Reversible mill rolling schedule optimization method based on equipower margin function

Abstract

The invention discloses a reversible mill rolling schedule optimization method based on an equipower margin function. The method is specifically implemented according to the following steps: S1, collecting equipment and incoming material related parameters; s2, the rolling pass is determined; s3, establishing an equipower margin objective function in the reversible cold rolling process; s4, determining constraint conditions; s5, obtaining the optimal pass reduction rate under the condition that the constraint condition in the S4 is met; and S6, according to the optimal reduction rate distribution result, obtained in the S5, of each pass, setting of the cold rolling schedule of the single-stand reversible rolling mill is completed. According to the rolling schedule optimization method for the reversible rolling mill based on the equipower margin function, the balance of power distribution of rolling mills of all passes is improved, so that the utilization rate of equipment and power fluctuation in the rolling process are improved, adjustment can be conducted according to different steel types and incoming material specifications, the production flexibility of the rolling mill is improved, and the production cost is reduced. Not only are the production efficiency and the product quality improved, but also the implementation effects of energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of cold rolling of single-stand reversible rolling mills, and relates to an optimization method for rolling schedules of reversible rolling mills based on an equal power margin function. Background Art

[0002] With the continuous increase in the demand for cold-rolled products by users, current cold-rolled strip products need to place production efficiency and energy consumption in an important position while ensuring product quality.

[0003] During the rolling process of cold-rolled strip in a reversible rolling mill, the reduction per pass on average is restricted. Traditional rolling schedules are often set based on empirical methods, which leads to great uncertainties in aspects such as energy consumption, load distribution, and strip shape quality during the rolling process.

[0004] To achieve a consistent exit thickness, a corresponding number of additional passes are required. For a reversible rolling mill, an increase in the number of passes means a significant increase in the energy consumption of the entire unit. Therefore, there is an urgent need to develop an optimization method for the rolling schedule of a reversible rolling mill to ensure more balanced power distribution in each pass during the rolling process, improve the utilization rate of equipment and rolling effect, and solve the problem of energy conservation and emission reduction in the current steel plant strip production line. Summary of the Invention

[0005] The purpose of the present invention is to provide an optimization method for the rolling schedule of a reversible rolling mill based on an equal power margin function, which solves the problem of uneven power distribution in each pass of rolling strip by a reversible rolling mill in the prior art.

[0006] The technical solution adopted by the present invention is an optimization method for the rolling schedule of a reversible rolling mill based on an equal power margin function, which specifically includes the following steps: S1. Collect relevant parameters of equipment and incoming materials; the equipment is a single-stand reversible rolling mill; S2. Determine the number of rolling passes; S3. Establish an equal power margin objective function in the reversible cold rolling process; S4. Determine the constraint conditions; S5. Obtain the optimal reduction ratio per pass under the condition of satisfying the constraint conditions in S4; S6. Complete the setting of the cold rolling schedule of the single-stand reversible rolling mill according to the optimal reduction ratio per pass allocation result obtained in S5.

[0007] The characteristics of the present invention also lie in: The specific steps of S2 are as follows: S2-1. Determine the maximum reduction ratio according to on-site equipment and process parameters ; S2-2. Calculate the minimum number of rolling passes: (1); Among them, represents the initial thickness; represents the target thickness; represents the maximum reduction ratio; S2-3. According to the calculated minimum number of passes , obtain the rolling passes : (2).

[0008] The specific steps of S3 are as follows: S3-1. Obtain the rolling force and the rolling torque for each pass from the Hill formula; S3-2. Establish a motor power model to obtain the motor power for each pass; S3-3. Construct a motor power margin model according to the motor power model; S3-4. Set the optimization objective in the rolling schedule and construct an equal power margin objective function.

