Chin-Chun Hsu1, Shung-Wen Kang 1 and Tung-Fu Hou1
1Department of Mechanical and Electro-Mechanical Engineering, Tamkang University Tamsui, Taiwan 251, R.O.C.
Received:
January 3, 2005
Accepted:
March 15, 2005
Publication Date:
June 1, 2005
Download Citation:
||https://doi.org/10.6180/jase.2005.8.2.05
ABSTRACT
A 60 mm x 33 mm x 0.8 mm micro loop heat pipe (MLHP), consisting of an evaporator, vapor line, condenser and two liquid lines, was fabricated and characterized. The wicking structure consists of parallel V-grooves with a hydraulic diameter of 47 μm, 67 μm and 83 μm, and is formed by bulk silicon etching. The MLHP was realized by bonding a glass wafer onto a silicon substrate, so as to result in a transparent cover for two-phase flow visualization. Water and methanol were used as the working fluids. The test results showed that water demonstrates a wider heat load performance range (3.3 W~12.96 W) than methanol (1.2 W~5.85 W) for the MLHP with an evaporator area of 1 cm2 and condenser temperature of 17 ºC. The best thermal resistance of the MLHP was 0.106 ºC/W, 64 times higher than that without fluid filling. The smaller diameter grooves caused the higher liquid capillarity and enhanced transfer capacity. It was observed that the presence of non-condensable gas negatively affected the reliability of the MLHP and significantly reduced the performance.
Keywords:
Micro Loop Heat Pipes, Two Phase Flow, Non-condensable Gas, Thermal Resistance
REFERENCES
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