Research On The Local Heat Transfer Based On The Stepped Cooling Of The Rolls

Flatness is an important index to measure the quality of cold rolled strip,the flatness of strip will directly affect the quality of strip.The flatness control methods can eliminate the defect shape of some common non high-order plate,but it is not enough to eliminate some of the asymmetric,or shape defects of local higher-order wave shape.The work roll cooling is the very effective solution.At present,more and more attention has been paid to the steeped cooling control method,which has become one of the most important methods for flatness control in cold rolling mill.The essence of heat convection roll cooling heat transfer is changed in different segments of the roller body of the heat transfer coefficient.Based on this,this paper established the heat transfer model of the local roller by using finite element software,so as to explore the local heat transfer characteristics of roll.First of all,as a complex cooling cooling system,it analyzes the principle and structure characteristics of piecewise flatness control cooling on the basis of 1650 mm cold rolling mill.And the injection beam was designed and established on the basis of subsection cooling control system more efficient model.The model of the cooling control problem is reduced to the control problem of single variable complex,simplifies the design of cooling controller.Secondly,the essence of subsection cooling is to change the coefficient of heat convection heat transfer.In this paper,the three-dimensional model is established,and the fluid simulation software FLUENT is used for numerical simulation.The distribution of the surface heat transfer coefficient of the working roll is simulated,and the influence of the physical properties of the coolant and the structural parameters of the spray beam on the heat transfer characteristics of the work roll is discussed in detail.It obtains the influence factor on the heat transfer coefficient and sorting through orthogonal experiment and discusses how to improve the heat transfer coefficient of each factor potential,so as to lay the foundation for improving the cooling efficiency of the cooling liquid researchs.Finally,combined with the actual situation of the factory,we get the heat and temperature distribution in the surface of the work roll,through the simulation of nozzlespacing convection in the 52 mm and 26 mm two under the condition of heat transfer,which provides a theoretical basis for the actual adjustment.