Cold and hot crossing scheduling and optimizing method for hot-rolled slabs

Abstract

The invention discloses a hot-rolling plate blank cold-hot crossing scheduling and optimizing method, which comprises the following steps of: firstly, building a fixed number of cold-hot mixed plate blanks according to a cold-hot crossing ratio; secondly, planning the cold and hot mixed plate blank to form a cold and hot cross plan; and finally, compiling the cold and hot cross plan by taking a block as a unit to form a hot rolling plan. According to the invention, hot billets can be concentrated in one heating furnace, other heating furnaces are all cold billets, and the hot billets are charged in batches to the maximum extent, so that the actual effects of energy conservation and consumption reduction are ensured.

Description

Technical Field

[0001] This invention relates to metallurgical automation technology, and more specifically, to a method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs. Background Technology

[0002] Hot rolling plans can generally be divided into the following three types based on the slab material condition and furnace charging mode:

[0003] Firstly, the physical CCR plan;

[0004] Secondly, virtual HCR plan;

[0005] Third, the Virtual DHCR program.

[0006] Unlike CCR (Consumer-Return Container) plans, which are based on physical materials, HCR (Hybrid Container) and DHCR (High-Degree Container) plans use virtual slabs as materials and aim to increase furnace charging temperature. However, HCR can only start furnace charging after all slabs have been produced, so its energy-saving effect is not as significant as DHCR. Some HCR plans also require waiting for hot test results before further operation. Some DHCR slabs cannot be used to form effective DHCR plans for various reasons, but these DHCR slabs can still be used as HCR plan materials. At the same time, some existing DHCR plans can be downgraded and treated as HCR plans. In short, to save energy, creating HCR plans as much as possible when DHCR cannot be formed is also an effective method.

[0007] To achieve energy savings in heating furnaces and reduce overheating loss of hot billets, it is required that hot billets in the same heating furnace be loaded into batches as much as possible to avoid mixing hot and cold billets. Based on actual operational experience, at least seven hot billets are generally required in a batch (this number varies depending on the heating furnace) to achieve good energy savings. Therefore, when developing a DHCR / HCR plan, the number of hot billets must reach a minimum lower limit N. h_min =7. If the value is less than this, and this type of plan is forcibly formulated, the actual energy-saving effect will be limited.

[0008] A typical hot rolling production line is equipped with 2 to 4 slab heating furnaces operating in parallel. However, in actual operation of the rolling sequence, the planned slab loading is done sequentially: slabs are loaded into furnaces 1 through 4 in turn. The quantity N of hot slabs is evenly distributed to N... fur The number of hot billets in each batch of the heating furnace is N / N fur Therefore, in this mode, N fu When multiple heating furnaces are operating simultaneously, only when the number of hot billets is ≥ N fur *N h_min Only when the hot billet is in block size can the energy-saving effect of the hot billet plan be realized.

[0009] For the total number of hot billets <Nfur *N h_min When using a block, a special hot and cold cross-scheduling optimization technology is provided, which is also a technical solution to ensure the energy-saving effect of the heating furnace: this technology requires a minimum number of hot billets from N fur *N h_min The block size is reduced to 1*N h_min This planning and scheduling technology can effectively improve the hot billet loading rate and enhance the actual effect of energy saving and consumption reduction.

[0010] Energy saving and consumption reduction technologies through hot rolling scheduling optimization are a hot research topic both domestically and internationally. Currently, the focus is mainly on optimizing the scheduling of DCHR / HCR plans, but this scheduling optimization technology has requirements on the batch size of hot billets; otherwise, the energy-saving effect is limited. A more effective energy-saving technology based on cold and hot cross-scheduling optimization has not been publicly reported. Summary of the Invention

[0011] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for scheduling and optimizing the cross-flow of hot and cold billets in hot-rolled slabs. This method ensures that hot billets are concentrated in one heating furnace, while all other heating furnaces contain cold billets, maximizing the batch loading of hot billets and thus ensuring the actual effect of energy saving and consumption reduction.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] A method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs;

[0014] First, according to the ratio of hot to cold cross-contamination, a fixed number of hot and cold mixed slabs are assembled;

[0015] Subsequently, the hot and cold mixed slabs are planned and compiled to form a hot and cold cross plan;

[0016] Finally, the hot and cold cross-plan is optimized and compiled on a block-by-block basis to form a hot rolling plan.

