A method for obtaining the reduction rate of a continuous rolling mill unit that can improve the hourly output

Abstract

A method for obtaining the reduction ratio of a continuous rolling mill unit that can improve the hourly output, comprising: inputting process parameters and continuous rolling mill equipment parameters; establishing an optimization target and constraint conditions for the maximum hourly output; preliminarily setting the reduction ratio of each stand using an optimization algorithm; calculating the inlet thickness and outlet thickness of the rolled piece for each stand; calculating the rolling force and energy parameters of each stand, wherein the rolling force and energy parameters of each stand include the rolling pressure, transmission torque, forward slip value, roll speed, and main motor power of each stand; and determining whether the optimization target and constraint conditions for the maximum hourly output are simultaneously satisfied. The present invention can be used for online preset calculation of the reduction ratio distribution of a continuous rolling mill unit, avoiding the errors caused by the traditional method of setting using a manual experience table, and the calculated reduction ratio distribution can make the hourly output of the continuous rolling mill unit reach the highest, thereby improving the production efficiency and production benefits of the unit.

Description

Technical Field

[0001] This embodiment relates to the field of rolling, and particularly to a method for obtaining the reduction ratio of a continuous rolling mill unit that can improve the hourly output. Background Art

[0002] In the production process of strip continuous rolling, the distribution of the reduction ratio of each stand of the continuous rolling mill is one of the most important continuous rolling process parameters, which directly determines the stability and smoothness of the production process, and is also a basic parameter for the thickness control and shape control of the rolled piece. The existing technology often uses the method of setting by manual experience table to distribute the reduction ratio of each stand of the continuous rolling mill. The establishment of this experience table requires a large amount of production practice data and operation experience in the early stage. When the product specifications are changed, it takes a long time to re-establish the new table data, and it cannot perform real-time online preset calculation on the reduction ratio distribution according to the new product specifications. In addition, there is no evaluation standard for the table data for comparison. For example, it is impossible to evaluate whether the production efficiency is optimal, resulting in a reduction in the hourly output of the unit due to the given continuous rolling reduction ratio distribution. Therefore, it is necessary to further develop a method for obtaining the reduction ratio of a continuous rolling mill unit that can improve the hourly output.

[0003] Content of the embodiment

[0004] In view of the above problems, this embodiment is proposed to provide a method for obtaining the reduction ratio of a continuous rolling mill unit that can overcome the above problems or at least partially solve the above problems and improve the hourly output.

[0005] To solve the above technical problems, the embodiments of the present application disclose the following technical solutions:

[0006] A method for obtaining the reduction ratio of a continuous rolling mill unit that can improve the hourly output, including:

[0007] S100. Input process parameters and continuous rolling mill equipment parameters;

[0008] S200. Establish the optimization objective and constraint conditions for the maximum hourly output;

[0009] S300. Initially set the reduction ratios η1, η2... η of the first stand to the (Q - 1)th stand using an optimization algorithm Q-1 ;

[0010] S400. Calculate the entrance thickness and exit thickness of the rolled piece for each stand;

[0011] S500. Calculate the rolling force and energy parameters for each stand, where the rolling force and energy parameters for each stand include the rolling pressure, transmission torque, forward slip value, roll speed, and main motor power of each stand;

[0012] S600. Determine whether the maximum hourly output optimization goal and the constraints are satisfied simultaneously: If not, adjust the reduction ratio values of each stand by the optimization algorithm, and then transfer to S400 for recalculation. If satisfied, the calculation ends.

[0013] Further, in S100, the process parameters include the incoming material thickness H (unit: mm), the finished product thickness h (unit: mm), the width B s (unit: mm) of the rolled piece, the number of stands Q, and the deformation resistance data of the rolled piece. The continuous rolling mill equipment parameters include the working roll body diameter D wk (unit: mm) of each stand, the working roll neck diameter D′ wk (unit: mm), the working roll body width B wk (unit: mm), the backup roll body diameter D bk (unit: mm), the backup roll neck diameter D′ bk (unit: mm), and the backup roll body width B bk (unit: mm), where the subscript k represents the stand number, and 1 ≤ k ≤ Q.

[0014] Further, in S200, the objective function of the maximum hourly output optimization goal is: In the formula, ρ is the density of the rolled piece, unit: kg / m 3 ; h 1Q - The rolled piece outlet thickness of the Qth stand (the last stand), unit: mm; v sQ is the rolled piece outlet speed of the Qth stand, unit: m / min, v sQ = v Q (1 + f Q ), v Q is the roll speed of the Qth stand, unit: m / min, f Q is the forward slip value of the Qth stand.

[0015] Further, in S400, calculate the rolled piece inlet thickness h 0k and the rolled piece outlet thickness h 1k specifically as follows: When k = 1, h 0k = H, h 1k = (1 - η k )H; When 2 ≤ k ≤ Q - 1, h 0k = h 1(k-1) , h 1k = (1 - η k )h 0k ; When k = Q, h 0k = h 1(k-1) , h 1k = h; The subscript k represents the stand number, 1 ≤ k ≤ Q, and η k is the reduction ratio of the kth stand.

[0016] Furthermore, in S500, calculate the rolling force energy parameters of each stand. The specific steps are as follows:

[0017] S501. Through iterative calculation of the stress differential equation and roll gap thickness equation in the roll gap deformation zone, calculate the unit pressure distribution, friction stress distribution, and roll gap thickness distribution in the roll gap deformation zone;

[0018] S502. Calculate the rolling pressure P k (unit: KN), transmission torque M k (unit: KN×m), and forward slip value f k ;

[0019] S503. Calculate the roll speed v k (unit: m / min) and main motor power N k (unit: KW).

