臺灣博碩士論文加值系統

本研究探討兩預混噴流火焰在停滯面流場的相互作用，並分析不同噴流間距、加熱間距、甲烷濃度與出口流速對火焰形態和加熱效率的影響。實驗中利用兩個可調整噴流間距與加熱間距的矩形燃燒器，在甲烷濃度12%~18%下，觀察兩火焰在不同噴流間距和加熱間距下的相互作用，定義其火焰形態臨界特性，並分析其對加熱效率的影響，以尋求在不同實驗條件下之最佳操作條件與其所對應的火焰形態。
研究結果顯示，火焰形態會隨著不同的甲烷濃度、噴流間距與加熱間距而改變；在層流火焰中，噴流出口流速的影響僅為火焰之大小。噴流間距對加熱效率的影響，以甲烷濃度來分類，得到甲烷濃度為12%，擴散火焰形態為內縮時，加熱效率隨噴流間距的增加，呈現先上升後下降的趨勢；擴散火焰為外張時，隨噴流間距的增加，加熱效率反而先下降後上升。甲烷濃度為13%與14%，在兩預混火焰獨立成形之後，其變化趨勢跟甲烷濃度12%相同。甲烷濃度為16%與18%時，加熱效率均隨噴流間距的增加而先上升後下降。加熱間距對加熱效率的影響則以預混火焰被停滯面壓破為界。加熱效率先隨加熱間距的減少而逐漸上升，在預混火焰被停滯面壓破處附近達到最大值，而後隨加熱間距的減少，加熱效率逐漸下降。加熱間距對加熱效率的影響會大於噴流間距。在不同操作位置下，最佳加熱效率的甲烷濃度，其火焰形態均為外層擴散火焰外張成喇叭狀，內層預混火焰仍為圓錐形火焰，未被停滯面壓破。
此一研究結果可實際應用於瓦斯爐具設計與燃燒調整，選擇適當的噴流間距、加熱間距或空燃比，以達燃燒之最佳化。

The influence of separation distance, heating height, concentration of fuel, and flow velocity on combustion characteristics of domestic gas burner was investigated experimentally by using two slot burners to generate two interacting jet premixed flames in this study. The experiment involves observations of flame appearance, classifications of flame shape, measurements of heating efficiency, and identification of optimum burning.
Results show that separation distance, heating height, and concentration of methane dominate the variations of flame shape and heating efficiency, and that flow velocity only influences the size of laminar flame. The heating efficiency influenced by separation distance is classified by concentration of methane. At the condition of concentration of methane is 12% and diffusion flame shape is converged, the heating efficiency first increases then decreases, by increasing the separation distance. However, when the diffusion flame shape is diverged, it first decreases then increases with increasing separation distance. When the concentrations of methane are 13% and 14%, the tendencies are similar to that of concentration of 12%. The heating efficiencies of concentrations of methane being 16% and 18% are first increased then decreased with increasing separation distance.
It was found that with decreasing heating height, the heating efficiency first increases then decreases for a fixed separation distance. The maximum of heating efficiency occurs when the flame has diverged diffusion flame, and closed premixed flame tip for stronger premixed flame tip or opened premixed flame tip for weaker premixed flame. It was further found that the heating height has a stronger influence than separation distance on heating efficiency.

摘要
英文摘要
誌謝
總目錄
圖目錄
一、前言
1-1 自由噴流流場特性及火焰相互作用
1-2 停滯面流場特性及火焰相互作用
1-3 衝擊火焰之熱傳研究
1-4 研究目的
二、實驗設備與儀器
2-1 燃燒器系統
2-2 停滯面系統
2-3 循環水溫控系統
2-4 影像處理系統
2-5 溫度量測系統
三、研究方法與步驟
3-1 參數設定
3-2 火焰形態觀察
3-3 加熱杯內水的溫度分析
3-4 水冷式停滯面之加熱效率分析
四、結果與討論
4-1 火焰形態觀察
4-1-1 噴流間距的影響
4-1-2 加熱間距的影響
4-2 火焰臨界特性分析
4-2-1 噴流間距與加熱間距的影響
4-2-2 噴流出口條件的影響
4-3 加熱杯內水的溫度分析
4-3-1 升溫曲線的探討
4-3-2 加熱效率分析
4-4 水冷式停滯面板之加熱效率分析
4-4-1 噴流間距與加熱間距的影響
4-4-2 甲烷濃度的影響
4-5 加熱效率綜合分析
五、結論
六、參考文獻
七、圖形

