镁合金板材轧辊流体传热液固耦合传热模型的建立及数值模拟

Establish Fluid-solid coupled heat transfer model and numerical simulate of fluid heated magnesium alloy sheet roll

摘要:

针对目前镁合金板材轧制过程轧辊温度控制方式简易，精度差，易造成板材的板形、板厚及裂纹等缺陷，本文采用流体循环流动传热的方式对轧辊进行温度控制，且使用fluent软件对二者间的流固耦合传热过程进行了数值模拟，并进行了实验验证，给出了其传热过程中轧辊温度场的趋势和规律。结果表明：该方法加热轧辊时，其表面温度分布较均匀，边部与中间的温差最大为6℃，且流体温度与速度对其影响较小；在不同的流体温度和流体速度下，轧辊表面温度均呈速率减小的趋势上升，流体温度升高及速度增大时，轧辊温升变快，且流体温度对轧辊温升的影响大于流体速度对其的影响；得出了在不同加热条件下，轧辊表面的温度值与时间的关系式；对轧辊停止加热后到轧辊表面开始温降有一段延续期，流体的温度越高，延长时间越长；轧辊温升阶段的模拟结果与实验结果相比，流体温度升高，其误差变大，轧辊温度升高，误差也变大，两者间最大误差为16.16%，总体结果较吻合，表明该模型可以正确表示流体加热轧辊的传热过程。

Abstract:

At present, the roll temperature control method of the magnesium alloy sheet rolling process is simple and accurate, which has a serious influence on the shape, thickness and crack. So adopting the method for fluid circulation to control temperature, using fluent software to simulate the fluid-solid coupled heat transfer process and verifying by experiment, then giving the heat transfer trends and laws. The results showed that heating the roll by this method, the surface temperature distribution is more uniform, the maximum temperature difference between the edge and the middle is 6℃, and fluid temperature and velocity have little effect on it; At different fluid temperature and velocities, the temperature of the roll rises with trend of decreasing rate, and when the fluid temperature rises and the velocity increases, the temperature rise of the roll becomes faster, the effect of the fluid temperature on the roll temperature rise is greater than the fluid velocity; The relationship between the temperature of the roll surface and the time is obtained under different heating conditions; The roll surface temperature drop has a period of extension when the roll is stopped heating, the higher the temperature, the longer the extension; There is an error between the simulation results and the experimental results in the roll temperature rise stage, fluid temperature increases, the error becomes larger, the roll temperature increases, the error also becomes larger, the maximum error is 16.16%, the results are consistent, indicating that the model can correctly represent the heat transfer process of the fluid heating roll.