Investigating the effect of double-layer wick thickness ratio on heat transfer performance of loop heat pipe

2014 ◽  
Vol 86 ◽  
pp. 292-298 ◽  
Author(s):  
Shen-Chun Wu ◽  
Dawn Wang ◽  
Yau-Ming Chen
2014 ◽  
Vol 595 ◽  
pp. 24-29 ◽  
Author(s):  
Shen Chun Wu ◽  
Kuei Chi Lo ◽  
Jia Ruei Chen ◽  
Chen Yu Chung ◽  
Weie Jhih Lin ◽  
...  

This paper specifically addresses the effect of the sintering temperature curve in manufacturing nickel powder capillary structure (wick) for a loop heat pipe (LHP) with flat evaporator. The sintering temperature curve is composed of three regions: a region of increasing temperature, a region of constant temperature, and a region of decreasing temperature. The most important region is the increasing temperature region, as the rate of temperature increase directly affects the performance of the wick.When the slope of the region of increasing temperature is 0.8 (equivalent to 8 OC/min), the structure of the manufactured wick is complete, with the best heat transfer performance result. Experimental resultsshowed that the optimal heat transfer performance is 160W, the minimal total thermal resistance is approximately 0.43OC/W, and the heat flux is 17W/cm2; the optimal wick manufactured has an effective pore radius of 5.2 μm, a permeability of 5.9×10-13m2, and a porosity of 64%.


2013 ◽  
Vol 711 ◽  
pp. 223-228 ◽  
Author(s):  
Shen Chun Wu ◽  
Jhih Huang Gao ◽  
Zih Yan Huang ◽  
Dawn Wang ◽  
Cho Jeng Huang ◽  
...  

This study investigates the effects of increasing the evaporating area of wick in a loop heat pipe (LHP). This work attempts to improve the performance of the loop heat pipe by increasing the number of grooves and thereby the surface area of the wick. The number of grooves is increased from eight to twelve. Experimental results show that increasing the number of grooves not only increases the surface area of the wick but also enhances LHP performance. When the evaporating surface area increases by 50%, which corresponds to increasing the number of grooves from eight to twelve, the heat transfer capacity increases from 310W to 470W and the thermal resistance is reduced from 0.21°C/W to 0.17°C/W. According to preliminary measurements, increasing the number of grooves in the loop heat pipe is highly promising for improving the heat transfer performance.


2018 ◽  
Vol 136 (1) ◽  
pp. 211-222 ◽  
Author(s):  
Emerald Ninolin Stephen ◽  
Lazarus Godson Asirvatham ◽  
Ramachandran Kandasamy ◽  
Brusly Solomon ◽  
Gnana Sundari Kondru

2016 ◽  
Vol 723 ◽  
pp. 282-287 ◽  
Author(s):  
Shen Chun Wu ◽  
Shih Hsuan Yen ◽  
Wei Chen Lo ◽  
Chen Yu Chung ◽  
Shen Jwu Su

This study investigated the use of sintered Nickel powder as the wick material of Loop heat pipe with flat evaporator (Flat loop heat pipe, FLHP) and its effect on the heat transfer performance. Add the 1-heptanol into water and form Self-rewetting Fluid (SRF), resulting in the Marangoni effect. The colder liquid can be transport to the heating surface, delaying the occurrence of dry-out and increasing the critical heat load. This paper use Surface tension measurements to measure the change of 1-heptanol SRF, then it was apply to nickel wick FLHP as working fluid to investigate its effect on the heat transfer performance. This study successfully established production process of Nickel wick structure. Results of wick structure for the effective pore radius of 2.6 μm, porosity of 62%, permeability of 5.7 × 10-13m2. Results of Surface tension measurements show that 1-heptanol aqueous solution’s surface tension increases with increasing temperature, Results from applying 0.1% 1-heptanol aqueous solution to FLHP as working fluid. For performance testing show that the critical heat load was 240 W and the total thermal resistance was 0.77 ° C/W. Compared with FLHP with pure water, SRF raised the maximum heat flux of 70%, the total thermal resistance of the system reduces 40%, SRF has the potential to enhance the heat transfer performance of FLHP.


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