Spot Cooling of Local-High Heat Load by High-Velocity Thin Liquid Flow

2006 ◽  
Author(s):  
Hiroyasu Ohtake ◽  
Yasuo Koizumi ◽  
Ken Nemoto ◽  
Hisashi Sakurai
Keyword(s):  
Heat Flux ◽  
Heat Load ◽  
Liquid Velocity ◽  
High Heat ◽  
Test Channel ◽  
Maximum Heat ◽  
Maximum Heat Flux ◽  
Dry Patch ◽  
High Heat Load ◽  
Spot Cooling

Spot cooling of local-high heat load by high-velocity thin liquid flow was examined experimentally. Steady state experiments were conducted using a copper thin-film and rectangular sub-millimeter-channels. The width of the test channel was 2 mm. The heights of the test channel were 0.5 and 0.2 mm. The width and length of a test heater was 2 mm and 2 mm, respectively. The test liquid was degassed pure water. The liquid velocities were 1.5, 5, 10 and 15 m/s. The liquid subcooling was 20 K. Location of the heater in the test channel also was an experimental parameter: the positions of the heater from the exit of the test channel were 30 mm (middle) and 0 mm (exit). Experimental results showed that the maximum heat flux (CHF or cooling limit) during experiment with the heater at exit of the test channel was similar to that with the heater at middle of the test channel: the maximum heat flux was independent of the position of heater in the test channel. The maximum heat flux occurred when bubbles coalesced together or a dry patch appeared on the heater. The coalescence bubble covered over the heater was observed at CHF in condition of low liquid velocity. For condition of high liquid velocity, a dry patch appeared on the heater, and then the dry region extended over the heater to come around the CHF. The maximum heat flux (critical heat flux) was about 8 MW/m2 in a range of present experiments. The CHF for the present sub-millimeter channel was similar to that for conventional channel. Furthermore, models were proposed using heat transfer around a coalesced bubble and at a dry patch on a heater.

Design of Compact Absorbers for High-Heat-Load X-ray Undulator Beamlines at SPring-8

1998 ◽  
Vol 5 (4) ◽  
pp. 1199-1201 ◽  
Author(s):  
T. Mochizuki ◽  
Y. Sakurai ◽  
D. Shu ◽  
T. M. Kuzay ◽  
H. Kitamura
Keyword(s):  
Heat Load ◽  
Open Channel ◽  
Normal Incidence ◽  
High Heat ◽  
Wire Mesh ◽  
Maximum Heat ◽  
X Ray ◽  
Maximum Heat Flux ◽  
Heat Absorber ◽  
High Heat Load

A compact and high-heat-load absorber for the SPring-8 X-ray undulator beamline has been developed and installed. It consists of an upper heat-absorber part and a lower photon duct part, which are configured together in a water-cooled GlidCop body. The absorber part has a horizontal notch shape and the photon duct part forms a rectangular open channel under the absorber part. Two types of absorber are designed: one, with wire mesh channels, is 486 mm long, 70 mm high and 64 mm wide; the other, with smooth-bore channels, is 610 mm long, 75 mm high and 70 mm wide. Thermal and stress analyses show that they withstand the 12.3 kW heat load and the maximum heat flux of 940 W mm−2 at normal incidence.

Innovative Realizations of High Heat-Flux Boiling and Condensing Flows for Milli-Meter and Micro-Meter Scale Applications

2014 ◽  
Author(s):  
Michael Kivisalu ◽  
Amitabh Narain ◽  
Patcharapol Gorgitrattanagul ◽  
Ranjeeth Naik
Keyword(s):  
Heat Flux ◽  
Heat Load ◽  
High Heat ◽  
Electronic Cooling ◽  
System Level ◽  
High Heat Flux ◽  
Zero Gravity ◽  
Pressure Drops ◽  
Condensing Flows ◽  
High Heat Load

For shear driven mm-scale flows, the traditional boiler and condenser operations pose serious problems of degraded performance (low heat-flux values, high pressure drops, and device-and-system level instabilities). The innovative devices are introduced for functionality and high heat load capabilities needed for shear dominated electronic cooling situations that arise in milli-meter scale operations, certain gravity-insensitive avionics-cooling and zero-gravity applications.

