黃秉鈞臺灣大學:機械工程學研究所黃煥翔Huang, Huan-HsiangHuan-HsiangHuang2010-06-302018-06-282010-06-302018-06-282009U0001-1506200900331700http://ntur.lib.ntu.edu.tw//handle/246246/187234本研究旨在探討迴路熱管(LHP)的動態行為，推導出迴路熱管的動態模型，並探討迴路熱管的動態行為、設計參數穩定度及啟動暫態特性。從迴路熱管能量平衡方程式可以得到迴路熱管動態模型，從模型中可以得知，迴路熱管是一個隨著操作條件變化的多變量系統，另外將材料物體性質代入模型中，可以將迴路熱管化簡為一個二階的系統，並透過識別實驗來修正動態模型，然後運用此一動態模型來進行溫度控制器的設計，並利用調整冷凝器散熱風扇的風量去控制蒸發器的溫度，其控制誤差為 0.5 oC，符合控制器的設計規格且具有抗干擾能力。在設計參數穩定度分析方面，根據分析結果可得知，增加毛細結構孔隙度及工作流體潛熱會造成迴路熱管不穩定，其餘參數如毛細結構熱傳導係數、液態工作流體熱傳導係數、毛細結構有效熱傳導係數、毛細結構長度及工作流體的沖灌量等皆不影響穩定性。在迴路熱管啟動暫態分析部分，根據分析的結果，迴路熱管的啟動暫態行為可以分成四種模式，分別是：(1)失敗模式；(2)震盪模式；(3)超越量模式；(4)常態模式。因為影響迴路熱管的啟動暫態原因很多，本研究針對工作流體、毛細結構的毛細力、工作流體充填量、迴路長度、熱負載及操作角度等參數，在不同的啟動暫態模式下進行測試，並識別出每個啟動暫態模型，來找出不同參數對啟動暫態特性的影響，其中以蒸發器的毛細力影響最顯著。The present study is to understand the dynamic behavior of a loop heat pipe (LHP) and deriving the dynamic model of a LHP. In addition, the stability analysis of the designed parameter and the analysis of start-up transient characteristics of a LHP are studied. he dynamic model of a LHP can be derived by the energy balance equation of a LHP. As a result, it is found that the system dynamics of a LHP is a multivariable system changing with operating conditions. The material properties are used in the model, which can be reduced a second-order system. Moreover, the model can be re-vised by the identified experiment. The dynamic model is used to develop a PI con-troller that the temperature of evaporator can be controlled within a deviation of 0.5 degree by changing the mass flow of a fan in the condenser. ccording to the results of stable analysis, porosity and latent heat of working fluid make unstable for the operation of a LHP except the thermal conductivity of wick, the thermal conductivity of liquid working fluid, the effectively thermal con-ductivity of wick, the length of wick, and charged volumes of working fluid.inal part of the present study has been carried out to test the start-up characte-ristics and behavior of a LHP with the different parameters, which are heat loads, orientation, working fluid, capillary forces, tube length, and charging volume. It is also found that the start-up phenomena of a LHP can be classified into four modes according to the heat loads: (1) failure mode,(2) oscillating mode, (3) overshoot mode, and (4) normal mode. System identification is used to identify those parameters of the start-up characteristics of a LHP and also to determine the relation-ship among those different factors affected the characteristics of a LHP in this study. The results show the major factor is the capillary forces and the secondary factors are working fluid, tube length, and charging volume.口試委員會審定書 I文摘要 II文摘要 II號表 IV錄 VIII目錄 X目錄 XX一章 前言 1.1 迴路熱管技術簡介 2.2 文獻回顧 6.3 研究動機與目的 8.4 研究內容 8二章 迴路熱管硬體製作與性能測試 9.1 迴路熱管硬體製作 9.2 迴路熱管穩態性能測試 18三章 迴路熱管動態模型推導 21.1 系統模型的建構方法 21.2 迴路熱管動態理論模型推導 23.3 迴路熱管動態理論模型建構 27.4 迴路熱管動態理論模型數值分析結果 32.5 迴路熱管動態模型系統識別方法 36.6 迴路熱管動態模型識別實驗設計 39.7 迴路熱管動態模型識別結果 40.8 設計參數之穩定度分析 61四章 迴路熱管啟動暫態特性分析 67.1 啟動理論分析 67.2 啟動暫態分析 74.3 工作流體種類影響 81.4 毛細力影響 89.5 工作流體充填量影響 97.6 迴路長度影響 105.7 啟動暫態分析與討論 113五章 迴路熱管控制系統設計 115.1 PI控制系統的設計分析 115.2 控制器硬體設計 122.3 控制器軟體設計 130.4 控制器實驗結果 132六章 結論 134考書目 137錄A 14116544067 bytesapplication/pdfen-US迴路熱管動態行為暫態行為系統識別啟動分析Loop heat pipesLoop Heat PipesDynamic BehaviorTransient BehaviorSystem IdentifycationStartup of Loop Heat Pipethesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/187234/1/ntu-98-D93522001-1.pdf