本論文研究以實驗的方式討論氧化亞氮(N2O)的分解反應對於乙烯(C2H4)反置擴散火焰中煙粒生成之影響。N2O分解效應包含著類似富氧空氣條件的富氧效應以及伴隨熱釋放的熱效應。相較於空氣條件下的乙烯擴散火焰，N2O / C2H4擴散火焰促使更多的煙粒(soot)生成。為了探討N2O的分解反應對於煙粒生成的影響，實驗採取不同的氧化劑條件，分別為N2O條件、33% O2 +67% N2(氧化亞氮完全分解的條件)富氧條件、21% O2 +79% N2空氣條件。在本實驗系統中，使用軸對稱三環噴流燃燒器產生出不同的流速比（R）的反置擴散火焰，操作區間為R = 0至6。實驗量測系統分別使用雷射誘導白熾光(Laser-Induced Incandescence，LII)以及雙色光測高溫法(Two-Color Pyrometry)對煙粒濃度以及煙粒溫度進行測量。結果顯示，N2O分解的作用促進了N2O / C2H4火焰中的煙塵負載。 與33％O2 + 67％N2的情況相比，隨著R的增加，N2O分解反應對總體煙粒形成的熱效應增強。 最大增強達到40％。 此外，在N2O / C2H4擴散火焰上游，由於熱效應，測得的煙粒溫度有顯著的增加。 但是，通過比較33％O2 + 67％N2富氧條件和空氣條件的結果，可以看出，隨著R值的增加，富氧效應對總體煙粒形成的影響從10％逐漸提升到60％。 通過沿火焰高度積分的煙粒濃度數值顯示，煙粒的形成速率和氧化速率可能會由於N2O分解效應的參與而重新平衡。

The effect of nitrous oxide (N2O) decomposition on soot formation of nitrous oxide/ethylene inverse diffusion flame had been investigated experimentally. The N2O decomposition is regarded as the combination of the oxy-enrichment effect and exothermic thermal effect. Burning ethylene with nitrous oxide is prone to deteriorate soot emission compared to the ethylene/air condition. In order to scrutinize the effect of N2O decomposition on the soot formation mechanism, the artifices of two manipulating oxidizer conditions had been implemented, that is, a fully N2O-decomposing condition of 33% O2 +67% N2 and air condition of 21% O2 +79% N2, respectively. A triple-port burner was employed to generate inverse diffusion flames with a variation of oxidizer injections (from R=0 to 6). Soot concentration was qualitatively measured by Laser-Induced Incandescence (LII) measurement technique, while soot temperature was detected by the Two-Color Pyrometry measurement technique. Results demonstrated that the effect of N2O decomposition promotes soot loading in N2O/C2H4 flames. Compared to the case of 33% O2 +67% N2, the impact factor of the thermal effect of N2O decomposition on soot formation increases with an increase of R ratios. The maximum impact factor of the thermal effect reaches 40%. Furthermore, the measured soot temperatures significantly increase by the thermal effect in the upstream of N2O/C2H4 flames. However, comparing the results of 33% O2 +67% N2 and air conditions, it appears that the effect of oxy-enrichment on the soot formation gradually amplifies from 10% to 60% depending upon the increasing R ratios. By integrating the soot concentration along the flame heights, it reveals that soot formation rate and soot oxidation rate may rebalance by the presence of N2O decomposition effect.

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