Permeability, Form Drag Coefficient and Heat Transfer Coefficient of Porous Copper

2020 ◽  
pp. 1-13
Author(s):  
Jan Mary Baloyo ◽  
Yuyuan Zhao
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Drag Coefficient ◽  
Form Drag ◽  
Porous Copper

Heat Transfer Performance of Micro-Porous Copper Foams with Homogeneous and Hybrid Structures Manufactured by Lost Carbonate Sintering

2015 ◽  
Vol 1779 ◽  
pp. 39-44 ◽  
Author(s):  
Jan Mary Baloyo ◽  
Yuyuan Zhao
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Transfer Performance ◽  
Hybrid Structures ◽  
High Porosity ◽  
Transfer Performance ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Porous Copper

ABSTRACTThe heat transfer coefficients of homogeneous and hybrid micro-porous copper foams, produced by the Lost Carbonate Sintering (LCS) process, were measured under one-dimensional forced convection conditions using water coolant. In general, increasing the water flow rate led to an increase in the heat transfer coefficients. For homogeneous samples, the optimum heat transfer performance was observed for samples with 60% porosity. Different trends in the heat transfer coefficients were found in samples with hybrid structures. Firstly, for horizontal bilayer structures, placing the high porosity layer by the heater gave a higher heat transfer coefficient than the other way round. Secondly, for integrated vertical bilayer structures, having the high porosity layer by the water inlet gave a better heat transfer performance. Lastly, for segmented vertical bilayer samples, having the low porosity layer by the water inlet offered the greatest heat transfer coefficient overall, which is five times higher than its homogeneous counterpart.

scholarly journals Heat transfer enhancement at evaporation and boiling of liquid on capillary-porous surfaces created by 3D printing

2021 ◽  
Vol 2119 (1) ◽  
pp. 012075
Author(s):  
O A Volodin ◽  
N I Pecherkin ◽  
A N Pavlenko
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
3D Printing ◽  
Transfer Coefficient ◽  
Heat Transfer Enhancement ◽  
Fold Increase ◽  
Transfer Enhancement ◽  
Enhance Heat Transfer ◽  
Porous Copper ◽  
Boiling Heat Transfer Coefficient

Abstract The paper presents the results of experiments on measuring heat transfer in laminar-wave films of R114/R21 refrigerant mixture flowing down a vertical plate (70 × 80 mm). The experiments were carried out on the saturation line at a pressure of 2 bar. To enhance heat transfer, a porous copper coating with a flat layer thickness of 400 μm and a porosity of 45% was applied to the heat-transfer surface by 3D printing. The effectiveness of the application of the technique used for the heat transfer enhancement is demonstrated: an increase in the boiling heat transfer coefficient is obtained up to three times in comparison with the reference smooth surface, as well as two-fold increase in heat transfer coefficient in the evaporation regime. Based on the obtained experimental results and analysis of the research data of other authors, the geometric structure of promising multiscale porous enhancing coating is proposed for further research.

Heat Transfer Performance of Lotus-Type Porous Copper Micro-Channel Heat Sink

2013 ◽  
Vol 749 ◽  
pp. 414-420
Author(s):  
Hai Feng Chen ◽  
Yuan Liu ◽  
Liu Tao Chen ◽  
Yan Xiang Li
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Channel Structure ◽  
Working Fluid ◽  
Transfer Performance ◽  
Micro Channel ◽  
Porous Copper

Lotus-type porous structure is a new kind of micro-channel structure and can be used as heat sink for heat elimination of high powered electronic devices. Numerical analysis based on the simple fin model was used to predict the equivalent heat transfer coefficient of lotus-type porous copper micro-channel heat sink. Compared with the water, GaInSn working fluid could further promote the heat transfer performance of the heat sink. According to the theoretical analysis, a heat transfer coefficient as high as 14W/(cm2K) was attainable when the pressure drop was 50 KPa and an appropriate structure parameters: 0.4 mm in pore diameter, 0.4 in porosity and 4mm in height of porous copper were achieved.

Evaporation of lignin-lean black liquor

TAPPI Journal ◽  
2015 ◽  
Vol 14 (7) ◽  
pp. 441-450
Author(s):  
HENRIK WALLMO, ◽  
ULF ANDERSSON ◽  
MATHIAS GOURDON ◽  
MARTIN WIMBY
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Black Liquor ◽  
Salt Content ◽  
Solubility Limit ◽  
Lignin Removal ◽  
Kraft Black Liquor ◽  
Black Liquors ◽  
The Heat Transfer Coefficient

Many of the pulp mill biorefinery concepts recently presented include removal of lignin from black liquor. In this work, the aim was to study how the change in liquor chemistry affected the evaporation of kraft black liquor when lignin was removed using the LignoBoost process. Lignin was removed from a softwood kraft black liquor and four different black liquors were studied: one reference black liquor (with no lignin extracted); two ligninlean black liquors with a lignin removal rate of 5.5% and 21%, respectively; and one liquor with maximum lignin removal of 60%. Evaporation tests were carried out at the research evaporator in Chalmers University of Technology. Studied parameters were liquor viscosity, boiling point rise, heat transfer coefficient, scaling propensity, changes in liquor chemical composition, and tube incrustation. It was found that the solubility limit for incrustation changed towards lower dry solids for the lignin-lean black liquors due to an increased salt content. The scaling obtained on the tubes was easily cleaned with thin liquor at 105°C. It was also shown that the liquor viscosity decreased exponentially with increased lignin outtake and hence, the heat transfer coefficient increased with increased lignin outtake. Long term tests, operated about 6 percentage dry solids units above the solubility limit for incrustation for all liquors, showed that the heat transfer coefficient increased from 650 W/m2K for the reference liquor to 1500 W/m2K for the liquor with highest lignin separation degree, 60%.

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