基于多指标正交试验的链箅机抽风干燥段热工参数优化

Thermal parameter optimization in the DDD of chain grate by orthogonal test with multi-targets

链箅机是铁矿球团干燥脱水和预热氧化的热工设备,球团在链箅机抽风干燥段的干燥效果直接影响着球团质量。基于传热学、局部非平衡热力学理论和干燥动力学原理建立抽风干燥段的流体力学(CFD)模型,采用CFD方法模拟球团料层在抽风干燥段(DDD)中的干燥过程,提出多指标正交试验法,并定义热能利用率的正交试验指标,得到球团料层在抽风干燥段的参数优化方案。在该优化参数方案下,抽风干燥段球团料层提前约14 s达到92%的干燥度。研究结果可为链箅机抽风干燥段的热能有效利用提供理论参考。

Chain grate is a thermal equipment for drying and dehydration,preheating and oxidation of iron ore pellets,and the drying effect of pellets in down draft drying of chain grate directly affects the quality of pellets.Based on the theory of heat transfer,local non-equilibrium thermodynamic theories and the principles of drying kinetics,a computational fluid dynamics(CFD) model in the down-draft drying(DDD) of pellets is established.The drying process of pellets in the DDD is simulated by the method of CFD.A multi-targets orthogonal test is proposed,the orthogonal test targets for the utilization of heat energy are defined,and the parameter optimization scheme of pellets in the DDD is obtained.Under the optimized parameter scheme,the pellets layer in the DDD is advanced about 14 s,up to 92% drying degree.So,a theoretical reference can be provided for the effective utilization of thermal energy in the DDD of chain grate.