Theoretical analysis of combustion process in pulverized coal fired burner using jets with velocity difference (I)

The pulverized coal fired burners using the central jet with a large velocity difference by means of a multifluid model for two-phase turbulence flow were simulated. The predicted results show that the distance between the nozzle and the side of the inner combustion chamber has an optimum value, where the largest recirculation amount of high-temperature gases and the best intensification effect of pulverized coal combustion can be achieved. The central jet with a large velocity difference can concentrate pulverized coal, but the effects of restricting the extension of pulverized coal and increasing the recirculation amount of high-temperature gases are not remarkable. The mixing of the primary air and coal with the recirculated high-temperature gases is improved, which makes the temperature more uniform.