Advanced Micro-Channel Vapor Chamber for Cooling High Power Processors

2007 ◽  
Author(s):  
Masataka Mochizuki ◽  
Yuji Saito ◽  
Fumitoshi Kiyooka ◽  
Thang Nguyen ◽  
Tien Nguyen ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Heat Dissipation ◽  
Metal Plate ◽  
Working Fluid ◽  
Micro Channel ◽  
Vapor Chamber ◽  
Processor Performance ◽  
Heat Spreading

After the introduction of Pentium™ processor in 1993, the trend of the processor performance and power consumption have been increased significantly each year. Heat dissipation has been increased but in contrast the size of die on the processor has been reduced or remained the same size due to nano-size circuit technology and thus the heat flux is critically high. The heat flux was about 10–15 W/cm2 in the year 2000 and had reached 100 W/cm2 in 2006. The processor’s die surface where the heat is generated is usually small, approximately 1 cm2. For effective cooling should required least temperature gradient between the heat source and radiating components. The best known devices for effective heat transfer or heat spreading with lowest thermal resistance is heat pipe and vapor chamber. Basically, heat pipe and vapor chamber are an evacuated and sealed container which contains a small quantity of working fluid which is water. When one side of the container is heated, causing the liquid to vaporize and the vapor to move to the cold side and condensed. Since the latent heat of evaporation is large, considerable quantities of heat can be transported with a very small temperature difference from end to end. The 2-phase heat transfer device has excellent heat spreading and heat transfer characteristics, is the key element in thermal management challenge of ever power-increasing processors. In this paper, authors presented case designs using vapor chamber for cooling computer processors. Proposed ideas of using micro-channel vapor chamber for heat spreading to replace the traditional metal plate heat spreader. Also included in the paper are ideas and data that showed performance improvement of heat spreading devices.

scholarly journals The effect of operating parameters on the heat transfer in the heat pipe

2021 ◽  
Vol 2119 (1) ◽  
pp. 012088
Author(s):  
A. A. Litvintceva ◽  
N. I. Volkov ◽  
N. I. Vorogushina ◽  
V. A. Moskovskikh ◽  
V. V. Cheverda
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Temperature Difference ◽  
Heat Pipes ◽  
Working Fluid ◽  
Operating Parameters ◽  
Temperature Stabilization ◽  
Ir Camera ◽  
Fluid Properties

Abstract Heat pipes are a good solution for temperature stabilization, for example, of microelectronics, because these kinds of systems are without any moving parts. Experimental research of the effect of operating parameters on the heat transfer in a cylindrical heat pipe has been conducted. The effect of the working fluid properties and the porous layer thickness on the heat flux and temperature difference in the heat pipe has been investigated. The temperature field of the heat pipe has been investigated using the IR-camera and K-type thermocouples. The data obtained by IR-camera and K-type thermocouples have been compared. It is demonstrated the power transferred from the evaporator to the condenser is a linear function of the temperature difference between them.

scholarly journals Thermal Assessment of Nano-Particulate Graphene-Water/Ethylene Glycol (WEG 60:40) Nano-Suspension in a Compact Heat Exchanger

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1929 ◽  
Author(s):  
M. Sarafraz ◽  
Mohammad Safaei ◽  
Zhe Tian ◽  
Marjan Goodarzi ◽  
Enio Bandarra Filho ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Ethylene Glycol ◽  
Thermal Performance ◽  
Evaluation Criteria ◽  
High Heat ◽  
Operating Conditions ◽  
Working Fluid ◽  
High Heat Flux ◽  
Micro Channel

In the present study, we report the results of the experiments conducted on the convective heat transfer of graphene nano-platelets dispersed in water-ethylene glycol. The graphene nano-suspension was employed as a coolant inside a micro-channel and heat-transfer coefficient (HTC) and pressure drop (PD) values of the system were reported at different operating conditions. The results demonstrated that the use of graphene nano-platelets can potentially augment the thermal conductivity of the working fluid by 32.1% (at wt. % = 0.3 at 60 °C). Likewise, GNP nano-suspension promoted the Brownian motion and thermophoresis effect, such that for the tests conducted within the mass fractions of 0.1%–0.3%, the HTC of the system was improved. However, a trade-off was identified between the PD value and the HTC. By assessing the thermal performance evaluation criteria (TPEC) of the system, it was identified that the thermal performance of the system increased by 21% despite a 12.1% augmentation in the PD value. Furthermore, with an increment in the fluid flow and heat-flux applied to the micro-channel, the HTC was augmented, showing the potential of the nano-suspension to be utilized in high heat-flux thermal applications.

