将石油焦与煤混烧是高效清洁利用石油焦的有效途径。利用热重分析实验与管式炉燃烧实验相结合的方法,开展了石油焦分别和烟煤、褐煤、煤矸石在不同质量比(石油焦质量分数分别为0%,25%,50%,75%,100%)下混合燃烧特性实验,研究了石油焦和煤混烧的燃烧特性和NO排放特性。结果表明:相较于褐煤和煤矸石,石油焦与烟煤的燃烧特性较为相似,两种燃料的着火温度均在450℃~500℃左右,两种燃料燃烧的DTG曲线中热量失重峰均出现在550℃左右;石油焦与烟煤混烧的燃烧特性优于石油焦与褐煤或石油焦与煤矸石混烧的燃烧特性,一定质量比下,石油焦与烟煤混烧的着火温度低于石油焦与煤矸石混烧的着火温度,石油焦与烟煤混烧的着火速度高于石油焦与褐煤或石油焦与煤矸石混烧的着火速度;石油焦与烟煤混合燃烧的着火特性、燃尽特性、综合燃烧特性均随着混合燃料中烟煤质量分数的提高而逐步改善,优于石油焦单烧的着火特性、燃尽特性、综合燃烧特性;由于综合燃烧特性的提升,相较于单烧,石油焦和烟煤混烧总是会提高燃烧过程中NO排放体积分数峰值和NO排放量,当石油焦与烟煤质量比为3∶1时,混烧时NO排放体积分数峰值较石油焦单烧时NO排放体积分数峰值提高75%左右,且主要反应在焦炭燃烧阶段,这与混合燃料的燃烧状态和氮的赋存形态密切相关。

Co-combustion of petroleum coke and coal is an effective way to utilize petrole-um coke efficiently and cleanly. The combination of thermogravimetric analysis and tubular fur-nace combustion experiments were applied to investigate the combustion characteristics and NO emission characteristics of petroleum coke mixed with different mass ratios of bituminous coal, lignite and coal gangue (petroleum coke mass fraction: 0%, 25%, 50%, 75%, and 100%). The results show that compared with lignite and coal gangue, the combustion characteristics of petro-leum coke are more similar to bituminous coal. The ignition temperature of both fuels is about 450 ℃-500 ℃, and the peak of heat release rate in the DTG curve occurred at around 550 ℃; When petroleum coke is co-combusted with bituminous coal, the combustion characteristics are better than when co-combusted with lignite or coal gangue. Specifically, at a certain mass ratio, the ignition temperature of co-combustion of petroleum coke and bituminous coal is lower than when co-combusted with coal gangue, and the ignition speed of co-combustion of petroleum coke and bituminous coal is higher than when petroleum coke is co-combusted with the other two fu-els; The ignition characteristics, burnout characteristics, and comprehensive combustion charac-teristics of the petroleum coke and bituminous coal co-combustion gradually improve with the in-crease of bituminous coal mass fraction, and are superior to the combustion of petroleum coke a-lone. Due to the improvement in comprehensive combustion characteristics, co-combustion of pe-troleum coke and bituminous coal always increases the peak volume fraction and emissions of NO during the combustion process compared with single combustion. When the mass ratio of petrole-um coke to bituminous coal is 3∶1, the peak value of NO emission volume fraction increases by approximately 75% compared to single combustion of petroleum coke, and this increase mainly occurs in the coke combustion stage, which is closely related to the combustion state of the mixed fuel and the form of nitrogen present.