scholarly journals CHF of Pool Boiling on Microwires

2009 ◽  
Author(s):  
Jian-Fu Zhao ◽  
Yang-Hui Lu ◽  
Jing Li
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Pool Boiling ◽  
Bond Number ◽  
Working Fluids ◽  
Similar Range ◽  
Minimum Heat

The present paper reports a new series of experimental data of CHF (critical heat flux) of pool boiling on cylinders. Platinum wires of 30 mm in length are simultaneously used as heaters and thermometers. Their diameters are 0.1, 0.06, and 0.025 mm, respectively. FC-72 and acetone are used as working fluids. The range of the subcooling is from 0 K to about 50 K. The gaps between CHF and MHF (minimum heat flux) become narrower and narrower with the decrease of the heater diameter. But it exists even in the saturated pool boiling on the smallest wire in the present study. The dependence of CHF on the subcooling in acetone differs from that in FC-72 though the data locate in the similar range of Bond number in the two different kinds of working fluids. It indicates that interactions between the influences of the subcooling and size on CHF will be important for the small Bond number, and that there may exist some other parameters, which may be material-dependant, in addition to the Bond number that play important roles in the CHF phenomenon with small Bond number.

An Investigation of the Effect of Inclination on Critical Heat Flux of PF-5060 Dielectric Liquid on Microporous Copper Surfaces

2013 ◽  
Author(s):  
Amir F. Ali ◽  
Mohamed S. El-Genk
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Inclination Angle ◽  
Pool Boiling ◽  
Dielectric Liquid ◽  
Copper Surfaces ◽  
Electrochemical Processes ◽  
Inclination Angles

Pool boiling experiments investigated the effect of inclination angle on the Critical Heat Flux (CHF) for saturation boiling of PF-5060 dielectric liquid on MicroPorous Copper (MPC) surfaces of different thicknesses (80 to 230 μm). The morphology of the surfaces, deposited using electrochemical processes, vary with the thickness, and hence CHF. The inclination angles investigated are 0° (upward facing), 60°, 90° (vertical), 120°, 150°, 160°, 170° and 180° (downward facing). CHF decreases with decreasing MPC thickness and/or increasing inclination angle. The CHF values in the upward facing orientation are 39%–67% higher than on smooth, polished Cu. For all MPC surfaces, CHF values in the downward facing orientation are ∼ 28% of those in the upward facing orientation (0°). The developed CHF correlation accounts for the effects of MPC thickness and inclination angle and is in agreement with experimental data to within ± 8%.

scholarly journals Method for calculating the critical heat flux at pool boiling on structured surfaces

2021 ◽  
Vol 2039 (1) ◽  
pp. 012034
Author(s):  
A V Stupakova ◽  
A V Dedov
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Pool Boiling ◽  
Calculated Data ◽  
Porous Space ◽  
Structured Surfaces ◽  
Evaporation Zone ◽  
Microstructured Surfaces ◽  
Irregular Geometries

Abstract A method of the critical heat flux enhancements at pool boiling using rough structures of various regular and irregular geometries is investigated. The experimental data are compared, and the critical heat flux is calculated since the V. V. Yagov model, which considers the additional inflow of liquid into the evaporation zone due to the action of capillary forces in the porous space. Based on the comparison of experimental and calculated data, it is concluded that the model is not universal for all microstructured surfaces. Recommendations for the calculation are given.

INVESTIGATING THE RELATIONSHIP BETWEEN SURFACE WICKABILITY AND CRITICAL HEAT FLUX DURING POOL BOILING

2018 ◽  
Author(s):  
Youngsup Song ◽  
Yangying Zhu ◽  
Daniel J. Preston ◽  
H. Jeremy Cho ◽  
Zhengmao Lu ◽  
...  
Keyword(s):  
Heat Flux ◽  
Critical Heat Flux ◽  
Pool Boiling ◽  
The Relationship

THE CRITICAL HEAT FLUX AT THE POOL BOILING OF SOME BINARY LIQUID MIXTURES

2019 ◽  
Author(s):  
Samson Semenovich Kutateladze ◽  
G.I. Bobrovich ◽  
I. I. Gogonin ◽  
N.N. Mamontova ◽  
V.N. Moskvicheva
Keyword(s):  
Heat Flux ◽  
Critical Heat Flux ◽  
Pool Boiling ◽  
Liquid Mixtures ◽  
Binary Liquid Mixtures ◽  
Binary Liquid

