#9 unit of Fenyi power plant is a 330 MW circulating fluidized bed unit. The spreading coal air is connected with the boiler’s secondary hot air

and the pressure of the secondary hot air is low since the long-term operation

so the pulverized coal can’t be sent into the bolier furnace smoothly

and the combustion of the boiler is unstable. After the optimization retrofit

the coal breeze is transferred from the heat primary air pipe

and the wind pressure and temperature of the coal can meet the requirements of the unit

and the operation of the unit is stable after the optimization.