[0009] The expression of the rolling force for each pass is: (3); In the formula, represents the pass number, represents the external friction influence coefficient, represents the average deformation resistance, represents the equivalent tension influence coefficient, represents the width of the rolled piece, represents the elastic flattening radius of the work roll, represents the entrance thickness, represents the exit thickness, represents the reduction; Thus, in formula (5), the external friction influence coefficient for each pass; the equivalent tension influence coefficient , is the unit front tension, is the unit back tension; the elastic flattening radius of the work roll for each pass; The expression of the rolling torque for each pass is: (4); In the formula, represents the pass number, represents the deformation resistance of the rolled piece at the entrance, represents the deformation resistance of the rolled piece at the exit, Denote the friction coefficient between the roll and the rolled piece; the friction influence coefficient of each pass 。

[0010] The motor power model during rolling is: (5); In the formula, Denote the motor efficiency; Denote the surface speed of the roll; Denote the rolling torque; Denote the roll radius; The variables for obtaining the motor power of each pass are ( Denote the pass number), that is: (6); In the formula, Denote the Motor efficiency of the pass.

[0011] The expression of the motor power margin model of a single stand is: (7); In the formula, Denote the rated efficiency of the main motor; Denote the Residual degree of the main motor power of the pass; Denote Average residual degree of the main motor power of the pass.

[0012] The optimization objective is The difference in the motor power margin of each pass is the smallest; Obtained from formula (7), the equal power margin objective function is: (8)。

[0013] The constraint conditions in S4 are: The rolling schedule conforms to the steel type, the incoming material, and the thickness, width, and speed limits of the finished product; The reduction ratio of each pass during rolling 、The rolling force And the motor power Are not greater than the maximum value allowed by the reversing mill; The reduction amount of each pass conforms to the shape condition of the strip and the allowable range of the bite angle of the rolled piece.

[0014] The formula for determining the maximum reduction amount by the bite angle of the rolled piece is: (9); In the formula, Denote the reduction amount of the pass, which is a fixed parameter of the main motor of the rolling mill; Denotes the maximum reduction per pass; Denotes the maximum bite angle; Maximum bite angle Is expressed by the friction coefficient between the roll and the rolled piece As: (10); Substituting Equation (11) into Equation (10), the condition that the reduction per pass should satisfy is obtained as: (11).

[0015] The specific steps of S5 are as follows: Substitute the reduction ratios of each pass into the equal-power margin objective function in S3, and judge whether each constraint condition is satisfied according to S4; the reduction ratio combinations include speed and reduction ratio ; If the constraint conditions in S4 are not satisfied, select other reduction ratio combinations within the feasible region and judge again until a reduction ratio combination that satisfies the constraint conditions is obtained; If the constraint conditions in S4 are satisfied, calculate according to the equal-power margin objective function to obtain the optimized final result. The specific steps are as follows: S5-1. Set the search step of the reduction ratio per pass ; S5-2. Calculate the equal-power margin objective function corresponding to each group of reduction ratios within the feasible range of the maximum reduction ratio, and obtain the results of the objective functions; S5-3. Compare all the results of the calculated objective functions and take the minimum value among them , The corresponding reduction ratios of each pass are the optimized final results.

[0016] The beneficial effects of the present invention are: The reversible rolling schedule optimization method based on the equal-power margin function of the present invention improves the balance of power distribution of each pass of the rolling mill, thereby improving the utilization rate of equipment, reducing the power fluctuation during the rolling process, and can be adjusted according to different steel grades and incoming material specifications, improving the production flexibility of the rolling mill. It not only improves production efficiency and product quality, but also achieves the implementation effect of energy conservation and emission reduction. Brief Description of the Drawings

[0017] Figure 1 Is the flowchart of the reversible rolling schedule optimization method based on the equal-power margin function of the present invention; Figure 2It is a schematic structural diagram of a single-stand reversible rolling mill used in the optimization method of the rolling schedule of a reversible rolling mill based on the equal power margin function of the present invention.

[0018] In the figure, 1. Upper coiling car, 2. Uncoiler, 3. Head straightener, 4. Coiler in front of the mill, 5. First uncoiling car, 6. Equipment in front of the mill, 7. Reversible cold rolling mill, 8. Equipment behind the mill, 9. Coiler behind the mill, 10. Second uncoiling car. Specific embodiments

[0019] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0020] As Figure 1 shown, the optimization method of the rolling schedule of a reversible rolling mill based on the equal power margin function adopted by the present invention is specifically implemented according to the following steps: S1. Collect relevant parameters of the equipment and the incoming material; The equipment is a single-stand reversible rolling mill, and the equipment parameters include roll radius , roll surface speed , motor parameters; the incoming material parameters include the type of incoming material, the characteristics of the incoming material, the incoming material thickness , incoming material width ; As Figure 2 shown in the schematic diagram of the rolling process of the reversible rolling mill, through the optimization method of the present invention, it is ensured that the power distribution in the rolling process of each pass is more balanced, and the utilization rate of the equipment and the rolling effect can be improved.

