Thermal performance of numerical model of hot strip mill runout table

Abstract

A model of the accelerated cooling of a hot strip mill runout table is developed. The cooling is simulated by considering a piece of hot strip, which is subsequently submitted to heat transfer mechanisms: conduction, convection, and radiation. The convective heat transfer is produced by the use of water curtains and water jets. As is usual in the literature, the zones of impingement and stable boiling were defined for each of these water cooling devices. To calculate the convective heat transfer coefficient, correlations were employed both for the impingement zone and the stable film boiling zone. The sensitivity to variations in the physical properties and to the usual experimentally adjusted parameters was analysed. The model is especially sensitive to variations in the specific heat and convective heat transfer coefficients for the impingement zone. An experimental study to validate the model indicates that it works reasonably well, predicting the coiling temperature with differences of less than 20 K for all the samples analysed. Moreover, the coiling temperature was predicted with differences of less than 10 K in 70% of the samples analysed.