薄板坯连铸结晶器窄面铜板传热分析及冷却结构优化

Analysis on Heat Transfer and Optimization for Cooling Structure of Mould Narrow Face Copper Plate for Thin Slab Continuous Casting

针对薄板坯连铸结晶器窄面铜板磨损大、使用寿命低的问题,分析了窄面铜板冷却结构对传热的影响,设计了一种用于提高结晶器窄面冷却能力的新型铜板,该铜板采用5个内径11 mm的圆管型水道进行冷却,在水量为230 L/min时,铜板内水速可由6.23 m/s提高到8.07 m/s,水的对流换热系数可由22 000 W/(m^2·℃)提高到29 000 W/(m^2·℃),弯月面处窄面铜板的热面温度能够降低25℃左右。采用新型窄面铜板进行了大量的工业试验。结果表明,过钢量为18 450 t(相当于123炉)后,窄面铜板下部最大磨损量由4.5 mm降低到1.3 mm,使得窄面铜板的单次使用寿命可与带镀层的宽面铜板相当,这种五孔冷却式窄面铜板具有附加锥度低、热流高、热面温度低和抗磨损等多方面的优点。

In oder to address the problem that narrow face of mould copper plate of thin slab continuous casting process present server wear and low service life, the effect of cooling structure of narrow face cop- per plate on heat transfer had been analyzed. A new copper plate used mould narrow face was designed. The copper plate was cooled using five for improving cooling round tube shaped inn ability of er gullets whose inner diameter was 11 ram. When the amount of water was 230 L/min, the velocity of water could be increased from 6.23 rn/s to 8.07 m/s, the convective heat transfer coefficient of water could be in- creased from 22 000 W/（ m2 ~ ~C ） to 29 000 W/（m2 ~ ~C ） ,and the hot side temperature of narrow face copper plate could be reduced about 25 ~C. Lots of industrial experiments had been made using this cop- per plate. The results showed that the maximum wear amount at the bottom of copper plate had been re- duced from 4.5 mm to 1.3 mm, which made the service life of the narrow face copper plate equal to that of wide-face galvanized copper plate. In a general way, this narrow-face copper plate cooled by five round tube shaped inner gullets had many advantages including low additional taper, high heat flux, low hot face temperature and high wear resistance.