Thermal module of surface light source using aligned array led
| Autor: | Chih-Lin Wang, 王芷琳 |
|---|---|
| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 96 The experiment is used of the different heat convection and the light density to research the temperature uniformity of the heat sink. Fixing the heat fins area, and load 30, 45 and 60 LEDs on the heat sink. To improve the temperature uniformity of the heat sink, it is adjusted the pitch of the heat fins and the shield and to change the airflow field of the heat convection, and to install the heat pipe which has the heat transfer buoyancy effect of the opposite direction. From the experiment, it is better when the heat sink without the shield and the average temperature is lower on the heat sink. Due to the heat buoyancy effect, the largest temperature difference of the top-and-bottom regions of the heat sink is about 6℃. When the temperature difference of the heat sink and the ambient is about 30℃, the heat buoyancy is caused gradually by the heat convection. Restricting the airflow field, the result shows that when the pitch of the heat fins and the shield is 0.5H, the largest temperature difference of the top-and-bottom regions of the heat sink is up to 12℃. With the power increases, it is expected that when the rated power is more than 1.5 times of the RGB-LED, the luminance will gradually decline. Installing the heat pipe to improve the heat distribution of the heat sink, it can reduce 10℃ of the average temperature when the heat sink with the shield. The result shows that the airflow field is restricted by the pitch of the heat fins and the shield, and increase the average temperature of the heat sink, and increase the temperature difference of the top-and-bottom regions of the sink. When the pitch is greater than 1H, it is useful to decrease the temperature difference of the top-and-bottom regions. If the installation of the heat pipe, it can play the function of the heat fins, and reduce the average temperature, and reduce the temperature difference of the top-and-bottom regions of the heat sink. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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