[0021] S2. Determine the rolling passes; the specific steps are as follows: S2-1. According to the equipment parameters, process parameters, and requirements of the characteristics of the incoming material of the single-stand reversible cold rolling mill unit, determine the maximum reduction rate. The maximum reduction rate of the single-stand cold rolling mill is controlled within 43%, and the minimum number of rolling passes is initially calculated: (1); Among them, represents the initial thickness; represents the target thickness; represents the maximum reduction rate; According to the initially calculated minimum number of passes , the rolling passes are obtained: (2).

[0022] S3. Establish an equal power margin objective function for the reversible cold rolling process; Establish the motor power model, rolling force and rolling torque model, power margin model, and power margin model for each pass in turn, and finally obtain the equal power margin objective function.

[0023] During the cold rolling process, the power distribution in each pass should be kept as uniform as possible to avoid overloading in some passes and insufficient power in other passes. Therefore, the optimization goal of the rolling schedule for a single-stand reversing mill is equal power margin in each pass.

[0024] S3-1. Obtain the rolling force in each pass during rolling through the Hill formula ; The rolling force in each pass is expressed as: (3); In the formula, represents the pass number, represents the external friction influence coefficient, represents the average deformation resistance, represents the equivalent tension influence coefficient, represents the width of the rolled piece, represents the elastic flattening radius of the work roll, represents the entrance thickness, represents the exit thickness, represents the reduction; Thus, in formula (5), the external friction influence coefficient ; the equivalent tension influence coefficient , is the unit front tension, is the unit back tension; the elastic flattening radius of the work roll ; The rolling torque is expressed as: (4); In the formula, represents the pass number, represents the deformation resistance of the rolled piece at the entrance, represents the deformation resistance of the rolled piece at the exit, represents the friction coefficient between the roll and the rolled piece; the friction influence coefficient ; S3-2. Establish the motor power model during rolling: (5); In the formula, represents the motor efficiency; represents the surface speed of the roll; represents the rolling torque; represents the roll radius; The variables of the motor power in each pass are ( Indicates the pass number), that is: (6); In the formula, express Pass roll surface speed, express Pass rolling torque; in, Indicates Pass motor efficiency; S3-3. Construct a motor power margin model based on the motor power model, and its expression is: (7); in, Indicates the rated efficiency of the main motor; Indicates The remaining power of the main motor per pass; express Average remaining power of main motor per pass; S3-4, setting the optimization target in the rolling schedule and constructing the equal power margin objective function; Set the optimization goal to The difference of motor power margin between passes is the smallest; According to formula (8), the equal power margin objective function is: (8); According to the process requirements, the thickness of the incoming material at the entrance and exit of the reversing mill is known, and the tension value of each pass is obtained by the tension set during the normal production of the production line. The intermediate thickness during the rolling process is unknown parameters, because Passes provided The power equation is missing a constraint and cannot be solved. It is necessary to find an optimal value within the possible solution range of each pass.

[0025] S4. Determine constraints; The optimization of rolling schedule needs to comprehensively consider the following aspects: The rolling procedure complies with the steel type, thickness, width of the incoming material and finished product, and the speed limit of the production line; different steel types have different deformation resistances and different calculated rolling forces; the thickness of the incoming material and finished product affects the rolling pass; the width affects the rolling force; the speed of the production line limits the rolling process parameters; Reduction rate of each pass during rolling , rolling force And motor power All of them are not greater than the maximum value allowed by the reversing mill; The reduction per pass conforms to the shape condition of the strip and the allowable range of the bite angle of the rolled piece, where: Adjust the range of reduction per pass according to the actual shape condition of the rolled piece; The maximum reduction per pass determined by the bite angle of the rolled piece is as follows: (9); In the formula, represents the reduction per pass and is a fixed parameter of the main motor of the rolling mill; represents the maximum reduction per pass; represents the maximum bite angle; Maximum bite angle is expressed by the friction coefficient between the roll and the rolled piece as: (10); Substitute Equation (11) into Equation (10), and the condition that the reduction per pass should satisfy is: (11).

