集束氧枪环流布置模式对射流流场影响规律研究

Effect of shrouding nozzle arrangement on the flow field characteristics of coherent jet

  • 摘要: 为进一步提高集束氧枪对熔池的冲击搅拌效果, 重点分析了在两种环境下, 不同环流布置模式对超音速氧气射流流场与冲击能力的作用效果.通过对比在高温喷射试验与数值模拟研究结果, 分析射流轴向速度与射流总温流动状态, 研究不同环流布置模式下集束射流冲击特性.通过分析不同数量网格的可靠性, 选取合适的数值模拟模型, 并采用涡耗散概念模型和多步燃烧反应机理计算超音速状态下氧气与甲烷的混合与燃烧过程.研究结果表明数值模拟结果与高温喷射试验数据吻合程度较好.环流布置对拉瓦尔管出口流速无明显影响, 主氧射流核心段随环流孔径与主氧射流间距的增大, 有先提高后下降的趋势, 且不同环流布置模式对主氧核心段均有延长效果.

     

    Abstract: The coherent lance technology is widely used in the electric arc furnace (EAF) steelmaking process.It achieves a better metallurgical effect compared with the conventional supersonic lance technology.Herein, to further improve the stirring ability of the coherent lance, the effects of shrouding nozzle arrangement on the flow field and stirring ability of coherent jet were analyzed under two environment temperatures.Based on the results of the numerical simulation and combustion experiment, the characteristics of axial velocity and total temperature distributions has been introduced for researching the impaction ability of coherent jet using various shrouding nozzle arrangements.The appropriate simulation model was built by testing three types of mesh levels.The eddy dissipation concept (EDC) model and chemical kinetic mechanism were adopted to represent the combustion reactions of the O2-CH4jet flame in the numerical simulation process.Resultsreveals that the numerical simulation data shows good agreement with combustion experiment.The initial velocity at the exit of main oxygen Laval nozzle does not change with different shrouding nozzle arrangements.With increase in the distance between the main oxygen and shrouding nozzles, the length of the velocity potential core first increases and then reduces.Moreover, all shrouding nozzle arrangements increase the length of velocity potential core.

     

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