Effects of Surface Coating on the Critical Heat Flux for Pool Boiling from a Downward Facing Surface

2004 ◽  
Vol 11 (2) ◽  
pp. 133-150 ◽  
Author(s):  
M. B. Dizon ◽  
J. Yang ◽  
F. B. Cheung ◽  
J. L. Rempe ◽  
K. Y. Suh ◽  
...  
Keyword(s):  
Heat Flux ◽  
Critical Heat Flux ◽  
Surface Coating ◽  
Pool Boiling

On the Role of Marangoni Effects on the Critical Heat Flux for Pool Boiling of Binary Mixtures

1996 ◽  
Vol 118 (1) ◽  
pp. 103-109 ◽  
Author(s):  
W. R. McGillis ◽  
V. P. Carey
Keyword(s):  
Surface Tension ◽  
Heat Flux ◽  
Binary Mixtures ◽  
Critical Heat Flux ◽  
Full Range ◽  
Pool Boiling ◽  
Marangoni Effect ◽  
Restoring Force ◽  
Marangoni Effects

The Marangoni effect on the critical heat flux (CHF) condition in pool boiling of binary mixtures has been identified and its effect has been quantitatively estimated with a modified model derived from hydrodynamics. The physical process of CHF in binary mixtures, and models used to describe it, are examined in the light of recent experimental evidence, accurate mixture properties, and phase equilibrium revealing a correlation to surface tension gradients and volatility. A correlation is developed from a heuristic model including the additional liquid restoring force caused by surface tension gradients. The CHF condition was determined experimentally for saturated methanol/water, 2-propanol/water, and ethylene glycol/water mixtures, over the full range of concentrations, and compared to the model. The evidence in this study demonstrates that in a mixture with large differences in surface tension, there is an additional hydrodynamic restoring force affecting the CHF condition.

Deep learning strategies for critical heat flux detection in pool boiling

2021 ◽  
Vol 190 ◽  
pp. 116849
Author(s):  
Seyed Moein Rassoulinejad-Mousavi ◽  
Firas Al-Hindawi ◽  
Tejaswi Soori ◽  
Arif Rokoni ◽  
Hyunsoo Yoon ◽  
...  
Keyword(s):  
Heat Flux ◽  
Deep Learning ◽  
Learning Strategies ◽  
Critical Heat Flux ◽  
Pool Boiling

The Mechanism of and Stability Criterion for Nucleate Pool Boiling of Sodium

1969 ◽  
Vol 91 (3) ◽  
pp. 315-328 ◽  
Author(s):  
I. Shai ◽  
W. M. Rohsenow
Keyword(s):  
Heat Flux ◽  
Liquid Metals ◽  
Bubble Formation ◽  
Pool Boiling ◽  
Heat Fluxes ◽  
Nucleate Pool Boiling ◽  
Thermal Layer ◽  
Minimum Heat ◽  
Bubble Growth And Departure ◽  
Recorded Temperature

Experimental data for sodium boiling on horizontal surfaces containing artificial cavities at heat fluxes of 20,000 to 300,000 Btu/ft2 hr and pressures between 40 to 106 mm Hg were obtained. Observations are made for stable boiling, unstable boiling and “bumping.” Some recorded temperature variations in the solid close to the nucleating cavity are presented. It is suggested that for liquid metals the time for bubble growth and departure is a very small fraction of the total bubble cycle, hence the delay time during which a thermal layer grows is the most significant part of the process. On this basis the transient conduction heat transfer is solved for a periodic process, and the period time is found to be a function of the degree of superheat, the heat flux and the liquid thermal properties. A simplified model for stability of nucleate pool boiling of liquid metals is postulated from which the minimum heat flux for stable boiling can be found as a function of liquid-solid properties, liquid pressure, the degree of superheat, and the cavity radius and depth. At relatively low heat fluxes, convection currents have significant effects on the period time of bubble formation. An empirical correlation is proposed, which takes into account the convection effects, to match the experimental results.

Effect of subcooling on critical heat flux during pool boiling on a horizontal heated wire

1998 ◽  
Vol 33 (5-6) ◽  
pp. 481-488 ◽  
Author(s):  
T. Inoue ◽  
N. Kawae ◽  
M. Monde
Keyword(s):  
Heat Flux ◽  
Critical Heat Flux ◽  
Pool Boiling ◽  
Heated Wire
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