[0026] S5. Under the condition of satisfying the S4 constraint conditions, obtain the optimal reduction ratio per pass; Substitute the reduction ratio combination set in the rolling process specification into the equal power margin objective function in S3, and judge whether each constraint condition is satisfied according to the constraint conditions in S4; the reduction ratio combination includes the speed and reduction ratio ; If the reduction ratio combination does not satisfy the constraint conditions in S4, select other reduction ratio combinations within the feasible region and judge again; If the reduction ratio combination satisfies the constraint conditions in S4, perform the following steps: S5-1. Set the search step size of the reduction ratio per pass ; The smaller the step size, the higher the accuracy and the longer the calculation period; S5-2. Within the feasible interval of the maximum reduction ratio, calculate the equal power margin objective function corresponding to each set of reduction ratios; Judge whether the reduction ratio combinations corresponding to the search points within the feasible region have all been calculated. If not all have been calculated, search for other reduction ratio combinations within the feasible region and calculate again; If all have been calculated, obtain the number of objective functions , and proceed to the next step; S5-3. Compare the results of all the calculated objective functions and take the minimum value among them. The reduction ratio per pass corresponding to it is the final optimized result; S6. Based on the optimized pass reduction rate distribution results obtained in S5, set the cold rolling process schedule of the single-stand reversible rolling mill.

[0027] Example 1 Equipment parameters: The diameter of the work roll of the rolling mill is 330 mm, and the maximum rolling speed is 1300 m / min. Incoming material parameters: Q195 type strip steel, with a specification of 2.95 mm × 1000 mm (thickness × width); Target parameters: A thin-gauge steel plate with a thickness of 0.145 mm.

[0028] The reversible rolling mill rolling process optimization method based on the equal power margin function in this example is as follows: S1. Collect relevant parameters of the equipment and incoming materials; Diameter of the work roll of the rolling mill = 330 mm, maximum rolling speed = 1300 m / min, maximum rolling pressure = 12000 kN, maximum rolling power = 5400 kW, strip width = 1000 mm, strip thickness = 2.95 mm, target thickness = 0.145 mm; S2. Determine the rolling passes; Maximum reduction rate = 43%, calculate the minimum number of rolling passes = 6, because ≤ 6, finally obtain the number of rolling passes = 6; S3. Establish an equal power margin objective function in the reversible cold rolling process; S4. Determine the constraint conditions; S5. Obtain the optimal pass reduction rate under the condition of satisfying the S4 constraint conditions; The initial speed of each pass is ={202, 465, 707, 727, 750, 704} m / min; The initial pass reduction rate before optimization The data is shown in Table 1 below; Calculate the rolling pressure of each pass before optimization corresponding to the initial parameters and the motor power of each pass The specific data is shown in Table 1 below; Set the search step of the pass reduction rate = 0.01, calculate the corresponding objective function of the equal power margin to obtain the optimal pass reduction rate; Complete the calculation of all reduction ratio combinations to obtain the number of objective functions in the archive record , compare the objective functions corresponding to each reduction ratio combination in the archive results , obtain , and the reduction ratios of each pass corresponding to it are the final optimized results; S6. Output the optimized results obtained from the above calculations; After optimization, the number of rolling passes is obtained = 6; the reduction ratio of each pass , the rolling pressure of each pass , the motor power of each pass The specific data is shown in Table 1 below.

[0029] Table 1

[0030] Table 1 shows the comparison of data before and after optimization in this embodiment. It can be seen from the above table that after optimization, the rolling power distribution of each pass is more uniform, which can effectively improve the utilization rate of equipment and reduce the power fluctuation during rolling.

[0031] Example 2 Equipment parameters: The diameter of the work roll of the rolling mill is 330 mm, and the maximum rolling speed is 1300 m / min; Incoming material parameters: The type of strip steel is Q195, and the specification is 2.95 mm × 1000 mm (thickness × width); Target parameter: A thin-gauge steel plate with a thickness of 0.108 mm.

