Self-Contained, Oscillating Flow Liquid Cooling System for Thin Form Factor High Performance Electronics

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
R. Wälchli ◽  
T. Brunschwiler ◽  
B. Michel ◽  
D. Poulikakos
Keyword(s):  
Heat Transfer ◽  
Form Factor ◽  
Waste Heat ◽  
Cooling System ◽  
Heat Removal ◽  
Flow Loop ◽  
Liquid Cooling ◽  
High Heat Transfer ◽  
Cold Plates ◽  
Liquid Cooling System

A self-contained, small-volume liquid cooling system for thin form-factor electronic equipment (e.g., blade server modules) is demonstrated experimentally in this paper. A reciprocating water flow loop absorbs heat using mesh-type microchannel cold plates and spreads it periodically to a larger area. From there, the thermal energy is interchanged via large area, low pressure drop cold plates with a secondary heat transfer loop (air or liquid). Four phase-shifted piston pumps create either a linearly or radially oscillating fluid flow in the frequency range of 0.5–3 Hz. The tidal displacement of the pumps covers 42–120% of the fluid volume, and, therefore, an average flow rate range of 100–800 ml/min is tested. Three different absorber mesh designs are tested. Thermal and fluidic characteristics are presented in a time-resolved and a time-averaged manner. For a fluid pump power of 1 W, a waste heat flux of 180 W/cm2(ΔT=67 K) could be dissipated from a 3.5 cm2 chip. A linear oscillation flow pattern is advantageous over a radial one because of the more efficient heat removal from the chip and lower hydraulic losses. The optimum microchannel mesh density is determined as a combination of low pump losses and high heat transfer rates.

Study on Copper Cold Plate Designs for Electronics Liquid Cooling System

2006 ◽  
Author(s):  
Yi. Feng ◽  
Y. Wang ◽  
C. Y. Huang
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Cooling System ◽  
Pure Copper ◽  
Cold Plate ◽  
Performance Limits ◽  
Liquid Cooling ◽  
Cold Plates ◽  
Management Approaches ◽  
Liquid Cooling System

The increasing power consumption of microelectronic systems and the dense layout of semiconductor components leave very limited design spaces with tight constraints for the thermal solution. Conventional thermal management approaches, such as extrusion, fold-fin, and heat pipe heat sinks, are somehow reaching their performance limits, due to the geometry constraints. Currently, more studies have been carried out on the liquid cooling technologies, as the flexible tubing connection of liquid cooling system makes both the accommodation in constrained design space and the simultaneous cooling of multi heating sources feasible. To significantly improve the thermal performance of a liquid cooling system, heat exchangers with more liquid-side heat transfer area with acceptable flow pressure drop are expected. This paper focuses on the performance of seven designs of source heat exchanger (cold plate). The presented cold plates are all made in pure copper material using wire cutting, soldering, brazing, or sintering process. Enhanced heat transfer surfaces such as micro channel and cooper mesh are investigated. Detailed experiments have been conducted to understand the performance of these seven cooper cold plates. The same radiators, fan, and water pump were connected with each cooper cold plate to investigate the overall thermal performance of liquid cooling system. Water temperature readings at the inlets and outlets of radiators, pump, and colder plate have been taken to interpret the thermal resistance distribution along the cooling loop.

Application of Micro-Channel Fin for Cold Plate of Liquid Cooling System and Vapor Chamber

2009 ◽  
Author(s):  
Koichi Mashiko ◽  
Masataka Mochizuki ◽  
Yuji Saito ◽  
Yasuhiro Horiuchi ◽  
Thang Nguyen ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Cooling System ◽  
Cold Plate ◽  
Micro Channel ◽  
Vapor Chamber ◽  
Liquid Cooling ◽  
Liquid Cooling System ◽  
Heat Spreading

