The mixed-burning test with large proportion of lignite was performed on low NOxaxis swirling burner(LNASB)of a supercritical 600MW unit once-through boiler using bituminous as the design coal.According to the conventional operation mode

optimization and adjustment on such running operational factors as pulverizing system

LNASB operating arm and air volume were conducted to make the lignite proportion on one coal mill reach 50%.For boilers with front and back wall opposed swirling combustion

on the premise of not changing the devices

the middle two layers of the burner can burning lignite with proportion of 50%;under condition with oxygen content of 4.2%and the opening degree of OFA damper of 30%

the operation state reached the best.