循环流化床锅炉给煤系统设计优化与应用研究

Design Optimization and Application Research of Circulating Fluidized Bed Boiler Coal Feeding System

在煤炭市场等压力下,燃煤机组入炉煤指标偏离设计值的情况普遍存在,一定程度上造成给煤系统堵煤、断煤等故障频发,同时能源保供、掺配掺烧需求等内外部环境对给煤系统等辅机系统的安全稳定可靠运行提出了更高要求。从项目建设期开始介入,提出了简化给煤系统组成,改进落煤管布置倾角、增加播煤风文丘里环形喷射器接入形式、减少密封隔离挡板设置等关键节点设计,注重称重皮带给煤机、中心给料机等关键设备选型,完善了中心给料机与给煤机相匹配的给煤量自动调节控制策略,创新性地对给煤机缓冲仓进行了结构改造,增加特定倾角的缓冲板,将频发的积煤堵煤点从给煤机后的落煤管处转移到给煤机前的缓冲仓,实现了堵煤矛盾空间转移。机组投产后近三年的连续运行情况表明,系统设计方案满足循环流化床锅炉对给煤系统的各项技术要求,其功能完善、给煤连续均匀、运行和检修隔离措施完善以及自动控制精准可靠。对循环流化床机组给煤系统开展的设计优化和应用研究紧密结合现场实际,解决了一些长期存在的技术难题,研究成果具有一定的行业推广价值。

Under the pressure of the coal market,the deviation of the coal feeding index of coal-fired units from the design value is widespread,which to some extent causes frequent failures such as coal blockage and coal cutoff in the coal feeding system.At the same time,the internal and external environment such as energy supply guarantee,blending and burning demand put forward higher requirements for the safe,stable and reliable operation of auxiliary systems such as the coal feeding system.From the beginning of the project construction period,it proposed to simplify the composition of the coal feeding system,improve the dip angle of the coal chute arrangement,increase the access form of the coal seeding Venturi annular injector,reduce the setting of the sealing isolation baffle and other key node designs,pay attention to the selection of the weighing belt feeder,the central feeder and other key equipment,and improve the automatic adjustment control strategy of the coal feeding quantity matching the central feeder and the coal feeder.The structure of the buffer bin of the coal feeder was innovatively modified,and the buffer plate with a specific inclination angle was added to transfer the frequent coal blockage points from the coal chute behind the coal feeder to the buffer bin in front of the coal feeder,realizing the spatial transfer of the coal blockage contradiction.The continuous operation of the unit for nearly three years after it was put into operation shows that the system design scheme fully meets the technical requirements of the circulating fluidized bed boiler for the coal feeding system,with complete functions,continuous and uniform coal feeding,complete operation and maintenance isolation measures,and accurate and reliable automatic control.The design optimization and application research on the coal feeding system of the circulating fluidized bed unit are closely combined with the actual situation on the site,and a series of long-term technical problems have been solved.The research results have certain industrial promotion value.