高浓度煤粉火焰中煤质对最佳煤粉浓度的影响

Effect of Coal Quality on the Optimum Fuel Concentration in High-concentration Pulverized Coal Flame

高浓度煤粉火焰对装有浓淡燃烧器的煤粉燃烧系统的着火具有十分重要的作用。本文在一简化的燃烧系统和一配备浓淡燃烧器的1 MW切圆煤粉炉内进行了大量试验,研究了煤质对最佳煤粉浓度C_(opt)的影响规律,在该最佳煤粉浓度下燃烧系统具有最高的火焰温度及最低的飞灰含碳.试验结果表明:对于所有的高浓度煤粉火焰均存在一最佳的煤粉浓度,着火特性差的无烟煤的最佳煤粉浓度显著高于着火特性更佳的烟煤,该最佳煤粉浓度随着煤质发热量Q与挥发分V乘积的增大而降低,并存在一经验公式C_(opt)=1.069-0.051·10^(-5)·V·Q。

High-concentration pulverized coal flame plays an important role of ignition for coal combustion system with rich-lean burners. In the presented works, a series of tests have been performed in a 1 MW tangentially pulverized coal-fired furnace with rich-lean burners and in a simplified down-fired furnace to investigate the relation between the coal quality and the optimum fuel concentration （kg/kg）, which is corresponding to the highest flame temperature and the lowest content of unburned carbon. The results show that there is always an optimum fuel concentration corresponding to the highest furnace temperature and the shortest ignition length for each group of tests on the high-concentration pulverized coal flame, and the optimum fuel concentration generally decreases with the product of volatile content and heating value linearly as the empirical formula Copt=1.069-0.051·10^-5·V·Q.