Operating characteristics of an anti-gravity loop heat pipe with a flat evaporator that has the capability of a loop thermosyphon

2020 ◽  
Vol 205 ◽  
pp. 112431 ◽  
Author(s):  
Noriyuki Watanabe ◽  
Nguyen Phan ◽  
Yuki Saito ◽  
Shota Hayashi ◽  
Naoki Katayama ◽  
...  
Keyword(s):  
Heat Pipe ◽  
Loop Heat Pipe ◽  
Operating Characteristics ◽  
Flat Evaporator

Experimental Investigation of Heat Transfer Performance of a Miniature Loop Heat Pipe with Flat Evaporator

2011 ◽  
Vol 71-78 ◽  
pp. 3806-3809
Author(s):  
Xian Feng Zhang ◽  
Shuang Feng Wang
Keyword(s):  
Heat Pipe ◽  
Heat Load ◽  
Temperature Oscillation ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Operating Characteristics ◽  
Maximum Heat ◽  
Power Cycle ◽  
Flat Evaporator ◽  
Compensation Chamber

The present work experimentally investigated the operating characteristics of a miniature loop heat pipe (LHP) under different power cycle. The miniature LHP with flat evaporator of 8mm thick is made of copper. The evaporator with sintered copper power wick is in series structure with compensation chamber. Water is working fluid. It is found that the LHP can start up at heat load of 15W with temperature oscillation and the maximum heat load is 160W with Rl=0.068°C/W. The LHP operates unstably under low heat load. The oscillating frequency of temperature rises with heat load increased. The operating performance of the LHP is affected by the power cycle.

Effect of Sintering Temperature Curve in Wick Manufactured for Loop Heat Pipe with Flat Evaporator

2014 ◽  
Vol 595 ◽  
pp. 24-29 ◽  
Author(s):  
Shen Chun Wu ◽  
Kuei Chi Lo ◽  
Jia Ruei Chen ◽  
Chen Yu Chung ◽  
Weie Jhih Lin ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Sintering Temperature ◽  
Temperature Curve ◽  
Loop Heat Pipe ◽  
Transfer Performance ◽  
Total Thermal Resistance ◽  
Flat Evaporator ◽  
Increasing Temperature

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%.

scholarly journals Titanium-Water Loop Heat Pipe Operating Characteristics Under Standard and Elevated Acceleration Fields

2010 ◽  
Vol 24 (1) ◽  
pp. 184-198 ◽  
Author(s):  
Andrew J. Fleming ◽  
Scott K. Thomas ◽  
Kirk L. Yerkes
Keyword(s):  
Heat Pipe ◽  
Loop Heat Pipe ◽  
Operating Characteristics

scholarly journals A Novel Analytical Modeling of a Loop Heat Pipe Employing Thin-Film Theory: Part II—Experimental Validation

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2403 ◽  
Author(s):  
Eui Guk Jung ◽  
Joon Hong Boo
Keyword(s):  
Steady State ◽  
Heat Pipe ◽  
Film Theory ◽  
Design Parameters ◽  
Working Fluid ◽  
Coolant Temperature ◽  
Loop Heat Pipe ◽  
Analysis Model ◽  
Proposed Model ◽  
Flat Evaporator

Part I of this study introduced a mathematical model capable of predicting the steady-state performance of a loop heat pipe (LHP) with enhanced rationality and accuracy. Additionally, investigation of the effect of design parameters on the LHP thermal performance was also reported in Part I. The objective of Part II is to experimentally verify the utility of the steady-state analytical model proposed in Part I. To this end, an experimental device comprising a flat-evaporator LHP (FLHP) was designed and fabricated. Methanol was used as the working fluid, and stainless steel as the wall and tubing-system material. The capillary structure in the evaporator was made of polypropylene wick of porosity 47%. To provide vapor removal passages, axial grooves with inverted trapezoidal cross-section were machined at the inner wall of the flat evaporator. Both the evaporator and condenser components measure 40 × 50 mm (W × L). The inner diameters of the tubes constituting the liquid- and vapor-transport lines measure 2 mm and 4 mm, respectively, and the lengths of these lines are 0.5 m. The maximum input thermal load was 90 W in the horizontal alignment with a coolant temperature of 10 °C. Validity of the said steady-state analysis model was verified for both the flat and cylindrical evaporator LHP (CLHP) models in the light of experimental results. The observed difference in temperature values between the proposed model and experiment was less than 4% based on the absolute temperature. Correspondingly, a maximum error of 6% was observed with regard to thermal resistance. The proposed model is considered capable of providing more accurate performance prediction of an LHP.

scholarly journals Miniature Loop Heat Pipe With Flat Evaporator for Cooling Computer CPU

2007 ◽  
Vol 30 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Randeep Singh ◽  
Aliakbar Akbarzadeh ◽  
Chris Dixon ◽  
Mastaka Mochizuki ◽  
Roger R. Riehl
Keyword(s):  
Heat Pipe ◽  
Loop Heat Pipe ◽  
Flat Evaporator
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