Recently energy saving is most important concept for all electric products and production. Especially, in Data-Center cooling system, power consumption of current air cooling system is increasing. For not only improving thermal performance but also reducing electric power consumption of this system, liquid cooling system has been developed. This paper reports the development of cold plate technology and vapor chamber application by using micro-channel fin. In case of cold plate application, micro-channel fin technology is good for compact space design, high thermal performance, and easy for design and simulation. Another application is the evaporating surface for vapor chamber. The well-known devices for effective heat transfer or heat spreading with the lowest thermal resistance are heat pipes and vapor chamber, which are two-phase heat transfer devices with excellent heat spreading and heat transfer characteristics. Normally, vapor chamber is composed of sintered power wick. Vapor chamber container is mechanically supported by stamped pedestal or wick column or solid column, but the mechanical strength is not enough strong. So far, the application is limited in the area of low strength assembly. Sometime the mechanical supporting frame is design for preventing deformation. In this paper, the testing result of sample is described that thermal resistance between the heat source and the ambient can be improved approximately 0.1°C/W by using the micro-channel vapor chamber. Additionally, authors presented case designs using vapor chamber for cooling computer processors, and proposed ideas of using micro-channel vapor chamber for heat spreading to replace the traditional metal plate heat spreader.

Analysis and Optimization of Flow and Heat Transfer in a Liquid Cooling System for an LED Array

2011 ◽  
Vol 8 (2) ◽  
pp. 72-82
Author(s):  
Samhitha Poonacha ◽  
Basawaraj ◽  
Hemanth Kumar T.R. Seetharam ◽  
K.N. Seetharamu
Keyword(s):  
Heat Transfer ◽  
Cooling System ◽  
Liquid Cooling ◽  
Flow And Heat Transfer ◽  
Led Array ◽  
Liquid Cooling System

Study on the Heat Sink Structure and Heat Transfer Effect of Liquid Cooling System for High Power LEDs

2015 ◽  
Vol 35 (3) ◽  
pp. 0323003
Author(s):  
田立新 Tian Lixin ◽  
文尚胜 Wen Shangsheng ◽  
黄伟明 Huang Weiming ◽  
夏云云 Xia Yunyun ◽  
姚日晖 Yao Rihui
Keyword(s):  
Heat Transfer ◽  
High Power ◽  
Heat Sink ◽  
Cooling System ◽  
Transfer Effect ◽  
Liquid Cooling ◽  
Liquid Cooling System

Microjet Impingement Cooling With Phase Change

2004 ◽  
Author(s):  
Evelyn N. Wang ◽  
Juan G. Santiago ◽  
Kenneth E. Goodson ◽  
Thomas W. Kenny
Keyword(s):  
Heat Transfer ◽  
Cooling System ◽  
Heated Surface ◽  
Heat Removal ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Impingement Cooling ◽  
Heat Transfer Coefficients ◽  
High Heat Transfer ◽  
Wall Superheat

The large heat generation rates in contemporary microprocessors require new thermal management solutions. Two-phase microjet impingement cooling promises high heat transfer coefficients and effective cooling of hotspots. We have fabricated integrated microjet structures with heaters and temperature sensors to study local heat transfer at the impingement surface of a confined microjet. Circular jets with diameters less than 100 μm are machined in glass. Preliminary temperature measurements (for Rej = 100–500) suggest that heat transfer coefficients of 1000 W/m2C close to the jet stagnation zone can be achieved. As the flowrate of the jet is increased, a tradeoff in heat removal capability and wall superheat is observed. To aid in understanding the mechanism for wall superheat during boiling at the heated surface, the devices allow for optical access through the top of the device. However, the formation of vapor from the top reservoir makes visualization difficult. This study aids in the design of microjet heat sinks used for integration into a closed-loop cooling system.

Numerical Investigation of Electronic Liquid Cooling Based on the Thermomagnetic Effect

2012 ◽  
Author(s):  
Giti Karimi-Moghaddam ◽  
Richard D. Gould ◽  
Subhashish Bhattacharya
Keyword(s):  
Magnetic Field ◽  
High Power ◽  
Heat Load ◽  
Waste Heat ◽  
Cooling System ◽  
Numerical Study ◽  
Electronic Systems ◽  
Power Electronic ◽  
Flow Loop ◽  
Liquid Cooling

