The air-staged combustion technology has been adopted in design of a newly constructed 670 t/h coal-water slurry(CWS) fired boiler.In order to understand the influence of said technology upon the air distribution mode

the coefficient of excess air

the mode of putting coal-water slurry guns into operation

the burnout efficiency of CWS

the slagging condition

and the NOx emission

a large amount of tests has been carried out.Results show that the operation of said boiler is under a load of 530 t/h after adopting the air-staged combustion technology

through adjustment of the excess air coefficient and the air distribution mode

the NOx emission reaches 380 mg/m3(standard condition

similarly hereinafter)

the coefficient of excess air has to be controlled at about 1.2

at the same time

the adjustment of air distribution can ensure low NOx emission as well as stable and effective combustion

but without substantial change in burnout and slagging of CWS.