Numerical study of high heat flux pool boiling heat transfer

Spherical glass and copper beads have been used to create bead packed porous structures for an investigation of two-phase heat transfer bubble dynamics under geometric constraints. The results demonstrated a variety of bubble dynamics characteristics under a range of heating conditions. The bubble generation, growth, and detachment during the nucleate pool boiling heat transfer have been filmed, the heating surface temperatures and heat flux were recorded, and theoretical models have been employed to study bubble dynamic characteristics. Computer simulation results were combined with experimental observations to clarify the details of the vapor bubble growth process and the liquid water replenishing the inside of the porous structures. This investigation has clearly shown, with both experimental and computer simulation evidence, that the millimeter scale bead packed porous structures could greatly influence pool boiling heat transfer by forcing a single bubble to depart at a smaller size, as compared with that in a plain surface situation at low heat flux situations, and could trigger the earlier occurrence of critical heat flux by trapping the vapor into interstitial space and forming a vapor column net at high heat flux situations. The results also proved data for further development of theoretical models of pool boiling heat transfer in bead packed porous structures.

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Pool Boiling Heat Transfer on Vertical Micro Porous Coated Surface in Confined Space

ASME 2008 6th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2008-62241 ◽

2008 ◽

Author(s):

Chien-Yuh Yang ◽

Chien-Fu Liu

Keyword(s):

Heat Transfer ◽

Boiling Heat Transfer ◽

Heat Transfer Performance ◽

Pool Boiling ◽

High Heat ◽

Heat Fluxes ◽

High Heat Flux ◽

Confined Space ◽

Pool Boiling Heat Transfer ◽

Coated Surface

Attributed to its high heat transfer coefficient, evaporating cooling involving the use of micro heat exchangers is considered a possible thermal management solution for cooling of high heat flux electronic devices. The present work desires to develop high-performance micro heat exchangers operating in the evaporation regime. The pool boiling heat transfer performance on one plain plate and one micro porous coated plate were tested in a vertical open and a 1-mm confined spaces. The test results show that the heat transfer was enhanced by the confined space at low and moderate heat fluxes but degraded at high flux condition on plain surface. The micro porous coating may significantly enhance the pool boiling performance. However, the heat transfer characteristic in confined space is not exactly the same as that on open surfaces. Owing to the interaction of forced removal of the superheated liquid due to the bubble departure and retard the departure of bubbles by the confined plate, there is no much difference for pool boiling heat transfer on micro porous coated surface in confined and unconfined spaces at low and moderate heat fluxes. At high heat flux, large amount of bubbles were confined by the cover plate. This caused the partial dry out and significant degrade on heat transfer performance.

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Pool Boiling Heat Transfer of Water on Copper Surfaces With Nanoparticles Coating

Volume 8: Heat Transfer and Thermal Engineering ◽

10.1115/imece2017-71303 ◽

2017 ◽

Cited By ~ 3

Author(s):

Zhen Cao ◽

Calle Preger ◽

Zan Wu ◽

Sahar Abbood ◽

Maria E. Messing ◽

...

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Heat Transfer Coefficient ◽

Transfer Coefficient ◽

Boiling Heat Transfer ◽

Deposition Time ◽

Pool Boiling ◽

Working Fluid ◽

High Heat Flux ◽

Pool Boiling Heat Transfer

Saturated pool boiling heat transfer is investigated experimentally on a copper substrate with copper nanoparticle coatings at atmospheric pressure, in terms of critical heat flux (CHF) and heat transfer coefficient (HTC). Experiments are carried out on the substrate surface with a diameter of 12 mm using DI water as the working fluid. The coating is formed by stacking copper nanoparticles generated by an aerosol method. The aerosol nanoparticles are generated by a spark discharge generator with nitrogen gas as carrier gas and size-selected prior to electrostatic deposition. The thickness of the coating is quantified by the deposition time. In the present study, copper particles with diameter 35± 5 nm are selected, considering better coverage on the surface, while the deposition time is controlled as 4h and 8h, respectively. The boiling curves and heat transfer coefficient of MS-1 (4h deposition) and MS-2 (8h deposition) were compared with the BS (bare surface). The results show that CHFs of MS-1 and MS-2 are increased by 24% and 36%, respectively compared with the BS, while heat transfer is enhanced as well. High speed visualization tells that the coating provides more active nucleate sites and the hydrophobicity of the coating helps bubbles departure from the surface at low and moderate heat flux. At high heat flux, a hollow well occurs on MSs to supply liquid effectively to avoid dryout. Therefore, CHF and heat transfer are both improved.