[0020] Furthermore, the specific steps of S501 are as follows:

[0021] S5011. Set the initial roll profile curve and determine the entrance position of the rolled piece;

[0022] S5012. Calculate the unit pressure and friction stress of each section in the back slip zone from the entrance to the exit

[0023] S5013. Calculate the unit pressure and friction stress of each section in the forward slip zone from the exit to the entrance;

[0024] S5014. Determine the unit pressure and friction stress of each section in the roll gap deformation zone;

[0025] S5015. Calculate the roll gap thickness distribution from the unit pressure distribution;

[0026] S5016. Determine whether the roll gap thickness distributions obtained from the previous and current calculations converge: If they converge, end the calculation; if not, go to step S5012 for the next round of iterative calculation until the roll gap thickness distribution converges.

[0027] Furthermore, in S502, calculate the rolling pressure P k (unit: KN), transmission torque M k (unit: KN×m), and forward slip value f k , and the specific calculation formulas are as follows:

[0028]

[0029]

[0030]

[0031] In the formula, n kis the number of discrete segments of the roll gap of the k-th stand, ΔX k is the length of the discrete segment of the roll gap of the k-th stand, in mm, p k (i) is the unit pressure of the i-th segment of the roll gap of the k-th stand, in MPa, t k (i) is the friction stress of the i-th segment of the roll gap of the k-th stand, in MPa, Δh k (i) is the thickness difference between the (i + 1)-th segment and the i-th segment of the roll gap of the k-th stand, in mm, Δh k (i) = h k (i + 1) - h k (i), x k (i) is the abscissa of the i-th segment of the roll gap of the k-th stand, in mm, m wb is the rolling friction force arm between the work roll and the backup roll, in mm, Among them, E wk is the elastic modulus of the work roll, in MPa, E bk is the elastic modulus of the backup roll, in MPa, L wb is the contact length between the work roll and the backup roll, in mm, when B wk ≤B bk then, L wb = B wk when B wk >B bk then, L wb = B bk ; ρ bk is the friction circle radius of the backup roll bearing, in mm, Among them, μ′ k is the rolling friction coefficient of the backup roll bearing; h k (r) is the roll gap thickness of the corresponding segment of the neutral plane of the roll gap of the k-th stand (the r-th segment of the roll gap of the k-th stand), in mm, Δh k (r) = h k (r + 1) - h k (r).

[0032] Furthermore, in S503, calculate the roll speed v k (unit: m / min) and the main motor power N k (unit: KW), the specific steps are as follows:

[0033] S5031. Calculate the second flow rate value V k_max with the maximum roll speed v k set for each stand, and the calculation formula is: V k = h 1k v k_max (1 + f k );

[0034] S5032. Find the minimum value V of the second flow rate values V1 to V of each stand Q and calculate the roll speed v' of each stand according to the second flow rate theorem from V min . The calculation formula is: min k

[0035] S5033. Calculate the main motor power N' of each stand k and the ratio φ of the main motor power N' k to the rated power N of the main motor of this stand k_max . The calculation formula is: k where M k is the driving torque and D wk is the body diameter of the working roll;

[0036] S5034. Find the maximum value φ of φ1 to φ Q ; max

[0037] S5035. Judge whether φ max is greater than 1: If φ max > 1, then limit the roll speed of each stand by φ max . The limited roll speed is the calculated roll speed of each stand, that is When φ max ≤1, then v k = v' k ;

[0038] S5036. Calculate the main motor power N of each stand k . The calculation formula is:

[0039] Furthermore, in S300, the reduction ratio of each stand is initially set by the optimization algorithm and the reduction ratio of each stand is adjusted by the optimization algorithm. The optimization algorithm uses a genetic algorithm or a particle swarm algorithm.

[0040] Furthermore, in S600, judge whether the maximum hourly output optimization goal and the constraint conditions are simultaneously satisfied. The constraint conditions are specifically that all stands simultaneously satisfy the following inequalities:

[0041] η k_min ≤η k ≤η k_max , v k ≤v k_max , P k ≤P k_max , M k ≤M k_max , N k ≤N k_max ​​​​, where the subscript k represents the stand number, 1 ≤ k ≤ Q; η k_max is the maximum reduction ratio of the k-th stand, η k_min is the minimum reduction ratio of the k-th stand, v k_max is the maximum roll speed of the k-th stand, P k_max is the maximum rolling pressure of the k-th stand, M k_max is the maximum transmission torque of the k-th stand, N k_max is the rated power of the main motor of the k-th stand.

[0042] The beneficial effects of the above technical solutions provided by this embodiment at least include:

[0043] A method for obtaining the reduction ratio of a continuous rolling mill unit that can improve the hourly output disclosed in the present invention establishes a reduction ratio distribution model of the continuous rolling mill unit with the maximum hourly output as the optimization goal through theoretical analysis. In the calculation process, an optimization algorithm is used to continuously obtain a better reduction ratio distribution, and according to the given process parameters and equipment parameters, the rolling force and energy parameters of each stand under the corresponding reduction ratio distribution are repeatedly calculated, including rolling pressure, transmission torque, forward slip value, roll speed, and main motor power. Finally, the optimal reduction ratio distribution that meets the optimization goal and constraint conditions is obtained.

[0044] The principle of the method disclosed in the present invention is clear and definite, the iterative calculation is stable and rapid, it can be used for the online preset calculation of the reduction ratio distribution of the continuous rolling mill unit, avoiding the errors brought by the traditional manual experience table setting method, and the calculated reduction ratio distribution can make the hourly output of the continuous rolling mill unit reach the highest, thereby improving the production efficiency and production benefits of the unit.

