A width optimization control method for positive and negative skip width adjustment during continuous casting production

Abstract

The application discloses a width optimization control method for positive and negative jump width adjustment in continuous casting production and belongs to the field of control. The method comprises the following steps: obtaining furnace data; determining the width adjustment direction of the furnace; adjusting the contract order in the furnace; obtaining relevant process parameters; establishing a width optimization control model; solving the width optimization control model; and issuing the production of the furnace, and the continuous casting machine performs positive jump width adjustment or negative jump width adjustment according to the tapping scheme. The method can accurately determine the positive and negative jump width adjustment direction and the optimal casting width in each furnace according to the relevant process parameter requirements of the continuous casting process, provide a basis for the width adjustment production of the continuous casting machine, reduce the width adjustment frequency, improve the efficiency of the continuous casting production, and can be widely used in the automatic control field of the continuous casting production process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of metallurgical automatic control, and particularly relates to a width optimization control method for positive and reverse jump width adjustment in continuous casting production. BACKGROUND

[0002] Steel manufacturing is a typical long process industry, in which steelmaking and continuous casting are important links of steel production. The basic unit of steelmaking is a heat, which is a group of contracts according to the capacity of a converter, and the molten iron is smelted in the converter according to the chemical composition requirements to become liquid steel. Then, the liquid steel is transported by a ladle to a rotary table of a continuous casting process, and then poured into a crystallizer of a continuous casting machine through a funnel, slowly cooled and solidified to crystallize, and cast into a solid slab of a predetermined width.

[0003] A continuous casting machine is a continuous steel casting equipment, and must be continuously cast after starting. Therefore, a plurality of heats usually form a heat sequence, and are cast on the continuous casting machine in sequence. Because of the diversification of customer demand, the contract specifications of the heats may be various, and therefore the continuous casting machine usually needs to be adjusted in width for casting. The continuous casting machine has specific process requirements for width adjustment, and the process parameters of different continuous casting machines are different. If the process requirements of the continuous casting machine cannot be met, the casting must be stopped.

[0004] When the width is adjusted for casting, the process requirements of the continuous casting machine itself and the process requirements of the tapping mark also need to be considered. The tapping mark, also called steel grade or steel type, represents the chemical composition and physical properties of the molten steel. In continuous casting, the tapping mark also has specific process requirements for width adjustment, and the process parameters of different tapping marks are also different.

[0005] The width adjustment of the continuous casting machine is generally from wide to narrow, which is called positive jump width adjustment. With the development of process technology, the width adjustment can also be from narrow to wide, which is called reverse jump width adjustment. In continuous casting production, the positive jump width adjustment is usually used, and the reverse jump width adjustment is used only when necessary, such as for continuous casting between different steel types.

[0006] When the steel is smelted, a heat plan is formed for each tapping mark, and then a plurality of heat plans of different tapping marks are connected together to form a heat sequence according to the requirements of continuous casting between different steel types, so as to be continuously cast on a continuous casting machine. After the heat plans are connected in sequence, a width adjustment scheme for the heat plans on the continuous casting machine needs to be developed, which may be positive jump or reverse jump. The general principle is to minimize the number of width adjustments, because the width adjustment will affect the production efficiency of the continuous casting machine and may also cause molten steel leakage. SUMMARY

[0007] The technical problem to be solved by this invention is to provide a width optimization control method for forward and reverse width adjustment in continuous casting production. Based on the relevant process parameters of the continuous casting process, it can accurately determine the forward and reverse width adjustment direction and the optimal casting width for each heat sequence planned for continuous casting on a certain continuous casting machine. This provides a basis for width adjustment production on the continuous casting machine, reduces the number of width adjustments, and improves the efficiency of continuous casting production.

[0008] The technical solution of this invention is: to provide a width optimization control method for forward and reverse width adjustment during continuous casting production, characterized by:

[0009] Based on the relevant process parameters of the continuous casting process, for a heat sequence planned to be continuously cast on a certain continuous casting machine, a width optimization control model is established to optimize and control its width.

