- 學位論文
壓電風扇應用於高功率LED燈具之散熱實驗
A Study on the Heat Dissipation of High Power LEDs by Piezoelectric Fans
摘要
壓電風扇是屬於一種微型之散熱元件，它係利用壓電材料具有的逆電壓效應，以共振的情況來驅動扇葉擺動，並產生氣流以達到散熱之目的。它具有體積小、耗能低、噪音低等優點，適合應用在小型電子產品上。 本文主要是利用實驗的方法將壓電風扇架設在一開放空間，並以LEDs當熱源貼附在直板型之散熱鰭片上，觀察壓電風扇在不同的擺放方式 (包括: 擺放角度、擺放高度、擺放深度)下對散熱效能之影響。其實驗結果顯示，散熱性能的好壞會隨著扇葉尖端位移與共振頻率的增加而增加，而且共振頻率的重要性又大於尖端位移，同時，本實驗所設計之壓電風扇在最佳擺放方式下具有讓LEDs溫度在90℃以下之散熱能力。此外，實驗結果也顯示出擺放的位置也是影響散熱性能的重要參數之一，當壓電風扇水平擺放時，扇葉擺動方向與鰭片方向平行下，其最佳擺放位置在擺放深度為0.6、擺放高度為0.4，而當扇葉擺動方向與鰭片方向垂直時，最佳擺放位置在擺放深度為0.3、擺放高度為0.04，並且散熱性能會隨著擺放高度上升而下降。
並列摘要
Piezoelectric fan is belonging to a kind of micro-component of cooling device. It uses the piezoelectric effect to drive the fans and then produce the airflow to cool the heat source. This fan is of low power consumption, small size, and low noise. Piezoelectric fan is suitable for thermal management of miniature electronic device. An experimental method was used in this research. The piezoelectric fan was mounted on an opening space and a LED lamp which is fixed on the straight-type heat sink is used as the heat source. The thermal performances of piezoelectric fan at different positions were observed. The results show that the cooling capacity increases with bigger tip displacement and larger resonant frequency. Besides, the effect of resonant frequency outweighs that of tip displacement. The temperature of the LED lamps can be kept under 90℃ with the optimum location of the piezoelectric fan. Furthermore, the results also show that the placement of the piezoelectric fan is one of the important parameters affecting the cooling performance of the heat generating device. In the horizontal orientation, where the swing direction and the fin direction are in parallel, the optimal dimensionless depth of fan position is 0.6 and dimensionless height of fan position is 0.4 but they are 0.3 and 0.04, respectively for the vertical orientation. In general, the thermal performance decreases while the height of fan position increases.