基于不同保温措施下的铁水包热状态模拟分析

Thermal state simulation analysis of molten iron ladle based on different insulation measures

  • 摘要: 在铁钢界面现有模式下的铁水运输过程中,由于铁水包运行周期及保温效果不够理想,导致在高炉接铁时铁包耐材温度低,热状态差,使得铁水在铁水包内的热量损失较大.减小铁水温降能有效防止铁水包结壳结瘤,降低离线烘烤频率,间接提高铁水包周转率;同时在转炉冶炼过程中,低温铁水将严重影响废钢的加入量和吹氧等操作.由此可见,铁水温度控制是钢铁企业节能降耗和高效有序生产的关键因素之一.为了减小铁水温降,本文建立了多种不同保温措施情况下的铁水包传热模型,通过fluent软件对各模型在不同空包时间情况下的温度场进行数值计算,分析不同保温措施及空包时间下热状态对铁水温降的影响规律.分析结果表明:无保温措施的情况下空包时间由5 h缩短至3 h能降低下一周期铁水温降2.2 K·h-1;空包阶段最合理的保温措施为增设6 mm左右绝热层并加包盖,能提高工作层平均温度约155 K,在空包3~5 h内能减小铁水温降3.4~3.7 K·h-1.该结论为铁水包空包阶段采取合理保温措施及不同保温情况下空包运行时间控制提供了理论指导.

     

    Abstract: The turnover time for transporting a hot metal from a blast furnace to a basic oxygen furnace is long and therefore the heat preservation effects are not ideal. These factors affect the temperature and thermal state of the ladle refractories, which leads to the heat loss of the hot metal. Reducing the temperature drop of the hot metal can effectively prevent the hot metal nodules and decrease the frequency of offline baking; moreover, it indirectly increases the turnover rate of the hot metal ladle. At the same time, a hot metal with low temperature seriously affects the addition amount of scrap steel and oxygen blowing operations during the smelting process in the converter. Therefore, it can be observed that controlling the hot metal temperature is one of the key factors for energy saving and efficient production in a steel plant. To reduce the temperature drop of a hot metal, a variety of computation models of ladles with several insulation measures were established. In addition, the Ansys fluent software was used to simulate the temperature fields after the end of the charging. The influence of thermal states of ladles with different insulation measures and unloaded time on the temperature drop of the hot metal was investigated. The analysis shows that reducing the unloaded time from 5 h to 3 h can decrease the temperature loss of the hot metal by 2.2 K·h-1. Using a ladle with an insulation layer of about 6 mm and an insulation cap is the most sensible measure to realize insulation. It can increase the average temperature of a working layer by almost 155 K, and this improvement can reduce the temperature loss of hot metal by 3.4-3.7 K·h-1 during the 3 to 5 h unloaded time. The conclusions provide some academic bases and references for the reasonable insulation measures and control of the unloaded time of a multifunctional hot metal ladle.

     

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