Responding to the urgent needs of clean and efficient utilization of coal under the background of national “carbon peaking and carbon neutrality”

the pulverized coal preheating combustion technology has been developed in industrial boilers

power plant boilers and other fields. In this technology

pulverized coal is modified at high temperature in a fluidized preheating burner

then the preheated fuel enters the furnace for graded air distribution combustion

thus high efficiency and low NO_x combustion of pulverized coal is realized. Moreover

technical verification was carried out on a 60 t/h pulverized coal boiler

which adopts two preheating burners with side wall hedge arrangement

and one preheating burner is designed with thermal power of 26 MW. Using bituminous coal as raw material

the operation and NO_x emission properties of the boiler at 10%～100% operating loads were studied experimentally

and the results showed that

the boiler operated stably and well at each load

it achieved stable operation of 10% ultra-low load without any auxiliary means. The preheating burners had reasonable operating parameters and stable circulation state

which can meet the requirements of wide load operation of the boiler. The combustion efficiency of the boiler at each operating load were all above 97%

the thermal efficiency of the boiler were above 85% at 10% and 20% operating load

and above 90% at 30% and above operating load. By adjusting the air distribution

the original NO_x mass emission of the boiler at each operating load can be controlled lower than 50 mg/m~3(φ(O_2)=9%). The successful demonstration of the 60 t/h pulverized coal preheating combustion boiler provides important support for the development and application of clean

efficient and flexible combustion technology of pulverized coal.