scholarly journals Magnetic Fusion Energy Plasma Interactive and High Heat Flux Components: Volume 5, Technical assessment of critical issues in the steady state operation of fusion confinement devices

1988 ◽  
Author(s):  
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Fusion Energy ◽  
High Heat ◽  
High Heat Flux ◽  
Magnetic Fusion ◽  
Magnetic Fusion Energy ◽  
Steady State Operation ◽  
Critical Issues ◽  
Technical Assessment

The Steady-State Modeling and Analysis of a Two-Loop Cooling System for High Heat Flux Removal

2009 ◽  
Author(s):  
Rongliang Zhou ◽  
Juan Catano ◽  
Tiejun Zhang ◽  
John T. Wen ◽  
Greg J. Michna ◽  
...  
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Heat Exchangers ◽  
Cooling System ◽  
High Heat ◽  
System Structure ◽  
High Heat Flux ◽  
Vapor Compression ◽  
Vapor Compression Cycle ◽  
Compression Cycle

Steady-state modeling and analysis of a two-loop cooling system for high heat flux removal applications are studied. The system structure proposed consists of a primary pumped loop and a vapor compression cycle (VCC) as the secondary loop to which the pumped loop rejects heat. The pumped loop consists of evaporator, condenser, pump, and bladder liquid accumulator. The pumped loop evaporator has direct contact with the heat generating device and CHF must be higher than the imposed heat fluxes to prevent device burnout. The bladder liquid accumulator adjusts the pumped loop pressure level and, hence, the subcooling of the refrigerant to avoid pump cavitation and to achieve high critical heat flux (CHF) in the pumped loop evaporator. The vapor compression cycle of the two-loop cooling system consists of evaporator, liquid accumulator, compressor, condenser and electronic expansion valve. It is coupled with the pumped loop through a fluid-to-fluid heat exchanger that serves as both the vapor compression cycle evaporator and the pumped loop condenser. The liquid accumulator of the vapor compression cycle regulates the cycle active refrigerant charge and provides saturated vapor to the compressor at steady state. The heat exchangers are modeled with the mass, momentum, and energy balance equations. Due to the projected incorporation of microchannels in the pumped loop to enhance the heat transfer in heat sinks, the momentum equation, rarely seen in previous refrigeration system modeling efforts, is included to capture the expected significant microchannel pressure drop witnessed in previous experimental investigations. Electronic expansion valve, compressor, pump, and liquid accumulators are modeled as static components due to their much faster dynamics compared with heat exchangers. The steady-state model can be used for static system design that includes determining the total refrigerant charge in the vapor compression cycle and the pumped loop to accommodate the varying heat load, sizing of various components, and parametric studies to optimize the operating conditions for a given heat load. The effect of pumped loop pressure level, heat exchangers geometries, pumped loop refrigerant selection, and placement of the pump (upstream or downstream of the evaporator) are studied. The two-loop cooling system structure shows both improved coefficient of performance (COP) and CHF overthe single loop vapor compression cycle investigated earlier by authors for high heat flux removal.

scholarly journals High-heat flux tests of tungsten divertor mock-ups with steady-state plasma and e-beam

2020 ◽  
Vol 25 ◽  
pp. 100816
Author(s):  
V.P. Budaev ◽  
S.D. Fedorovich ◽  
A.V. Dedov ◽  
A.V. Karpov ◽  
A.T. Komov ◽  
...  
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
High Heat ◽  
High Heat Flux ◽  
State Plasma

Steady-State Subcooled Nucleate Boiling on a Downward-Facing Hemispherical Surface

1998 ◽  
Vol 120 (2) ◽  
pp. 365-370 ◽  
Author(s):  
K. H. Haddad ◽  
F. B. Cheung
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Heat Transport ◽  
Bubble Dynamics ◽  
Flow Direction ◽  
Heating Surface ◽  
Nucleate Boiling ◽  
High Heat ◽  
Bubble Nucleation ◽  
High Heat Flux

Steady-state nucleate boiling heat transfer experiments in saturated and subcooled water were conducted. The heating surface was a 0.305 m hemispherical aluminum vessel heated from the inside with water boiling on the outside. It was found that subcooling had very little effect on the nucleate boiling curve in the high heat flux regime where latent heat transport dominated. On the other hand, a relatively large effect of subcooling was observed in the low-heat-flux regime where sensible heat transport was important. Photographic records of the boiling phenomenon and the bubble dynamics indicated that in the high-heat-flux regime, boiling in the bottom center region of the vessel was cyclic in nature with a liquid heating phase, a bubble nucleation and growth phase, a bubble coalescence phase, and a large vapor mass ejection phase. At the same heat flux level, the size of the vapor masses was found to decrease from the bottom center toward the upper edge of the vessel, which was consistent with the increase observed in the critical heat flux in the flow direction along the curved heating surface.

Thermal performance and 3D analysis of advanced mechanically joined divertor plate for LHD under steady state high heat flux

2001 ◽  
Vol 56-57 ◽  
pp. 205-210 ◽  
Author(s):  
Y Kubota ◽  
N Noda ◽  
A Sagara ◽  
R Sakamoto ◽  
K Yamazaki ◽  
...  
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Thermal Performance ◽  
High Heat ◽  
High Heat Flux ◽  
3D Analysis ◽  
Divertor Plate

Burnout experiments on the externally-finned swirl tube for steady-state and high-heat flux beam stops

1989 ◽  
Vol 9 ◽  
pp. 225-230 ◽  
Author(s):  
Masanori Araki ◽  
Masayuki Dairaku ◽  
Takashi Inoue ◽  
Masao Komata ◽  
Masaaki Kuriyama ◽  
...  
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
High Heat ◽  
High Heat Flux
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