| Summary: | 碩士 === 國立成功大學 === 工程科學系 === 102 === With the rising awareness of global environmental protection, energy saving has become a trend. LED industry is one of the most watched industry in recent years. Developed so far, LED products have the features of energy saving, high efficiency, fast response, long life, no mercury and environmental benefits etc. However, about 20% input power of high power LED products is converted into light and the remaining 80% is into heat. If the heat cannot be well dissipated, the LED junction temperature will be too high, which will influence the life cycle, luminous efficiency and stability of the LED. In the study, different shapes of heat-dissipated lamp holders are made by the precision casting technique with different materials. Afterwards, the LED’s, installed in the holders, are lit and the holder temperatures are measured simultaneously. Based on the measured temperatures, the COMSOL simulation software and the Taguchi method are employed to estimate the convection heat transfer coefficients and the interfacial heat transfer coefficients. With the estimated heat transfer coefficients, the temperature distributions and the heat transfers in the lamp holder can be analyzed. The key point of the heat dissipation is the interfacial heat transfer coefficient or the interfacial contact resistance. If the interfacial thermal resistance is small, it is not necessary to use the thermal grease to increase the heat dissipation at the interface. If the holder have fins on its surface, the fins can help the heat transfer. However, if the contact at the interface is good enough, the fins can be saved or eliminated, which could make the product more competitive. The analysis results obtained from the thesis could be used as an important reference for the future design of lamp holder.
|
|---|
