Numerical analysis of work roll cooling in hot rolling process

Abstract

In hot rolling process the work rolls subjected to succeeding heating and cooling cycles with the net effect of heat influx. This nature of heating might cause damage at the same time as shape imperfections in the rolled slabs. Therefore it is the essential to know how the temperature of the work rolls increases. This particular phenomenon has been modeled and simulated with the help of ANSYS 13 Software. Based on the three dimensional conduction equations and temperature fields of a roll were investigated using finite element method (FEM) and Finite volume Method (FVM). The differences in the surface temperature of the roll during hot rolling process were illustrated. The results confirmed that the highest roll surface temperature is 723oC. The effect of orientations of the water jets, heat transfer coefficient at roll surface and hot strip entry temperature also been deliberated by this model, and their effect on roll temperature has been analyzed. The change of angle of jet has shown that the effect is minimum. A method is illustrated for determine the heat transfer coefficient distribution of an array of liquid water spray type used to cool the rolls on a steel strip rolling mill. Heat transfer data are obtainable for an array of 60o cone sprays including the effect of controlling off array members. The average heat transfer coefficient of the jet impingement is 5000W/m2K. All the results are given for both steady state and transient changes in roll.