[0032] The method for optimizing the rolling schedule of a reversible rolling mill based on the equal power margin function in this embodiment is as follows: S1. Collect relevant parameters of the equipment and incoming materials; The diameter of the work roll of the rolling mill = 330 mm, the maximum rolling speed = 1300 m / min, the maximum rolling pressure = 12000 kN, the maximum rolling power = 5400 kW, the strip width = 1000 mm, the strip thickness = 2.95 mm, the target thickness = 0.108 mm; S2. Determine the number of rolling passes; The maximum reduction ratio = 43%, calculate the minimum number of rolling passes = 6, because ≤ 6, finally obtain the number of rolling passes = 6; S3. Establish the equal - power margin objective function in the reversible cold rolling process; S4. Determine the constraint conditions; S5. Obtain the optimal reduction ratio per pass under the condition of satisfying the S4 constraint conditions; The initial speed of each pass is ={302, 726, 913, 820, 903, 830} m / min; The initial reduction ratio per pass before optimization The specific data is shown in Table 2 below; Calculate the rolling pressure per pass and the motor power per pass before optimization corresponding to the initial parameters and the motor power of each pass , The specific data is shown in Table 2 below; Set the search step of the reduction ratio per pass = 0.01, calculate the objective function of the corresponding equal - power margin , Obtain the optimal reduction ratio per pass; Complete the calculation of all reduction ratio combinations, and obtain the number of objective functions recorded in the archive , Compare the objective functions corresponding to each reduction ratio combination in the archive results , Obtain , The reduction ratio per pass corresponding to it is the final optimized result; S6. Output the optimized results obtained from the above calculations; After optimization, the number of rolling passes obtained is = 6; The reduction ratio per pass , The rolling pressure per pass , The motor power of each pass The specific data is shown in Table 2 below.

[0033] Table 2

[0034] Table 2 shows the comparison of data before and after optimization in this embodiment. It can be seen from the above table that after optimization, the rolling power distribution of each pass is more uniform, which can effectively improve the utilization rate of equipment and reduce the power fluctuation during rolling.

[0035] Example 3 Equipment parameters: The diameter of the working roll of the rolling mill is 330 mm, and the maximum rolling speed is 1300 m / min; Incoming material parameters: Q195 type strip steel, with a specification of 2.95 mm × 1000 mm (thickness × width); Target parameter: Thin - gauge steel plate with a thickness of 0.145 mm.

[0036] The rolling schedule optimization method for a reversible rolling mill based on an equal power margin function in this embodiment is as follows: S1. Collect relevant parameters of the equipment and incoming materials; Working roll diameter of the rolling mill = 330 mm, maximum rolling speed = 1300 m / min, maximum rolling pressure = 12000 kN, maximum rolling power = 5400 kW, strip width = 1000 mm, strip thickness = 2.95 mm, target thickness = 0.145 mm; S2. Determine the number of rolling passes; Maximum reduction ratio = 43%, calculate the minimum number of rolling passes = 6, because ≤ 6, finally obtain the number of rolling passes = 6; S3. Establish an equal power margin objective function in the reversible cold rolling process; S4. Determine the constraint conditions; S5. Obtain the optimal reduction ratio per pass under the condition of satisfying the S4 constraint conditions; The initial speed of each pass is = {390, 791, 954, 1005, 1058, 1086} m / min; The initial reduction ratio per pass before optimization The data is shown in Table 3 below; Calculate the rolling pressure of each pass before optimization corresponding to the initial parameters and the motor power of each pass , the specific data is shown in Table 3 below; Set the search step of the reduction ratio per pass = 0.01, calculate the corresponding objective function of the equal power margin , obtain the optimal reduction ratio per pass; Complete the calculation of all reduction ratio combinations, and obtain the number of objective functions in the archive record , compare the objective functions corresponding to each reduction ratio combination in the archive results , obtain , and the reduction ratio of each pass corresponding to it is the final optimized result; S6. Output the optimized results obtained from the above calculations; After optimization, obtain the number of rolling passes = 6; The reduction ratio of each pass , the rolling pressure of each pass , the motor power of each pass The specific data is shown in Table 3 below.

