Transient Thermal and Hydrodynamic Performances of Flat Heat Pipe Subjected to Heating With Multiple Electronic Components

2008 ◽  
Author(s):  
R. Sonan ◽  
S. Harmand ◽  
J. Pelle´ ◽  
D. Leger ◽  
M. Fake`s
Keyword(s):  
Heat Pipe ◽  
Heat Removal ◽  
Copper Plate ◽  
Working Fluid ◽  
Governing Equations ◽  
Electronic Components ◽  
Pressure Distributions ◽  
Change Mechanisms ◽  
Transient Thermal ◽  
Flat Heat Pipe

This work is aimed to simulate the transient performances of a flat heat pipe (FHP) used to cool electronics components in automotive applications. A transient 3D thermal model (T3DTM) of the FHP wall is performed to calculate the heat transfer through the wall of the FHP. This model is coupled with a transient 2D hydrodynamic model (T2DHM) which determines the flows both in wick and vapour core. An energy balance and Clausius-Clapeyron law permit to represent the phase change mechanisms at the liquid-vapour interface. The performed T2DHM model includes the solution of the complete governing equations in both wick and vapor core. The T2DHM is able to predict the velocity and pressure distributions of the FHP working fluid and then the FHP transient response. That analysis helps determine the maximum pore radius of the wick necessary to support the total pressure drop in the FHP. The heat removal capability of the FHP is highlighted through a comparison with a solid copper plate of the overall dimensions as the FHP.

scholarly journals Heat Removal from Bipolar Transistor by Loop Heat Pipe with Nickel and Copper Porous Structures

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Patrik Nemec ◽  
Martin Smitka ◽  
Milan Malcho
Keyword(s):  
Grain Size ◽  
Heat Pipe ◽  
Nickel Powder ◽  
Heat Removal ◽  
Bipolar Transistor ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Porous Structures ◽  
Porous Wick ◽  
Wick Structure

Loop heat pipes (LHPs) are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements’ influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT) have been made.

scholarly journals Analysis of a Vertical Flat Heat Pipe Using Potassium Working Fluid and a Wick of Compressed Nickel Foam

Energies ◽  
2016 ◽  
Vol 9 (3) ◽  
pp. 170 ◽  
Author(s):  
Geir Hansen ◽  
Erling Næss ◽  
Kolbeinn Kristjansson
Keyword(s):  
Heat Pipe ◽  
Nickel Foam ◽  
Working Fluid ◽  
Flat Heat Pipe

Simulation of Heat Flux Effect in Straight Heat Pipe as Passive Residual Heat Removal System in Light Water Reactor Using RELAP5 Mod 3.2

2016 ◽  
Vol 819 ◽  
pp. 122-126 ◽  
Author(s):  
M. Hadi Kusuma ◽  
Nandy Putra ◽  
Surip Widodo ◽  
Anhar Riza Antariksawan
Keyword(s):  
Heat Flux ◽  
Heat Pipe ◽  
Saturation Temperature ◽  
Heat Removal ◽  
Working Fluid ◽  
Steady State Condition ◽  
Set Up ◽  
Heat Removal System ◽  
Removal System ◽  
Residual Heat

Heat pipe is considered being used as a passive system to remove residual heat that generated from reactor core when incident occur or from spent fuel pool. The present research is aimed to studying the characteristics of straight heat pipe as passive residual heat removal system. As an initial step, a numerical simulation was conducted to simulate the best experimental design set up being prepared for the next step of the research. The objective is to get the thermal hydraulic characteristic due to variation of heat flux of heat source. The thermal hydraulic RELAP5 MOD 3.2 code is used to simulate and analyze the straight heat pipe characteristics. Variations of heat flux are 1567 Watt/m2, 3134 Watt/m2, 4701 Watt/m2, 6269 Watt/m2, and 7837 Watt/m2. Water as working fluid is heated on evaporation section with filling ratio 60%. Environmental air with variation 5 m/s and 10 m/s of velocity are used as external cooler. Straight heat pipe used in the simulation is wickless with 0.1 m of diameter and 6 m of length. The results show that higher heat flux given to the evaporator section will lead to more rapid heat transfer and achievement of steady state condition. The increasing of heat flux leads to an increase of evaporation of the working fluid and of pressure built in the heat pipe affecting higher saturation temperature of working fluid. Heat flux loading must consider the velocity of air as heat removal in the condenser to prevent dry out phenomenon in the evaporator. Based on the results, given the experimental set-up, the optimum range of experimental parameters could be determined.