[0017] Preferably, the setting of the hot-cold cross ratio is as follows:

[0018] Let N be the number of furnaces in the hot rolling heating furnace. fur The ratio of hot to cold crossover is n1:n2, and n1+n2=N fur This indicates that cold billets are loaded into the first n1 furnace and hot billets are loaded into the second n2 furnace.

[0019] When the number of hot billets is N, the maximum value of n2 is [N / N]. fur ].

[0020] Preferably, the optimization of the hot-cold crossover plan includes the following steps:

[0021] S1, group plan block;

[0022] S2, group of mixed blocks;

[0023] S3, based on the plan of step S2.

[0024] Preferably, step S1 specifically includes the following processes:

[0025] Set the hot-cold crossover ratio to N. c :N h ;

[0026] Collect all hot billets from the programmable slabs, and group them into several program blocks based on similar slabs, with each block containing N billets. h The blocks are then sorted in descending order according to the first slab of each block, in the order of "width↓ + thickness↓ + hardness↑ temperature↓", to obtain the block sequence: B1, ..., Bm;

[0027] Similarly, all cold billets in the programmable slab are grouped into blocks based on similar slabs, with each block containing N billets. c The cold block sequence is obtained: A1, ..., An.

[0028] Preferably, when the hot billet or the cold billet cannot meet the minimum number of blocks N h or N c In this case, the nearest slab that does not violate the hot-rolled adjacent specification is selected for expansion.

[0029] Preferably, step S2 specifically includes the following processes:

[0030] If the block sequence Bj of the hot billet and the block sequence Ak of ​​the cold billet can be connected sequentially, then a block BjAk is formed, where j = 1, ..., m; k = 1, ..., n;

[0031] By sequentially grouping the mixed blocks, a mixed block sequence is obtained: C1, ..., Cq.

[0032] Preferably, during the process of assembling and mixing blocks, the following conditions must be met:

[0033] Centered on the block sequence Bj of the hot billet, select the block sequence Ak of ​​the cold billet that can be matched;

[0034] The tail of the block sequence Bj of the hot billet and the head of the block sequence Ak of ​​the cold billet must have similar slab properties.

[0035] Based on the block sequence Bj of the hot billet, the preferred selection sequence for the subsequent block sequence Ak of ​​the cold billet is: the sequence with the smallest distance from the block sequence Bj of the hot billet is preferred.

[0036] If the distances are equal, the selection should be made in the order of decreasing rolling width, decreasing rolling thickness, and increasing slab hardness.

[0037] Preferably, step S3 specifically includes the following processes:

[0038] The mixed block sequence C1, ..., Cq is sorted in ascending order by "rolling width ↓, rolling thickness ↓, slab hardness ↓, furnace exit temperature ↓" to obtain the sorted mixed block sequence C1, ..., Cq; and then a complete planning segment is formed according to the following steps:

[0039] S31, use a greedy algorithm to find the initial maximum plan block: try to use Ck+1 to continue at the end of Ck, k=1,...,q-1, to form the t block plan segment sequence: D1,...,Dt;

[0040] S32, try to connect Dj+1 to the tail of Dj in sequence, j=1,...,t-1, and replace the last cold blank at the tail of Dj until they can be adjacent;

[0041] S33. If the final number of plan segments is greater than 1, relax the plan adjacency procedure and repeat the above steps S31 to S32 until all plan segments are adjacent to one plan segment. Otherwise, proceed to step S34.

[0042] S34, select the longest planning segment as the final hot-cold crossover planning segment;

[0043] S35, for the final sequence of adjacentable planned blocks D1, ..., Dk, and the mixed block set M = {Ck1, Ck2, ...}, the following further optimization is performed:

[0044] Using the mixed block Cx of M in sequence, try to see if it can be inserted in front of Dj, j=1,...,k, without violating the rolling specifications, thereby expanding the planned block sequence D1,...,Dk, until every mixed block in M ​​has been tried;

[0045] S36, matching the hot ironing roller material and transition material for this segment to form a complete scheme.