[0037] Table 3

[0038] In Table 3, the data before and after optimization in this embodiment is compared. It can be seen from the above table that after optimization, the rolling power distribution in each pass is more uniform, which can effectively improve the utilization rate of equipment and reduce the power fluctuation during rolling.

[0039] Example 4 Equipment parameters: The diameter of the working roll of the rolling mill is 330 mm, and the maximum rolling speed is 1300 m / min; Incoming material parameters: Q195 type strip steel, with a specification of 2.95 mm × 1000 mm (thickness × width); Target parameter: A thin-gauge steel plate with a thickness of 0.105 mm.

[0040] The rolling schedule optimization method for a reversible rolling mill based on the equal power margin function in this embodiment is as follows: S1. Collect relevant parameters of the equipment and incoming materials; Diameter of the working roll of the rolling mill = 330 mm, maximum rolling speed = 1300 m / min, maximum rolling pressure = 12000 kN, maximum rolling power = 5400 kW, strip width = 1000 mm, strip thickness = 2.95 mm, target thickness = 0.105 mm; S2. Determine the number of rolling passes; Maximum reduction ratio = 43%, and the minimum number of rolling passes is calculated as = 6, because ≤ 6, and finally the number of rolling passes = 6; S3. Establish an equal power margin objective function in the reversible cold rolling process; S4. Determine the constraint conditions; S5. Obtain the optimal reduction ratio for each pass under the condition of satisfying the S4 constraint conditions; The initial speed of each pass is = {500, 741, 863, 806, 908, 809} m / min; The initial reduction ratio of each pass before optimization The data is shown in Table 4 below; Calculate the rolling pressure of each pass before optimization corresponding to the initial parameters and the motor power of each pass , and the specific data are shown in Table 4 below; Set the search step of the reduction ratio of each pass = 0.01, calculate the objective function of the corresponding equal power margin , and obtain the optimal reduction ratio of each pass; Complete the calculation of all reduction ratio combinations, and obtain the number of objective functions in the archived records , compare the objective functions corresponding to each reduction ratio combination in the archived results , and obtain , and the reduction ratio of each pass corresponding to it is the final optimized result; S6. Output the optimized result obtained from the above calculation; After optimization, the number of rolling passes is obtained = 6; the reduction ratio of each pass , the rolling pressure of each pass , and the motor power of each pass The specific data are shown in Table 4 below.

[0041] Table 4

[0042] Table 4 shows the comparison of data before and after optimization in this embodiment. It can be seen from the above table that after optimization, the rolling power distribution of each pass is more uniform, which can effectively improve the utilization rate of equipment and reduce the power fluctuation during rolling.

[0043] Example 5 Equipment parameters: The diameter of the work roll of the rolling mill is 290 mm, and the maximum rolling speed is 1300 m / min; Incoming material parameters: Q195 type strip steel, with a specification of 3 mm × 1000 mm (thickness × width); Target parameter: A thin-gauge steel plate with a thickness of 0.21 mm.

[0044] The reversible rolling mill rolling schedule optimization method based on the equal power margin function in this embodiment is specifically as follows: S1. Collect relevant parameters of the equipment and incoming materials; The diameter of the work roll of the rolling mill = 290 mm, the maximum rolling speed = 1300 m / min, the maximum rolling pressure = 12000 kN, the maximum rolling power = 5400 kW, the strip width = 1000 mm, the strip thickness = 3 mm, the target thickness = 0.21 mm; S2. Determine the rolling passes; The maximum reduction ratio = 43%, calculate the minimum number of rolling passes = 5, because ≤ 6, finally obtain the number of rolling passes = 5; S3. Establish the equal - power margin objective function in the reversible cold rolling process; S4. Determine the constraint conditions; S5. Obtain the optimal reduction ratio per pass under the condition of satisfying the S4 constraint conditions; The initial speed of each pass is = {390, 850, 1000, 1250, 1000} m / min; The initial reduction ratio of each pass before optimization The data is shown in Table 5 below; Calculate the rolling pressure of each pass before optimization corresponding to the initial parameters and the motor power of each pass , the specific data is shown in Table 5 below; Set the search step of the reduction ratio per pass = 0.01, calculate the corresponding objective function of the equal - power margin , obtain the optimal reduction ratio per pass; Complete the calculation of all reduction - ratio combinations, obtain the number of objective functions in the archived records , compare the objective functions corresponding to each reduction - ratio combination in the archived results , obtain , and the reduction ratio of each pass corresponding to it is the final optimized result; S6. Output the optimized results obtained from the above calculations; After optimization, obtain the number of rolling passes = 5; The reduction ratio of each pass , the rolling pressure of each pass , the motor power of each pass The specific data is shown in Table 5 below.

