Notice of RetractionNumerical Simulation of Inlet Oxygen Influence on NO Emission under Preheated Air Condition

Numerical simulation was carried out on the High Temperature Air Combustion in an industrial furnace with a multi-jet burner. The effect of inlet oxygen concentration of the preheated air on the combustion characteristics was investigated. The standard k-ε model was used to calculate the flow field and β function PDF was used to simulate the gas combustion. The radiation was simulated by a Discrete Ordinates method. NO was simulated by thermal NO model. The furnace was a rectangular chamber of 800 mm × 800 mm × 1400 mm. A circular fuel jet of a diameter of 10 mm is at the center of the wall. 5 circular air jets equably distributed around the fuel jet with different straddle angles. The results showed that inlet oxygen concentration of preheat air had a considerable influence on the local temperature, oxygen and NO distribution, resulting in a stable flame, an enlarged low-oxygen zone, an equable temperature distribution and a suppressed local high temperature, which led to the lower product of local NO. When the inlet oxygen concentration is 10%, the local NO concentration is lowered 2 factors than that under a 21% inlet oxygen concentration. The final NO emission is no more than 20 × 10-6 at an inlet oxygen concentration of 10%.