中速磨煤机磨制生物质颗粒料的适应性研究

Study on the adaptability of medium speed coal mill to mill bio-mass pellets

生物质燃烧不会增加二氧化碳排放量,发展生物质与燃煤耦合发电技术是加快电力转型升级的可行途径。采用压型后的生物质与煤粉在不同的磨煤机中磨制且不掺混,由不同的燃烧器分别送入炉膛,该方式不需要增加额外的生物质处理设备和设置生物质燃料处理车间,可大大节省投资和厂区空间。其关键限制性技术因素在于电厂的磨煤机是否能够有效研磨生物质颗粒燃料,以及如何评估现有磨煤机对新型耦合燃料的适应性。为此,搭建了中速磨煤机实验台,分析中速磨煤机磨制生物质颗粒的适应性。结果表明:中速磨煤机碾磨木屑生物质颗粒时碾磨出力降低,有效出力修正系数为0.65~0.70;ZGM型中速磨煤机碾磨木屑成型颗粒时,加载力特性、分离器特性均在料粉粒径0.2 mm分界下变化明显,可考虑将筛分细度R200和R500定为磨煤机研磨生物质颗粒料粉均匀性指标的衡量标准;相对于磨制煤粉,磨制成型生物质颗粒加载力的增加或现行分离器转速的提升对细度分布影响规律有较大差异,亟待进一步的深入研究。

The combustion of biomass will not increase carbon dioxide emissions,and the development of biomass coal coupled power generation technology is a feasible way to accelerate the transformation and upgrading of electricity.The compressed biomass and coal powder are ground in different coal mills without mixing,and are fed into the furnace by different burners.This method does not require additional biomass treatment equipment or setting up a biomass fuel treatment workshop,which can greatly save investment and factory space.The key limiting technical factor is whether the pulverizer of the power plant can effectively grind biomass Pellet fuel,and how to evaluate the adaptability of the existing pulverizer to the new coupling fuel.To this end,a medium speed coal mill experimental platform was built to analyze the adaptability of the medium speed coal mill in grinding biomass particles.The results show that the grinding output of the medium speed coal mill decreases when grinding wood chip biomass particles,and the effective output correction coefficient is 0.65~0.70;When the ZGM medium speed coal mill grinds sawdust particles,the loading force characteristics and separator characteristics both vary significantly at the particle size boundary of 0.2 mm.Therefore,the screening fineness R200 and R500 can be considered as the measurement standards for the uniformity of biomass particle materials ground by the coal mill;Compared with pulverized coal,the increase of loading force of milled biomass particles or the increase of rotating speed of the current separator has a large difference in the influence of fineness distribution,which needs further in-depth research.