The Investigation of Thermal Performance of Two-Phase Thermal Module
Date Issued
2007
Date
2007
Author(s)
Wang, Jung-Chang
DOI
zh-TW
Abstract
This paper investigates mainly two-phase heat transfer devices applied to electronic cooling modules. By using experimentation with a thermal resistance analysis model, we construct a theoretical model for embedded heat pipe heat sink coolers. To this end we developed a Windows-based application called EHPHSC v1.0, giving the industry a suitable tool for analyzing the thermal performance of this type of cooler. The theoretical values computed by the program fall within a 12% error of the experimental values, meeting industry requirements for use. The results show that the total thermal resistance value of the embedded heat pipe heat sink cooler is affected by the function of the embedded heat pipes. When a heat sink cooler with two embedded heat pipes is at a heating power of 140W, the total thermal resistance is at its minimum of 0.27°C/W. When a heat sink cooler with four embedded heat pipes is at a heating power of between 40W and 240W, the total thermal resistance is 0.24°C /W, which is not much of a change. If we replace the heat pipes used in this study with an ideal U-shaped heat pipe, then the heat capacity ratios of the two-pipe and four-pipe heat sink coolers are 46% and 63%, respectively.
Regarding the thermal performance of a two-phase closed loop thermosyphon cooling module, this paper looks at the working fluid within the entire cooling system mainly by measuring the temperature distribution in the walls of the condenser pipes. The differences in vapor pressure and cross sectional area between the evaporation end and condensation end result in a great difference in fluid level. According to the nucleate pool boiling theory and film condensation theory, we derive a method for calculating the internal fluid level differences between two-phase closed loop thermosyphon cooling modules. The results show that the temperature at the exit of the condenser is equal to the ambient temperature; the working fluid will permeate into the condenser. In this study we find conclude that the length of the condenser may be reduced from 14.28cm to 10.14cm without losing effectiveness.
Subjects
U型熱管
兩相熱傳
嵌入式熱管熱沉散熱模組
熱阻
兩相封閉迴路式熱虹吸管散熱模組
U-Shaped Heat Pipe
Two-Phase Heat Transfer
Embedded Heat Pipe Heat Sink Cooler
Thermal Resistance
Two-Phase Closed Loop Thermosyphon Cooling Module
Type
thesis
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