Distribution of heat transfer agent in the capillary structure of rotating heat pipes with a displaced axis of rotation

1991 ◽  
Vol 60 (5) ◽  
pp. 642-645 ◽  
Author(s):  
M. G. Semena ◽  
Yu. A. Khmelev ◽  
E. V. Shevel'
Keyword(s):  
Heat Transfer ◽  
Heat Pipes ◽  
Heat Transfer Agent ◽  
Capillary Structure ◽  
Axis Of Rotation

Choice of heat-transfer agent for heat pipes operating in the temperature range 300–500°C

1980 ◽  
Vol 39 (5) ◽  
pp. 1214-1216
Author(s):  
V. K. Shchukin ◽  
I. I. Mosin ◽  
Yu. V. Matveev
Keyword(s):  
Heat Transfer ◽  
Heat Pipes ◽  
Heat Transfer Agent ◽  
Temperature Range

Heat transfer capacity of channel heat pipes with triangular capillary structure

1985 ◽  
Vol 49 (4) ◽  
pp. 1181-1185 ◽  
Author(s):  
V. D. Portnov ◽  
T. M. Grigor'eva
Keyword(s):  
Heat Transfer ◽  
Heat Pipes ◽  
Capillary Structure ◽  
Heat Transfer Capacity

Development of Thinned Aluminum Flat Heat Pipe Through Inclined Wall and Press Process

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Seok-Hwan Moon ◽  
Su-Hyun Hong ◽  
Hyun-Tak Kim
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Heat Dissipation ◽  
Heat Pipes ◽  
System Level ◽  
Total Thickness ◽  
Capillary Structure ◽  
Flat Heat Pipe

Heat pipes, commonly used for heat dissipation and thermal management in small electronic and communication devices, are regarded as an excellent solution. Heat pipes must be in surface rather than line contact to be applied to the module and system-level heat dissipation package. As such, a round copper heat pipe is transformed into a plate-like shape through a secondary press process. In this study, an extrusion structure is designed to be sloped to solve the difficulty of making it relatively thin compared with the large area of the plate structure. Specifically, substantial partitions separating the working fluid flow space in the plate-type heat pipe are designed to be inclined at 45 deg, and the extruded envelope is developed to obtain the desired total thickness through the secondary press process. The capillary structure is inserted and positioned within the envelope prior to the secondary press process. In this study, an aluminum flat heat pipe (AFHP) with 0.95 mm total thickness, 150 mm total length, and a capillary structure with braided or carbon wire bundles added thereto was designed and manufactured. Performance test results indicated that the heat transfer performance of the AFHP with inclined wall did not show any deterioration characteristic compared with the AFHP with a normal vertical wall. The isothermal characteristics and heat transfer rate of the AFHP with Cu braid wick were superior to those of AFHP with a simple rectangular groove wick. By contrast, when the carbon wire bundle is added in the Cu braid, the isothermal characteristic was enhanced twice, and the heat transfer rate was 15.5 W by improving approximately 42% under the conditions that inclination angle is −90 deg and the evaporator temperature does not exceed 110 °C.

Limiting characteristics of inclined thermosyphons and heat pipes with excess heat-transfer agent

1984 ◽  
Vol 46 (5) ◽  
pp. 505-510
Author(s):  
L. L. Vasil'ev ◽  
L. P. Grakovich ◽  
D. K. Khrustalev
Keyword(s):  
Heat Transfer ◽  
Heat Pipes ◽  
Heat Transfer Agent ◽  
Excess Heat

scholarly journals Research of the process of obtaining capillary-porous materials from metal powders for heat pipes

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 5-12
Author(s):  
L. P. Pilinevich ◽  
M. V. Tumilovich ◽  
A. G. Kravtsov ◽  
D. M. Rumiantsav ◽  
K. V. Hryb
Keyword(s):  
Heat Transfer ◽  
Porous Materials ◽  
Heat Pipe ◽  
Heat Pipes ◽  
Pore Distribution ◽  
Metal Powders ◽  
Capillary Structure ◽  
Efficient Operation ◽  
Pore Sizes ◽  
Heat Transfer Capacity

