Taking an ultra supercritical 1 000 MW boiler with dual tangential circle as the research object

the flue gas components(O_2

CO and H_2S) near the water wall were detected under different operational conditions. Moreover

the influences of several factors

such as the second-air distribution mode

the separated over-fired air(SOFA) flow rate

the circumferential air flow rate and the second-air flow rate distribution at the same layer burners

on the volume fraction of O_2

CO and H_2S close to the water wall were analyzed. The results show that

affected by the special aerodynamic field inside the furnace

the areas close to burners 2

3

5 and 8 have the relative stronger reductive atmosphere and higher temperature. Regulating the secondary air distribution and SOFA flow rate

as well as increasing air flow rate of the primary combustion zone and reducing zone

could weaken the reductive atmosphere near the water wall. The reductive atmosphere near the hot corner water wall could be decreased by adjusting the circumferential air flow rate and second-air flow rate distribution at the same layer burner

and increasing the second air jet momentum of burners 1

4

6 and 7.