高功率MR16 LED燈具之散熱分析

Thermal Analysis of a High Power MR16 LED Lamp

賈翊平(I-Pin Chia)

指導教授 ： 李有璋

中原大學/工學院/機械工程研究所/碩士(2010年)

https://doi.org/10.6840/cycu201000095

摘要

摘 要
發光二極體（Light Emitting Diode, LED）已成為眾所皆知的新世代光源，不過只要是使用LED光源就有可能面臨散熱的問題，如果無法有效將積存在LED晶片上的熱量帶走，導致LED接面溫度（Junction temperature）過高，將會造成LED的光衰並且降低壽命。為了因應市場需求，如何開發高功率的LED燈具並解決散熱的問題儼然成為目前研究的重點。
本論文將針對仿傳統MR16設計的LED燈具作散熱分析，目前低瓦數（3～5 W）的MR16 LED以自然對流的散熱方式已經足夠，而7 W或以上的高功率MR16 LED由於散熱問題嚴重，仍然缺乏有效的散熱解決方案。本研究主要目的即在於採用數值模擬分析的方式，探討自然對流與強制對流時MR16 LED的各種熱效應影響。首先在不改變鰭片數量的情況下以鰭片上開孔的改良設計方式提升低瓦數MR16 LED整體的散熱效能，藉由模擬結果分析散熱鰭片上不同開孔位置與大小對散熱性能的差異。另外，為了因應高功率MR16 LED的需求，以加裝超微風扇形成強制對流的散熱方式來開發新的風扇型MR16 LED，同樣透過模擬結果討論不同鰭片數量和不同風扇氣體流量與散熱之間的相互關係，本研究亦搭配不同功率LED參數進行模擬，期望能找出較適合MR16 LED的散熱方式，並以此當作日後開發MR16 LED的參考依據。

關鍵字

高功率LED ； 散熱分析 ； 散熱鰭片 ； MR16 LED

並列摘要

Abstract
Light emitting diodes (Light Emitting Diode, LED) are well-known for the new generation of light source. However, thermal dissipation is a critical problem for the application of LEDs. If the heat cannot be taken away adequately, this thermal problem will lead to high junction temperature which will reduce the luminous flux and also reduce the lifetime of LEDs. For the market demand, how to develop high power LED lamps and also provide thermal solutions become the critical issue in LED research.
In this study, I will do the thermal analysis of MR16 LED lamps. For low power (3~5 W) MR16 LEDs, heat dissipation could depend on the natural convection only, but for higher power MR16 LEDs, natural convection is not strong enough to overcome serious thermal problem. The purpose of this paper focuses on the thermal analysis of MR16 LED lamps and discusses thermal effects of MR16 LEDs under natural convection or forced convection by using numerical simulation method.
First, without changing the number of fins I investigated how the location and size of opening of fins influence the junction temperature for the low power MR16 LEDs. Second, I added a micro-cooling fan to enhance the heat transfer to investigate the effect of forced convection on high power MR16 LEDs. From the numerical simulations, number of fin, gas flow rate of micro-fan and lamp power were discussed to understand the junction temperature. Finally, we hope to find out the best cooling design MR16 LEDs.

並列關鍵字

MR16 LED ； high power LED ； cooling fin ； thermal analysis

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