Numerical Simulati On And Improvement Of Long Flame Burner

In order to investigate the problem of temperature uniformity in the width direction of a steel rolling furnace,a burner for a steel heating furnace in a steel plant was investigated,which mainly provides heat supply in the furnace width direction.It is found that the burner flame shortening and NO content increase caused by the reduction of load occurred in the actual production.The numerical simulation was carried out by Fluent software.During the numerical simulation,the standard k-ε turbulence model and the PDF turbulence diffusion combustion model simplified by βfunction were used.We have simulated the combustion characteristics of six kinds of burners including furnace burner,three concentric burners and two three-arc burners under three loads.The simulations found that the furnace burner have the problem of reduced flames length and sharply increased NO levels with loads reduced.Referring to the relevant literature,it is concluded that different levels of mixing of the air and gas have an effect on combustion.According to the characteristics of the coaxial jet diffusion combustion,three concentric burners with different ring pitches and arc burner with two different circle pitches are designed.Different ring spacing were designed to investigate the effect of different mixing conditions of air and gas on burner temperature and NO.Comparing the six burners’ speed,temperature,H2 consumption,and NO,it was found that as the load decreases,the furnace burner flame becomes shorter and the NO content increases dramatically;as the load decreases,The flame length of concentric burners and the three-arc burner is basically the same,and the NO content increases little;Under the same load,with the increase of the ring distance,the temperature of the three concentric burners in the high temperature zone changes,the position in the high temperature zone changes,and the NO content increases.