Cold Simulation Experiment And Numerical Simulation On A New Type Of Low NOx Combustion Swirl Burner

With China's rapid development of power system,the problem of the rise of pollutant emissions has become more and more serious.With the proposed goal of energy conservation and emission reduction,the reduction of pollutant emissions will be a more challenging task in the future.NO_x,which has caused serious harm to the environment,is one of the main pollutants of the combustion products of fossil fuel.More and more attentions have been paid to its formation and emission.Today,the low NO_x combustion of swirl burner in utility boilers remains the significant challenges facing the power plants at home and abroad.Therefore,it is anxious to research and develop a new-type swirl burner with good low NO_x combustion performance in China.Firstly,this article presents the research and development situation of main swirl burner in domestic and international market,summarizes the main features of current main low NO_x combustion swirl burners.The formation mechanisms of three kinds of NO_x in the utility boilers are summarized.Various influence facts affecting the low NO_x combustion performance of swirl burner are analyzed.The aerodynamic field that is suitable for low NO_x combustion is proposed,providing the evidence for the theoretical basis.Secondly,based on the absorption and integration of multiple swirl burners,this article introduces the invention of a new-type low NO_x combustion swirl burner,and a cold simulation experiment is carried out.By changing central air expanding angle,central air boundary,primary air rate,primary air velocity,non-swirl air velocity,the swirl strength of secondary air,the effects of each parameter on the aerodynamic field at the burner outlet are studied respectively,and the contributions to the NO_x emission reduction are also analyzed.In addition,the numerical simulation is conducted based on the cold simulation experiment.By setting up the two-dimensional physical model and using theκ-εtwo-equation model,the distributions of aerodynamic field at the burner outlet are simulated. The parameters,which are difficult to analyze like recirculation area,the recirculation flux, turbulence intensity,are carefully analyzed under relatively higher precision;the simulation results between the new-type swirl burner and the main radial bias combustion swirl burner are contrasted,and the advantages of the new-type swirl burner are illustrated;the three-dimensional simulation on the curve boundary of central air tube is carried out to analyze the effects of different shapes on the low NO_x combustion.