EMC3-EIRENE simulations of neon impurity seeding effects on heat flux distribution on CFETR

2022 ◽  
Author(s):  
Shuyu Dai ◽  
Defeng Kong ◽  
Vincent Chan ◽  
Liang Wang ◽  
Yuhe Feng ◽  
...  
Keyword(s):  
Heat Flux ◽  
Heat Load ◽  
Flux Distribution ◽  
Three Dimensional ◽  
Input Power ◽  
Heat Flux Distribution ◽  
Maximum Heat ◽  
Maximum Heat Flux ◽  
Heat Loads ◽  
Injection Location

Abstract The numerical modelling of the heat flux distribution with neon impurity seeding on CFETR has been performed by the three-dimensional (3D) edge transport code EMC3-EIRENE. The maximum heat flux on divertor targets is about 18 MW m-2 without impurity seeding under the input power of 200 MW entering into the scrape-off layer. In order to mitigate the heat loads below 10 MW m-2, neon impurity seeded at different poloidal positions has been investigated to understand the properties of impurity concentration and heat load distributions for a single toroidal injection location. The majority of the studied neon injections gives rise to a toroidally asymmetric profile of heat load deposition on the in- or out-board divertor targets. The heat loads cannot be reduced below 10 MW m-2 along the whole torus for a single toroidal injection location. In order to achieve the heat load mitigation (<10 MW m-2) along the entire torus, modelling of sole and simultaneous multi-toroidal neon injections near the in- and out-board strike points has been stimulated, which indicates that the simultaneous multi-toroidal neon injections show a better heat flux mitigation on both in- and out-board divertor targets. The maximum heat flux can be reduced below 7 MWm-2 on divertor targets for the studied scenarios of the simultaneous multi-toroidal neon injections.

Analysis of Vapor Blanket Formation in the Porous Wick of a Loop Heat Pipe With High Heat Load

2013 ◽  
Author(s):  
X. M. Huang ◽  
X. Jin ◽  
B. B. Chen ◽  
W. Liu
Keyword(s):  
Mass Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Heat And Mass Transfer ◽  
Heat Load ◽  
High Heat ◽  
Loop Heat Pipe ◽  
Porous Wick ◽  
High Heat Load ◽  
Theoretical Results

A loop heat pipe has different transport mechanisms depending on heat flux. The interface of liquid and vapor cannot maintain at the surface of the wick when heat flux is high, and a vapor blanket will form in the wick. To investigate when the vapor blanket appears and how it affects heat and mass transfer in the system is very import to minimize the device. A mathematical model of heat and mass transfer in the evaporator, coupled with analysis of fluid flow in the loop, is developed in the paper. The model is applied to calculate the critical heat load that the vapor blanket forms, and to analyze how the blanket delays. A comparison of theoretical results and experimental measurements is further presented. The consistence of the results validates the model and the mechanisms.

Investigation of On-Chip Hot Spot Cooling Using Microchannel Heat Sink

2013 ◽  
Vol 455 ◽  
pp. 466-469
Author(s):  
Yun Chuan Wu ◽  
Shang Long Xu ◽  
Chao Wang
Keyword(s):  
Heat Flux ◽  
Heat Sink ◽  
Hot Spots ◽  
Hot Spot ◽  
High Heat ◽  
High Heat Flux ◽  
Microchannel Heat Sink ◽  
Three Dimensional Model ◽  
Spot Cooling ◽  
On Chip

With the increase of performance demands, the nonuniformity of on-chip power dissipation becomes greater, causing localized high heat flux hot spots that can degrade the processor performance and reliability. In this paper, a three-dimensional model of the copper microchannel heat sink, with hot spot heating and background heating on the back, was developed and used for numerical simulation to predict the hot spot cooling performance. The hot spot is cooled by localized cross channels. The pressure drop, thermal resistance and effects of hot spot heat flux and fluid flow velocity on the cooling of on-chip hot spots, are investigated in detail.

Improved monochromator design for high heat load beamlines at CHESS (abstract)

1996 ◽  
Vol 67 (9) ◽  
pp. 3351-3351
Author(s):  
K.W. Smolenski ◽  
R. Pahl ◽  
P. Doing ◽  
C. Conolly ◽  
B. Clark ◽  
...  
Keyword(s):  
Heat Load ◽  
High Heat ◽  
High Heat Load

scholarly journals Simulated high heat load performance of an inclined crystal monochromator

1993 ◽  
Author(s):  
Albert T. Macrander ◽  
Ali M. Khounsary ◽  
Mark Graham
Keyword(s):  
Heat Load ◽  
High Heat ◽  
High Heat Load
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