[0046] Preferably, the process for collecting the programmable slab is as follows:

[0047] The current inventory includes all programmable cold-rolled billets: {Xj: j = 0, ..., n}; and programmable hot-rolled billets: {Yk: k = 0, ..., m}.

[0048] The distinction between the hot billet and the cold billet is determined by the current temperature Tmin of the slab: if the temperature of the slab is less than Tmin... min If yes, it is a cold billet; otherwise, it is a hot billet.

[0049] The present invention provides a method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs, where the number of furnace starts is N. fur The standard requirement is a minimum number of hot billets from N slab Block down to N slab / N fur This planned programming technology can effectively increase the hot billet loading rate, further enhancing the actual effect of energy saving and consumption reduction. This invention can also effectively increase the hot billet loading rate and reduce the energy consumption for billet heating. Detailed Implementation

[0050] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with embodiments.

[0051] This invention provides a method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs;

[0052] When developing a cold-hot crossover plan, firstly, according to a certain cold-hot crossover ratio, a fixed number of cold-hot mixed slabs are assembled;

[0053] Subsequently, these slabs with mixed hot and cold temperatures are planned and compiled to form a hot and cold cross-plan.

[0054] Finally, the hot and cold cross-plan is optimized and compiled on a block-by-block basis to form a complete hot rolling plan.

[0055] In the method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs provided by this invention, the selection of programmable slabs is as follows:

[0056] Programmable slab collection: All currently available programmable cold slabs: {Xj: j = 0, ..., n}, and programmable hot slabs: {Yk: k = 0, ..., m}. The distinction between hot and cold slabs is based on the current slab temperature T. min Judgment: Slab temperature < T min If the blank is cold, it is a cold blank; otherwise, it is a hot blank.

[0057] Hot billets can also be virtual slabs that are about to be produced, and the latest planned production time of these virtual slabs shall not exceed a preset value T. max .

[0058] In practice, when there are not enough effective virtual hot billets, physical hot billets can be selected and spliced ​​at the beginning and end of the virtual hot billet mixing plan segment to improve the success rate of compiling the cold and hot cross plan.

[0059] The specific settings for the hot-cold cross ratio are as follows:

[0060] Before developing a hot-cold crossover plan, it is necessary to set the hot-cold crossover ratio and the minimum number of hot billets per furnace. Within the heating furnace, adjacent planned slabs are continuously charged into a certain scale N.h_min Energy-saving effects are only achieved when the number of hot billets N is [specifically, the number of hot billets N]. h_min When the energy consumption is less than 7 hours, energy saving is not ideal.

[0061] Let N be the number of furnaces in the hot rolling heating furnace. fur The ratio of hot to cold crossover is n1:n2, and n1+n2=N fur This indicates that cold billets are loaded into the first n1 furnace and hot billets are loaded into the second n2 furnace.

[0062] Clearly, the number of hot billets that can be programmed is currently only ≥ n²*N. h_min Only when the minimum number of hot billets required for the cross-planning is met can the energy-saving effect be ensured. Therefore, when the number of hot billets is N, the maximum value of n² is [N / N]. fur ].

[0063] The slabs are grouped as follows:

[0064] Slabs are classified and grouped according to their specifications and planned attributes, so that slabs in the same group have the same or similar specifications and classification attributes.

[0065] The grouping rules are defined as follows:

[0066] Steel types are the same or similar

[0067] Slab rolling width range [w j w j+1 ]:j=1,...,N1

[0068] Slab rolling thickness range [g k g k+1 ]:k=1,...,N2

[0069] Slab rolling hardness range [h p h p+1 ]:p=1,...,N3

[0070] Slab tapping temperature range [t] q , t q+1 ]:q=1,...,N4

[0071] Slabs that simultaneously meet the above conditions are grouped together. Slabs in the same group are called identical or similar slabs.

