非同質相向噴流衝擊擴散火焰動量比值對燃燒效率之影響

The Effect of Momentum Ratio to the Combustion Efficiency in Un-like Jet Impinging Diffusion Flame

曾俞勲(Yu-Hsun Tseng)

指導教授 ： 蘇艾

元智大學/工程學院/機械工程學系/碩士(2004年)

摘要

本文主要研究非同質相向噴流衝擊擴散火焰動量比值對燃燒效率之影響，相向衝擊火焰架構中，以助燃空氣替代另一支燃料管，經由調整不同質流量條件觀察火焰燃燒結構及火焰燃燒結構溫度差異以及經由調整不同質動量比條件觀察火焰燃燒結構及火焰燃燒結構溫度差異，並於甲烷氣燃料管加裝一遠紅外線節能器比較同流量不同質動量比火焰燃燒結構溫度差異。
實驗主要是將噴嘴固定在72.5度衝擊角度參數條件下。研究目標是求得在不同動量比及流量條件下，對火焰結構產生之溫度的影響，並找出最佳的流量及動量比趨勢。在同質燃燒條件下，火焰結構包含兩個噴流的衝擊結果，但不易看出混合效益。但由本實驗以空氣取代另一支噴流，助燃特性的空氣，在相向噴流火焰結構內，提供明顯的混合關係。
由XY平面溫度圖及Schlieren光學觀測，在七組動量比條件中，當甲烷及空氣動量比為1：1.25時，火焰燃燒場單位面積平均溫度達到978.33度、高溫區及火焰結構穩定性為所有動量比搭配中最佳，在加裝節能器條件中以甲烷及空氣動量比為1：1時，提升燃燒效率最佳達到9.64%。非同質相向噴流擴散火焰藉由有效控制空氣與甲烷對衝動量比，使燃燒場內高溫區能夠集中且穩定作用，火焰內部溫度的瞬時變化將會減至最低，而有助於控制燃燒室火焰燃燒溫度及火焰高度。

關鍵字

相向噴流衝擊擴散火焰 ； 非同質燃料

並列摘要

Abstract
The research is to study the effect of jet momentum ratio to the combustion efficiency in unlike jet impinging diffusion flame. In the set-up, one of the methane tubes is substituted by the air, by adjusting the momentum ratio to observe the flame structure and measure the flame temperature to determine the efficiency. In addition, an infrared economizer is added to the methane tube to compare the difference.
The impinging angle is fixed at 72.5 degrees. By changing the fuel supply rate, momentum ratio between air and methane and economizer, we visualize the flame structure and calculate the average temperature per unit area. The results of X-Y plane temperature profile and Schlieren photoghaphy indicate the optimum momentum ratio between methane and air is 1:1.25. The high temperature area is highly concentrated and the flame is stabilized. The average temperature per unit area reaches 978 degrees. The results with infrared economizer can increase efficiency up to 9.6% at momentum ratio 1:1.
Keywords：impinging diffusion flame, un-like fuel

並列關鍵字

impinging diffusion flame ； un-like fuel

參考文獻

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