Heat pipes are designed to effective removing heat from heating elements and reducing the temperature of various devices. Heat pipes with capillary porous structures are designed to operate under conditions of unfavorable gravity forces. Their main advantages are their high heat transfer capacity, as well as the ability to retain the coolant in a capillary-porous structure under dynamic power loads. The purpose of this work is to study the process of obtaining capillary-porous materials from metal powders for heat pipes with increased efficiency of using the vibration molding method. The article substantiates the relevance of creating heat pipes from metal powders. The information about the influence of the contact angle, surface tension and capillary pressure on the heat transfer capacity of a heat pipe is provided. It is shown that for the efficient operation of the heat pipe it is necessary to create such a capillary structure of the porous material, which could simultaneously provide a high speed of movement of the coolant and its rise to a given height. The above requirements can be satisfied by creating a capillary structure using powder metallurgy methods by optimizing the distribution of pore sizes. In this case, the most promising method seems to be the method of molding when applying a vibration to a mold with a powder. It is possible to obtain the required pore distribution in this way by choosing the correct particle size, shape and vibration parameters. This makes it possible to ensure the packing of particles in size, which affects their packing density, pore size, tortuosity and length of pore channels. The distribution of the maximum pore sizes over the thickness of the samples obtained from powders of various granulometric composition with the use of vibration has been investigated. As a result, a process was developed for obtaining capillary structures by the method of vibration molding of metal powders, depending on the size of the powder particles, the amplitude and frequency of vibration. It is shown that this method can provide a given pore distribution of the capillary structure for heat pipes, which makes it possible to increase their heat transfer capacity.

scholarly journals Testing algorithm for heat transfer performance of nanofluid-filled heat pipe based on neural network

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 751-760
Author(s):  
Lei Lei
Keyword(s):  
Neural Network ◽  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Volume Fraction ◽  
Heat Pipes ◽  
Transfer Performance ◽  
Analysis Model ◽  
Accurate Analysis ◽  
Testing Algorithm

AbstractTraditional testing algorithm based on pattern matching is impossible to effectively analyze the heat transfer performance of heat pipes filled with different concentrations of nanofluids, so the testing algorithm for heat transfer performance of a nanofluidic heat pipe based on neural network is proposed. Nanofluids are obtained by weighing, preparing, stirring, standing and shaking using dichotomy. Based on this, the heat transfer performance analysis model of the nanofluidic heat pipe based on artificial neural network is constructed, which is applied to the analysis of heat transfer performance of nanofluidic heat pipes to achieve accurate analysis. The experimental results show that the proposed algorithm can effectively analyze the heat transfer performance of heat pipes under different concentrations of nanofluids, and the heat transfer performance of heat pipes is best when the volume fraction of nanofluids is 0.15%.

Three-dimensional heat transfer analysis of flat-plate oscillating heat pipes

2021 ◽  
pp. 117189
Author(s):  
Kimihide Odagiri ◽  
Kieran Wolk ◽  
Stefano Cappucci ◽  
Stefano Morellina ◽  
Scott Roberts ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Three Dimensional ◽  
Heat Pipes ◽  
Heat Transfer Analysis

Thermal Modeling of Unlooped and Looped Pulsating Heat Pipes

2001 ◽  
Vol 123 (6) ◽  
pp. 1159-1172 ◽  
Author(s):  
Mohammad B. Shafii ◽  
Amir Faghri ◽  
Yuwen Zhang
Keyword(s):  
Heat Transfer ◽  
Finite Difference ◽  
Heat Pipes ◽  
Analytical Models ◽  
Charge Ratio ◽  
Sensible Heat ◽  
Governing Equations ◽  
Heating Wall ◽  
Heat Mode ◽  
Explicit Finite Difference

Analytical models for both unlooped and looped Pulsating Heat Pipes (PHPs) with multiple liquid slugs and vapor plugs are presented in this study. The governing equations are solved using an explicit finite difference scheme to predict the behavior of vapor plugs and liquid slugs. The results show that the effect of gravity on the performance of top heat mode unlooped PHP is insignificant. The effects of diameter, charge ratio, and heating wall temperature on the performance of looped and unlooped PHPs are also investigated. The results also show that heat transfer in both looped and unlooped PHPs is due mainly to the exchange of sensible heat.

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