An experimental study on the heat transfer performance of a loop heat pipe system with ethanol-water mixture as working fluid for aircraft anti-icing

Author(s):  
Qian Su ◽  
Shinan Chang ◽  
Mengjie Song ◽  
Yuanyuan Zhao ◽  
Chaobin Dang
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.


2012 ◽  
Vol 197 ◽  
pp. 216-220
Author(s):  
Zhong Chao Zhao ◽  
Rui Ye ◽  
Gen Ming Zhou

To solve the cooling problem in modern electronic device, a kind of heat pipe radiator was designed and manufactured in this paper. The heat transfer performance of heat pipe radiator and its relationship with air velocity were investigated by experimental method. The experimental results show that the heat pipe radiator can meet the temperature requirement of electronic device with the power range from 40W to 160W. To keep the operational temperature of electronic device with power of 160W under 75°C,the air velocity should be keep at 1.7m/s. The heat dissipation performance of heat pipe radiator was enhanced with the air velocity increased from 0.2m/s to 1.7m/s.for the electronic equipment with power of 160W.


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%.


2015 ◽  
Vol 88 ◽  
pp. 391-397 ◽  
Author(s):  
Hui Li ◽  
Bo Zhou ◽  
Yong Tang ◽  
Rui Zhou ◽  
Zhongshan Liu ◽  
...  

Author(s):  
Lilin Chu ◽  
Yulong Ji ◽  
Chunrong Yu ◽  
Yantao Li ◽  
Hongbin Ma ◽  
...  

Abstract In order to understand the heat transfer performance, startup and fluid flow condition of oscillating heat pipe (OHP) with hydraulic diameter far exceeding the maximum hydraulic diameter (MHD), an experimental investigation on heat transfer performance and visualization was conducted. From the experimental performance, it is found that the OHP can still work well with ethanol as the working fluid when the tube diameter has exceeded the MHD of 91.6%. In addition, the detailed flow patterns of the OHP were recorded by a highspeed camera for vertical and horizontal orientation to understand its physical mechanism. In the vertical orientation, initially working fluid generates small bubbles, and then the small bubbles coalesce and grow to vapor plugs, the vapor plugs finally pushes the liquid slugs to oscillate in the tube. In the horizontal orientation, the working fluid surface fluctuates due to the vapors flow from the evaporator to the condenser and bubbles burst in the evaporator. When the peak of liquid wave reaches the upper surface of tube, a liquid slug has been formed, and then the steam flow pushes the liquid slugs to oscillate in the tube.


2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Tingting Hao ◽  
Hongbin Ma ◽  
Xuehu Ma

A new oscillating heat pipe (OHP) charged with hybrid fluids can improve thermal performance. The key difference in this OHP is that it uses room temperature liquid metal (Galinstan consisting of gallium, indium, and tin) and water as the working fluid. The OHP was fabricated on a copper plate with six turns and a 3 × 3 mm2 cross section. The OHP with hybrid fluids as the working fluid was investigated through visual observation and thermal measurement. Liquid metal was successfully driven to flow through the OHP by the pressure difference between the evaporator and the condenser without external force. Experimental results show that while added liquid metal can increase the heat transport capability, liquid metal oscillation amplitude decreases as the filling ratio of liquid metal increases. Visualization of experimental results show that liquid metal oscillation position and velocity increase as the heat input increases. Oscillating motion of liquid metal in the OHP significantly increases the heat transfer performance at high heat input. The lowest thermal resistance of 0.076 °C/W was achieved in the hybrid fluids-filled OHP with a heat input of 420 W. We experimentally demonstrated a 13% higher heat transfer performance using liquid metal as the working fluid compared to an OHP charged with pure water.


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