Boiling heat transfer performance enhancement using micro and nano structured surfaces for high heat flux electronics cooling systems

2017 ◽  
Vol 127 ◽  
pp. 484-498 ◽  
Author(s):  
Abdolali Khalili Sadaghiani ◽  
Nawzat S. Saadi ◽  
Sorour Semsari Parapari ◽  
Tansel Karabacak ◽  
Mehmet Keskinoz ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Heat Transfer Performance ◽  
Performance Enhancement ◽  
Electronics Cooling ◽  
High Heat ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Cooling Systems ◽  
Structured Surfaces

Nanofluid Boiling Heat Transfer and Critical Heat Flux Enhancement: Mechanism to Be Revealed

2013 ◽  
Author(s):  
Junmei Wu ◽  
Jiyun Zhao ◽  
Yun Wang
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Boiling Heat Transfer ◽  
Heat Transfer Performance ◽  
Bubble Dynamics ◽  
High Heat ◽  
Solid Particles ◽  
High Heat Flux ◽  
Transfer Performance

As a novel strategy to improve heat transfer characteristics of fluids by the addition of solid particles with diameters below 100 nm, nanofluids exhibits unprecedented heat transfer properties and are being considered as potential working fluids to be used in high heat flux systems such as nuclear reactors, electronic cooling systems and solar collectors. The present paper reviews the state-of-the-art studies on nanofluid boiling heat transfer performance and critical heat flux (CHF) enhancement. It is found that some results on nanofluids boiling heat transfer performance are inconsistent or contradictory in data published. The knowledge on the mechanism of nanofluids boiling CHF enhancement is insufficient. Bubble dynamics of nanofluids boiling is suggested to be investigated to identify the exact contributions of solid surface modifications and suspended nanoparticles to CHF enhancement in nanofluids boiling heat transfer.

Study of Boiling Heat Transfer on Heterogeneous Wetting Surface With MD Simulation

2021 ◽  
Author(s):  
Zeyu Liu ◽  
Runkeng Liu ◽  
Peng Li ◽  
Anyi Xu ◽  
Zhenyu Liu
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Evaporation Rate ◽  
Heat Transfer Performance ◽  
Nucleate Boiling ◽  
High Heat ◽  
Area Fraction ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Hydrophobic Region

Abstract Wettability has been proved as an important issue to the thermal transport at solid-liquid interface at different scales, however, its enhancement mechanism has not been clearly understood till now. In this study, the nucleate boiling behavior of argon fluid on heterogeneous wetting surfaces were examined with the non-equilibrium molecular dynamics (MD) method, the ring-patterned and stripe-patterned schemes were designed and analyzed, respectively. By comparing the boiling inception time and evaporation rate of liquid argon atoms, it is found that the ring-patterned surface shows an advantage in the nucleate boiling heat transfer compared with the stripe-patterned one. The differences in heat transfer characteristics for different surfaces can be explained through the qualitative analysis of fluid density distribution and solid-fluid interaction energy. Furthermore, the boiling phenomena on ring-patterned surfaces with alternated hydrophilic and hydrophobic intervals were simulated to study the influence of area fraction of hydrophilic region on the heat transfer performance. It is observed that bubble nucleus firstly appears over the hydrophobic region of the substrate. The substrate with more hydrophilic area will have a better heat transfer performance. It is also demonstrated that there is an optimal area fraction, which can make the evaporation rate of fluid reach the highest value. The findings in this work can contribute to the design and fabrication of nanocoating surface to enhance its heat transfer performance under high heat flux condition.

Working Fluid Inventory Effect on Heat Transfer Performance of a Grooved Micro Heat Pipe

2013 ◽  
Vol 589-590 ◽  
pp. 559-564
Author(s):  
Xi Bing Li ◽  
Yun Shi Ma ◽  
Xun Wang ◽  
Ming Li
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Mathematic Model ◽  
High Heat ◽  
Working Fluid ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Flux Concentration

As a highly efficient heat transfer component, a micro heat pipe (MHP) has been widely applied to the situations with high heat flux concentration. However, a MHPs heat transfer performance is affected by many factors, among which, working fluid inventory has great influence on the security, reliability and frost resistance of its heat transfer performance. In order to determine the appropriate working fluid inventory for grooved MHPs, this paper first analyzed the working principle, major heat transfer limits and heat flux distribution law of grooved MHPs in electronic chips with high heat flux concentration, then established a mathematic model for the working fluid inventory in grooved MHPs. Finally, with distilled water being the working fluid, a series of experimental investigations were conducted at different temperatures to test the heat transfer performances of grooved MHPs, which were perfused with different inventories and with different adiabatic section lengths. The experimental results show that when the value of α is roughly within 0.40±0.05, a grooved MHP can acquire its best heat transfer performance, and the working fluid inventory can be determined by the proposed mathematic model. Therefore this study solves the complicated problem of determining appropriate working fluid inventory for grooved MHPs.

