筆記型電腦散熱設計中散熱鰭片與風扇擺置之間距對散熱效能影響之探討研究

The study of the effect of the gap between blower and heat exchanger in Notebook PC thermal module design

林昇照(Samy Lin)

指導教授 ： 張永鵬

中原大學/工學院/機械工程研究所/碩士(2006年)

https://doi.org/10.6840/cycu200600031

摘要

現今,用於計算散熱鰭片散熱能力的方法都是假設在熱交換器端的熱管為等溫而熱交換的空氣為均勻流場,只有少數已發表的論文已經開始討論熱管有溫度降之熱交換器然,而其流場仍然為均勻流場.筆記型電腦中的側吹式風扇則是提供非均勻流動的空氣進入散熱鰭片作為熱交換之用.由於流場不均勻加上散熱鰭片端的熱管有較大的溫度降,因此側吹式風扇相對應於散熱鰭片的預留間隙與擺置方式會影響到鰭片的散熱效能.本篇論文的目的是討論熱交換鰭片端的熱管有較大溫度降時與側吹式風扇間預留間隙與擺置之方式對散熱效能之影響與彼此間交互作用的關係,並同時紀錄實驗過程中所觀測到的現象以提供建議給筆記型電腦的設計工程師.
實驗的結果顯示,在散熱鰭片端的熱管的確有不小的溫度差,而筆記型電腦使用之側吹式風扇其出口處的流場速度分佈變化量也相當大.因此,如果小心地置放風扇使其位於相對適當的散熱鰭片位置則能有效地降低散熱鰭片的熱阻.譬如,保留7mm的間距能消除側吹式風扇所造成非均勻流場的影響,而將側吹式風扇的高速端擺放於對應的散熱鰭片中熱管溫度較高端時的散熱鰭片熱阻會較風扇反向置放時鰭片的熱阻低8.67%.而於此同時,使用適當發熱測試載具的重要性,在文中也將述及與說明.

關鍵字

側吹式風扇 ； 熱交換器 ； 熱管 ； 筆記型電腦

並列摘要

Up to today, the method used to calculate the heat dissipated by heat exchanger is based on the assumption of uniform temperature at heat pipe of a heat exchanger with uniform air flow. Few papers published have started to discuss the effect of temperature drop of the heat pipe at heat exchanger but still assume the air flow is uniform. The blower in Notebook PC pumps non-uniform flow of air into heat exchanger to dissipate heat. Because of the non-uniform flow and large temperature drop at heat pipe, the gap between blower and heat exchanger and the location to place blower associate with heat pipe will affect the efficiency of heat exchanger. The goal of the dissertation is to study the effect of the gap between blower and heat exchanger when heat pipe at the heat exchanger has large temperature drop, and the effect to the efficiency of heat exchanger when place blower at the location associated with higher temperature portion of the heat pipe vs. reversed configuration, then list the observations during the experiment and provide recommendations for Notebook PC industry.
The experimental results show that heat pipe at heat exchanger has large temperature drop and the velocity variation at blower outlet is also huge. If properly locate blower will maximize heat exchanger efficiency. For example, keeping 7mm gape can eliminate non-uniform flow effect, and placing higher flow velocity area of the blower at the portion where heat pipe has higher temperature, gains 8.67% of benefit in comparison with the reversed configuration. In the mean time, the importance of the usage of thermal test vehicle is also been introduced.

並列關鍵字

blower ； notebook ； heat exchanger ； heat pipe

參考文獻

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