對於工業應用，燃燒器的結構主導了氣體燃料的混合與燃燒過程的效率，因此如何設計燃燒器，成為燃燒工業發展之重要課題。一個性能良好的燃燒器必須保證燃料與空氣能進行充分的混合。本研究提出了在撞擊式燃燒器上利用兩個斜向噴流甲烷/空氣預混火焰燃燒器和一個粉煤噴流進料器組成來實現潔淨高效燃燒的概念。本研究進行了粒子圖像測速、氣體分析儀、火焰溫度測量和電子顯微鏡進行實驗測量，以檢查甲烷 /空氣與不同比例、氣體燃料流速、偏轉角，以及不同粉煤/空氣進給流速的預混撞擊火焰的燃料混合和反應。
燃燒流場的速度及渦度分佈表明，兩股射流相互撞擊，會構築兩種流場結構，即碰撞區和回流區。在燃燒器上游的氣流中增加了動量傳遞，產生兩個主要的特點:1.形成預熱區2.加強燃料與空氣的混合。當粉煤顆粒進入燃燒器上游中會在回流區並使其滯留一段時間產生熱解反應，熱解是實現煤炭清潔高效利用的重要途徑，粉煤因為熱解過程中顆粒內部溫度梯度增加的熱壓力使大顆粒傾向於破碎成小塊，其中溫度是決定工藝程度的最大影響參數，高溫會使粉煤劇烈裂解，有利於提高揮發產出，例如甲烷和一氧化碳等，而這些可燃氣體會於下游的對衝火焰區進行燃燒。理論上，此燃燒器可以實現潔淨且穩定的粉煤燃燒。
為了驗證所提出的斜向噴流燃燒器的燃燒特性，在偏轉角（30°、45°、60°）、預混火焰之當量比（1.5, 1, 0.8），與氣體燃料流速流速（0.6, 0.9, 1.2 m/s）、粉煤/空氣進給流速(9.75 (L/min)、6.75 (L/min))等參數進行檢視，並探討其參數對於溫度場及流場的影響。在本研究中，使用粒子圖像測速儀以檢視其淨煤燃燒器的流場速度、渦度結構，並使用熱電偶溫度計測量粉回流區內的流場溫度分佈。此外，使用掃描電子顯微鏡觀察流線中粉煤顆粒縮減的狀況以探討粉煤顆粒在回流區內的燃燒情形。最後，根據掃描式電子顯微鏡所量測之粉煤顆粒大小之數據，利用粉的縮減率檢視參數之影響程度。由結果得知，在提高甲烷-空氣流速以及燃燒器中心流速提高對於粉煤燃盡率的性能有所提升。

For industrial applications, the structure of a burner dominates the mixing and burning efficiency of gaseous fuel, thus, how to design burners becomes an important issue in the development of combustion industry. A good burner must ensure sufficient mixing of fuel and air. This study proposes a concept for clean and efficient combustion using two oblique jet methane/air premixed flame burners and a coal dust jet feeder on an impinging burner. Experimental measurements were conducted using particle image velocimetry, gas analyzer (GA), flame temperature measurement, and electron microscopy to examine the fuel mixing and reaction of premixed impinging flames with different ratios of methane/air, gas fuel flow rate, deflection angle, and different coal dust/air feed speeds.
The velocity and vorticity distribution of the combustion flow field shows that when two jets collide, they build two types of flow field structures: the collision zone and the recirculation zone. Adding momentum transfer in the upstream airflow of the burner creates two main characteristics: 1. the formation of a preheating zone, 2. the enhancement of fuel and air mixing. When coal dust particles enter the upstream of the burner, they stay in the recirculation zone for a while to undergo pyrolysis. Pyrolysis is an important way to realize the clean and efficient use of coal. The thermal stress due to the increased temperature gradient inside the particles during the pyrolysis process causes large particles to tend to break into small pieces. Among them, the temperature is the most influential parameter determining the degree of the process. High temperatures cause the coal dust to pyrolyze violently, which is conducive to the increase of volatile output, such as methane and carbon monoxide, and these combustible gases will burn in the downstream counter-flame zone. Theoretically, this burner can achieve clean and stable coal dust combustion.
In order to verify the combustion characteristics of the proposed oblique jet burner, the deflection angle (30°, 45°, 60°), the equivalence ratio of premixed flames (1.5, 1, 0.8), gas fuel flow rate (0.6, 0.9, 1.2 m/s), and coal dust/air feed speed (9.75 (L/min), 6.75 (L/min)) were examined and their effects on the temperature field and flow field were investigated. In this study, Particle Image Velocimetry (PIV) was used to inspect the flow velocity and vorticity structure of the clean coal burner, and a thermocouple thermometer was used to measure the temperature distribution in the recirculation zone. In addition, scanning electron microscopy was used to observe the reduction of coal dust particles in the flow line to investigate the combustion situation of coal dust particles in the recirculation zone. Finally, based on the coal dust particle size data measured by SEM, the reduction rate of dust and the density of coal dust particles per unit area were examined to see the degree of influence of the parameters. The results show that increasing the methane-air flow speed and the central flow speed of the burner improves the performance of the coal dust burnout rate.

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