[0045] The following further describes the technical solutions of this embodiment in detail through the drawings and embodiments. Description of the Drawings

[0046] The drawings are used to provide a further understanding of this embodiment, and constitute a part of the specification. Together with this embodiment, they are used to explain the present invention and do not constitute a limitation to this embodiment. In the drawings:

[0047] Figure 1 is the calculation flow chart of a method for obtaining the reduction ratio of a continuous rolling mill unit that can improve the hourly output in Embodiment 1;

[0048] Figure 2 is the calculation flow chart of the rolling force and energy parameters of the k-th stand in Embodiment 1;

[0049] Figure 3 is the calculation flow chart of the repeated iteration of the stress differential equation and the roll gap thickness equation in the roll gap deformation zone in Embodiment 1;

[0050] Figure 4For Embodiment 1, it is the calculation flowchart of the roll speed and the main motor power;

[0051] Figure 5 For Embodiment 2, it is the curve of the fitness value changing with the number of evolutionary generations during the iterative calculation using the genetic algorithm;

[0052] Figure 6 For Embodiment 2, it is the curve of the fitness value changing with the number of evolutionary generations during the iterative calculation using the particle swarm algorithm. Detailed implementation manners

[0053] Hereinafter, the exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0054] To solve the problems existing in the prior art, this embodiment provides a method for obtaining the reduction ratio of a continuous rolling mill unit that can increase the hourly output.

[0055] Embodiment 1

[0056] A method for obtaining the reduction ratio of a continuous rolling mill unit that can increase the hourly output, as Figure 1 , includes:

[0057] S100. Input process parameters and continuous rolling mill equipment parameters; specifically, in S100 of this embodiment, the process parameters include the incoming material thickness H (unit: mm), the finished product thickness h (unit: mm), the width B s (unit: mm) of the rolled piece, the number Q of stands, and the rolled piece deformation resistance data. The continuous rolling mill equipment parameters include the working roll body diameter D wk (unit: mm) of each stand, the working roll neck diameter D' wk (unit: mm), the working roll body width B wk (unit: mm), the backup roll body diameter D bk (unit: mm), the backup roll neck diameter D' bk (unit: mm), and the backup roll body width B bk (unit: mm), where the subscript k represents the stand number, and 1 ≤ k ≤ Q.

[0058] S200. Establish the maximum hourly output optimization objective and constraint conditions; in S200 of this embodiment, the objective function of the maximum hourly output optimization objective is: In the formula, ρ is the density of the rolled piece, with the unit kg / m 3 ; h 1Q- The exit thickness of the rolled piece at the Qth stand (the last stand), unit: mm; v sQ is the exit speed of the rolled piece at the Qth stand, unit: m / min, v sQ = v Q (1 + f Q ), v Q is the roll speed of the Qth stand, unit: m / min, f Q is the forward slip value of the Qth stand.

[0059] The constraint conditions include the maximum reduction ratio η k_max of each stand, the minimum reduction ratio η k_min , the maximum roll speed v k_max (unit: m / min), the maximum rolling pressure P k_max (unit: KN), the maximum transmission torque M k_max (unit: KN×m), and the rated power N k_max (unit: KW) of the main motor.

[0060] S300. Use an optimization algorithm to preliminarily set the reduction ratios η1, η2…η Q-1 from the 1st stand to the (Q - 1)th stand; in this embodiment S300, the reduction ratios of each stand are preliminarily set by the optimization algorithm and adjusted by the optimization algorithm. Preferably, a genetic algorithm or a particle swarm algorithm is used; the principles of the genetic algorithm and the particle swarm algorithm belong to the publicly known knowledge in the industry and will not be elaborated here.

[0061] S400. Calculate the entry thickness and exit thickness of the rolled piece for each stand; specifically, in S400, calculate the entry thickness h 0k and exit thickness h 1k of the rolled piece for each stand, specifically: when k = 1, h 0k = H, h 1k = (1 - η k )H; when 2 ≤ k ≤ Q - 1, h 0k = h 1(k-1) , h 1k = (1 - η k )h 0k ; when k = Q, h 0k = h 1(k-1) , h 1k = h; the subscript k represents the stand number, 1 ≤ k ≤ Q, and η k is the reduction ratio of the kth stand.

[0062] S500. Calculate the rolling force and energy parameters of each stand, where the rolling force and energy parameters of each stand include the rolling pressure, transmission torque, forward slip value, roll speed, and main motor power of each stand;

[0063] Specifically, taking the calculation of the k-th stand as an example, as Figure 2 shown, the specific steps are as follows:

[0064] S501. Repeatedly iterate using the stress differential equation and roll gap thickness equation in the roll gap deformation zone to calculate the unit pressure distribution, frictional stress distribution, and roll gap thickness distribution in the roll gap deformation zone;

[0065] S502. Calculate the rolling pressure P k (unit: KN), transmission torque M k (unit: KN×m), and forward slip value f k ;

[0066] S503. Calculate the roll speed v k (unit: m / min) and main motor power N k (unit: KW).

[0067] Among them, as Figure 3 shown, S501 is specifically as follows:

[0068] S5011. Set the initial roll profile curve and determine the entrance position of the rolled piece;

[0069] Assume that the roll is undeformed and is circular arc-shaped. At this time, the roll flattening amount distribution is δ(x) = 0; Discretize the deformation zone: Divide the deformation zone into n segments along the rolling direction. The roll gap thickness model equation under the circular arc-shaped roll profile is where x k (i) is the abscissa of the i-th segment, h k (i) is the thickness of the rolled piece in the i-th segment, x k (n) = 0, h k (n) = h 1k , h k (1) = h 0k , so Discrete segment length xk(i) = xk(1) + (i - 1)ΔX, Δh k (i) = h k (i + 1) - h k (i).

