熱電致冷散熱模組理論分析及實驗研究

Theoretical and Experimental Investigation of Thermoelectric cooling module

張育瑋(Yu-Wei Chang)

指導教授 ： 陳希立

國立臺灣大學/工學院/機械工程學研究所/博士(2009年)

https://doi.org/10.6342/NTU.2009.00603

摘要

隨著電子產業製程技術的進步及人們對電子產品功能上的需求，電子晶片在製造上趨於輕薄短小而功能強大；然而，這也造成嚴重的電子熱傳問題。目前主要的電子散熱方案為在晶片上安裝散熱鰭片以導出晶片上的熱，再利用風扇引起空氣流將熱散至外界。但是氣冷式散熱技術己達到了瓶頸，己無法作為下一世代電子晶片的散熱方案，所以許多研究人員致力於新散熱技術的開發，熱電致冷技術為其中的一種。熱電致冷（thermoelectric cooling）技術是藉由輸入電流造成珀爾帖效應（Peltier effect）將熱量由低溫端傳至高溫端，以降低熱源溫度。本論文首先對熱電晶片（thermoelectric cooler）進行理論分析，並建立一套實驗方法求出其性能參數。接著，本論文將熱電晶片與氣冷式鰭片、水冷散熱模組、嵌入式熱管散熱模組、及蒸氣腔體整合為熱電散熱模組，藉由實驗研究及理論分析探討熱源加熱功率、電熱晶片輸入電流對於熱電散熱模組的影響，進而找出各散熱模組與熱電晶片整合後能有效提升原本散熱器性能的有效操作範圍。此外，本論文亦發展了適用於CFD商用軟體的熱電晶片數值模擬模型，可供研究人員在進行相關的研究之用。
結果顯示欲使電熱晶片的COP大於1，則冷熱端溫差必須控制在10℃以內。而在散熱模組實驗方面，熱電散熱模組性能在低加熱功率下會有較好的表現，且在各加熱功率下存在著最佳化操作電流以達到在該加熱功率下的最佳性能，在本研究中，各熱電晶片搭配散熱模組的最佳電流操作點約為6~7A。研究結果也顯示出與熱電晶片整合後不一定能提升散熱器的熱傳性能，本研究歸納實驗結果找出各熱電散熱模組的有效操作範圍，在此操作範圍內散熱器加上熱電晶片後能夠有效的提升其熱傳性能。由有效操作範圍的結果得知，各熱電散熱模組都存在著加熱功率極限，當高於此加熱功率極限，與熱電晶片整合後的性能會比未與熱電晶片整合時還差。可提升散熱效果的有效加熱功率極限，當熱源面積為30×30mm2時，在氣冷熱電模組為57W，在水冷熱電模組為57W，蒸氣腔體散熱電模組為58W，而嵌入式熱管為60W。本論文也提供了一個半經驗關係式可預測此有效加熱功率極限。本研究建立了適用於熱電散熱模組的熱網路理論分析模式，實驗結果顯示此理論分析模式所得到的結果與實驗結果相吻合。此外，本研究所發展之數值模擬模型的模擬結果與理論分析模式的預測結果相當吻合，這兩個理論分析模式可供熱電晶片相關設計者作為設計上的參考。

關鍵字

熱電致冷 ； 熱阻模型 ； 電子散熱 ； 數值模擬

並列摘要

Owing to the growth of electronic manufacture and the requirement for electronic product performance, micro-chip is produced in small size with powerful performance, which causes serious electronic cooling problem. Among nowadays electronic cooling solutions, air-cooling is the most popular. In air-cooling solution, heat is conducted through heat sink and then released into air by forced convection. Nevertheless, air-cooling solution counters its performance limit in recent years. It is no longer the cooling solution for next generation micro-chips. Therefore, a lot of pioneers dedicate in developing new cooling technologies, and thermoelectric cooling is one of them. Thermoelectric cooling employs Peltier effect, which is caused by input electric current, to lower heat source temperature. Firstly, this thesis theoretically analyzes thermoelectric cooler and develops an experimental method to measure the physical properties. This thesis, then, integrates thermoelectric cooler with different heat sinks as thermoelectric cooling modules. Those heat sinks are air-cooling heat sink, water-cooling module, heat pipe embedded heat sink, and vapor chamber heat sink. The impacts of heating power and input electric current on thermal performance are experimentally and theoretically studied. Furthermore, this investigation figures out the effective operating range under which the performance of heat sink with thermoelectric cooler can be better than without thermoelectric cooler. Besides, this study proposes numerical model of thermoelectric cooler for CFD commercial package. The model could be an aid for simulation involving thermoelectric cooler.
The result shows that the temperature difference between thermoelectric sides must be less than 10oC to achieve the COP larger than one. The total thermal resistance of thermoelectric cooling module increases with increasing heating power at a specific input current. An optimal input current exists for lowest total thermal resistance under every heating power. In this study, the optimal input currents of thermoelectric cooling modules are 6-7A. Being integrated with thermoelectric cooler does not guarantee the performance improvement of heat sink. There exists maximal heating power over which heat sinks perform worse when integrated with thermoelectric cooler. In this investigation, the maximal heating power is 57W for air-cooling, 57W for water-cooling, 58W for vapor chamber, and 60W for heat pipe embedded heat sink when the heating area is 30 mm square. Furthermore, this thesis develops a theoretical analysis model, and the prediction by the model matches the experimental result. And also, the simulation result by the proposed numerical model highly matches the prediction by the theoretical model.

並列關鍵字

thermoelectric cooling ； thermal resistance model ； electronic cooling ； numerical simulation

參考文獻

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