Homogenization control method for transverse temperature during laminar cooling of hot-rolled strip

A method for homogeneously controlling a transverse temperature during laminar cooling of a hot-rolled strip, comprising following steps:

• (I) dividing a transverse area of an upper surface of the strip, according to distribution of the transverse temperature of the strip, into a middle area, a left edge area, and a right edge area, the middle area having a uniform transverse temperature and the left edge area and the right edge being symmetrical, having a same width, and having transverse temperature drop in a width direction;
• (II) determining model parameters by collecting geometric parameters and initial temperature parameters of the strip, wherein:
• the geometric parameters comprise a strip thickness t, a strip width b, a strip length e, a width of an edge temperature drop area of the strip c, and a transverse center coordinate, a left edge coordinate, and a right edge coordinate of the strip, and
• the initial temperature parameters comprise a temperature T0 of the middle area of the strip and a temperature T0′ of an edge of the strip;
• (III) establishing a finite element model, according to the geometric parameters collected in step (II), by:
• establishing a geometric model of the strip,
• assigning material thermophysical parameters and the initial temperature parameters to the geometric model, and
• performing element discretization by grid division of the model;
• (IV) setting third-type boundary conditions for the finite element model established in step (III), comprising:
• setting a heat transfer coefficient of a lower surface of the strip, and
• setting at least two parameters selected from the group consisting of a heat transfer coefficient in the middle area of the strip hc, a heat transfer coefficient at the edge of the strip hw, and a convexity ratio m;
• (V) obtaining an analytical solution T(x, t) of a transverse temperature field of the strip through a heat conduction partial differential equation according to the geometric parameters, the initial temperature parameters, and the third-type boundary conditions;
• (VI) designing different types of middle convexity water cooling heat transfer coefficient curves H(x);
• (VII) calculating a transverse water flow density distribution of the cooling water in a laminar cooling area corresponding to the different types of middle convexity water cooling heat transfer coefficient curves;
• and
• (VIII) selecting an optimal middle convexity water cooling heat transfer coefficient curve to determine optimal transverse water flow density distribution of the cooling water in the laminar cooling area and to determine optimal middle convexity water volume distribution.