[0070] S5012. Calculate the unit pressure and frictional stress of each segment in the back slip zone from the entrance to the exit; Specifically:

[0071] Use the back slip zone formula to calculate from the entrance to the exit and judge the partition situation between sliding friction and sticking friction:

[0072] Calculate the unit pressure p k (1) b _sli of the entrance segment (the 1st segment) under sliding friction conditions as:

[0073]

[0074] Wherein, K k (1) is the deformation resistance of the rolled piece in the first section of the roll gap, with the unit of MPa, and μ k is the roll gap friction coefficient of the k-th stand;

[0075] Then use the Aitken iterative method to solve for p k (1) b _sli;

[0076] Judge μ at the entrance section k p k (1) b _sli and sizes, which are divided into two cases:

[0077] (i) If Then it indicates that the entrance section is under sliding friction, and the unit pressure p k (1) b = p k (1) b _sli. Use the stress differential equation in the back slip zone under sliding friction conditions to calculate the unit pressure of the second section, the third section... the n-th section in sequence, and judge μ k p(i) b _sli (1 ≤ i ≤ n) and sizes; specifically:

[0078] The unit pressure of the (i + 1)-th section in the back slip zone under sliding friction conditions is:

[0079] The frictional stress of the i-th section in the back slip zone under sliding friction conditions is: t k (i) b _sli = μ k p k (i) b _sli.

[0080] There are also two cases in the calculation process:

[0081] 1) If it satisfies from the entrance section (the first section) to the exit section (the n-th section) (1 ≤ i ≤ n), it indicates that the calculation from the entrance to the exit is under sliding friction using the stress differential equation in the back slip zone under sliding friction conditions; at this time, the unit pressures of each section calculated using the back slip zone formula are: p k (1) b = p k (1) b _sli, p k (2) b = pk (2) b _sli…p k (n) b =p k (n) b _sli;

[0082] 2) If at the m-th (1 < m ≤ n) segment, there is: Then it indicates that from the m-th segment to the outlet, it is all adhesive friction; convert to using the stress differential equation in the backward slip zone under the condition of adhesive friction to calculate the unit pressure of the m-th segment, the (m + 1)-th segment... the n-th segment in sequence; specifically:

[0083] The unit pressure of the (i + 1)-th segment in the backward slip zone under the condition of adhesive friction is:

[0084]

[0085] The friction stress of the i-th segment in the backward slip zone under the condition of adhesive friction is:

[0086] At this time, the unit pressures of each segment calculated using the backward slip zone formula are respectively: p k (1) b =p k (1) b _sli、p k (2) b =p k (2) b _sli…p k (m - 1) b =p k (m - 1) b _sli、p k (m) b =p k (m) b _sti、p k (m + 1) b =p k (m + 1) b _sti…p k (n) b =p k (n) b _sti;

[0087] (ii) If Then it indicates that the inlet segment is adhesive friction, and from the inlet segment to the outlet segment is all adhesive friction; the unit pressure of the inlet segment Use the stress differential equation in the backward slip zone under the condition of adhesive friction to calculate the unit pressure of the 2nd segment, the 3rd segment... the n-th segment in sequence; the unit pressures of each segment calculated using the backward slip zone formula are p k (1) b= p k (1) b _sti, p k (2) b = p k (2) b _sti……p k (n) b = p k (n) b _sti.

[0088] S5013. Calculate the unit pressure and frictional stress of each section in the forward slip zone from the outlet to the inlet; similar to the calculation method in the backward slip zone, specifically:

[0089] Use the forward slip zone formula to calculate from the outlet to the inlet and determine the division of the sliding friction and adhesive friction zones.

[0090] 1. Calculate the unit pressure p at the outlet section under the condition of sliding friction k (n) f _sli is:

[0091] Solve for p using the Aitken iteration method k (n) f _sli;

[0092] 2. Judge μ at the outlet section k p k (n) f _sli and size, divided into two cases:

[0093] (i) If Then it means that the outlet section is in sliding friction, and the unit pressure p at the outlet section k (n) f = p k (n) f _sli; Use the stress differential equation in the forward slip zone under the condition of sliding friction to calculate the unit pressure of the n - 1th section, the n - 2th section... in turn, and judge μ k p k (i) f _sli(1 ≤ i ≤ n) and size. Specifically:

[0094] The unit pressure of the ith section in the forward slip zone under the condition of sliding friction is:

[0095]

[0096] Solve for p using the Aitken iteration method k (i) f _sli.

[0097] The friction stress of the i-th section in the forward slip zone under sliding friction conditions is: t k (i) f _sli = -μ k p k (i) f _sli. The negative sign indicates that the direction of the friction stress in the forward slip zone is towards the entrance side (opposite to the rolling direction).

[0098] Among them, there are two situations in the calculation process:

[0099] 1) If it satisfies from the exit section to the entrance section It means that when calculating using the stress differential equation of the forward slip zone under sliding friction conditions, it is sliding friction from the exit to the entrance. At this time, the unit pressures of each section calculated using the forward slip zone formula are: p k (1) f = p k (1) f _sli, p k (2) f = p k (2) f _sli…p k (n) f = p k (n) f _sli;

[0100] 2) If at the s-th section (1 < s ≤ n) there is: It means that from the s-th section to the entrance, it is sticking friction; then, use the stress differential equation of the forward slip zone under sticking friction conditions to calculate the unit pressures of the s-th section, the s - 1-th section... the 1st section in turn; specifically:

[0101] The unit pressure of the i-th section in the back slip zone under sticking friction conditions is:

[0102]

[0103] The friction stress of the i-th section in the back slip zone under sticking friction conditions is:

[0104] At this time, the unit pressures of each section calculated using the forward slip zone formula are: p k (1) f = p k (1) f _sti, p k (2) f = p k (2) f _sti…p k (s) f = p k (s)f _sti,p k (s+1) f =p k (s+1) f _sli…p k (n) f =p k (n) f _sli;

[0105] (ii) If This means that the outlet section is adhesive friction, and the friction is adhesive friction from the outlet section to the inlet section; the unit pressure of the outlet section is The stress differential equation of the rear sliding zone under the condition of adhesive friction is used to calculate the unit pressure of the n-1th section, the n-2th section, and the 1st section in sequence;

[0106] At this time, the unit pressure of each section calculated by the forward sliding zone formula is p k (1) f =p k (1) f _sti,p k (2) f =p k (2) f _sti……p k (n) f =p k (n) f _sti.

