臺灣博碩士論文加值系統

本論文使用計算流體力學套裝軟體CFD-ACE+，針對具不同燃料注入模式、燃燒室入口面積及駐焰器構型之微燃燒室進行三維燃燒數值模擬，其主要研究參數為等值比(Φ)、質量流率(mf)及熱傳係數(h)等，而採用之燃料為乙烯。本研究之模擬結果經與實驗值及前人之數值結果進行比較後發現在定性上具有相同的趨勢，亦即當Φ過高時，微燃燒室將發生回火現象，而當mf過大或過小時，將因不足的駐留時間或過少的熱生成率而導致熄火之狀況。此外，研究中也發現必須在適當之熱損下微燃燒室才會具有較佳之效率，而改變不同之燃料注入方式對於燃燒室效率之影響有限，但改變燃燒室之入口面積則影響較為顯著。就駐焰器構型對於燃燒室效率之影響而言，槽狀駐焰器較環狀駐焰器為佳。

In this study, three-dimensional combustion phenomena in ethylene fueled micro-combustors with different fuel-injection type, combustor inlet area, and flame holder geometry are simulated by using commercial computational fluid dynamics software (CFD-ACE+). Effects of the key parameters including equivalence ratio (Φ), mass flow rate (mf), and heat transfer coefficient (h) are explored in details. The simulation results reveal that upstream burning may happen under large Φ and the flame can be blown out/quenched causing by less residence time/heat release rate for high/low mf. The above phenomena reflect similar qualitative trends with experimental data and past numerical results. It is also found that proper heat loss is crucial for micro-combustors to operate at better combustion efficiency. Different fuel-injection type has less effect on micro-combustor efficiency, and different combustor inlet area has more obvious effects on combustor efficiency. In addition, micro-combustor with slotted flame holder had better combustor efficiency than the one with annular flame holder.

誌謝 I
中文摘要 II
ABSTRACT III
目錄 IV
圖目錄 VI
符號說明 X
第一章 緒論 1
1.1 研究背景與動機 1
1.2 文獻回顧 2
1.3 研究目的 8
第二章 數學模式及數值方法 10
2.1 數學模式 10
統御方程式 10
化學反應模式 12
2.2 數值方法 13
2.2.1 有限體積法 14
2.2.2 SIMPLEC數值法 18
2.3 幾何構型及邊界條件 21
第三章 結果與討論 23
3.1 預混燃燒 24
3.1.1 非燃燒及燃燒流場之比較 24
3.1.2 駐焰器構型對於燃燒之影響 25
3.2非預混燃燒 27
3.2.1不同空氣-燃料注入模式之比較 27
3.2.2 不同燃燒室入口面積之比較 41
第四章 結論與建議 45
4.1 結論 45
4.2 建議 46
參考文獻 47

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