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Pool Boiling Heat Transfer and Bubble Dynamics Over Plain and Enhanced Microchannels

Journal of Heat Transfer ◽

10.1115/1.4003046 ◽

2011 ◽

Vol 133 (5) ◽

Cited By ~ 74

Author(s):

Dwight Cooke ◽

Satish G. Kandlikar

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Boiling Heat Transfer ◽

Bubble Dynamics ◽

Pool Boiling ◽

High Heat ◽

Heat Fluxes ◽

High Heat Flux ◽

Silicon Chips ◽

Heat Of Evaporation

Pool boiling is of interest in high heat flux applications because of its potential for removing large amount of heat resulting from the latent heat of evaporation and little pressure drop penalty for circulating coolant through the system. However, the heat transfer performance of pool boiling systems is not adequate to match the cooling ability provided by enhanced microchannels operating under single-phase conditions. The objective of this work is to evaluate the pool boiling performance of structured surface features etched on a silicon chip. The performance is normalized with respect to a plain chip. This investigation also focuses on the bubble dynamics on plain and structured microchannel surfaces under various heat fluxes in an effort to understand the underlying heat transfer mechanism. It was determined that surface modifications to silicon chips can improve the heat transfer coefficient by a factor up to 3.4 times the performance of a plain chip. Surfaces with microchannels have shown to be efficient for boiling heat transfer by allowing liquid to flow through the open channels and wet the heat transfer surface while vapor is generated. This work is expected to lead to improved enhancement features for extending the pool boiling option to meet the high heat flux removal demands in electronic cooling applications.

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A Review of Boiling Heat Transfer Processes at High Heat Flux

10.21236/ada584968 ◽

1991 ◽

Author(s):

G. R. Beitel

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Boiling Heat Transfer ◽

High Heat ◽

High Heat Flux ◽

Transfer Processes

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Numerical study of pool boiling heat transfer in a large-scale confined space

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2017.02.110 ◽

2017 ◽

Vol 118 ◽

pp. 188-198 ◽

Cited By ~ 8

Author(s):

Yongsheng Tian ◽

Keyuan Zhang ◽

Naihua Wang ◽

Zheng Cui ◽

Lin Cheng

Keyword(s):

Heat Transfer ◽

Boiling Heat Transfer ◽

Large Scale ◽

Numerical Study ◽

Pool Boiling ◽

Confined Space ◽

Pool Boiling Heat Transfer

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Observations of the Critical Heat Flux Process During Pool Boiling of FC-72

Journal of Heat Transfer ◽

10.1115/1.4025697 ◽

2014 ◽

Vol 136 (4) ◽

Cited By ~ 42

Author(s):

J. Jung ◽

S. J. Kim ◽

J. Kim

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Critical Heat Flux ◽

Pool Boiling ◽

High Heat ◽

Line Length ◽

Boiling Curve ◽

High Heat Flux ◽

Transfer Coefficients ◽

Ir Camera

Experimental work was undertaken to investigate the process by which pool-boiling critical heat flux (CHF) occurs using an IR camera to measure the local temperature and heat transfer coefficients on a heated silicon surface. The wetted area fraction (WF), the contact line length density (CLD), the frequency between dryout events, the lifetime of the dry patches, the speed of the advancing and receding contact lines, the dry patch size distribution on the surface, and the heat transfer from the liquid-covered areas were measured throughout the boiling curve. Quantitative analysis of this data at high heat flux and transition through CHF revealed that the boiling curve can simply be obtained by weighting the heat flux from the liquid-covered areas by WF. CHF mechanisms proposed in the literature were evaluated against the observations.

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Experimental Investigation of Boiling Heat Transfer in a Liquid Chamber With Partially Soluble Nanofluids

10.1115/ipack2021-67330 ◽

2021 ◽

Author(s):

Noriyuki Unno ◽

Kazuhisa Yuki ◽

Risako Kibushi ◽

Rika Nogita ◽

Atsuyuki Mitani

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Boiling Heat Transfer ◽

Electronic Devices ◽

High Heat ◽

Experimental Result ◽

High Heat Flux ◽

Promising Technique ◽

Cooling Device ◽

Cooling Devices

Abstract Boiling heat transfer (BHT) is a promising technique to remove a high heat flux emitted from next-generation electronic devices. However, critical heat flux (CHF) is a big problem in BHT because it restricts the maximum performance of the cooling devices using BHT. Nanofluid has been widely used to improve the CHF. In this study, the authors investigated the BHT of a compact cooling device at low pressure using a special nanofluid: that is made with partially soluble particles in water. The experimental result found that the CHF with the special nanofluid is 170 W/cm2 and is higher than that with nanofluid made with an insoluble nanoparticle.

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