[0072] The distance is defined as follows:

[0073] The distance between slabs a and b is defined as follows, based on the maximum allowable jump value and weighting of the rolling specifications:

[0074] d(a, b)=w1*(abs(r_with1-r_width2) / w_delta)+

[0075] w2*(abs(r_thick1-r_thick2) / t_delta)+

[0076] W3*(abs(hardness 1-hardness2) / h_delta)+

[0077] W4*(abs(sTemp2-sTemp1) / s_delta)

[0078] When a and b cannot satisfy the adjacency jump specification, we define d(a, b) = ∞.

[0079] Where: w1, ..., W4 are influence factors, with values ​​ranging from [0, 1], which can be set according to actual needs. Generally, w1 + ... + W4 = 1.0 is required.

[0080] w_delta: The maximum allowable jump in rolling width between adjacent slabs;

[0081] t_delta: The maximum allowable jump in rolling thickness between adjacent slabs;

[0082] h_delta: The maximum allowable jump in hardness between adjacent slabs;

[0083] s_delta: The maximum allowable jump in furnace temperature between adjacent slabs;

[0084] abs(x): Takes the absolute value of x.

[0085] r_with1, r_thick1, hardness1, sTemp1; r_with2, r_thick2, hardness2, sTemp2 are the rolling width, rolling thickness, slab hardness, and furnace exit temperature of the front and rear slabs, respectively.

[0086] d(a, b) describes the smoothness between adjacent connecting slabs in the rolling plan, and is also one of the important indicators for measuring the quality of the plan.

[0087] The distance between slab connecting blocks A and B can be defined based on the distance between the slabs:

[0088] d(A, B) = d(a1, b0)

[0089] Where a1 and b0 are the last slab blank of block A and the first slab blank of block B, respectively.

[0090] The specific definition of the slab and its block sequence sorting is as follows:

[0091] Sort the slab sequence S1, ..., Sn in ascending order according to the following rules:

[0092] For Sj to precede Sk, one of the following conditions must be met:

[0093] 1) r_width1(Sj) <r_width2(Sk)

[0094] 2)r_width1(Sj)==r_width2(Sk)&&r_thick1(Sj)>r_thick2(Sk)

[0095] 3)r_width1(Sj)==r_width2(Sk)&&r_thick1(Sj)==r_thick2(Sk)&&hardness1(Sj) <hardness2(Sk)

[0096] 4)r_width1(Sj)==r_width2(Sk)&&r_thick1(Sj)==r_thick2(Sk)&&hardness1(Sj)>hardness2(Sk)&&stemp1(Sj) <stemp2(Sk)

[0097] Where r_with1, r_thick1, hardness1, sTemp1; r_with2, r_thick2, hardness2, sTemp2 are the rolling width, rolling thickness, slab hardness, and furnace exit temperature of the front and rear slabs, respectively.

[0098] The above sorting specification is equivalent to the priority being: "rolling width > rolling thickness > slab hardness > furnace exit temperature" and sorted in a combined manner according to "decreasing rolling width, decreasing rolling thickness, increasing slab hardness, and decreasing furnace exit temperature" (abbreviated as "width↓ + thickness↓ + hardness↑ + temperature↓").

[0099] Similarly, a combined descending sort can be defined by simply replacing "<" with ">" in the above condition.

[0100] Based on the ascending / descending sorting definition of the slab sequence, the ascending / descending sorting definition of the head or tail of the block sequence can be defined:

[0101] Sort the head or tail of the block sequence B1, ..., Bn in ascending / descending order, which is equivalent to sorting the slab sequence a1, ..., an in ascending / descending order. Here, a1, ..., an represents the first slab at the head of block B1, ..., Bn or the last slab at the tail.

[0102] The preparation of a hot-cold cross-contamination plan includes the following steps:

[0103] S1, group plan block;

[0104] Set the hot-cold crossover ratio to N. c :N h Generally, to maximize the batch size of hot billets, N is set. h =1, N c =N fur -N h Here, N fur This refers to the total number of hot rolling heating furnaces that have been started.

