臺灣博碩士論文加值系統

隨著引擎科技的進步，引擎的熱效率越高，汽缸內的燃燒溫度及壓力也越大，對散熱水箱的性能要求也越高，但引擎蓋下的配置空間有限，要求散熱水箱的體積越小越好，造成引擎冷卻系統內部水流的阻力很大。這些技術的演進，使得引擎水幫浦更易產生空蝕現象，氣泡也更容易滲入冷卻液中，使得引擎性能、可靠度、壽命都受到極大的損害。氣泡及水幫浦空蝕現象也常在老化及設計不當的引擎系統中出現，造成日常維修保養上的許多困難及盲點。
由於氣泡及水泵浦的空蝕現象關係著冷卻系統能否正常運作，且影響深遠，而目前已有一些針對消除冷卻系統中氣泡的裝置問世。除氣系統的工作就是在不增加冷卻系統及引擎負荷下將冷卻系統內部的氣泡主動且連續性地排出系統之外，並避免水幫浦在極惡劣的操作狀況下也不會發生空蝕現象，使冷卻系統維持高效能。但現今各除氣裝置尚有缺失。
本研究將使用全滿式除氣水箱來改良現有水箱的缺失，並提高冷卻系統的可靠度，進而使引擎各機件壽命增長、能源使用效率提高及降低製造成本等。研究中將探討水幫浦空蝕現象及氣泡流的產生、運動機制及對引擎系統的影響；並探討全滿式除氣水箱對冷卻系統性能的影響。

Since the advancement of engine technology, new engines can have much higher power and thermal efficiency, and also much higher combustion temperature and pressure inside the cylinder than before. The higher combustion temperature makes coolant temperature higher, while the higher combustion pressure possibly forces more gas seep into the coolant. High combustion temperature also requires more radiator performance, however, modern vehicle packaging only leaves very limited space for radiator installation. These limitations on radiator make the engine cooling system have very high internal flow resistance. All the factors mentioned above imply that the engine cooling system is going to have serious problems of water pump cavitation and coolant bubble flow if there is no deaeration system installed. The function of deaeration system is to continuously remove the gas from the engine coolant and avoid the water pump cavitation. This study has disclosed the mechanism of the water pump cavitation and coolant bubble flow, and their effects on the engine system.

論文授權書............................................iii
中文摘要...............................................iv
英文摘要................................................v
致謝...................................................vi
目錄..................................................vii
圖目錄.................................................ix
表目錄................................................xii
第一章 緒論............................................1
1.1 研究背景...................................1
1.2 研究重要性.................................2
1.3 引擎的空蝕.................................3
1.4 冷卻水的沸騰...............................5
1.5 相關技術研究...............................7
第二章 氣泡對冷卻系統的影響...........................13
2.1 氣泡可能產生的方式........................13
2.2 氣泡可能造成的損害........................15
2.3 水幫浦空蝕溫度............................17
第三章 除氣系統的設計與配置...........................18
3.1 設計配置原則..............................18
3.2 全滿式除氣系統............................20
第四章 實驗方法.......................................22
4.1 實驗設備..................................22
4.1.1 實驗測試台.........................22
4.1.2 除氣水箱的製作.....................24
4.1.3 引擎動力計.........................25
4.1.4 溫度量測裝置.......................26
4.1.5 壓力量測裝置.......................26
4.2 實驗步驟..................................26
4.2.1 無除氣裝置的冷卻系統空蝕實驗步驟...26
4.2.2 除氣裝置的除氣效果實驗步驟.........28
第五章 結果與討論.....................................29
5.1 水泵浦空蝕現像之實驗觀察..................29
5.1.1 冷卻液：水.........................29
5.1.2 冷卻液：乙二醇.....................29
5.2 水泵浦空蝕現像之數據分析..................32
5.2.1 冷卻液為純水.......................32
5.2.2 冷卻液含30%體積的乙二醇............36
5.2.3 冷卻液含50%體積的乙二醇............40
5.2.4 冷卻液含68%體積的乙二醇............42
5.3 不同百分比含量乙二醇的比較....................44
5.4 除氣裝置對冷卻系統的探討..................47
5.4.1 除氣水箱之水泵前後壓力差............47
5.4.2 除氣水箱之除氣效果..................49
第六章 結論............................................59
參考文獻...............................................63

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