Abstract：Factors of influencing mixing effect of post-combustion air, such as the position of post-combustion air nozzles, the number of nozzles, and the proportion of post-combustion air were studied using computational fluid dynamics method. The velocity in different section planes with Realizable k-ε turbulent model was compared with the experimental data on a cold simulation test platform. The results indicate that the numerical results agree well with the experiments. When the post-combustion nozzle is arranged on the lower part of the test section flue and above of it, the mixing correlation coefficient is about 0.6. When the nozzles are arranged on the lower part of the flue, they are better to reduce the nozzles number to increase the momentum ratio. To the upper part of the flue, it needs to increase the number of nozzles to increase the jet area. Increasing the proportion of the post-combustion air in the bottom and the upper part of the flue will improve the mixing effect.

Keywords： circulating fluidized bed boiler; post-combustion air; nitrogen oxides; mixing; numerical simulation