Passivation and Performance of Inorganic Aqueous Solutions in a Grooved Aluminum Flat Heat Pipe

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Michael J. Stubblebine ◽  
Ivan Catton
Keyword(s):  
Aqueous Solutions ◽  
Heat Pipe ◽  
Operating Performance ◽  
Heat Pipes ◽  
Hydrogen Gas ◽  
Working Fluid ◽  
Heating Section ◽  
And Performance ◽  
Aluminum Plates ◽  
Flat Heat Pipe

Aluminum heat pipes have traditionally been incompatible with water and water-based fluids because they quickly react to generate noncondensable hydrogen gas (NCG). Two different inorganic aqueous solutions (IAS) are tested in a flat heat pipe (FHP). Grooved aluminum plates were used as the heat pipe wick and the tests were run with the heating section raised above the condenser. Compatibility between the working fluid and the aluminum heat pipe was established by running the device to dryout and observing thermal resistance results along the way. De-ionized (DI) water was also tested, as a baseline for comparison, to establish that it did indeed fail as expected. Operating performance of each mixture was obtained from zero heat input until dryout was reached for two angles of inclination. The data suggest that both IAS mixtures are compatible with aluminum heat pipes and exhibit performance similar to that of a copper and water heat pipe. It is demonstrated that IAS and aluminum heat pipes show potential for replacing existing copper and water devices for some applications and provide alternative options for heat pipe designers who value both the thermophysical property advantages of water and reduced weight of aluminum devices.

Investigation of a Novel Flat Heat Pipe

2005 ◽  
Vol 127 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Yaxiong Wang ◽  
G. P. Peterson
Keyword(s):  
Heat Pipe ◽  
Heat Transport ◽  
Thermal Design ◽  
Experimental Results ◽  
Design Parameters ◽  
Working Fluid ◽  
Transport Capacity ◽  
Maximum Heat ◽  
Mesh Screen ◽  
Flat Heat Pipe

A novel flat heat pipe has been developed to assist in meeting the high thermal design requirements in high power microelectronics, power converting systems, laptop computers and spacecraft thermal control systems. Two different prototypes, each measuring 152.4 mm by 25.4 mm were constructed and evaluated experimentally. Sintered copper screen mesh was used as the primary wicking structure, in conjunction with a series of parallel wires, which formed liquid arteries. Water was selected as the working fluid. Both experimental and analytical investigations were conducted to examine the maximum heat transport capacity and optimize the design parameters of this particular design. The experimental results indicated that the maximum heat transport capacity and heat flux for Prototype 1, which utilized four layers of 100 mesh screen were 112 W and 17.4W/cm2, respectively, in the horizontal position. For Prototype 2, which utilized six layers of 150 mesh screen, these values were 123 W and 19.1W/cm2, respectively. The experimental results were in good agreement with the theoretical predictions for a mesh compact coefficient of C=1.15.

Development of a Passive Cooling Panel for Residential Buildings, Integrated Into a Novel “Magnetic/PCM” Ground Coupled Flat Heat Pipe

2008 ◽  
Author(s):  
Gustavo Gutierrez ◽  
Josean Aponte
Keyword(s):  
Heat Pipe ◽  
Residential Buildings ◽  
Low Cost ◽  
Heat Pumps ◽  
Design Parameters ◽  
Working Fluid ◽  
Passive Cooling ◽  
Ground Source Heat Pumps ◽  
Reluctance Motor ◽  
Flat Heat Pipe

