迷你級聲波電子冷卻系統之研究

Study of a Miniature Acoustic Electric Cooling System

洪鼎鈞(Ding-Jyun Hong)

指導教授 ： 黃博全

國立臺北科技大學/機電學院/能源與冷凍空調工程系碩士班/碩士(2008年)

摘要

利用熱聲效應將熱由一熱庫傳至另一熱庫，達成散熱冷卻的效果技術，由於結構簡單、可靠、使用環保工質，且有高熱傳率，在電子設備熱管理的領域上已漸成為被重視的新科技--迷你級聲波冷卻器。該型冷卻器使用壓電型聲波驅動器，且無傳統水冷式熱交換器，體積小，以致可應用於電子冷卻用途上。本研究目的要研製一迷你級主動式聲波電子冷卻器，並以數值模擬為主，實驗方法為輔，探討其相關運作原理與電子冷卻性能。此外，並探討不同設計參數，如壓電(pzt)聲波驅動器之輸入功率、充氣壓力大小、工作流體種類、片堆造型等，對熱聲效應所產生之片堆兩端溫差△T及電子元件散熱冷卻的影響。研究結果顯示，聲波電子冷卻器之共振腔內片堆中存有熱聲效應現象，即沿片堆方向有溫度梯度存在，且片堆兩端最大溫差值會隨輸入PZT之電壓和充氣壓力的增加與使用較小普朗特數的工作流體而增大，但變換片堆擺設位置與長度亦會影響此溫度差，唯不如前者明顯。聲波冷卻器在電子散熱冷卻方面，凡熱聲效應愈佳，片堆冷端溫降愈大者，對電子散熱冷卻能力越好，並可降低發熱元件內部的最高溫度，延長元件壽命。本研究結果將可作為未來設計高效能熱聲電子冷卻系統及其衍生應用的參考。

關鍵字

熱聲效應 ； 聲波冷卻器 ； 壓電型聲波驅動器 ； 片堆

並列摘要

The technique using thermoacoustic effect to move heat from one reservoir to another reservoir for cooling need have gradually emphasized a novel approach to thermal management in the electric devices. This is because of simple structure, efficiency, environmental safety, and high heat transfer rate. A miniature acoustic cooler without water-cooling heat exchanger is such a device case, which utilizes piezoelectric driver to create sound wave and have a mini-scale size.
The purpose of this study is to develop a miniature acoustic cooler for electronic cooling by implementation. Then a numerically and experimentally study is performed to explored the mechanism of related thermoacoustic operation and its characteristics of electronic cooling. In addition, the effects of various design parameters (e.g., input power of piezoelectric driver, gas-filling pressure, working fluid, and stack geometry) on the temperature difference exists on both end sides of the stack, and on cooling of electronic component are analyzed.
The research results show that the phenomenon of thermoacoustic effect exists on the porous stack, i.e., there is a temperature gradient along the stack. The maximum temperature difference existing on the whole stack increases with increasing input power of piezoelectric driver, and gas-filling pressure, and increases with decreasing Prandtl number of the gas. The changes in the position and length of porous stack have smaller on the temperature distribution along the stack. Furthermore, it was found that the better the thermoacoustic effect that the acoustic cooler has, the better the cooling capacity which reduces the maximum temperature appearing in the interior of electronic component and prolongs its life in use. The results of this study may be used as a reference for the goal to design a high-performance commercialized acoustic cooler or to perform an extensive application based on the present technique in the future.

並列關鍵字

Thermoacoustic effect ； Acoustic cooler ； Piezoelectric loudspeaker ； Stack

參考文獻

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