[0107] S5014. Determine the unit pressure and friction stress of each section of the roll gap deformation zone;

[0108] Compare the two sets of unit pressure p calculated using the front sliding zone formula and the rear sliding zone formula k (1) f 、p k (2) f …… k (n) f and p k (1) b 、p k (2) b …… k (n) b , find the segment with the smallest difference (assuming it is the rth segment), then this segment is the boundary segment between the front slip zone and the back slip zone (i.e. the segment corresponding to the neutral plane), xk(r) = x k (1)+(r-1)ΔX, retain p k (1) b 、p k (2) b ……、p k (r-1) b、p k (r) b or p k (r) f 、p k (r+1) f …… k (n) f ; So far, the unit pressure distribution under the specified roll profile has been calculated, that is, p k (1) = p k (1) b 、p k (2) = p k (2) b ,……,p k (r-1) = p k (r-1) b 、p k (r) = p k (r) b or p k (r) = p k (r) f 、p k (r+1)=p k (r+1) f …… k (n) = p k (n) f , and friction stress distribution t k (1) = t k (1) b ,t k (2) = t k (2) b ……、t k (r-1) = t k (r-1) b ,t k (r) = t k (r) b or k (r) = t k (r) f ,t k (r+1)=t k (r+1) f ……t k (n) = t k (n) f ;

[0109] S5015. Calculate the roll gap thickness distribution by the unit pressure distribution;

[0110] Calculate the roll gap thickness h using unit pressure distribution k(i); however, to ensure convergence, a smoothing coefficient e needs to be introduced here to make the unit pressure of each segment calculated in the previous and current two iterations change smoothly;

[0111] That is, p k m+1 (i) = ep k (i) + (1 - e)p k m (i), 0 < e < 1, p k (i) - the unit pressure of the i-th segment of the roll gap under the specified roll profile calculated; p k m (i) - the unit pressure of the i-th segment of the roll gap used in the m-th iteration; p k m+1 (i) - the unit pressure of the i-th segment of the roll gap used in the (m + 1)-th iteration;

[0112] Using the smoothed unit pressure distribution p k m+1 (i) to calculate the elastic flattening deformation amount δ(x k (j)), and calculate the elastic flattening amount of the roll at the abscissa x k (j) by the method of cumulative summation j = 1, 2, 3…n, s i is the abscissa corresponding to the unit pressure p k m+1 (i), in unit of mm; E wk is the elastic modulus of the working roll of the k-th stand, in unit of MPa; v wk is the Poisson's ratio of the working roll of the k-th stand;

[0113] Then the distribution of the deformed roll profile curve is obtained as:

[0114]

[0115] The roll gap thickness distribution is:

[0116] In the formula, y(x k (j)) min - the ordinate corresponding to the lowest point of the deformed roll profile curve, in unit of mm;

[0117] S5016. Judge whether the roll gap thickness distributions obtained from the previous and current calculations converge: If they converge, end the calculation; if not, go to step S5012 for the next round of iterative calculation until the roll gap thickness distribution converges;

[0118] Corresponding to the unit pressure distribution, smooth the roll gap thickness, that is, h k m+1 (j) = ehk (j) + (1 - e)h k m (j), where h k (j) - the thickness of the j-th segment of the roll gap calculated; h k m (j) - the thickness of the j-th segment of the roll gap used in the m-th iteration; h k m +1 (j) - the thickness of the j-th segment of the roll gap used in the (m + 1)-th iteration.

[0119] Using the new roll gap thickness distribution (h k m+1 (j)), re-solve the unit pressure distribution and friction stress distribution under the roll profile in the same method as above, and iterate repeatedly until convergence; the convergence condition is: the absolute value of the difference in the thickness of the corresponding segments of the roll gap calculated in the previous and current two times is less than the precision value, that is, |h k (j) - h k m (j)| ≤ ε × h k (j), ε - convergence precision coefficient.

[0120] After iterative convergence, the unit pressure distribution p k (1), p k (2), p k (3), … p k (n), the friction stress distribution t k (1), t k (2), t k (3), … t k (n) and the roll gap thickness distribution h k (1), h k (2), h k (3), … h k (n).

[0121] In S502 of this embodiment, calculate the rolling pressure P k (unit: KN), the driving torque M k (unit: KN×m) and the forward slip value f k , and the specific calculation formulas are:

[0122]

[0123]

[0124]

[0125] where n k is the number of discrete segments of the roll gap of the k-th stand, ΔXk is the length of the discrete section of the roll gap of the kth stand, in mm, p k (i) is the unit pressure of the i-th section of the roll gap of the k-th stand, in MPa, t k (i) is the friction stress of the i-th section of the roll gap of the k-th stand, unit: MPa, Δh k (i) is the thickness difference between the i+1th section and the ith section of the roll gap of the kth frame, in mm, Δh k (i) = h k (i+1)-h k (i), x k (i) is the horizontal coordinate of the i-th section of the roll gap of the k-th frame, in mm, m wb is the rolling friction arm between the working roll and the support roll, in mm. Among them, E wk E is the elastic modulus of the working roll, in MPa. bk is the elastic modulus of the support roller, unit: MPa, L wb The contact length between the working roll and the backup roll, in mm. wk ≤B bk When L wb =B wk , when B wk >B bk When L wb =B bk ρ bk is the friction circle radius of the support roller bearing, in mm, Among them, μ′ k is the rolling friction coefficient of the support roller bearing; h k (r) is the roll gap thickness of the k-th frame roll gap corresponding to the neutral plane (the r-th roll gap of the k-th frame), in mm, Δh k (r) = h k (r+1)-h k (r).

