Numerical Simulation On Swirl Burner With Central Bluff Body And Pulverized Coal Concentrator

Because of the center circumfluence, which can make the high temperate gas flow back to facilitate the combustion and ignition of pulverized coal, swirling burner has been widely used in engineering. In this paper, the flow filed of new type two-passage swirlmg burner is researched. Moreover, the resistance coefficient and separating-effect of coal particle concentrator is analyzed.Firstly, this paper introduces the new type swirling burner of domestic and overseas, then the research object of this paper is brought forward.Secondly, this paper compares different kinds of turbulent models and two-phase models; then evaluates their advantages and disadvantages. For weak swirl-flow, the standard k - e model can meet the precision requirement of engineering, but for the flow with circumfluence the RNG k - e model will be more suitable. The RSM model can accurately simulate swirl-flow, but its convergence standard is hard to reach.Then, the flow field at the outlet of swirling burner is simulated by RNG k - e model. The result of simulation shows that there is a large center circumfluence area at the outlet of burner, which can facilitate the combustion and ignition. Furthermore, the influence of bluff body on the size of circumfluence area and the velocity distribution near the bluff body is researched.Finally, the particle track method is used to simulate the resistance coefficient and separating-effect of coal particle concentrator. And, the influence of impeller obliquity , impeller number, first stage air velocity, first stage air pulverized coal density on these parameters is analyzed.