New perspectives for reducing heat and electricity consumption in building are emerging with innovative techniques such as highly insulating glazing and super insulated structures, utilization of solar energy, solar cells, hybrid ventilation solutions, energy efficient and demand-controlled ventilation, as well as integration of solutions, energy production in building. A relatively new innovation is the use of ground-source heat pumps that have become popular for both residential and commercial heating and cooling applications because of their higher energy efficiency compared to conventional systems. In this study, a flat heat pipe is proposed for using the enormous heat capacity of the soil as a heat sink to remove heat from the ambient, integrated the principal idea of a linear reluctance motor for the recirculation of the working fluid. Linear oscillating motors have a long history as rotary motors; but the complexity in the design and difficulties on their control limited the use of them. The motor consists of an iron bar, moving inside a coil. During the path of the iron bar an incremental force appears opposing the movement of the bar. For that reason, it is important to control the system and take advantage of that behavior. Reluctance motors can have high power density at a low cost, making them ideal for many applications. In this study, an implementation of the reluctance motor is proposed for using in a recirculation process of a passive cooling panel for residential buildings. Parametric studies are carried out to optimize the design parameters.

Integrated Flat Plate Heat Pipe-Pulsation Heat Pipe for the High-Flux Electronics Cooling

2014 ◽  
Vol 960-961 ◽  
pp. 389-393
Author(s):  
Ya Ping Zhang ◽  
J.G. Wang
Keyword(s):  
Flat Plate ◽  
Heat Pipe ◽  
Electronics Cooling ◽  
High Heat ◽  
Heat Fluxes ◽  
Working Fluid ◽  
Electronic Components ◽  
Plate Heat ◽  
Effective Combination ◽  
Flat Plate Heat Pipe

A trend towards increasingly dense and compact architectures has led to unmanageably high heat fluxes in electronic components. A novel heat pipe will be developed. Heat pipe designed is based on the flat plate heat pipe and pulsation heat pipe effective combination. Channel quantity is greatly increased ,as well as compact and homogeneous red copper pulsation plank is severed as the wick，dense and connected channels are served as the passage of the working fluid.

Passivation and Performance of Inorganic Aqueous Solutions in a Grooved, Aluminum Flat Heat Pipe

2013 ◽  
Author(s):  
Michael Stubblebine ◽  
Ladan Amouzegar ◽  
Ivan Catton
Keyword(s):  
Aqueous Solutions ◽  
Heat Pipe ◽  
Heat Pipes ◽  
Hydrogen Gas ◽  
Working Fluid ◽  
Aerospace Applications ◽  
Heating Section ◽  
And Performance ◽  
Aluminum Plates ◽  
Flat Heat Pipe

Aluminum heat pipes have traditionally been incompatible with water and water-based fluids because they quickly react with the casing to generate non-condensable hydrogen gas (NCG). The NCGs inhibit the operation of evaporation and condensation based devices, eventually plugging the condenser end of the heat pipe. The heat pipe is then unable to remove heat from the condenser and the device fails. Terdtoon [1] found that these events often happen so rapidly between aluminum and water that measurements cannot even be taken. The present work tested two different, patented inorganic aqueous solutions (IAS) in a flat heat pipe setup. Grooved aluminum plates were used as the heat pipe wick and the tests were run with the heating section raised above the condenser. Compatibility between the working fluid and aluminum heat pipe was established by running the device to dryout and then reducing the heat flux to check for hysteresis. De-ionized water (DI water) was also tested, as a baseline, to establish that it did indeed fail as expected. Operating performance of each mixture was obtained from zero heat input until dryout was reached for multiple angles of inclination. The data show that both IAS mixtures are compatible with aluminum heat pipes and exhibit performance similar to that of a copper and water heat pipe. IAS and aluminum heat pipes could replace existing copper and water devices and deliver similar performance while reducing overall weight by more than three times. An IAS and aluminum heat pipe could also replace existing aluminum and ammonia combinations, currently favored in aerospace applications, to allow for increased performance and a larger operating temperature range while maintaining low device weight.

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