Abstract: Through the optimization and adjustment testing on multiple coal type blending, air distribution mode, racemic rod position, operating oxygen, outlet temperature of the grinding coal mill, furnace flame temperature, and temperature distribution measurement, the W-flame boiler combustion status is studied under different working conditions. The study results show that the R₉₀ of the anthracite-combustion units is substantially high, which is the major cause of the high carbon contents of the fly ash. After the air distribution is optimized and adjusted, the local CO contents at multiple points have been reduced from (3 000~5 000)×10^-6 to less than 350×10^-6 with the carbon contents of the fly ash lowered down and the boiler efficiency improved. The NO_x emission is also controlled within the specified range. When the anthracite coal is burned, the grinding mill can be operated safely and stably at the outlet temperature of 118℃. Moreover, after the racemic rod is optimized and adjusted, the boiler efficiency can be distinctly improved while the superheater desuperheating water is reduced by more than 10 t/h. Meanwhile, the carbon contents of the fly ash are also reduced to some extents.

Key words: boiler, combustion adjustment test, boiler efficiency, unburned carbon content, exhaust flue gas temperature, racemic rod position