鈍體燃燒器結合帽頂機構之反應流場的實驗研究

Experimental Study of Thermal Flow Structure in an Innovative Burner with Cap-induced Premixing Combustion

方爾凱(Er-Kai Fang)

指導教授 ： 潘國隆

國立臺灣大學/工學院/機械工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.01664

摘要

本研究針對鈍體燃燒器與加入帽頂機構之燃燒器後方尾流之燃燒情形，利用化學螢光法(Chemiluminscence)、粒子影像測速儀(PIV)及溫度測量裝置，可分別得到局部螢光強度、流場結構與溫度場。第一部分鈍體燃燒器測量在固定環空氣噴流下並改變中心噴流流速，不同流場結構將主導著燃氣混合特性，因此形成不同的火焰型態，分別為迴流火焰、中心噴流主導火焰及似噴流火焰。第二部份則固定環空氣噴流為0.45m/s，中心燃料噴流為0.53、1.73與8.8m/s，結果顯示對於火焰對流場的影響為熱釋放導致流體加速，流場將會影響火焰生成的位置。
隨著中心噴流流速逐漸增強會使迴流區逐漸縮小，在迴流轉向處，將提供一絕佳引燃位置。在溫度分布圖中，可以看出迴流區將提供下游一穩定熱源。由縮小尺寸所量測出的可燃極限圖中將發現，帽頂駐焰裝置對高速中心噴流能有效拓展燃燒的可燃極限。最後，使用同步技術將化學螢光法與PIV作結合，以拍攝火焰與流場中之動態行為。

關鍵字

鈍體燃燒器 ； 粒子影像測速儀 ； 化學螢光法 ； 帽頂助焰裝置

並列摘要

The wake of bluff-body combustor and cap combustor in the reaction flow are investigated. To understand flame reaction zone, Particle Image Velocimetry (PIV) and Chemiluminscence methods are utilized to detect flow pattern and the local inten-sity of light. Besides, the distribution of temperature is established by thermocouple.
In the Bluff-body burner, flame structures which are dominated by the air veloc-ity and the central fuel jet are classified into three modes: recirculation flame, jet-dominated flame, and jet-like flame. In the cap combustor, the air velocity is fixed at 0.45m/s and the central jet are at 0.53, 1.73 and 8.8m/s. The result reveals that the heat release leads to buoyancy effect and induce the fluid to accelerate. The position of flame is dependent on the flow flied. Once the fuel jet has been increased, the recirculation zone will be decreased. The sparking position is motivated by the loca-tion of separation flow.
The distribution of temperature shows that the recirculation zone will provide heat source for downstream and the flammable limit figure conclude that the cap combustor will improve flammable range in the high velocity of fuel jet. Most im-portantly, Chemiluminscence and PIV enable us to fully describe the dynamic beha-viors between flame and flow instantly.

並列關鍵字

Bluff-Body Combustor ； Particle Image Velocimetry ； Chemiluminscence ； Cap Combustor

參考文獻

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