Directing against the problems resulted from mixedly burning brown coal in large proportion for the low rank bituminous coal fired 1 025 t/h boiler in Hunjiang Power Generation Co Ltd

a mid-temperature flue gas inerting and drying system was additionally installed in the coal pulverizing sytsem

a temperature-regulating air system was installed in the hot air transporting pulverized coal system

and a nitrogen blanketing system was installed in the pulverized coal bunker

and the pulverized coal burners with two channels were retrofitled into honrizontal dense and thin burners.After retrofitting

according to proportion of 50% to burn brown coal

the operation of boiler is safe and stable

the fuel expenses can be saved by 5.436 million yuan in one year

boasting remarkable economic benefit.