Heat Transfer Performance of Water Flow in Porous Copper Pipes Fabricated by Explosive Welding Technique

2018 ◽  
Vol 2018 (0) ◽  
pp. 0175
Author(s):  
Yuki Abe ◽  
Kazuhisa Yuki ◽  
Yoshiaki Sato ◽  
Risako Kibushi ◽  
Noriyuki Unno ◽  
...  
2009 ◽  
Vol 1188 ◽  
Author(s):  
Liping Zhang ◽  
David Mullen ◽  
Kevin Lynn ◽  
Yuyuan Zhao

AbstractThe heat transfer coefficients of porous copper fabricated by the lost carbonate sintering (LCS) process with porosity range from 57% to 82% and pore size from 150 to 1500 μm have been experimentally determined in this study. The sample was attached to the heat plate and assembled into a forced convection system using water as the coolant. The effectiveness of the heat removal from the heat plate through the porous copper-water system was tested under different water flow rates from 0.3 to 2.0 L/min and an input heat flux of 1.3 MW/m2. Porosity has a large effect on the heat transfer performance and the optimum porosity was found to be around 62%. Pore size has a much less effect on the heat transfer performance compared to porosity. High water flow rates enhanced the heat transfer performance for all the samples.


2015 ◽  
Vol 1779 ◽  
pp. 39-44 ◽  
Author(s):  
Jan Mary Baloyo ◽  
Yuyuan Zhao

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.


Author(s):  
Sun-Joon Byun ◽  
Sang-Jae Lee ◽  
Jae-Min Cha ◽  
Zhen-Huan Wang ◽  
Young-Chul Kwon

This study presents the comparison of heat transfer capacity and pressure drop characteristics between a basic fin-tube heat exchanger and a modified heat exchanger with the structural change of branch tubes and coiled turbulators. All experiments were carried out using an air-enthalpy type calorimeter based on the method described in ASHRAE standards, under heat exchanger experimental conditions. 14 different kinds of heat exchangers were used for the experiment. Cooling and heating capacities of the turbulator heat exchanger were excellent, compared to the basic one. As the insertion ratio of the coiled turbulator and the number of row increased, the heat transfer performance increased. However, the capacity per unit area was more effective in 4 rows than 6 rows, and the cooling performance of the 6 row turbulator heat exchanger (100% turbulator insert ratio) was down to about 6% than that of 4 row one. As the water flow rate and the turbulator insertion ratio increased, the pressure drop of the water side increased. This trend was more pronounced in 6 rows. In the cooling condition, the pressure drop on the air side was slightly increased due to the generation of condensed water, but was insignificant under the heating condition. The power consumption of the pump was more affected by the water flow rate than the coiled turbulator. The equivalent hydraulic diameter of a tube by the turbulator was reduced and then the heat transfer performance was improved. Thus, the tube diameter was smaller, the heat flux was better.


2018 ◽  
Vol 136 ◽  
pp. 518-521 ◽  
Author(s):  
Kio Takai ◽  
Kohei Yuki ◽  
Kazuhisa Yuki ◽  
Risako Kibushi ◽  
Noriyuki Unno ◽  
...  

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