[0045] Table 5

[0046] Table 5 shows the comparison of data before and after optimization in this embodiment. It can be seen from the above table that after optimization, the rolling power distribution of each pass is more uniform, which can effectively improve the utilization rate of equipment and reduce the power fluctuation during rolling.

[0047] Example 6 Equipment parameters: The diameter of the work roll of the rolling mill is 330 mm, and the maximum rolling speed is 1300 m / min; Incoming material parameters: Q195 type strip steel, with a specification of 3mm 1000mm (thickness × width); Target parameters: thin gauge steel plate with a thickness of 0.15mm.

[0048] The rolling schedule optimization method of the reversible rolling mill based on the equal power margin function in this embodiment is as follows: S1. Collect relevant parameters of the equipment and incoming material; Working roll diameter of the rolling mill = 290mm, maximum rolling speed = 1300m / min, maximum rolling pressure = 12000kN, maximum rolling power = 5400kW, strip width = 1000mm, strip thickness = 3mm, target thickness = 0.15mm; S2. Determine the number of rolling passes; Maximum reduction ratio = 43%, calculate the minimum number of rolling passes = 4, because ≤ 6, finally obtain the number of rolling passes = 4; S3. Establish the equal power margin objective function in the reversible cold rolling process; S4. Determine the constraint conditions; S5. Obtain the optimal pass reduction ratio under the condition of meeting the S4 constraint conditions; The initial speed of each pass is ={420, 850, 1000, 1000}m / min; The initial pass reduction ratio before optimization The data is shown in Table 6 below; Calculate the rolling pressure of each pass before optimization corresponding to the initial parameters and the motor power of each pass , the specific data is shown in Table 6 below; Set the search step of the pass reduction ratio = 0.01, calculate the corresponding objective function of the equal power margin , obtain the optimal pass reduction ratio; Complete the calculation of all reduction ratio combinations, obtain the number of objective functions in the archive record , compare the objective functions corresponding to each reduction ratio combination in the archive results , obtain , the reduction ratio of each pass corresponding to it is the final optimized result; S6. Output the optimized results calculated above; After optimization, the number of rolling passes is obtained = 4; the reduction ratio of each pass , the rolling pressure of each pass , the motor power of each pass The specific data are shown in Table 6 below.

[0049] Table 6

[0050] Table 6 shows the comparison of the data before and after optimization in this embodiment. It can be seen from the above table that after optimization, the rolling power distribution of each pass is more uniform, which can effectively improve the utilization rate of the equipment and reduce the power fluctuation during rolling.

Claims

1. A rolling schedule optimization method for a reversible rolling mill based on an equal power margin function, characterized in that The implementation is carried out according to the following steps: S1. Collect relevant parameters of the equipment and incoming materials; the equipment is a single-stand reversing cold rolling mill; S2. Determine the rolling passes; S3. Establish an equal power margin objective function in the process of reversible cold rolling; S4. Determine the constraint conditions; S5. Obtain the optimal reduction ratio per pass under the condition of satisfying the constraints in S4; S6. Complete the setting of the cold rolling schedule for the single-stand reversing cold rolling mill according to the optimal reduction ratio allocation results per pass obtained in S5.

2. The reversible rolling mill rolling schedule optimization method based on the equal power margin function according to claim 1, characterized in that The specific steps of S2 are as follows: S2-1. Determine the maximum reduction rate based on on-site equipment and process parameters ; S2-2. Calculate the minimum number of rolling passes; （1）； In the formula, represents the initial thickness; represents the target thickness; S2-3. Obtain the rolling passes according to the minimum number of passes , and obtain the rolling passes : （2）。 3. The reversible rolling mill rolling schedule optimization method based on the equal power margin function according to claim 1, characterized in that The specific steps of S3 are as follows: S3-1. Obtain the rolling force and rolling torque in each pass according to the Hill formula and ; S3-2. Establish a motor power model to obtain the motor power per pass; S3-3. Construct a motor power margin model according to the motor power model; S3-4. Set the optimization objective in the rolling schedule and construct an equal power margin objective function.