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.

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.

A Mathematical Modeling Method for Capillary Limit of Micro Heat Pipe with Sintered Wick

2011 ◽  
Vol 175 ◽  
pp. 335-341
Author(s):  
Xi Bing Li ◽  
Chang Long Yang ◽  
Gong Di Xu ◽  
Wen Yuan ◽  
Shi Gang Wang
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Heat Dissipation ◽  
High Heat ◽  
Experimental Investigations ◽  
High Heat Flux ◽  
Micro Heat Pipe ◽  
Copper Powders ◽  
Capillary Limit

With heat flux increasing and cooling space decreasing in microelectronic and chemical products, micro heat pipe has become an ideal heat dissipation device in high heat-flux products. Through the analysis of its working principle, the factors that affect its heat transfer limits and the patterns in which copper powders are arrayed in circular cavity, this paper first established a mathematical model for the crucial factors in affecting heat transfer limits in a circular micro heat pipe with a sintered wick, i.e. a theoretical model for capillary limit, and then verified its validity through experimental investigations. The study lays a powerful theoretical foundation for designing and manufacturing circular micro heat pipes with sintered wicks.

An Experimental Investigation of a Low Heat Flux, Wickless Heat Pipe

1983 ◽  
Vol 7 (2) ◽  
pp. 96-99
Author(s):  
B.S. Larkin
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Heat Fluxes ◽  
Working Fluid ◽  
Transfer Coefficients ◽  
Electronic Package ◽  
Ambient Temperatures ◽  
Heat Transfer Coefficients ◽  
Flux Charge

This paper reports tests on a wickless heat pipe to be used for transporting heat from the ground to protect an electronic package from low ambient temperatures. Evaporating heat transfer coefficients were measured for low heat fluxes where the behaviour of the evaporating film is unpredictable. The effects of type of working fluid, heat flux, charge quantity and tube inclination were investigated.

scholarly journals Numerical Research of Flow Heat Transfer through Micro Channel of Mems Device

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1551-1557
Keyword(s):  
Heat Transfer ◽  
Heat Dissipation ◽  
Force Convection ◽  
Input Power ◽  
Working Fluid ◽  
Micro Channel ◽  
Mems Devices ◽  
Compact Size ◽  
Flow Heat ◽  
Mems Device

Micro-channel has been increasingly applied in MEMS devices and electronics devices due to its higher efficiently heat dissipation rate, more compact size and lower cost. The present work demonstrates that the theoretical analysis of single phase micro channel has been investigated. To predict the behavior of micro-channel, the non-linear thermal hydraulic equations are developed namely mass, momentum and energy conservation, these equations are solved to predict the thermal physical properties and hydrodynamic behavior of the fluid in micro-channel. The configuration geometry of the problem has been made in design modular of commercial software ANSYS 15.0 Workbench and meshing of it has been done in ANSYS 15.0 Workbench fluent. Water is used as the working fluid in the micro-channel and the problem has been solved in ANSYS 15.0. To analyze the thermal behavior of micro-channel in force convection for various input power. Numerical simulation is carried out to calculate the wall temperature of the micro-channel, heat transfer coefficient (HTC) values etc. Next more simulation have been performed to investigate the parametric effect on the circular micro channel in terms of different diameter and length, and optimize the geometric parameters and coolant flow rate to maintain the critical temperature of the MEMS device (geometry and thermodynamic performance of micro-channel).

An Experimental Study of Heat Pipe Performance Using Binary Mixture Fluids That Exhibit Strong Concentration Marangoni Effects

2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Kenneth M. Armijo ◽  
Van P. Carey
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Heat Pipe ◽  
Pure Water ◽  
Working Fluid ◽  
Strong Concentration ◽  
Alcohol Mixtures ◽  
Marangoni Effects ◽  
Water Alcohol

This paper summarizes the results of an experimental investigation of the performance characteristics of a gravity/capillary driven heat pipe using water/alcohol mixtures as a working fluid. This investigation specifically explored the use of water/alcohol mixtures that exhibit strong concentration-based Marangoni effects. Experiments to determine heat pipe performance were conducted for pure water and water/alcohol solutions with increasing concentrations of alcohol. Initial tests with pure water determined the optimal working fluid charge for the heat pipe; subsequent performance tests over a wide range of heat input levels were then conducted for each working fluid at this optimum value. The results indicate that some mixtures can significantly enhance the heat transfer coefficient and heat flux capability of the heat pipe evaporator. For the best mixture tested, the maximum evaporator heat flux carried by the coolant without dryout was found to be 52% higher than the value for the same heat pipe using pure water as a coolant under comparable conditions. Peak evaporator heat flux values above 100 W/cm2 were achieved with some mixtures. Evaporator and condenser heat transfer coefficient data are presented, and the trends are examined in the context of the expected effect of the Marangoni mechanisms on heat transfer.