[0105] Collect all hot billets from the programmable slabs, and group them into several program blocks based on similar slabs, with each block containing N billets. h The blocks are then sorted in descending order according to the first slab of each block, in the order of "width↓ + thickness↓ + hardness↑ temperature↓", to obtain the block sequence: B1, ..., Bm;

[0106] Similarly, all cold billets in the programmable slab are grouped into blocks based on similar slabs, with each block containing N billets. c The cold block sequence is obtained: A1, ..., An.

[0107] When hot or cold billets cannot meet the minimum number of blocks N h or N c In this case, the nearest slab that does not violate the hot-rolled adjacent specification is selected for expansion to meet the minimum number requirement.

[0108] S2, group of mixed blocks;

[0109] Combinations of Bj and Ak: j = 1, ..., m; k = 1, ..., n. If the block sequence Bj of the hot billet and the block sequence Ak of ​​the cold billet can be connected sequentially, then a block BjAk is formed, where j = 1, ..., m; k = 1, ..., n.

[0110] By sequentially grouping the mixed blocks, a mixed block sequence is obtained: C1, ..., Cq.

[0111] During the process of grouping mixed blocks Ct = Bj + Ak, the following must be satisfied:

[0112] Centered on the block sequence Bj of the hot billet, select the block sequence Ak of ​​the cold billet that can be matched;

[0113] The tail of the block sequence Bj of the hot billet and the head of the block sequence Ak of ​​the cold billet should have slab properties as close as possible (dist(Bj,Ak) should be as small as possible), and the general requirement is to ensure the principle of decreasing rolling width, decreasing rolling thickness, and increasing slab hardness as much as possible.

[0114] Based on the block sequence Bj of the hot billet, the preferred sequence for the subsequent block sequence Ak of ​​the cold billet is: the sequence with the smallest distance from the block sequence Bj of the hot billet is preferred.

[0115] If the distances are equal, the selection should be made in the order of decreasing rolling width, decreasing rolling thickness, and increasing slab hardness.

[0116] S3, based on the plan of step S2.

[0117] The mixed block sequence C1, ..., Cq is sorted by a combined ascending order based on rolling width, rolling thickness, slab hardness, and furnace exit temperature to obtain the sorted mixed block sequence C1, ..., Cq; then, a complete planning segment is assembled according to the following steps:

[0118] S31, use a greedy algorithm to find the initial maximum plan block: try to use Ck+1 to continue at the end of Ck (k=1,...,q-1) to form a plan segment sequence of t blocks: D1,...,Dt;

[0119] S32, try to connect Dj+1 to the tail of Dj (j=1,...,t-1) in turn, and replace the last cold blank at the tail of Dj until they can be adjacent;

[0120] S33. If the final number of plan segments is greater than 1, relax the plan adjacency procedure and repeat the above steps S31 to S32 until all plan segments are adjacent to one plan segment. Otherwise, proceed to step S34.

[0121] S34, from the above planning segments, select the longest planning segment as the final hot-cold cross-planning segment; assuming the total number of hot billets in this planning segment is... <N fur *N h_min When the hot billet is a virtual slab, you can select all the hot billets in the current inventory, form a hot-cold mixed block according to the above method, and try to splice them at the beginning and end of the current planning segment until they can no longer be connected.

[0122] S35, Insertion Optimization: For the final sequence of adjacentable planned blocks D1, ..., Dk, and the mixed block set M = {Ck1, Ck2, ...}, the following further optimization is performed:

[0123] Using the mixed block Cx of M in sequence, try whether it can be inserted in front of Dj (j=1,...,k) without violating the rolling specifications, thereby expanding the planned block sequence D1,...,Dk, until every mixed block in M ​​has been tried;

[0124] S36, matching the hot ironing roller material and transition material for this segment to form a complete scheme.

