運用於電源供應器中之多點熱源散熱片最佳化設計

Heat sink Optimization of Multi-Heat Source for Power Supply Units

黃喻鴻(Yu-hung Huang)

指導教授 ： 徐 業 良

元智大學/工程學院/機械工程學系/碩士(2006年)

https://doi.org/10.6838/YZU.2006.00216

摘要

近年來拜資訊產業發達之賜，伺服器應用服務市場大幅成長，市場上幾乎每天都有新伺服器產品問世，而應用在伺服器上的電源供應器也趨向於高電源密度(High Power Density)設計，可靠性、穩定性及品質的要求極為重要。此外由於生產電源供應器的技術層次不高，進入障礙低，競爭激烈，成本上的控制也是重要的因素。
電源供應器中之熱源大多來至功率晶體，為了降低熱源的產生，將晶體鎖在散熱片上，利用強制對流方式將晶體所產生的熱量帶走，以風扇對空氣作功造成氣體分子的擾動，再以對流的方式於散熱片表面或邊界做能量交換，進而達到冷卻的效果。由「牛頓冷卻定律(Newton’s Law of Cooling)」之對流熱傳關係式 得知，當對流熱傳係數值或接觸面積越大，所能帶走的熱量就越多，所以目前的散熱片設計都趨向於加大散熱片面積，增大風扇的流量，來提高散熱效能。然而考慮到空間與成本的限制下，散熱片的設計就不只是加大面積或增大風量，而是要在空間和成本的限制下，達到最佳效能的散熱片設計。
本文將針對高瓦數電源供應器之功率晶體散熱片進行最佳化設計，以尋找最適當的尺寸去達成最佳的散熱效率。許多相關研究針對單一熱源在強制對流下的熱傳現象做散熱片最佳化的探討，本文的重點則在於研究多熱源時的散熱情況。本研究中，由散熱鰭片熱阻分析出發，探討單卅多顆晶體不同位置對散熱片的影響，並導出晶體熱源方程式，再以典型的最佳化過程來求得散熱片最佳的設計參數，最後透過對最佳解之靈敏度分析與參數分析，提出多熱源散熱片之設計準則，以為工程師設計時之參考。

關鍵字

多點熱源 ； 最佳化設計 ； 散熱片

並列摘要

Most of the heat source of power supply comes from the power device; in order to decrease the heat, power device should be attached on the heat sink. The cooled air can take away the heat which produced by the power device, after that, using a fan to pull air, continue to have energy exchange on the heat sink surface or boundary through the heat convection, thus the cool off effect can be achieved. The heat diffusion equation from” Newton’s Law of Cooling” shows that, when the heat transfer coefficient number or heat sink surface is bigger and larger, the more heat can be taken away. Therefore, increasing the area of the heat sink with higher fan speed is the current design trend to increase the performance of heat exchange. However, there are some limitation from space and cost, so the current design trend needs to take space and cost into consideration to have the best heat sink design.

並列關鍵字

heatsink ； multi-heat source ； optimization

參考文獻

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