Prediction model of interfacial heat transfer coefficient changing with time and ingot diameter

Abstract

We established and simulated finite element solidification models of ingots with 180, 380, 800, 1,300, and 1,880 mm diameters, and the solidification process temperature distributions for the five ingot sizes were assessed by Fluent. On this basis, we established a mathematical model for the interfacial heat transfer coefficient between the ingot and the ingot mold, as well as the ingot diameter and solidification time, using the regression analysis method. The results showed that the change law for the interfacial heat transfer coefficients of the ingots with different sizes and times conformed to the change law of the exponential function, and the interfacial heat transfer coefficient and the ingot diameter had a linear relationship. The interfacial heat transfer coefficient, based on a measured temperature of about 36 tons of ingot with an average diameter of 1,500 mm and about 8.5 tons of ingot with an average diameter of 820 mm, was compared to the interfacial heat transfer coefficient calculated by the model. We found that the variation law of the two was essentially the same, indicating that this model could correctly reflect the interfacial heat transfer coefficient between the ingot and the ingot mold in the literature.

Keywords

• ingots
• interfacial heat transfer coefficient
• numerical simulation
• prediction model