| Summary: | 碩士 === 聖約翰科技大學 === 機械與電腦輔助工程系碩士班 === 103 === The light emitting diode (LED) illumination assembly is one of the important energy saving technologies. However, the brightness, color temperature and life span are strongly depended on the temperature distribution. In order to improve the LED cooling design, the Icepak software is used to simulate the heat transfer of cooling package of LED. After the simulations of commercial LED product cooling, the experimental measurements are compared to the numerical results. The grid independence and convergence independence are also conducted. Some parameters of cooling system are simulated to find the relation between the highest temperature of cooling package and parameter change. The investigated parameters include the number of fin, the thickness of fin, the length of fin, and the anisotropic thermal conductivity ratio of heat spreading substrate. The numerical results show that the number of cooling fin changed from 28 to 45, the highest temperature of cooling package decreased about 2℃. The reason is even the fin number increased the heat cooling area increased but the passage between two fins decreased which limited the development of natural convection. When the fin thickness changed from 0.5mm to 1.5mm, the highest temperature decreased about 14℃. The reason is that the fin thickness is proportional to the heat flux of thermal conduction. When the fin length changed from 4mm to 12mm, the highest temperature decreased from 90 to 64℃. This shows the increase of single fin area is much better than increase of fin number which also extended the heat transfer area too. If the anisotropic thermal conductivity ratio of heat spreading substrate changed from 1 to above 10, the highest temperature dropped about 5℃. The reason is most of heat can transfer to fins but along the other direction. This is why the cooling performance is improved.
|
|---|
