
第37卷第6期 2016年12月
特殊钢
SPECIAL STEEL
Vol. 37. No. 6 December
2016
.17.
预防中间包尾坏浇注过程中钢液卷渣的数学模拟和工艺优化效果
霞
王卫华刘洋赵新宇陈
(首钢技术研究院,北京100043)
摘要为降低中间包尾坏判废率,预防中间包尾坏降拉速过程钢液卷渣,应用流体力学软件FLUENT,对尾坏降拉速过程进行优化,研究尾坏拉坏过程的拉速变化对钢厂3"板坏连铸机80t中间包钢液紊流卷渣的影响。通过每次降拉速后的停留时间历程的动能时间跟踪曲线分析,确定了中间包尾坏降拉速优化方案。该方案在原方案基础上,将8t铸余增加到10t,缩短了各拉速下的持续拉坏时间,并将封顶操作从0.1m/min提高到0.2m/min, 000 mm×2000mm3板坏连铸机采用优化操作后,每月尾坏废品总量从576.4t降低到139.1t。
关键词80t中间包300mm板坏尾坏卷渣数学模拟优化效果
gonPreventingSlagEntrapmentofLiquidin
MathematicalModelling
TundishduringTailingSlabCastingandProcessOptimizedResults
Wang Weihua, Liu Yang, Zhao Xinyu and Chen Xia(Shougang Research Institute of Technology, Beijing 100043)
Abstract In order to reduce the rejection rate of tundish tailing slab,prevent the slag entrapment of liquid in tundish in tailing slab decreasing casting speed process ,the effect of casting speed change during tailing slab casting process on turbulence slag entrapment of liquid in a 80 t tundish for No3 slab caster at steelworks has been studied, and the optimization of process of decreasing tailing slab casting speed is carried out by using fluid dynamics software FLUENT. The optimization scheme to de-crease the tundish tailing slab casting speed is defined by analysis on the turbulent kinetic energy-time tracking curves in re-main time course after each casting deceleration. Based on the original scheme the casting heel increases from 8 t to 10 t,the duration of casting at each casting speed shortens and the final casting closing-up operation increases from 0. 1 m/min to 0. 2 m/min to reduce the possibility of tailing slab slag entrapment and decrease the production cost, the time of tundish tailing slab casting duration saves by 266. 8 s and the amount of saving liquid is 5. 08 t._ After using the optimized operation at 300 mm ×2 000 mm No3 slab caster the total amount of rejected tail slab per month decreases from 576. 4 t to 139. 1 t.
80 t Tundish, 300 mm Slab, Tail Slab, Slag Entrapment, Math Model, Optimized Results
MaterialIndex
在瓷注的最后阶段如果钢液流股控制不好,中间包渣会大量抽吸至结晶器内,使结晶器传热和润滑急速恶化,极易产生漏钢。另一方面,如果降速过程中拉速变化幅度和频率过大,有可能会弓起液面剧烈波动,造成钢液卷渣(1-5)。
钢厂在尾坏浇注过程中,由于尾坏在低拉速过程中停留时间过长,导致尾坏质量废品发生量占废品总量的平均比例为31.3%。
应用流体力学(CFD)计算软件对中间包流场进行数值模拟,成为成本低、速度快、效果好的研究手段[69]。本研究以3"板坏连铸机带稳流器的中间包为研究对象,借助大型流体力学软件FLUENT,研究尾坏拉坏过程的拉速变化对中间包钢液卷渣的影响。
流体动力学方程 1
假设中间包内钢水的流动为湍流流动,描述钢水流动的基本控制方程(101见式(1)~(4):
连续性方程:
a
(pu,))=0
ox
Navier-Stokes方程:(pu)=+
e ax
axax,t
(ou;,ou ax;
ax;/
(1)(2)
(pouh) a
=G-p(3)
滞流动能方程:
ax,
满动能耗散方程:
Mde
a
pu,6
ax,
Geax,/
O, ax, C,G C,p82
k
其中:G=:(x)
oui(du;du,)
xe
μer =μ +μ Cnpk2 μ=
6
(4)
式中: C, =1.45; C,= 1.92; Cp=0.09; 0,= 1.0;