Abstract：A numerical simulation was carried out on the High Temperature Air Combustion in an industrial furnace with a multi-jet burner. The furnace was a rectangular chamber of 800mm×800mm×1400mm. A circular fuel jet of a diameter of 10mm is at the center of the wall. 5 circular air jets equably distributed around the fuel jet with different straddle angles. PDF (Probability Density Function) combustion model based on a function was selected to simulate the gas combustion combined with the standard k- model to simulate the flow field. The radiation was simulated by a Discrete Ordinates method. The NOx emission was simulated by thermal NOx model. The effect of the burner configuration on the combustion characteristics was discussed. When the distance between the air and fuel jets increased, the mixing of the fuel and air could be effectively delayed and an obvious recirculation zone appeared between the air jets and fuel jet that reduced the local oxygen concentration. More fuel would be burnt in the low oxygen region and combustion zone and the flame volume were both increased which made the temperature distribution became more equable and local high temperature was suppressed. When the dimensionless distance between the air and fuel jets was 2.5, a minimum NOx emission of 45 ppm was achieved at 15% O2. The smaller the straddle angle of the preheated air was, the better the mixing of the fuel, oxygen and the flue gas became, which resulted in a stable flame, an enlarged low-oxygen zone, an equable temperature distribution and a suppressed local high temperature. When the straddle angle of the preheated air increased, the burner disposal is more like the jets with the same axis. The recirculation of the high temperature flue gas in the furnace only played the role to stabilize the combustion and the local low oxygen region will disappear. At the 15% O2 condition, when the straddle angle of the preheated air is 120°, the final NOx emission can be reduced about 65% compared with that when the straddle angle of the preheated air is360°. When the declining angle of the fuel jet increased from 0 to 30°, the maximum and mean temperature in the furnace both decreased and the final NO emission decreased.
苏亚欣 汪文辉 赵丹 杨艳超. 射流参数对单烧嘴燃烧室高温空气燃烧特性的影响的数值研究[J]. 钢铁, 2010, 45(7): 94-94.
. Numerical simulation of High Temperature Air Combustion in an industrial furnace with different burner configuration. Iron and Steel, 2010, 45(7): 94-94.
2010, Vol. 45 
