为降低一台670t/h燃用贫煤锅炉NO_x排放并提高锅炉稳燃性能,采用水平浓淡风煤粉燃烧器技术对4层一次风进行了改造。通过炉内空气动力场测量和锅炉的燃烧调整,使锅炉NO_x排放量较改前降低了37.9％。研究了不同配风方式、给粉方式及入炉总风量变化对NO_x排放量和固体未完全燃烧热损失的影响,对燃用贫煤的锅炉的运行和改造具有一定参考作用。 In order to reduce the NO_x emission of a 670t / h fuel-lean boiler and improve the stable combustion performance of the boiler, the horizontal primary air pulverized coal burner technology was used to revamp the 4-layer primary air. Through the measurement of the aerodynamic field in the furnace and the combustion adjustment of the boiler, the NO_x emission of the boiler was reduced by 37.9% compared with that before the change. The effects of different gas distribution modes, powder feeding methods and the total air volume change on the NO_x emission and the heat loss of solid incomplete combustion were studied, which would be helpful to the operation and reforming of coal lean burning boiler.