[0010] By solving the model, the positive and negative width adjustment directions, as well as the casting width required for each heat and each contract, can be accurately calculated.

[0011] Its specific control process includes the following steps:

[0012] Step 1: Obtain furnace batch data;

[0013] Step 2: Determine the direction of the furnace width adjustment;

[0014] Step 3: Adjust the contract sequence within the furnace cycle;

[0015] Step 4: Obtain relevant process parameters;

[0016] Step 5: Establish a width optimization control model;

[0017] Step 6: Solve the width optimization control model;

[0018] Step 7: Production is initiated for the heat batch, and the continuous casting machine adjusts the width either forward or reverse according to the steel tapping plan.

[0019] Specifically, in step 1, obtaining the furnace data includes: obtaining a batch of furnace data to be produced, which is planned to be continuously cast sequentially on a certain continuous casting machine;

[0020] The specific furnace data items include:

[0021] n: Total number of contracts; s i : The tapping mark for furnace number i; c k Contract number of contract k; The minimum width of contract k; Maximum width of contract k; d k : The number of slab blocks in contract k.

[0022] Specifically, in step 2, the determining of the width adjustment direction of the furnace campaign comprises:

[0023] The average width of each furnace campaign is calculated as follows

[0024]

[0025] Where i is the serial number of the furnace campaign, B i is the contract set in the furnace campaign i, d k is the number of slab blocks of the contract k, is the minimum width of the contract k, is the maximum width of the contract k;

[0026] The width adjustment direction of the furnace campaign is determined according to the average width and whether there is a subsequent furnace campaign;

[0027] The width adjustment direction of the furnace campaign i is determined as follows:

[0028] 1) If the furnace campaign i has no subsequent furnace campaign, the furnace campaign i is by default positively adjusted in width;

[0029] 2) If the furnace campaign i has a subsequent furnace campaign i+1, then:

[0030] ① If then the furnace campaign i is positively adjusted in width to the furnace campaign i+1;

[0031] ② If then the furnace campaign i is negatively adjusted in width to the furnace campaign i+1.

[0032] Further, in step 3, the adjusting of the contract sequence in the furnace campaign comprises:

[0033] The center width of each contract is calculated as follows

[0034]

[0035] Wherein is the minimum width of the contract k, is the maximum width of the contract k;

[0036] The contracts in the furnace campaign are sequenced according to the width adjustment direction of each furnace campaign;

[0037] The contracts of the furnace campaign i are sequenced as follows:

[0038] 1) If the width adjustment direction is positively adjusted in width, the contracts are sequenced in descending order according to the center width of the contracts from large to small;

[0039] 2) If the width adjustment direction is reverse jump width adjustment, the center width of the contract Sort from small to large in ascending order.

[0040] Further, in step 4, the acquisition of the relevant process parameters includes:

[0041] 1) Acquisition of process parameters of the continuous casting machine:

[0042] Acquisition of process parameters of the continuous casting machine, including maximum and minimum width of the continuous casting machine, minimum width adjustment amount, maximum positive jump width adjustment amount, and maximum reverse jump width adjustment amount;

[0043] The number of available casting width gears of the continuous casting machine is calculated as follows:

[0044] Gear number = [(maximum width of the continuous casting machine - minimum width of the continuous casting machine) / minimum width adjustment amount] + 1;

[0045] The specific process parameter data items are as follows:

[0046] W1: minimum width of the continuous casting machine;

[0047] W2: maximum width of the continuous casting machine;

[0048] L: minimum width adjustment amount of the continuous casting machine;

[0049] Z: maximum positive jump width adjustment amount of the continuous casting machine;

[0050] F: maximum reverse jump width adjustment amount of the continuous casting machine;

[0051] m: number of width gears of the continuous casting machine;

[0052] 2) Acquisition of process parameters of the tapping mark:

[0053] Summarize the tapping marks of all heats, and acquire process parameters of each tapping mark, including maximum positive jump width adjustment amount and maximum reverse jump width adjustment amount;

[0054] Map the process parameters of the tapping marks to each contract of each heat, and the specific process parameter data items are as follows:

[0055] P k : maximum positive jump width adjustment amount of the tapping mark corresponding to contract k;

[0056] R k : maximum reverse jump width adjustment amount of the tapping mark corresponding to contract k.