Liquid cooling for thermal management has been widely applied in high power electronic systems. Use of pumps may often introduce reliability and mechanical limitations such as vibration of moving parts, noise problems, leakage problems, and considerable power consumption. This paper presents a theoretical design of circulating a liquid coolant using magnetic and thermal fields which surround high power electronic systems by means of thermomagnetic effects of temperature sensitive magnetic fluids. Numerical simulation models of the heat transfer process from a magnetic liquid contained in a closed flow loop in the presence of an external magnetic field have been developed. These models include the coupling of three fundamental phenomena, i.e. magnetic, thermal, and fluid dynamic features. In this cooling device, the thermomagnetic convection is generated by a non-uniform magnetic field from a solenoid, which is placed close to the fluid loop. The device cooling load is calculated in the region near the solenoid. No energy is needed, other than the heat load (i.e. waste heat from actual electrical device), to drive the cooling system, and as such, the device can be considered completely self-powered. In effect, the heat added to the ferrofluid in the presence of a magnetic field is converted into useful flow work. In this numerical study, the effects of different factors such as input heat load, magnetic field strength and magnetic distribution (based on solenoid dimensions and the applied electrical current) along the loop, on the performance of the cooling system are analyzed and discussed. Finally, the variation of the local Nusselt number along the heated and cooled regions of the flow loop are calculated and compared with laminar entry length analytical solutions.

scholarly journals Thermo-Optic Numerical Research on Segmented Circular LD Arrays Side-Pumping a Nd:YAG Laser Rod

2020 ◽  
Vol 10 (20) ◽  
pp. 7316
Author(s):  
Wei Wang ◽  
Qin Zhao ◽  
Wenqing Gao ◽  
Zhenyue Hu ◽  
Qihang Zhao ◽  
...  
Keyword(s):  
Cooling System ◽  
Beam Quality ◽  
Heat Removal ◽  
Liquid Cooling ◽  
Temperature Distributions ◽  
Side Pumping ◽  
Laser Systems ◽  
Numerical Research ◽  
Liquid Cooling System ◽  
Complex Liquid

The configuration designs of the laser diode (LD) side-pumping laser rods focus on how to solve the space conflict between the pump and heat-removal devices because both want to use the larger lateral surface of the laser rod. The conflict is better balanced in the three different side-pumping geometries: the segmented circular LD array side-pumping configuration, the annular liquid-cooling structure, and the compensated semicircular LD array side-pumping arrangement. The temperature distributions and thermo-optic effects of the laser rod in the segmented circular LD array side-pumping configuration are analyzed in contrast with those in the other arrangements. The numerical results indicate that the periodical segment-pumping scheme provides higher beam quality than the compensated semicircular side-pumping scheme, enabling removal of the complex liquid cooling system in medium-power applications, thus showing the potential to be used in compact and miniature laser systems.

scholarly journals A Review on Development of Liquid Cooling System for Central Processing Unit (CPU)

2020 ◽  
Vol 78 (2) ◽  
pp. 98-113
Author(s):  
Muhammad Arif Harun ◽  
Nor Azwadi Che Sidik
Keyword(s):  
Heat Transfer ◽  
Heat Generation ◽  
Heat Transfer Performance ◽  
Cooling System ◽  
Electronic Devices ◽  
Working Fluid ◽  
Transfer Performance ◽  
Liquid Cooling ◽  
Cooling Performance ◽  
Liquid Cooling System

Electronic devices are becoming more efficient while getting a smaller size and compact design thus increase heat generation significantly. High heat generation from high technology electronic devices are needed to be cool down or control its temperature to prevent overheating problems. Due to the high cooling performance of liquid cooling, the electronic cooling system is shifting from an air-cooling system to a liquid cooling system. In the past few decades, numerous methods proposed by researchers for the central process unit (CPU) cooling using the liquid system either active cooling or passive cooling system. Other than physical configuration such as heat sink design, different configurations of working fluids are widely been studied by most of the researchers. Different working fluids have different heat transfer performance. Furthermore, a recent study has come out more interesting finding using nanofluid which can enhance heat transfer performance of liquid cooling. Nanofluid is a working fluid that has nanoparticles disperse in the base fluid which can increase the thermal properties of the based fluid. In this paper, comprehensive literature on the type of working fluid used in the respective system and methods of liquid cooling system for CPU including its cooling performance. Furthermore, this review paper discussed the different configuration of the liquid block and also the working fluid that had been used in the CPU cooling system.

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