4. The method for optimizing the rolling schedule of a reversible rolling mill based on an equal power margin function according to claim 3, wherein The rolling force of each pass has the following expression: （3）； In the formula, represents the pass number, represents the influence coefficient of external friction, represents the average deformation resistance, represents the influence coefficient of equivalent tension, represents the width of the rolled piece, represents the elastic flattening radius of the work roll, represents the entry thickness, represents the exit thickness, represents the reduction; In this way, in formula (5), the external friction influence coefficient for each pass ; the equivalent tension influence coefficient for each pass , is the unit front tension, is the unit back tension; Radius of elastic flattening of work roll for each pass ; Rolling torque for each pass The expression is: （4）； In the formula, represents the pass number, represents the deformation resistance of the rolled piece at the entrance, represents the deformation resistance of the rolled piece at the exit, represents the friction coefficient between the roll and the rolled piece; the friction influence coefficient of each pass 。 5. The optimized rolling schedule method for a reversible rolling mill based on an equal power margin function according to claim 3, wherein The motor power model during rolling is: （5）； In the formula, represents the motor efficiency; represents the surface speed of the roll; represents the rolling torque; represents the roll radius; The variables of the motor power for each pass are , namely: （6）； In the formula, represents the pass number, represents the motor efficiency of the pass.

6. The reversible rolling mill rolling schedule optimization method based on the equal power margin function according to claim 3, characterized in that The expression of the motor power margin model is: （7）； In the formula, represents the rated efficiency of the main motor; represents the remaining degree of the main motor power at the th pass; represents the average remaining degree of the main motor power at the pass.

7. The method for optimizing the rolling schedule of a reversible rolling mill based on an equal power margin function according to claim 3, characterized in that The optimization objective is to minimize the difference in the power margin of the pass motor; Obtained from formula (7), the equal power margin objective function is: （8）。 8. The method for optimizing the rolling schedule of a reversible rolling mill based on an equal power margin function according to claim 1, characterized in that The constraint conditions of S4 are: The rolling schedule conforms to the steel type, incoming materials, and the thickness, width, and speed limits of the production line of the finished product; Reduction ratio of each pass during rolling , rolling force and motor power shall not be greater than the maximum value allowed by the reversing mill; The reduction amount per pass conforms to the shape condition of the strip and the allowable range of the bite angle of the rolled piece.

9. The method for optimizing the rolling schedule of a reversible rolling mill based on an equal power margin function according to claim 8, characterized in that, The formula for determining the reduction amount range by the bite angle of the rolled piece is: （9）； In the formula, represents the reduction per pass, which is a fixed parameter of the main motor of the rolling mill; represents the maximum reduction per pass; represents the maximum biting angle; Maximum biting angle Using the friction coefficient between the roll and the rolled piece Expressed as: （10）； Substitute formula (11) into formula (10) to obtain the conditions that the reduction amount per pass should satisfy: （11）。 10. The reversible rolling mill rolling schedule optimization method based on the equal power margin function according to claim 1, characterized in that, The specific steps of S5 are as follows: Substitute the reduction rate combination into the equal power margin objective function in S3, and determine whether each constraint condition is satisfied according to S4; the reduction rate combination includes the speed and reduction rate of each pass and reduction rate ; If the reduction ratio combination does not satisfy the constraints in S4, select other reduction ratio combinations within the feasible region and judge again until a reduction ratio combination that satisfies the constraints is obtained; If the reduction ratio combination satisfies the constraints in S4, calculate according to the equal power margin objective function to obtain the optimized final result. The specific steps are as follows: S5-1. Set the search step of the reduction rate per pass ; S5-2. Within the feasible range of the maximum reduction rate, calculate the equal power margin objective function corresponding to each group of reduction rates to obtain the results of the objective functions; S5-3. Compare the results of all the objective functions calculated and take the minimum value among them ; The reduction ratio of each pass corresponding to it is the final optimized result.

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