[0057] Further, in step 5, the establishment of the width optimization control model includes: establishing a width optimization control model according to the contract data after adjustment of the order and the process parameters;

[0058] Wherein, the decision variables include:

[0059] x k : non-negative integer variable, representing the casting width of contract k;

[0060] y kt : 0-1 variable, representing whether the tth width notch is used for contract k, taking 1 for use and 0 otherwise;

[0061] z k : 0-1 variable, representing whether the width is adjusted from contract k to contract k+1, taking 1 for adjustment and 0 otherwise;

[0062] The optimization objective of the width optimization control model includes:

[0063] 1) The number of width adjustments is as small as possible:

[0064]

[0065] 2) The contract uses the largest width notch as much as possible:

[0066]

[0067] Finally, the two objectives are weighted into a composite objective:

[0068]

[0069] wherein f1 and f2 are the weight coefficients of the objectives;

[0070] The constraint conditions of the width optimization control model are:

[0071] 1) Each contract must and can only select one width notch:

[0072]

[0073] 2) Each contract calculates the casting width according to the selected notch:

[0074]

[0075] 3) The range of the casting width of each contract is limited:

[0076]

[0077] 4) The maximum positive jump width limit of the continuous casting machine is limited:

[0078] x k -x k+1 ≤ Z, k = 1,..., n-1 (5)

[0079] 5) The maximum positive jump width limit of the tapping mark is limited:

[0080] x k -x k+1 ≤P k ,k=1,...,n-1 (6)

[0081] 6) The maximum limit of the reverse jump width adjustment of the continuous casting machine:

[0082] x k+1 -x k ≤F,k=1,...,n-1 (7)

[0083] 7) The maximum limit of the reverse jump width adjustment of the tapping mark:

[0084] x k+1 -x k ≤R k ,k=1,...,n-1 (8)

[0085] 8) Determine whether to adjust the width between adjacent contracts:

[0086] T·z k ≥|x k -x k+1 |,k=1,...,n-1 (9)

[0087] where T is a very large constant.

[0088] Further, in step 6, the specific method for solving the width optimization control model is as follows:

[0089] new auxiliary decision variables u k , v k , let x k -x k+1 = u k -v k , then |x k -x k+1 |= u k +v k , change the constraint condition (9) to the following two constraints:

[0090] x k -x k+1 = u k -v k ,k=1,...,n-1 (10)

[0091] T·z k ≥ u k +v k ,k=1,...,n-1 (11)

[0092] For the linear integer programming model consisting of optimization objective (1) and constraints (2)-(8), (10)-(11), the branch and bound method is used to solve it; the relevant data are substituted into the model to obtain the solution of the model and determine the casting width adopted by each contract.

[0093] Compared with the prior art, the advantages of the present invention are:

[0094] 1. This technical solution is designed for a series of heats to be continuously cast. Based on the relevant process parameters of the continuous casting process, after reasonably adjusting the order of the contracts within the heat, the casting width and adjustment direction of each contract are determined by the model. The width is optimized and controlled to reduce the number of width adjustments required by the continuous casting machine. At the same time, each contract produces slabs with the largest possible width, thereby improving production efficiency.

[0095] 2. This technical solution addresses the issue of how to adjust the casting width in the heat sequence by establishing a width optimization control model. It accurately calculates the required casting width for each heat and each contract, determines the direction of width adjustment, and minimizes the number of width adjustments required by the continuous casting machine while ensuring that the contract uses the largest possible casting width for production. Attached Figure Description

[0096] Figure 1 This is a flowchart of the optimized control method of the present invention. Detailed Implementation

[0097] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0098] The present invention provides a width optimization control method for forward and reverse width adjustment in continuous casting production. This optimization control method establishes a width optimization control model to accurately calculate the casting width to be used in the continuous casting process. The specific process is as follows:

[0099] Step 1, Obtain the data of the heat:

[0100] Acquire a batch of heats to be produced, which are planned to be cast sequentially on a continuous casting machine. The data includes the tapping mark, contract number, maximum and minimum width corresponding to the contract, number of slabs, etc., to prepare for model calculation.

