The burners of lowermost layer(A layer) on the backwall of opposed-firing boilers for 600 MW units in Huadian Changsha Power Generation Co Ltd have been retrofitted into micro-oil ignition burners

the basic structure and working principle of said micro-oil ignition burners being presented.Under condition of frequent coal quality change

and trends generally to lower quality

the coal-feed from separate bunker has been adopted

a small amount of high quality coal being sent into the micro-oil ignition burners(from A bunker) located on the lowermost layer of backwall

and sent into burners of the lowermost layer on the opposite side(from F bunker)

being used as the ignition coal

at the same time

the steam air heating system has to be put into operation in advance

to creat condition for starting the coal pulverizer up

enhancing the temperature of feed-water

realizing cold-state start-up using large oil gun to be decreased from more than 100 t/each time to less than 4 t/each time

obtaining remarkable oil-saving effect.