[0126] In S503 of this embodiment, the roller speed v is calculated. k (Unit: m / min) and main motor power N k (Unit KW), such as Figure 4 As shown, the specific steps are:

[0127] S5031, the maximum roll speed v set for each stand k_max Calculate the second flow value V k , the calculation formula is: V k =h 1k v k_max (1+f k );

[0128] S5032. Find the minimum value V of the second flow rate values V1 to V of each stand Q among them min , and calculate the roll speed v' of each stand according to the second flow rate theorem from V min , the calculation formula is: k

[0129] S5033. Calculate the main motor power N' of each stand k , and the ratio φ of the main motor power N' k to the rated power N of the main motor of this stand k_max , the calculation formula is: k

[0130] S5034. Find the maximum value φ of φ1 to φ Q among them max ;

[0131] S5035. Judge whether φ max is greater than 1: If φ max > 1, then limit the roll speed of each stand by φ max , and the roll speed after limiting is the calculated roll speed of each stand, that is When φ max ≤1, then v k = v' k ;

[0132] S5036. Calculate the main motor power N of each stand k , the calculation formula is:

[0133] So far, the rolling force and energy parameters of the k-th stand have been calculated, including the rolling pressure P k (unit: KN), transmission torque M k (unit: KN×m), forward slip value f k , roll speed v k (unit: m / min) and main motor power N k (unit: KW). The calculation methods of the rolling force and energy parameters of other stands are similar to the above, and will not be elaborated here.

[0134] S600. Judge whether the maximum hourly output optimization goal and constraint conditions are satisfied at the same time: If not, adjust the reduction ratio values of each stand by the optimization algorithm, and then transfer to S400 for recalculation. If satisfied, the calculation ends.

[0135] Specifically, in S600, judge whether the maximum hourly output optimization goal and constraint conditions are satisfied at the same time. The constraint conditions are specifically that all stands simultaneously satisfy the following inequality:

[0136] η​​k_min ≤ η k ≤ η k_max , v k ≤ v k_max , P k ≤ P k_max , M k ≤ M k_max , N k ≤ N k_max , where the subscript k represents the stand number, 1 ≤ k ≤ Q; η k_max is the maximum reduction ratio of the k-th stand, η k_min is the minimum reduction ratio of the k-th stand, v k_max is the maximum roll speed of the k-th stand, P k_max is the maximum rolling pressure of the k-th stand, M k_max is the maximum transmission torque of the k-th stand, N k_max is the rated power of the main motor of the k-th stand.

[0137] A method for obtaining the reduction ratio of a continuous rolling mill unit that can improve the hourly output disclosed in this embodiment establishes a reduction ratio distribution model of the continuous rolling mill unit with the maximum hourly output as the optimization goal through theoretical analysis. In the calculation process, an optimization algorithm is used to continuously obtain a more optimal reduction ratio distribution, and the rolling force and energy parameters of each stand under the corresponding reduction ratio distribution are repeatedly calculated according to the given process parameters and equipment parameters, including rolling pressure, transmission torque, forward slip value, roll speed, and main motor power. Finally, the optimal reduction ratio distribution that meets the optimization goal and constraint conditions is obtained.

[0138] The principle of the method disclosed in this embodiment is clear and definite, and the iterative calculation is stable and rapid. It can be used for the online preset calculation of the reduction ratio distribution of the continuous rolling mill unit, avoiding the errors brought by the traditional manual experience table setting method, and the calculated reduction ratio distribution can make the hourly output of the continuous rolling mill unit reach the highest, thereby improving the production efficiency and production benefits of the unit.

[0139] Embodiment 2

[0140] For the sake of easy understanding, the following further illustrates with Embodiment 2. In this embodiment, the process parameters include: the incoming material thickness H = 17 mm, the finished product thickness H = 2 mm, the width B of the rolled piece s = 1600 mm, and the number of stands Q = 5. The equipment parameters are shown in Table 1. The constraint condition parameters are shown in Table 2.

[0141] Table 1 shows the equipment parameters of Embodiment 2

[0142]

[0143] Table 2 shows the constraint condition parameters of Embodiment 2

[0144]

[0145] Other parameters include: the number of segments n = 500 divided along the rolling direction in the roll gap deformation zone, the convergence precision coefficient ε = 0.001 of the roll gap thickness distribution, the smoothing coefficient e = 0.3, and the density ρ of the rolled piece = 7800 kg / m 3 , the roll gap friction coefficients of each stand are μ1 = μ2 = μ3 = μ4 = μ5 = 0.3, and the elastic modulus E of the work rolls of each stand w1 = E w2 = E w3 = E w4 = E w5 = 206000 MPa, and the elastic modulus E of the backup rolls of each stand b1 = E b2 = E b3 = E b4 = E b5 = 206000 MPa, and the Poisson's ratio v of the work rolls of each stand w1 = v w2 = v w3 = v w4 = v w5 = 0.3, and the rolling friction coefficients of the backup roll bearings of each stand are μ′1 = μ′2 = μ′3 = μ′4 = μ′5 = 0.002.

[0146] As shown in Table 3, the data of the deformation resistance of the rolled piece are given in the form of a data table of the change of the deformation resistance of the rolled piece with the reduction ratio.

[0147] Table 3 is the data of the deformation resistance of the rolled piece

[0148]

[0149] The deformation resistance of the rolled piece at each position of the roll gap of each stand is calculated by the linear interpolation method:

[0150] Taking the 3rd stand as an example, assuming that the calculated inlet thickness of the rolled piece of the 3rd stand is 5 mm and the outlet thickness is 3.2 mm, then the total reduction ratio of the inlet rolled piece of this stand is The total reduction ratio of the outlet rolled piece is Then, the deformation resistance of the inlet rolled piece of this stand can be calculated by the linear interpolation method as The deformation resistance of the outlet rolled piece of this stand is

[0151] Furthermore, taking the i-th segment (1 ≤ i ≤ 500) of the roll gap of the 3rd stand as an example, the reduction ratio per pass of this stand is Assuming that the thickness of the rolled piece h3(i) of the i-th segment of the roll gap of the 3rd stand is 4 mm, then the reduction ratio of the rolled piece of the i-th segment is Then, the deformation resistance of the rolled piece in the i-th section of the roll gap of the third stand can be calculated by further using the linear interpolation method as follows:

[0152]

[0153] The deformation resistance of the rolled piece at each position of the roll gap of each other stand can be calculated according to the above method, which will not be elaborated here.