[0125] The specific controls for loading and unloading steel are as follows:

[0126] Set the hot-cold crossover ratio to N. c :N hN fur =N c +N h The cross-rolling plan is divided into two parts according to the rolling sequence: P1 + P2, where P1 is the hot roll material + transition material part of the rolling plan, and P2 is the main part of the hot and cold cross-rolling plan. Part P2 is defined by a length of N. fur The slab blanks are sequentially grouped into groups Gj, ensuring that each group Gj consists of consecutive N. c cold billet, N h Composition of hot billet: P2 = G1 + G2 + ... + Gk. The planned loading of P1 continues the sequential order of the previous plan. Starting from P2, the steel loading and unloading are controlled sequentially according to the order of Gj (j = 1, ..., k) as follows:

[0127] Planned slab charging control: 1, 2, ..., N c The heating furnace is sequentially loaded with the cold-planned slabs from Gj; N c +1, N c +2, ..., N fur The hot slabs in the heating furnace are sequentially loaded into the furnace. Slab extraction control: Ensure that the extraction sequence of the slabs is consistent with the loading sequence.

[0128] Example

[0129] In this embodiment, there are 15 hot billets and 100 CCR slabs in stock. See Tables 1 and 2 below:

[0130] Table 1 Hot Billet Information Table

[0131] slabno r_width r_thick r_hard temp cut_time pri 1 1540 3.50 3 1170 20230224020919 7 2 1540 3.53 3 1170 20230224021102 7 3 1546 3.53 3 1170 20230224021302 7 4 1516 3.83 2 1190 20230224021907 5 5 1516 3.11 2 1190 20230224022051 5 6 1407 3.11 2 1190 20230224022853 5 7 1407 3.53 2 1190 20230224023038 5 8 1391 3.53 3 1190 20230224052741 5 9 1391 3.53 3 1190 20230224052747 5 10 1391 3.53 3 1170 20230224053540 7 11 1391 3.53 3 1170 20230224054343 7 12 1391 3.21 3 1170 20230224054536 7 13 1217 3.21 3 1170 20230224055248 7 14 1217 3.21 3 1170 20230224055418 7 15 1217 3.21 3 1170 20230224060330 7

[0132] Table 2 CCR Slab Information Table

[0133]

[0134] The planned jump specifications for adjacent slabs are as follows: the maximum jump in width is 350, the maximum jump in thickness is 1.2, and the maximum jump in hardness is 3.

[0135] The number of heating furnaces is 3, and the cross ratio is 1:2, that is, each hot billet is matched with 2 CCR slabs.

[0136] Based on the hot billets in Table 1, the "hot-cold-cold" cross-blocks of group 1:2 are shown in Table 3:

[0137] Table 3 Cross Block Information Table

[0138]

[0139] For the cross blocks M01, ..., M15, the heads are sorted in descending order of width, descending order of thickness, and ascending order of hardness, resulting in the following sorted composite slab table 4:

[0140] Table 4 Information Table of Ordered Intersection Blocks

[0141]

[0142] For the ordered cross blocks in Table 4, a planning sequence is arranged to ensure that adjacent blocks meet the requirements of the adjacent slab jump specification, resulting in the cross planning sequence shown in Table 5 below:

[0143] Table 5 Cross-Plan Slab Information

[0144]

[0145] For this cross-plan sequence, matching the hot roll transition material, a complete rolling plan table 6 is formed:

[0146] Table 6. Overview of Slabs under Cross-Rolling Plans

[0147]

[0148] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs, characterized in that: First, according to the ratio of hot to cold cross-contamination, a fixed number of hot and cold mixed slabs are assembled; Subsequently, the hot and cold mixed slabs are planned and compiled to form a hot and cold cross plan; Finally, the hot and cold cross-plan is optimized and compiled on a block-by-block basis to form a hot rolling plan.

2. The method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs according to claim 1, characterized in that, The specific setting of the hot-cold cross ratio is as follows: Let N be the number of furnaces in the hot rolling heating furnace. fur The ratio of hot to cold crossover is n1:n2, and n1+n2=N fur This indicates that cold billets are loaded into the first n1 furnace and hot billets are loaded into the second n2 furnace. When the number of hot billets is N, the maximum value of n2 is [N / N]. fur ].

