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.

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.

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%.

Flow Regime Analysis of Forced Flow Boiling Hydrogen Subjected to High Heat Flux

2005 ◽  
Author(s):  
James Pasch ◽  
Michael Popp ◽  
Samim Anghaie
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Flow Boiling ◽  
High Heat ◽  
Forced Flow ◽  
Film Boiling ◽  
High Heat Flux ◽  
Two Phase ◽  
Transfer Data ◽  
Flow Pattern Map

This paper presents an analysis of forced flow two-phase hydrogen heat transfer data for the purpose of interpreting the various flow regimes of inverted annular flow. Hydrogen heat transfer data available from an early 1960s NASA experimental investigation were used for the analysis. The data was evaluated in light of a heat transfer characteristics map and related flow pattern map which were established by more recent work on inverted flow film boiling of freon R113. It was shown that the hydrogen data exhibit the same three flow patterns as found in the R113 data. This may allow the use of film boiling heat transfer models developed for such fluids to be used for hydrogen film boiling heat transfer predictions.

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