In order to consume the electricity generated by new energy

circulating fluidized bed(CFB) boiler needs to participate in depth and peak regulation. But this will bring out the problem of over low bed temperature and denitration efficiency reduction

which affects the safe and stable operation of the boiler. To solve this problem

it is proposed to control the separation efficiency by opening holes in the cone of the cyclone separator and passing in the interfering wind

which has the advantages of low cost and no pollution. The cold state experiment and numerical simulation were combined to conduct the research. Firstly

the cold state experiment device was built to carry out the experimental study on the inlet form and velocity of the interference wind. Then

the CFD numerical simulation was perfomed and the result was compared with the experimental result. Moreover

the verified numerical simulation method was applied to a 330 MW unit CFB boiler. The results show that

in the hole of 180°and 270°

the separation efficiency increases at first and then decreases with the increase of interference wind speed. In the hole of 0°and 180°

the separation efficiency decreases with the increase of interference wind speed. In general

introducing interference wind in the 90° hole has relative better effect in reducing the separation efficiency. The separation efficiency can be further reduced by blowing down 45°. This paper can provide reference for flexibility retrofitting of CFB boilers participating in deep and peak regulation.