[0154] As a comparison, Table 4 shows the reduction ratio distribution of each stand and the calculated force and energy parameters given by a traditional manual experience table setting method in a certain steel plant. The reduction ratios of each stand are shown in the fourth column of Table 4. The roll speed of the fifth stand (the last stand) calculated is 465.75 m / min, and the forward slip value is 0.06735. The hourly output under this reduction ratio distribution can be further calculated as:

[0155]

[0156] Table 4 shows the reduction ratio distribution of each stand and the calculated force and energy parameters given by a traditional manual experience table setting method

[0157]

[0158] Specifically, in this embodiment, the optimization algorithms respectively adopt the genetic algorithm and the particle swarm algorithm. When the genetic algorithm is used as the optimization algorithm, the principle of the genetic algorithm belongs to the publicly known knowledge in the industry and will not be elaborated here. The relevant calculation parameters of the genetic algorithm adopted in this embodiment are: the population size is 80, the crossover probability is 0.95, the mutation probability is 0.1, the selection method is roulette wheel selection, the crossover method is single-point crossover, the maximum number of evolution generations is 100, and the curve of the fitness value changing with the number of evolution generations during the iterative calculation process is as Figure 5 shown.

[0159] The reduction ratios of each stand calculated in this embodiment are shown in the fourth column of Table 5. The roll speed of the fifth stand (the last stand) calculated is 528.78 m / min, and the forward slip value is 0.07047. The hourly output under this reduction ratio distribution can be further calculated as:

[0160]

[0161] Comparison with the data given by the traditional manual experience table setting method (Table 4) shows that the method of this embodiment can increase the hourly output by about 13.87%.

[0162] Table 5 shows the reduction ratio distribution and force and energy parameters of each stand calculated in the second embodiment

[0163]

[0164] When the optimization algorithm adopts the particle swarm algorithm, the principle of the particle swarm algorithm belongs to the publicly known knowledge in the industry and will not be elaborated here. The relevant calculation parameters of the particle swarm algorithm adopted in this embodiment are as follows: the population size is 30, the maximum number of evolutionary generations is 50, the inertia weight is 0.5, the acceleration coefficient of the particle's optimal position is 2, the acceleration coefficient of the global optimal position is 2, and the curve of the fitness value changing with the number of evolutionary generations during the iterative calculation process is as Figure 6 shown.

[0165] The reduction ratios of each stand calculated in this embodiment are shown in the fourth column of Table 6, and the reduction ratios of each stand calculated are shown in the fourth column of Table 5. The roll speed of the fifth stand (the last stand) calculated is 544.33 m / min, and the forward slip value is 0.0689. The hourly output under this reduction ratio distribution can be further calculated as:

[0166]

[0167] Comparison with the data (Table 4) given by the traditional manual experience table setting method shows that the method of this embodiment can increase the hourly output by about 17.04%.

[0168] Table 6 Reduction ratio distribution and energy parameters of each stand calculated in Embodiment III

[0169]

[0170] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the present disclosure. The appended method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy recited.

[0171] In the above detailed description, various features are combined in a single embodiment to simplify the present disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are expressly stated in each claim. On the contrary, as reflected in the appended claims, this embodiment is in a state with fewer features than all the features of the disclosed single embodiment. Therefore, the appended claims are hereby expressly incorporated into the detailed description, where each claim stands alone as a separate preferred embodiment of this embodiment.

[0172] Those skilled in the art should also understand that all the illustrative logical blocks, modules, circuits and algorithm steps described in conjunction with the embodiments herein can be implemented as electronic hardware, computer software or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the above various illustrative components, blocks, modules, circuits and steps have been generally described in terms of their functions. Whether such a function is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Skilled technicians can implement the described functions in a flexible manner for each specific application, however, such implementation decisions should not be construed as departing from the protection scope of the present disclosure.

[0173] The steps of the methods or algorithms described in conjunction with the embodiments herein can be directly embodied as hardware, software modules executed by a processor, or a combination thereof. The software modules can be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium well-known in the art. An exemplary storage medium is connected to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC. The ASIC can be located in a user terminal. Of course, the processor and the storage medium can also exist as discrete components in the user terminal.

[0174] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented inside the processor or outside the processor. In the latter case, it is communicatively coupled to the processor via various means, which are well-known in the art.

[0175] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but those of ordinary skill in the art should recognize that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the protection scope of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the way this term is covered is similar to the term "including", as is explained when "including" is used as a transitional word in the claims. In addition, any term "or" used in the specification and claims of the patent application is to mean "non-exclusive or".

