LED具有低耗電、體積小、無汞、反應時間快、使用壽命長、及符合環保需求等優點，因此發光二極體應用於照明以取代傳統光源已是無可避免的趨勢；但由於高功率LED的發光效率及壽命，會隨著晶片溫度的升高而快速遞減，所以設計出良好的散熱模組有效降低晶片溫度，以提升LED發光效率及壽命，將是高功率LED於路燈上應用的重要關鍵。有鑑於此本文針對一款LED路燈實體模型進行散熱設計，利用計算流體力學分析軟體，針對高功率LED路燈的原始模型進行模擬分析與缺失探討，並透過實際量測的方式將其數據與模擬值作比較，以探討本文所建構之模擬結果與實際量測間之誤差；接著以模擬的方式針對原型之缺失進行改良設計分析，並加入輻射進行模擬，使其更加貼近真實情況。最後之研究結果顯示此新型散熱設計，在高瓦數200W下仍能具有相當良好之散熱效能，與原始設計相比可降低約22℃之效果，且能使LED晶片在90℃之安全溫度下運作，並且具有良好之均溫性。總結來說本研究所建立之結合數值模擬與實驗驗證的研發設計流程，將能幫助解決LED應用於路燈時之散熱問題，並可作為後續LED路燈散熱研究參考與應用。

Due to the advancement of technology, the performance of light-emitting diode (LED) has been improved significantly to surpass that of the conventional light sources. Light-emitting diode has the advantages of low power consumption, compact size, fast response time, and long lifetime. On top of that, it is mercury free and environmentally friendly. As the result, LED has become one of the important green technologies for remedying the rising threats of global warming and energy shortage in the world. The use of LEDs to replace traditional lighting sources is the trend for the future, particularly in street lighting applications. For this reason, the development of high-power LEDs has been the focus of many LED manufacturing companies. However, since the efficiency and lifetime of light-emitting diode will be gradually decreased by its rising temperature over time, developing a good thermal module to efficiently reduce the LED chip temperature, hence improving the LED efficiency and lifetime, will be the key for adopting high-power LEDs in street lighting applications.
In this study, the thermal management of a high-power LED street light prototype will be investigated via the numerical technique. Commercial CFD software Fluent is employed to develop a numerical model to simulate the heat transport phenomenon of LED street lights. By comparing the simulation results with the measured data, deviation of the developed thermal model from actual results was found within an acceptable 5% range. Based on the simulation results, design improvement for the LED street light prototype was proposed. In addition, radiation effect was incorporated into the developed CFD model to better predict the calculated results. Finally, it has been demonstrated that the newly developed thermal design can effectively dissipate the heat produced from a 200-W LED street light. A 22℃ reduction in temperature for the newly designed LED street light was achieved as compared with the original one. Moreover, the LED chip with improved design can be operated under the safe temperature of 90℃ with a quiet uniform temperature distribution. In summary, the developed thermal design based on the simulation results successfully overcomes the heat dissipation problem usually encountered in LED street lights. Also, the outcome could serve as useful basis for related studies conducted in the future.

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