In order to solve the problems occurred in operation of a CFB boiler mixedly burning high-sulphur petroleum coke with coal

such as high carbon content in fly ash

low boiler efficiency

and low desulphurization efficiency etc.

an operation test has been carried out on two 310 t/h CFB boilers

the excess air coefficient

the bed temperature

the Ca/S ratio

and the ratio of petroleum coke to coal being adjusted.Tset shows that the optimal operation parameters are as follows:the excess air coefficient is 1.15~1.2

the bed temperature is 890~900 ℃

and the ratio of petroleum coke to coal is 2.5∶1~3∶1.On this basis

an optimization test of boiler performance has been conducted.After optimization

the carbon content in fly ash has decreased 8.05% than that under reference operating condition

the boiler efficiency has increased 2.49%

and the concentration of SO2 emission has reduced from 834.42 μL/L to 480 μL/L.