转炉底吹枪优化布置的数值模拟

Optimization of arrangement of bottom tuyeres through numerical simulation

为了优化转炉底吹搅拌效果,以某钢厂转炉为研究对象,运用软件Ansys-Fluent建立三维Euler数学模型,研究了底枪支数对底吹氩转炉内钢液混匀行为的影响规律。结果表明,4支底枪分布,单支底吹流量大,熔池内回流区发展充分,底吹元件不易堵塞,并且熔池内钢液的平均速度大,弱流区、低速区和死区的范围小,混匀时间短,是最佳的底枪支数分布。部分底枪集中布置的8支和12支分布,流动形式等效于4支底枪分布,但能量的利用率较低,这种多支底枪分布有利于熔池上半部分的混匀,但是由于底吹元件多,单支底吹流量小,对炉底的搅拌作用差。实践表明,采用4支底枪分布,转炉吹炼终点各项技术指标得到很大的改善,与数值模拟结果相符合。

In order to optimize stirring effect of converter bottom blowing,based on the converter in a steel plant,a three-dimensional Euler mathematical model was established through the commercial software Ansys-Fluent to study the effect of the number of bottom tuyeres on the mixing behaviors of the molten metal in converter. The results indicate that with 4 bottom tuyeres and large flow through each tuyere,the recirculation zone develops fully and the blocking of tuyeres can be controlled. Meanwhile,the average velocity of the molten metal is large,the coverage of weak zone,low velocity zone and dead zone are small and the mixing time is short. Therefore,4 bottom tuyeres is the best number of the bottom tuyeres. For the distribution of 8 and 12 bottom tuyeres arranged closely,the flow fields are similar to the one of 4 tuyeres,but the energy utilization rate is lower. The arrangement of multiple tuyeres is beneficial to the mixing of upper half of the molten pool. However,with more bottom tuyeres,the flow rate of the gas through per bottom tuyere is smaller,so the mixing effect at the bottom of converter is bad. Practices show that the technical indexes of the converter are greatly improved at the end of smelting when using the arrangement of 4 bottom tuyeres,which is consistent with the results through numerical simulation.