板坯连铸结晶器内钢液过热消除过程的数值模拟

利用数值模拟方法研究了连铸结晶器内钢液的三维温度分布和传热,分析了水口浸入深度、水口侧孔倾角、结晶器宽度、拉速、钢液过热度、吹Ar、电磁制动及吹Ar量和电流强度等对结晶器内过热钢液的温度分布和传热的影响.结果表明,凝固坯壳前沿的最大热量传入处出现在结晶器窄面的钢液冲击点附近,钢液的大部分过热耗散发生在这一区域附近;过热钢液传递到凝固坯壳表面的热流量与拉速和过热度的增加成正比;吹Ar导致结晶器窄面冲击区域和宽面上部区域的热流密度增加;电磁制动有利于提高结晶器上部区域的温度,但对热流密度分布没有明显影响;吹Ar和电磁制动的双重作用使结晶器上部区域的宽面热流密度提高,冲击区域的热流密度分布没有明显变化.

NUMERICAL SIMULATION OF LIQUID STEEL SUPERHEAT REMOVAL IN SLAB CONTINUOUS CASTING MOLD

Mathematical model was developed to study the 3D temperature distribution and heat transfer from superheated liquid steel to the inside of the solidifying shell in the slab continuous casting mold. The effects of some factors, such as submergence depth and port angle of submerged entry nozzle (SEN), mold width, casting speed, superheat temperature, argon gas injection, electromagnetic brake (EMBr) and also including the argon gas flow rate and current intensity etc., on the temperature distribution and heat transfer of superheated liquid steel in the mold were analyzed. The results indicate that the maximum heat input to the solidifying shell forefront occurs near the impingement point of liquid steel on the narrow face of mold, and the most superheat of superheated liquid steel is dissipated near the impingement zone. Heat flux of superheated liquid steel delivered to the shell  surface increases in direct proportion to the casting speed and superheat temperature, respectively. Argon gas injection leads to a substantial increase in superheat flux to the impingement zone of narrow face and the upper region of wide face. EMBr is beneficial in increasing the temperature of upper region of the mold, but has no obvious effect on the heat flux distribution. The double action of argon gas injection and EMBr also produces an increase in heat flux to the upper region of wide face, which has no visible influence for the hat flux distribution of impingement zone.