A novel acquisition approach for heat transfer coefficient during periodic cooling process

Abstract

Temperature is an important parameter affecting the microstructure of slab and an important guarantee to improve the performance index of metallurgical products. However, the temperature level is affected by the heat transfer coefficient. Taking laminar cooling as an example, a method for calculating the heat transfer coefficient of a system with periodic characteristics is proposed in this study. Firstly, it was assumed that the distribution of heat transfer coefficient is a piecewise function composed of positive half wave of sine function and line function. The calculation methods of characteristic parameters?through structural parameters and operating parameters?in three cases of "separation", "adjacent" and "intersection" are given; Secondly, heat transfer model of slab was established. Surface temperature and center temperature distribution of slab were compared with the test results. The relative errors of surface and center temperature were 2.46% and 1.33% respectively, which verified the accuracy of this method. Finally, the coupling relationship between the characteristic parameters in the heat transfer coefficient distribution function is obtained by calculation. Compared with the methods presented in the literature?this method reduces the number of unknown parameters while ensuring the accuracy of the model, and gives guidance on how to change the slab temperature and improve product performance by adjusting the structure and operating parameters.