钢管超快冷过程数学模型的研究与开发

Development of mathematical model for ultra-fast cooling process of a steel pipe

为了提高钢管超快冷过程的温度控制精度、冷却均匀性以及组织性能控制的精准度,分析了钢管超快冷过程的换热机理,确定射流冲击为钢管超快冷过程的主要换热方式。利用反传热法对钢管表面换热系数进行测定;利用导热方程,建立钢管超快冷过程射流冲击换热数学模型,采用第三类边界条件和有限差分法求解该数学模型。应用此数据模型可以计算特定温度范围内的平均冷却速度和所用时间,也可以计算一定时间范围内的温降和平均冷却速度。经现场测试,由该数学模型计算得到的温降曲线与实际温降曲线基本相同,模型计算精度很高,具有可应用性和执行性。

In order to improve the temperature control precision, cooling uniformity and the control accuracy of microstructure and performance during ultra-fast cooling process of a steel pipe, the heat transfer mechanism of cooling process was analyzed for determining that jet impingement was the main heat transfer way of steel pipe ultra-fast cooling process. The heat transfer coefficient of the pipe surface was measured using the inverse heat conduction method. The jet impingement heat transfer mathematical model of ultra-fast cooling process was built using heat conduction equation, and it is solved by the third boundary condition and finite difference method. Utilizing this mathematical model, the average cooling rate and the spent time within a specific temperature range can be calculated; the temperature drop and the average cooling rate within a certain time can also be calculated. After field tests, the temperature drop curve calculated by this mathematical model is basically the same as the actual temperature drop curve, verifying that the mathematical model has high accuracy, and its practical.