Claims

1. A method for obtaining the reduction ratio of a continuous rolling mill unit that can improve the hourly output, characterized in that Including: S100. Input process parameters and continuous rolling mill equipment parameters; S200. Establish the optimization objective and constraints for the maximum hourly output; in S200, the objective function of the optimization objective for the maximum hourly output is: , where is the density of the rolled piece, with the unit ; is the width of the rolled piece, with the unit ; is the exit thickness of the rolled piece at the th stand, and the th stand is the last stand, with the unit ; is the exit speed of the rolled piece at the th stand, with the unit , , is the roll speed at the th stand, with the unit , is the forward slip value at the th stand, is the number of stands; S300. Initially set the reduction ratios of the first stand to the stand using an optimization algorithm , , …, ; S400. Calculate the entrance thickness and exit thickness of the rolled piece for each stand; S500. Calculate the rolling force and energy parameters for each stand, where the rolling force and energy parameters for each stand include the rolling pressure, transmission torque, forward slip value, roll speed, and main motor power of each stand; In S500, the specific steps for calculating the rolling force and energy parameters for each stand are as follows: S501. Through repeated iteration of the stress differential equation and roll gap thickness equation in the roll gap deformation zone, calculate the unit pressure distribution, friction stress distribution, and roll gap thickness distribution in the roll gap deformation zone; S502. Calculate the rolling pressure , unit , transmission torque , unit and the forward slip value , subscript indicates the stand number, , is the number of stands; S503. Calculate the roll speed , unit and the main motor power , unit ; In S503, calculate the roll speed , unit and the main motor power , unit . The specific steps are as follows: S5031. At the maximum roll speed set for each stand Calculate the second flow rate value , and the calculation formula is: , is the thickness of the rolled piece at the outlet, with the unit of mm; S5032. Find the second flow rate value of each stand the minimum value , and according to the second flow rate theorem, from calculate the roll speed of each stand , the calculation formula is: , is the thickness of the rolled piece at the outlet, unit is mm; S5033. Calculate the main motor power of each stand , and the main motor power and the rated power of the main motor of this stand ratio , the calculation formula is: , , where is the transmission torque, is the roll body diameter of the work roll; S5034. Find out the maximum value of ; S5035. Judgment Is it greater than 1: If , then use to limit the roll speed of each stand. The limited roll speed is the calculated roll speed of each stand, that is ; When , then ; S5036. Calculate the main motor power of each rack , and the calculation formula is: ; S600. Determine whether the maximum hourly output optimization goal and constraint conditions are simultaneously met: If not, adjust the reduction ratio value of each stand by the optimization algorithm, and then transfer to S400 for recalculation. If satisfied, the calculation ends.

2. The method for obtaining the reduction ratio of a continuous rolling mill unit capable of increasing the hourly output according to claim 1, characterized in that, In S100, the process parameters include the incoming material thickness , unit , the finished product thickness , unit , the width of the rolled piece , unit , the number of stands and the deformation resistance data of the rolled piece. The equipment parameters of the continuous rolling mill include the working roll body diameter of each stand , unit , the working roll neck diameter , unit , the working roll body width , unit , the backup roll body diameter , unit , the backup roll neck diameter , unit and the backup roll body width , unit , where the subscript represents the stand number, .

3. The method for obtaining the reduction ratio of a continuous rolling mill unit capable of increasing the hourly output according to claim 2, characterized in that, In the S400, calculate the entrance thickness of the rolled piece for each stand and the exit thickness of the rolled piece . Specifically: when , , ; when , , ; when , , ; The subscript represents the stand number, , is the reduction ratio of the stand 4. The method for obtaining the reduction ratio of a continuous rolling mill unit capable of increasing the hourly output according to claim 1, characterized in that, The specific steps of S501 are as follows: S5011. Set the initial roll profile curve and determine the entrance position of the rolled piece; S5012. Calculate the unit pressure and friction stress for each section in the back slip zone from the entrance to the exit; S5013. Calculate the unit pressure and friction stress for each section in the forward slip zone from the exit to the entrance; S5014. Determine the unit pressure and friction stress for each section in the roll gap deformation zone; S5015. Calculate the roll gap thickness distribution from the unit pressure distribution; S5016. Determine whether the roll gap thickness distributions obtained from the previous and current calculations converge: If they converge, end the calculation; If not, transfer to step S5012 for the next round of iterative calculation until the roll gap thickness distribution converges.

5. A method for obtaining the reduction ratio of a continuous rolling mill unit capable of increasing the hourly output, as described in claim 2, characterized in that In S502, calculate the rolling pressure , unit , transmission torque , unit and the forward slip value , the specific calculation formula is: ； ； In the formula, is the number of discrete segments of the roll gap of the stand, is the length of the discrete segment of the roll gap of the stand, in mm, is the unit pressure of the th segment of the roll gap of the stand, in , , n is the number of segments into which the roll gap deformation zone is divided along the rolling direction, is the frictional stress of the th segment of the roll gap of the stand, in , is the thickness difference between the th segment and the th segment of the roll gap of the stand, in , , and are respectively the thicknesses of the th segment and the th segment of the roll gap of the stand, in , is the abscissa of the th segment of the roll gap of the stand, in , is the rolling frictional force arm between the work roll and the backup roll, in , , where is the elastic modulus of the work roll, in , is the elastic modulus of the backup roll, in , is the contact length between the work roll and the backup roll, in , when , , when , ; is the friction circle radius of the backup roll bearing, in , , where is the rolling friction coefficient of the backup roll bearing, is the diameter of the backup roll neck, in ; is the thickness difference between the th segment + 1 and the r th segment of the roll gap of the r stand, in , , For the roll gap thickness of the corresponding section of the neutral plane of the stand roll gap, the corresponding section of the neutral plane of the stand roll gap is the corresponding section of the neutral plane of the stand roll gap for the stand roll gap of the stand, the section, unit , For the stand roll gap of the stand, the section, unit .

6. The method for obtaining the reduction rate of a continuous rolling mill unit capable of increasing the hourly output according to claim 1, characterized in that In S300, the reduction ratio of each stand is initially set by the optimization algorithm and the reduction ratio of each stand is adjusted by the optimization algorithm. The optimization algorithm uses a genetic algorithm or a particle swarm algorithm.

7. A method for obtaining the reduction ratio of a continuous rolling mill unit that can increase the hourly output, as described in claim 3, characterized in that In S600, determine whether the maximum hourly output optimization goal and constraint conditions are simultaneously met. The constraint conditions are specifically that all stands simultaneously satisfy the following inequalities: , where the subscript represents the stand number, , is the maximum reduction ratio of the th stand, is the minimum reduction ratio of the th stand, is the maximum roll speed of the th stand, is the maximum rolling pressure of the th stand, is the maximum transmission torque of the th stand, is the rated power of the main motor of the th stand.

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