The Design Parameter for the Maximum Heat Transfer Analysis on the Miniature Heat Pipe

• Main Authors: Lu, Chun-Chang, 盧俊彰
• Other Authors: Lin, Wei-Keng
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/11833897062301087483

博士 === 國立清華大學 === 工程與系統科學系 === 97 === Heat pipes are transport mechanisms that can carry heat fluxes ranging from 10 W/cm2 to 20 KW/cm2 at extremely fast speeds. Therefore, heat pipes are widely used in 1U servers, notebooks, PCs, etc. A heat pipe is a heat removal device comprising a vacuum pipe that charges a certain amount of working fluid and seals the tube. Hence, the heat pipe performance depends not only on the geometric parameters such as wall thickness, tube material, and wick material but also on the thermal properties of the working fluid such as latent heat, vapor pressure, viscosity, and vacuum pressure. This paper not only presents a theoretical model that predicts the maximum heat transfer rate (Qmax) for a round shape heat pipe, but also obtains Qmax values with different lengths of the evaporator and the condenser. The effect of the different operating temperature and the different vacuum pressure of the heat pipe on the Qmax were also shown in this study. All these data will be a very good benchmark for the comparison of the experiment and the simulated results. From the experiment, the Qmax was rising with the increasing amount of the heat pipe diameter and the operating temperature. The deviation value of the Qmax between simulations and experiments are less than 15 %. It means that the Qmax model is a very good tool for designing the heat pipe performance ability. This research not only to predict, but also to discuss the vacuum pressure from the Heat pipe by destroy measurement. Of the results, the data from measured is very close to actually vacuum pressure, and it also has the repeatability in the same vacuum pressure from different inventory.