Enhanced Boiling of FC-72 on Silicon Chips With Micro-Pin-Fins and Submicron-Scale Roughness

2001 ◽  
Vol 124 (2) ◽  
pp. 383-390 ◽  
Author(s):  
H. Honda ◽  
H. Takamastu ◽  
J. J. Wei
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Performance ◽  
High Heat ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Wall Superheat ◽  
Submicron Scale ◽  
Pin Fins ◽  
Scale Roughness

Experiments were conducted to study the effects of micro-pin-fins and submicron-scale roughness on the boiling heat transfer from a silicon chip immersed in a pool of degassed and gas-dissolved FC-72. Square pin-fins with fin dimensions of 50×50×60μm3 (width×thickness×height) and submicron-scale roughness (RMS roughness of 25 to 32 nm) were fabricated on the surface of square silicon chip 10×10×0.5mm3 by use of microelectronic fabrication techniques. Experiments were conducted at the liquid subcoolings of 0, 3, 25, and 45 K. Both the micro-pin-finned chip and the chip with submicron-scale roughness showed a considerable heat transfer enhancement as compared to a smooth chip in the nucleate boiling region. The chip with submicron-scale roughness showed a higher heat transfer performance than the micro-pin-finned chip in the low-heat-flux region. The micro-pin-finned chip showed a steep increase in the heat flux with increasing wall superheat. This chip showed a higher heat transfer performance than the chip with submicron-scale roughness in the high-heat-flux region. The micro-pin-finned chip with submicron-scale roughness on it showed the highest heat transfer performance in the high-heat-flux region. While the wall superheat at boiling incipience was strongly dependent on the dissolved gas content, it was little affected by the liquid subcooling.

Enhanced Flow Boiling Over Open Microchannels With Uniform and Tapered Gap Manifolds

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Satish G. Kandlikar ◽  
Theodore Widger ◽  
Ankit Kalani ◽  
Valentina Mejia
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Performance ◽  
Flow Boiling ◽  
Nucleate Boiling ◽  
High Heat ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients

Flow boiling in microchannels has been extensively studied in the past decade. Instabilities, low critical heat flux (CHF) values, and low heat transfer coefficients have been identified as the major shortcomings preventing its implementation in practical high heat flux removal systems. A novel open microchannel design with uniform and tapered manifolds (OMM) is presented to provide stable and highly enhanced heat transfer performance. The effects of the gap height and flow rate on the heat transfer performance have been experimentally studied with water. The critical heat fluxes (CHFs) and heat transfer coefficients obtained with the OMM are significantly higher than the values reported by previous researchers for flow boiling with water in microchannels. A record heat flux of 506 W/cm2 with a wall superheat of 26.2 °C was obtained for a gap size of 0.127 mm. The CHF was not reached due to heater power limitation in the current design. A maximum effective heat transfer coefficient of 290,000 W/m2 °C was obtained at an intermediate heat flux of 319 W/cm2 with a gap of 0.254 mm at 225 mL/min. The flow boiling heat transfer was found to be insensitive to flow rates between 40–333 mL/min and gap sizes between 0.127–1.016 mm, indicating the dominance of nucleate boiling. The OMM geometry is promising to provide exceptional performance that is particularly attractive in meeting the challenges of high heat flux removal in electronics cooling applications.

Heat transfer performance of uni-directional porous heat sinks under high heat flux conditions

2016 ◽  
Vol 2016 (0) ◽  
pp. I111
Author(s):  
Kio Takai ◽  
Kazuhisa Yuki ◽  
Yoshiki Indou ◽  
Risako Kibushi ◽  
Noriyuki Unno ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Performance ◽  
High Heat ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Transfer Performance

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

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.

