| Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 103 === In this research, two main kinds of compositions of syngas, carbon monoxide and hydrogen, have been added to premixed propane flame. A stratified burner with three concentric rings has been used to burn fuels. The objectives aim to find characteristics of co-incineration of propane and syngas flame in different exit speed, equivalence ratio and fuel compositions.
The basic flame patterns can be separated into cone flame, half-cone flame and liftoff flame when premixed fuels are only in the middle ring. The empirical results revealed that flame burning velocity can accelerate with addition of hydrogen or carbon monoxide in propane flames. However, due to its highly flammable nature, hydrogen is more powerful in stabilizing flame than carbon monoxide. Furthermore, in cases of co-incineration of propane and syngas, fixed volumetric proportion of propane and changeable mutual proportion of hydrogen and carbon monoxide are executed. As proportion of hydrogen increases, flames are stabilized and more fuels can pass through flame fronts effectively. It causes temperature distribution and CH* chemiluminescence intensity to increase. Besides, how flames react in different exit speed and equivalence ratio are also explored. On the one hand, fixed exit speed is 1.50 m/s and equivalence ratios are 0.55, 0.50 and 0.45. When equivalence ratios decrease, flames turn to unstable modes and temperature and CH* intensity diminish because of less fuel supply. On the other hand, fixed equivalence ratio is 0.55 and exit speeds are 1.50 m/s, 1.75 m/s and 2.00 m/s. As exit speeds increase, more heat can be removed easily and liftoff heights extend. The phenomena make flames unable to cover the whole middle ring and let fuels leak out which can be seen in PIV flow fields. Without burning effectively, heat release rates, temperature and CH* intensity decline accordingly.
|
|---|
