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http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/26879
Title: | 微流道蒸氣壓縮循環電子散熱系統 Micro-channel Vapor Compression Refrigeration System for Electrical Cooling |
Authors: | Meng-Hsun Wu 吳孟勳 |
Advisor: | 陳希立 |
Keyword: | 微流道,蒸氣壓縮循環,電子散熱,溫度控制, Micro-channel Vapor compression refrigeration cycle,Electronic cooling,Temperature control, |
Publication Year : | 2008 |
Degree: | 碩士 |
Abstract: | 本研究設計並製造微流道蒸發器,應用於蒸氣壓縮循環式電子散熱系統中。實驗規劃穩態及動態實驗,設計完整的實驗方法與流程,分析各實驗參數對系統性能之影響。實驗結果顯示本研究所開發之散熱系統最大散熱(冷凍)能力為250~400W、COP由1.7~3、第二定律效率最高達70%,並同時對熱源溫度做控制。
穩態實驗中,微流道蒸發器有效將CPU底板的熱和冷媒做熱交換,提升系統COP;微流道極高熱交換能力使得冷媒過熱,但是過多的氣態冷媒使得蒸發熱阻隨加熱瓦數提高呈指數型增加,本研究深入探討冷媒在微流道中兩相之流動機制,建立兩相蒸發熱阻理論模式驗證實驗結果,最後歸納出適當蒸發溫度對熱源溫度做控制。 動態實驗中,動態蒸發溫度可改變微流道中冷媒之流量與乾度,在加熱瓦數提升時,動態選取適當蒸發溫度,對CPU溫度做最佳化控制。未來將縮小系統體積及壓縮機變頻的方式,將蒸汽壓縮應用於電子散熱中。 This research apply Micro-channel Evaporator to Vapor Compression Refriger- ation System (VCRS) for electrical Cooling. Steady and transient States experimental investigations are conducted to analysis the thermal properties depends on the design experimental factor.The cooling capacity of the VCRS varied from 250W to 400W, with COP from 1.7 to 3, at pressure ratios of 1.6 to 2.8.The highest overall second-law efficiency was 70%. In steady state experiment. Micro-channel evaporator efficiently make the heat exchange between CPU base and the evaporator, improving the coefficient of perfor- mance .Because of the icreacing heat load ,too much gass R-134a decreased the heat transfer coefficient.This research discussed the mechanism of the two phase flow in high-heat-flux micro-channel ,using evaporator thermal resistance model in order to predict and control the CPU temperature. In transient experiment.Transient evaporator temperature can control R-134a quality and mass flow rate .A complete experimental and numerical medole was built and tested in order to find out optimimal control of the CPU temperature. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/26879 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 機械工程學系 |
Files in This Item:
File | Size | Format | |
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ntu-97-1.pdf Restricted Access | 2.5 MB | Adobe PDF |
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