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研究了加压O2/CO2气氛下压力、氧浓度、煤焦结构和煤种等因素对大同烟煤和神火无烟煤着火特性的影响,并采用可燃性指数和综合燃烧特性指数评价不同压力下煤的着火和燃烧特性。加压热重实验结果表明,压力从0.1MPa升高至2MPa,着火温度先降低后升高,在1MPa下着火温度最低,燃烧特性最佳。在常压和加压条件下,提高氧浓度均可加快煤的着火。在常压下,随氧浓度提高,着火温度下降的幅度较小,但在加压时,较高氧浓度会改变着火模式,着火温度降低明显。扫描电镜分析显示加压促进煤在脱挥发分过程的破碎,提高碳氧反应速率,降低着火温度。煤的着火与煤种有关,挥发分含量较高的煤,其着火越容易。结果反映了加压富氧燃烧比常压富氧燃烧更有优越性。
The effects of pressure, oxygen concentration, coal char structure and coal type on the ignition characteristics of Datong bituminous coal and Shenhuo anthracite coal under pressurized O2 / CO2 atmosphere were studied. Combustibility index and comprehensive combustion index were used to evaluate the ignition of coal under different pressures And combustion characteristics. The results of pressured thermo gravimetric test showed that the pressure increased from 0.1MPa to 2MPa, the ignition temperature decreased first and then increased, and the ignition temperature was the lowest at 1MPa, and the combustion characteristics were the best. Under normal pressure and pressure conditions, increasing the oxygen concentration can speed up the coal fire. Under normal pressure, with the increase of oxygen concentration, the decrease of the ignition temperature is small, but when the pressure is increased, the higher oxygen concentration changes the ignition mode and the ignition temperature decreases obviously. Scanning electron microscopy analysis showed that pressurization promoted the crushing of coal during devolatilization, increased the reaction rate of carbon and oxygen, and reduced the ignition temperature. Coal fire and coal-related, higher volatile content of coal, the easier it is to fire. The results reflect the advantages of pressurized oxy-fuel combustion over atmospheric pressure oxy-fuel combustion.