1.Jones, H. R. N. The Application of Combustion Principles to Domestic Gas Burner Design. British Gas, 1989.
2.Strenlow, R. A. Combustion Fundamentals. McGraw-Hill, 1984.
3.Sforza, P. M., Steiger, M. H., and Trentacoste, N., AIAA J. 4:800-806 (1966)
4.Trentacoste, N., and Sforza, P. M., AIAA J. 5:885-891 (1967)
5.Livinggood, J. N. B., and Hrycak, P., Impingement Heat Transfer from Turbulent Air Stream Jets to Flat Plates, NASA TM X-2778 (1973)
6.Miller, D. R., and Comings, E. W., J.Fluid Mech. 7:237-256 (1959)
7.Marsters, G. F., AIAA J. 15:1756-1762 (1977)
8.Krothapalli, A., Baganoff, D., and Karamcheti, K., AIAA J. 18:945-950 (1980)
9.Elbanna, H., Gahin, S., and Rashed M. I. I., AIAA J. 21:986-991 (1983)
10.Elbanna, H., and Sabbagh, J. A., AIAA J. 25:12-13 (1987)
11.Menon, R., and Gahin, S., ASME, New York, 1985, p. 127.
12.Menon, R., and Gollahalli, S. R., Combust. Sci. Technol. 60:375-389 (1988)
13.Roper, F. G., Combust. Flame 34:19-27 (1979)
14.許正忠, 層流擴散火焰的相互作用, 國立成功大學機械工程研究所碩士論文, 1995.
15.田思齊, 層流預混噴流火焰的相互作用, 國立成功大學機械工程研究所碩士論文, 1997.
16.Donaldson, C. D., and Snedeker, R. S., J. Fluid Mech. 45:281-319 (1971)
17.Martin, H., Advances in Heat Transfer 13:1-60 (1977)
18.Didden, N., and Ho, C. M., J. Fluid Mech. 160:235-256 (1985)
19.Saripalli, K. R., AIAA J. 21:483-484 (1983)
20.Sohrab, S. H., Ye, Z. Y., and Law, C. K., Twentieth Symposium (International) on Combustion, The Combustion Institute, 1984, p. 1957.
21.Lin, T. H., and Sohrab, S. H., Combust. Flame 68:73-79 (1987)
22.Hou, S. S., Chang, C. K., and Lin, T. H., Combust. Sci. Technol. 79:35-48 (1991)
23.Baukal, C. E., and Gebhart, Combust. Sci. Technol. 104:339-357 (1995)
24.Baukal, C. E., and Gebhart, Combust. Sci. Technol. 104:359-385 (1995)
25.Milson, A., and Chigier, N. A., Combust. flame 21:295-305 (1973)
26.Kilham, J. K., and Purvis, M. R. I., Combust. Sci. Technol. 18:81-90 (1978)
27.Fairweather, M., Kilham, J. K., and Nawaz, S., Inter. J. Heat and Fluid Flow 5:21-27 (1984)
28.Hargrave, G. K., Fairweather, M., and Kilham, J. K., Inter. J. Heat and Fluid Flow 8:55-63 (1987)
29.Hargrave, G. K., Fairweather, M., and Kilham, J. K., Inter. J. Heat and Fluid Flow 8:132-138 (1987)
30.van der Meer, T. H., Experimental Thermal and Fluid Science 4:115-126 (1991)
31.Viskanta, R., Experimental Thermal and Fluid Science 6:111-134 (1993)
32.柯永章, 單管噴流爐火的火焰溫度場及加熱效率分析, 國立成功大學機械工程研究所碩士論文, 1998.
33.Junus, R., Stubington, J. F., and Sergeant, G. D., Inter. J. Environmental Studies 45:101-121 (1994)