Proposal of a Micro/Mini Cooling Device Using Fins-Installed Porous Media for High Heat Flux Removal Exceeding 1000W/cm2

2009 ◽  
Author(s):  
Kazuhisa Yuki ◽  
Akira Matsui ◽  
Hidetoshi Hashizume ◽  
Koichi Suzuki
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
High Heat ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Cooling Device ◽  
Fin Thickness

Heat transfer characteristics of micro-sized bronze particle-sintered porous heat sinks and copper minichannel-fins heat sinks are experimentally investigated in order to clarify the feasibility of a newly proposed micro/mini cooling device using fins-installed porous media. Regarding the porous heat sinks, fin effect toward more inside of the porous medium is promoted by sintering the porous heat sink on the heat transfer surface, which results in increasing the heat transfer performance up to 0.8MW/m2K at heat flux of 8.2MW/m2 though there still remains a large pressure loss issue. In addition, the results clarify that the heat exchanging area exists only in the vicinity of the heat transfer surface. As to the minichannel-fins heat sinks, the influence of the channel width and the fin thickness are evaluated in detail. As a result, the minichannel-fins heat sink having the narrower channel width (i.e. scale effect) and lower porosity (i.e. thicker fin thickness with larger heat capacity) achieves higher heat transfer performance up to 0.10MW/m2K at 8.3MW/m2. However, rapid increase of pressure loss, which is occasionally observed in a microchannel due to vapor bubbles choking the narrow channel, still remains as an issue under flow boiling conditions in the minichannel. Finally, heat transfer performance of the fin-installed porous heat sink is numerically predicted by the control volume method. The simulation confirms that the heat transfer coefficient at each wall superheat of 0 and 30 degrees has performance 2.5 times and 2.0 times higher than that of the normal fins, which indicates that this heat sink coupling the micro and mini channels has high potential as efficient cooling method under high heat flux conditions exceeding 10MW/m2.

Experimental Study on Structured Surfaces for Nucleate Pool Boiling Enhancement

2017 ◽  
Author(s):  
Vishal V. Nirgude ◽  
Mayank Modak ◽  
Avadhesh K. Sharma ◽  
Santosh K. Sahu
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Atmospheric Pressure ◽  
Boiling Heat Transfer ◽  
Heat Transfer Performance ◽  
Pool Boiling ◽  
Transfer Performance ◽  
Structured Surfaces ◽  
Wall Superheat ◽  
Boiling Enhancement

In the present experimental study an attempt has been made to study the boiling heat transfer characteristics of variety of enhanced surfaces. Three different copper test surfaces: polished copper and two structured surfaces were used in the present investigation. The heat transfer performance of each surface is studied under saturated pool boiling conditions at atmospheric pressure by using water and isopropyl as pool liquid. The effect of intersecting tunnel geometry with 0.5 mm and 1 mm depth on heat transfer performance has been studied. The comparison of heat transfer coefficient indicates that the intersecting tunnel structure enhanced the boiling heat transfer performance and reduced the wall superheat at given heat flux inputs.

Biotemplated Superhydrophobic Surfaces for Enhanced Dropwise Condensation

2012 ◽  
Author(s):  
Emre Olceroglu ◽  
Stephen M. King ◽  
Md. Mahamudur Rahman ◽  
Matthew McCarthy
Keyword(s):  
Heat Transfer ◽  
Large Scale ◽  
Electronics Cooling ◽  
High Heat ◽  
The Self ◽  
High Heat Flux ◽  
Dropwise Condensation ◽  
Large Area ◽  
Hydrophobic Surfaces ◽  
Structured Surfaces

The increased heat transfer achieved through dropwise condensation, as compared to filmwise condensation, has the potential to substantially impact a variety of applications including high-heat flux thermal management systems, integrated electronics cooling, and various industrial and chemical processes. Here, we report stable dropwise condensation onto biotemplated nanostructured super-hydrophobic surfaces. We have demonstrated continuous droplet coalescence and ejection at diameters of less than 20 μm and compared directly with flat hydrophobic surfaces. The self-ejection mechanism characteristic of dropwise condensation has been shown using a simple bio-nano-fabrication technique based on the self-assembly and mineralization of the Tobacco mosaic virus (TMV). This process is extendable to commercially relevant nanomanufacturing of both microscale electronics devices as well as large-scale large-area industrial equipment. This manufacturing flexibility is unique as compared to many other micro/nano-structured surfaces fabricated to demonstrate similar increases in condensation heat transfer.

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