Parametric Study of the Effect of the Vapor Chamber Characteristics on Its Performance

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Hamdy Hassan ◽  
Souad Harmand
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Pipe ◽  
Hydrodynamic Model ◽  
Pressure Difference ◽  
Power Input ◽  
Working Fluid ◽  
Vapor Chamber ◽  
Vapor Region

In this work, the effect of vapor chamber characteristics, the properties of its working fluid and the operating parameters on the vapor chamber performance are studied. Also, the effects of these parameters on the cooling process are considered. A three dimensional hydrodynamic model is used for solving the fluid flow through the liquid and vapor regions of the vapor chamber. The hydrodynamic model is coupled with a three dimensional thermal model to calculate the model temperature. The hydrodynamic model takes into consideration the circulation of liquid between the two wick regions. An implicit finite difference method is used to solve the numerical model and a validation of the numerical model is presented. The effect of porosity of the wick material, wick structure, solid wall material, working fluid, wick region thickness, vapor region thickness, power input, and heat transfer coefficient of the cooling fluid are taken in the study. Their effects on the heat pipe temperature, pressure difference of the heat pipe, liquid and vapor velocities and mass evaporated are studied. The results show that, to increase the cooling performance of the heat pipe, the porosity, wick thickness, power input, and vapor region thickness should be decreased and the heat transfer coefficient should be increased. To minimize the maximum pressure difference of the heat pipe, increase porosity, wick thickness, and vapor thickness and decrease heat transfer coefficient and power input. The study shows that the increase of wick thickness by a factor of four decreases the maximum pressure difference by about 75% and increases the maximum vapor chamber temperature 30%. It also shows that the vapor region thickness has an insignificant effect on the vapor chamber temperature and pressure. The increase of the heat transfer coefficient of the cooling liquid decreases its effect on heat pipe performance.

An Experimental Study on the Thermal Performance of the Flat Heat Pipe

2016 ◽  
Author(s):  
Hao Xiaohong ◽  
Jiqing Guan ◽  
Jingbo Zhao
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Electronic Devices ◽  
Heat Pipes ◽  
Deionized Water ◽  
Working Fluid ◽  
Nano Fluid ◽  
Flat Heat Pipe

As the rapid growing of the semiconductor logic gate number and operation speed, the heat dissipated from electronic devices increases drastically. Moreover, most of the heat flux can reach about 100 W/cm2, therefore efficient removal of the heat from the electronic devices is essential to ensure the reliable operation of the electronic devices. The traditional direct cooling system, such as air cooling, liquid cooling, would not be able to transfer the high heat flux owing to their heat transfer limits, so advanced cooling solutions are necessary. The flat heat pipes have some advantages, such as small scale, strong heat transfer capacity, low weight penalty and low environmental requirements, therefore, in recent years, researchers have shown great interest for the flat heat pipe. But most of them played the important on the structure design of the flat heat pipes, and few of them focused on the study of the effect of the working fluid on the heat transfer performance. In this paper, a flat heat pipe with rectangular channel is designed and manufactured, and an experimental set up was built to study working fluid on the effects of the flat heat Pipe thermal performance. The flat heat pipe is heated via a 35mmx20mm rectangular electrical resistance (the evaporator side), and the other side (the condenser side) is cooled by convection of a heat sink. In the experimental work, three types of working fluid are used in the heat pipe: (A) deionized water, (B) deionized water-based Fe3O4 nano fluid (1, 1.5wt%). A comparison is performed for the thermal performance of different size flat heat pipe. Finally, the experimental results showed that nano fluid could improve the thermal performance of the FHP. With the same charge volume, the heat transfer coefficient of the FHPs filled with nano fluid were higher than that of DI water. There was an optimal mass concentration which was estimated to be 1.5 wt% to achieve the maximum heat transfer enhancement.

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