Due to the strong reducing atmosphere and H_2S formation around the water wall of a supercritical opposed firing boiler

serious high temperature corrosion occurred in the water walls.To solve this problem

the single factor alternate method was applied to experimentally investigate the effects of main operating parameters on H_2S concentrations around side water wall.The results show that

on the basis of customary boiler operating condition

after a series of regulations

such as weakening the tertiary air swirl of the main burner appropriately

distributing the tertiary air flow as bowl type

strengthening the secondary air swirl of the main burner appropriately

increasing the swirling air ratio of the OFA burner

reducing direct air ratio of the OFA burner

increasing the running oxygen concentration appropriately

distributing the mills output uniformly

increasing the primary air velocity appropriately

and reducing the coal fineness

the H_2S concentration around the side water wall decreased from 876.5mg/m~3 to 352.2mg/m~3.The atmosphere around the water wall surface was greatly improved

and the security of the boiler operation was enhanced.