Comparative experimental study on pool boiling performance of porous coating and solid structures with reentrant channels

Deng, Daxiang; Wan, Wei; Feng, Junyuan; Huang, Qingsong; Qin, Yu; Xie, Yanlin

doi:10.1016/j.applthermaleng.2016.06.172

Cited by 70 publications

(19 citation statements)

References 42 publications

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“…Deng et al [157,158] used solid-state sintering method to develop porous structures with re-entrant cavities (PS-RC). Omega-shaped porous copper powder coating, shown in Figure 15 and Table 4, and solid structure of the same shape and material were prepared for comparison of nucleate boiling heat transfer.…”

Section: Micro-scale Coatingsmentioning

confidence: 99%

Micro-Nano Scale Surface Coating for Nucleate Boiling Heat Transfer: A Critical Review

2018

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Nucleate boiling is a phase change heat transfer process with a wide range of applications i.e., steam power plants, thermal desalination, heat pipes, domestic heating and cooling, refrigeration and air-conditioning, electronic cooling, cooling of turbo-machinery, waste heat recovery and much more. Due to its quite broad range of applications, any improvement in this area leads to significant economic, environmental and energy efficiency outcomes. This paper presents a comprehensive review and critical analysis on the recent developments in the area of micro-nano scale coating technologies, materials, and their applications for modification of surface geometry and chemistry, which play an important role in the enhancement of nucleate boiling heat transfer. In many industrial applications boiling is a surface phenomenon, which depends upon its variables such as surface area, thermal conductivity, wettability, porosity, and roughness. Compared to subtractive methods, the surface coating is more versatile in material selection, simple, quick, robust in implementation and is quite functional to apply to already installed systems. The present status of these techniques for boiling heat transfer enhancement, along with their future challenges, enhancement potentials, limitations, and their possible industrial implementation are also discussed in this paper.

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Section: Micro-scale Coatingsmentioning

confidence: 99%

Micro-Nano Scale Surface Coating for Nucleate Boiling Heat Transfer: A Critical Review

2018

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“…These designs make use of dedicated feeding structures to enhance liquid supply while also providing vapor removal pathways. In pool boiling, recent studies have used porous wicks made from modulated post designs [14] or containing re-entrant cavities [15] to enhance the heat transfer coefficient and improve the critical heat flux (CHF). For enhanced capillary-fed boiling in evaporator wicks, heterogeneous wick designs aim to provide simultaneous high capillary pressure and high permeability, as an alternative to thick biporous wicks.…”

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confidence: 99%

Experimental investigation of boiling regimes in a capillary-fed two-layer evaporator wick

Sudhakar

Weibel

Garimella

2019

International Journal of Heat and Mass Transfer

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Vapor chambers with transformative evaporator wick designs capable of passively dissipating high heat fluxes over large areas, while maintaining low thermal resistances, can meet the thermal management needs of next-generation power semiconductor devices. Our prior work proposed a two-layer evaporator wick structure to enhance the performance of vapor chambers operating at high heat fluxes. The current study experimentally characterizes the capillary-fed boiling heat transfer behavior in such a two-layer evaporator wick, compared to a homogeneous (single-layer) wick, over a 1 cm 2 evaporator area. The two-layer design comprises a thin base wick layer that is fed with liquid from a thick cap wick layer above using an array of vertical posts. The two-layer wick is fabricated using a sequence of sintering and laser-machining steps to form the base wick layer (200 µm), array of liquid-feeding posts, and cap wick layer (800 µm) using 90-106 µm copper particles. A test facility is constructed to replicate the conditions that exist at the evaporator of a vapor chamber; the novel facility design uses a physical restriction to prevent flooding of the wicks during testing. Two-layer wicks having 5×5 and 10×10 arrays of liquid feeding posts are characterized, along with a 200 µm-thick single-layer evaporator wick. The 10×10 array provides a >400% enhancement in the dryout heat flux compared to the single-layer wick. High-speed visualizations are used to identify the characteristic regimes of boiling operations for the wicks. The single-layer wick exhibits a partial dryout mode of operation, where a dry spot formed in the center of the heated evaporator area causes an increase in the thermal resistance with heat flux. In contrast, the distributed feeding provided by the two-layer wicks mitigates the development of this partial dryout regime and maintains a constant low resistance (~ 0.1 K/W) during capillary-fed boiling until a complete dryout event occurs. This study demonstrates the significant enhancement in dryout heat flux offered by the liquid-feeding approach realized in the two-layer evaporator wicks characterized here.

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“…They studied the effect of the inter-fin channel width on the surface performance and heat transfer mechanisms in open microchannel surfaces with three coating configurations: sintered-throughout, sintered-fin-tops, and sintered-channels. The heat transfer coefficients obtained, up to 2900 kW/m 2 K, were large relative to the structured 10 x 10 mm 2 area, which gives about 1000 kW/m 2 K relative to the total surface of heat transfer (17 x 17 mm 2 ) In [2,3], the authors performed an experiment with water and ethanol at atmospheric pressure. The surfaces studied were :-shaped copper structures with circular cavities and narrow exit grooves upwards.…”

Section: Introductionmentioning

confidence: 99%

Effect of geometrical parameters of open microchannel surfaces on pool boiling heat transfer

2017

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Abstract. This study focuses on the effect of channel depth on the heat transfer coefficient during nucleate pool boiling. Experimental studies were performed for saturated deionized water, and Novec-649 as working fluids at atmospheric pressure. Copper surfaces were modified to form microchannels with different geometrical properties. The microchannels were from 0.2 mm to 0.4 mm deep, 0.3 mm wide and spaced every 0.1 mm. The experiment was conducted for increasing heat flux up to the critical heat flux point. The surface modification provided an appreciably higher heat transfer coefficient compared to the smooth surface for all boiling liquids. The maximum heat transfer coefficient obtained exceeded 60 kW/m 2 K.

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Comparative experimental study on pool boiling performance of porous coating and solid structures with reentrant channels

Cited by 70 publications

References 42 publications

Micro-Nano Scale Surface Coating for Nucleate Boiling Heat Transfer: A Critical Review

Micro-Nano Scale Surface Coating for Nucleate Boiling Heat Transfer: A Critical Review

Experimental investigation of boiling regimes in a capillary-fed two-layer evaporator wick

Effect of geometrical parameters of open microchannel surfaces on pool boiling heat transfer

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