boiling (ONB) and the Onset of Bubble Elongation (OBE). Single phase flows at the channel outlet were recorded and compared for different durations of nanofluid flow boiling. The addition of nanoparticles was found to stabilize bubble nucleation and growth and increase heat transfer in the thin film regions of the evaporating menisci.

Assessment of Flow Boiling Heat Transfer Correlations for Application to Mini-Channels

2006 ◽  
Author(s):  
Nurudeen O. Olayiwola ◽  
S. Mostafa Ghiaasiaan
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Boiling Heat Transfer ◽  
Flow Boiling ◽  
Forced Flow ◽  
Transfer Mode ◽  
Micro Channels ◽  
Mini Channels ◽  
Feasible Range ◽  
Conventional Cooling

Cooling systems that consist of mini-channels (channels with hydraulic diameters in the 0.5 mm to 2.0 mm range) and micro-channels (channels with hydraulic diameters in the 100 μm-500 μm range) can dispose of large volumetric thermal loads that are well beyond the feasible range of conventional cooling methods. Mini/micro-channel systems that utilize boiling fluids are particularly useful due to the superiority of boiling heat transfer mode over single-phase flow convention. Flowing boiling in mini and micro channels has been investigated experimentally by several research groups recently, and a number of empirical correlations have been developed, usually based on only a single set of experimental data. In this study, the capability of a number of widely used forced flow boiling correlations for application to mini channels is examined by comparing their predictions with experimental data from three separate sources. The tested correlations include well-established methods for conventional boiling systems, as well as correlations recently proposed for mini-channels. The experimental data all represent mini-channels. Based on these comparisons, the most accurate existing predictive methods for the tested mini-channel boiling data are identified.

A Numerical Study of Single Bubble Dynamics During Flow Boiling

2004 ◽  
Author(s):  
Ding Li ◽  
Vijay K. Dhir
Keyword(s):  
Heat Transfer ◽  
Bubble Dynamics ◽  
Numerical Study ◽  
Flow Boiling ◽  
Forced Flow ◽  
Single Bubble ◽  
Horizontal Line ◽  
Vapor Interface ◽  
Single Bubble Dynamics ◽  
Liquid Vapor

Nucleate flow boiling is a liquid-vapor phase-change process associated with high heat transfer rates. A complete 3D numerical simulation of single bubble dynamics on surfaces inclined at 90°, 45° and 30° to the horizontal line and subjected to forced flow parallel to the surface is performed in this work. The continuity, momentum and energy equations are solved with finite difference method and the level-set method is used to capture the liquid-vapor interface. The heat transfer contribution of the micro-layer between the solid wall and evolving liquid-vapor interface is included in this numerical analysis. The effect of dynamic contact angle is also included. The numerical result of bubble growth and sliding distance have been compared with experimental data.

Influencing Factors on Heat Transfer Performance for Flow Boiling of R410A in Horizontal Micro-Fin Tubes

2012 ◽  
Vol 472-475 ◽  
pp. 1676-1680
Author(s):  
Hong Ping He ◽  
Hu Gen Ma ◽  
Jian Mei Bai
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Boiling Heat Transfer ◽  
Flow Boiling ◽  
Forced Flow ◽  
Transfer Coefficients ◽  
Flow Boiling Heat Transfer ◽  
Boiling Heat Transfer Coefficient ◽  
Fin Tubes

Flow boiling heat transfer performances of refrigerant R410A in the horizontal micro-fin tubes with different geometric parameters were investigated. The dependencies of forced flow boiling heat transfer coefficient of R410A on mass flow rate, heat flux and were studied and the mechanism of flow boiling heat transfer under different working conditions were discussed. For a comparison, the influences of fin number and fin height of micro-fin tubes on heat transfer were also studied. The differences of heat transfer coefficient between R22 and R410A were analyzed. It is found that the heat transfer coefficients were nearly same for R22 and R410A and, in fact, the heat transfer coefficient of R22 was just a little higher than that of R410A by 4-7%.

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