3. The method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs according to claim 1, characterized in that, The optimization of the hot-cold crossover plan includes the following steps: S1, group plan block; S2, group of mixed blocks; S3, based on the plan of step S2.

4. The method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs according to claim 3, characterized in that, Step S1 specifically includes the following process: Set the hot-cold crossover ratio to N. c :N h ; Collect all hot billets from the programmable slabs, and group them into several program blocks based on similar slabs, with each block containing N billets. h The first slab of each block is sorted in descending order according to the sequence "width↓+thickness↓+hardness↑temperature↓", resulting in the block sequence: B1, ..., Bm; Similarly, all cold billets in the programmable slab are grouped into blocks based on similar slabs, with each block containing N billets. c The cold block sequence is obtained: A1, ..., An.

5. The method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs according to claim 4, characterized in that: When the hot blank or the cold blank cannot meet the minimum number of blocks N h or N c In this case, the nearest slab that does not violate the hot-rolled adjacent specification is selected for expansion.

6. The method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs according to claim 4, characterized in that, The specific steps S2 are as follows The process includes the following: If the block sequence Bj of the hot billet and the block sequence Ak of ​​the cold billet can be connected sequentially, then a block BjAk is formed, where j = 1,...,m; k = 1,...,n; By sequentially grouping the mixed blocks, a mixed block sequence is obtained: C1,...,Cq.

7. The method for scheduling and optimizing the hot and cold cross-grinding of hot-rolled slabs according to claim 6, characterized in that, During the process of assembling and mixing blocks, the following conditions must be met: Centered on the block sequence Bj of the hot billet, select the block sequence Ak of ​​the cold billet that can be matched; The tail of the block sequence Bj of the hot billet and the head of the block sequence Ak of ​​the cold billet must have similar slab properties. Based on the block sequence Bj of the hot billet, the preferred selection sequence for the subsequent block sequence Ak of ​​the cold billet is: the sequence with the smallest distance from the block sequence Bj of the hot billet is preferred. If the distances are equal, the selection should be made in the order of decreasing rolling width, decreasing rolling thickness, and increasing slab hardness.

8. The method for scheduling and optimizing the cross-cutting of hot and cold rolling slabs according to claim 6, characterized in that, The specific steps S3 are as follows The process includes the following: The mixed block sequence C1,...,Cq is sorted in ascending order by "rolling width ↓, rolling thickness ↓, slab hardness ↓, furnace exit temperature ↓" to obtain the sorted mixed block sequence C1,...,Cq; and then a complete planning segment is formed according to the following steps: S31, using a greedy algorithm to find the initial maximum plan block: try to use Ck+1 to continue at the end of Ck, k=1,...,q-1, to form the t-block plan segment sequence: D1,...,Dt; S32, try to connect Dj+1 to the tail of Dj in turn, j=1,...,t-1, and replace the last cold blank at the tail of Dj until they can be adjacent; S33. If the final number of plan segments is greater than 1, relax the plan adjacency procedure and repeat the above steps S31 to S32 until all plan segments are adjacent to one plan segment. Otherwise, proceed to step S34. S34, select the longest planning segment as the final hot-cold crossover planning segment; S35, for the final sequence of adjacentable planned blocks D1,...,Dk, and the mixed block set M={Ck1,Ck2,...}, the following further optimization is performed: Using the mixed block Cx of M in sequence, try whether it can be inserted in front of Dj, j=1,...,k, without violating the rolling specifications, thereby expanding the planned block sequence D1,...,Dk, until every mixed block in M ​​has been tried; S36, matching the hot ironing roller material and transition material for this segment to form a complete scheme.

9. The method for scheduling and optimizing the hot and cold cross-grinding of hot-rolled slabs according to claim 4, characterized in that, The process for collecting the programmable slab is as follows: Current inventory includes all programmable cold billets: {Xj:j=0,...,n}; programmable hot billets: {Yk:k=0,...,m}; The distinction between the hot billet and the cold billet is determined by the current temperature Tmin of the slab: if the temperature of the slab is less than Tmin... min If so, it is a cold blank; If not, then it is determined to be a hot billet.

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