Numerical Simulation and Optimization of Coke Oven Gas-Lanced Ladle Baking Process with Pure Oxygen Staged Combustion

To enhance the stability of the flame structure and elevate the overall combustion temperature during the staged combustion process, this study undertakes an optimization of the technology, specifically tailoring it to the context of the steel ladle baking process. Leveraging computational fluid dynamics (CFD) numerical simulation, the research conducts a thorough examination of the effects of varying ratios of primary and secondary oxygen supply on the steel ladle baking process. This examination is then juxtaposed with the conventional pure oxygen-assisted steel ladle baking process for a comparative analysis. The study reveals that, when the oxygen supply ratio for staged combustion is set at 3:7, the overall temperature within the steel ladle furnace can surpass 1500 K, aligning with the temperature achieved in the pure oxygen-assisted combustion process. This represents a notable advancement when compared to the temperatures attained with the 2:8 and 1:9 ratios. At a temperature of 1400 K, the flame exhibits a thick, rigid appearance, accompanied by a diminished area of swirling. The axial flow velocity at its core reaches 21 m/s, while the bottom impact velocity measures 8.5 m/s, both of which contribute to an enhanced convective heat transfer process. The average temperature of the steel ladle's inner wall surpasses that of the pure oxygen-assisted combustion process by 134.1 K, exhibiting a more gradual temperature gradient. Notably, the temperature discrepancy at the bottom decreases by 265.5 K, while the heating rate diminishes by 18.6%. The NOx concentration is reduced by 45%-49% compared to pure oxygen-assisted combustion. These findings provide theoretical support for energy-saving and emission reduction in the steel ladle baking process and the industrial application of staged combustion technology.