壓電風扇模組內置於散熱鰭片之研究

Abstract

在本研究中，多重壓電磁力風扇冷卻系統分別應用於以下兩個模組，模組 A:LED用散熱鰭片和模組B:PC用散熱鰭片。多重壓電磁力風扇冷卻系統是由一個壓電風扇和兩個磁力扇葉所組成的，在結合了壓電效應、磁鐵同級互斥效應、共振效應三者之後，藉由葉片的快速震動，多重壓電磁力風扇冷卻系統可以產生強制對流的效果。 實驗結果顯示，運用碳纖維布料作為磁力風扇扇葉的材料，具有更高的楊氏係數和低密度的優勢，在25W的LED熱源之下，PVC材質的風扇熱阻為1.13℃/W，而碳纖維材質的風扇熱阻為0.82℃/W，透過材質的更動，有效降低了27.4%的熱阻，證明碳纖維片確實是良好的扇葉材質，散熱的表現足以取代原本使用的PVC材質。 模組A運用T型扇葉的設計後，LED的表面溫度從68.7℃下降到45.2℃， 葉片(a)非T型葉片設計達到3.64℃/W的熱阻，M_p為168.6%，葉片(b)T型葉片達到2.47℃的熱阻，M_p為371.4%，相較之下，T型葉片的設計可以額外降低32.1%的熱阻。 模組B運用麥拉片與碳纖維片的複合葉片概念，可以有效地提升共振頻率，在最佳化的複合比例2:8和3:7之下，熱阻值達到1.4℃/W，M_p為165.8%，T型葉片和增加額外磁力的效益也有探討。

In this study, multiple piezoelectric-magnetic fans cooling system is applied on the thermal management of Light-emitting diodes lamp (module A) and CPU chip(module B). The multiple piezoelectric-magnetic fans system composed of one piezoelectric fan and two magnetic blades. By applying the piezoelectric effect, magnetic effect and resonance effect, multiple piezoelectric-magnetic fans system induces force convection by fast vibration. The experimental results show the application of carbon fiber sheet as magnetic fan have the advantage of higher Young’s modulus and low density. The thermal resistance is 0.82℃/W comparing with the PVC performance of 1.13℃/W under 25W LEDs lighting. Changing the material for blade can decrease the thermal resistance by 27.4%. Carbon fiber sheet is proved to be a nice choice for blade to replace the original usage of PVC. In module A with T shape blade design, the temperature of LEDs substrate can drop from 68.7℃ to 45.2℃. The thermal resistance with T shape blade design is 2.47℃/W comparing with no T shape blade design of 3.64℃/W. T shape blade design can decrease the thermal resistance by 32.1% In module B, the combination of mylar and carbon fiber increases resonance frequency. The optimum ratio is 2:8 and 3:7 whose thermal resistance is 1.4℃/W. The efficiency of T shape blade design and extra magnetic force are also tested in this module.