中厚板坯结晶器内钢液非对称流场的数值模拟

Numerical simulation of asymmetric flow field of molten steel in medium slab mould

以某钢厂中厚板坯连铸结晶器为研究对象,采用Fluent流体力学软件,对水口单侧结瘤、水口两侧不对称结瘤以及水口不对中情况下的结晶器流场进行数值模拟,通过改变水口结瘤程度、水口浸入深度、拉坯速度等条件模拟结晶器流场情况。模拟结果表明:水口结瘤率越大,结晶器内流场不对称情况越严重,结瘤率小的一侧液面流速更大;拉坯速度越快,结晶器流场不对称情况越严重,液面流速更快,甚至发生表面回流卷渣;水口浸入深度越大,结晶器内流场不对称情况未有明显改善,但液面流速随之减小;结晶器宽度的变化对流场的不对称性和液面流速的影响较小;当水口不对中程度为5%时,结晶器流场和钢渣界面处液面流速不对称情况较为明显。

Taking the continuous casting mold of medium and heavy plate in a steel plant as a study object,the flow field of the mold is simulated by using the three-dimensional hydrodynamics software under the conditions of one side of the nozzle,asymmetric and misaligned nozzle.Then,the flow field in the crystallizer is simulated by changing the degree of nozzle accretion,the depth of nozzle immersion and the speed of billet.The simulation results show that with the increase of the nozzle fouling rate,the flow field asymmetry in the mold becomes more serious,and the flow velocity on the small nozzle fouling rate side is larger;the faster the casting speed is,the more serious the flow field asymmetry in the mold will be,and the flow velocity on the liquid surface will be faster,even the surface reflux slag will occur;with the increase of the nozzle immersion depth,the flow field asymmetry in the mold is not significantly improved,while the flow velocity decreases with the increase of mold width;the asymmetry of flow field and liquid velocity is less affected by the change of mold width;when the nozzle misalignment is 5%,the asymmetry of flow field and liquid velocity at the interface of steel slag is more obvious.