[0101] The specific data items are as follows:

[0102] n: Total number of contracts;

[0103] s i The tapping mark for furnace number i;

[0104] c k Contract number of contract k;

[0105] the minimum width of contract k;

[0106] the maximum width of contract k;

[0107] d k the slab block number of contract k.

[0108] Step 2, Determine the width adjustment direction of the heat:

[0109] The average width of each heat is calculated as follows

[0110]

[0111] where i is the heat number, B i is the contract set within heat i, d k is the slab block number of contract k, is the minimum width of contract k, is the maximum width of contract k.

[0112] The width adjustment direction of a heat is determined according to the average width and whether there is a subsequent heat.

[0113] For heat i, the width adjustment direction is determined as follows:

[0114] 1) If heat i has no subsequent heat, heat i is by default positive jump width adjustment;

[0115] 2) If heat i has a subsequent heat i+1, then:

[0116] ① If then from heat i to heat i+1 is positive jump width adjustment;

[0117] ② If then from heat i to heat i+1 is negative jump width adjustment.

[0118] Step 3, Adjust the contract order within the heat:

[0119] The center width of each contract is calculated as follows

[0120]

[0121] where is the minimum width of contract k, is the maximum width of contract k;

[0122] According to the width adjustment direction of each heat, the contracts within the heat are sorted.

[0123] For heat i, its contracts are sorted as follows:

[0124] 1) If the width adjustment direction is a positive jump, the contract shall be based on the center width. Sort from largest to smallest (i.e., descending order);

[0125] 2) If the width adjustment direction is a reverse width adjustment, the contract shall be based on the center width. Sort in ascending order (from smallest to largest).

[0126] Step 4, Obtain the relevant process parameters:

[0127] 1) Obtain the process parameters of the continuous casting machine:

[0128] Obtain the process parameters of the continuous casting machine, including the maximum and minimum width of the continuous casting machine, the minimum width adjustment, the maximum forward width adjustment, and the maximum reverse width adjustment.

[0129] The available casting width of a continuous casting machine is divided into several sections, and the number of sections is calculated as follows:

[0130] Number of gears = [(maximum width of continuous casting machine - minimum width of continuous casting machine) / minimum width adjustment] + 1.

[0131] The specific process parameter data items are as follows:

[0132] W1: Minimum width of the continuous casting machine;

[0133] W2: Maximum width of the continuous casting machine;

[0134] L: Minimum width adjustment for continuous casting machines;

[0135] Z: Maximum positive jump width adjustment of the continuous casting machine;

[0136] F: Maximum rebound width adjustment of the continuous casting machine;

[0137] m: The number of width stops of the continuous casting machine, i.e., m = [(W2-W1) / L] + 1.

[0138] 2) Obtaining process parameters for tapping marks:

[0139] Summarize the tapping marks of all heats and obtain the process parameters for each tapping mark, including the maximum value of positive and negative tapping width adjustment.

[0140] The process parameters for the tapping marks are mapped to the specific contracts for each heat. The specific process parameter data items are as follows:

[0141] P k : The maximum positive jump width adjustment value of the steel tapping mark corresponding to contract k;

[0142] R k : The maximum value of the rebound width adjustment corresponding to the steel output mark of contract k.

[0143] Step 5, Establish the width optimization control model:

[0144] According to the adjusted contract data and the process parameters, a width optimization control model is established.

[0145] Decision variables:

[0146] x k : non-negative integer variable, representing the casting width of contract k;

[0147] y kt : 0-1 variable, representing whether the tth width block is used for contract k, taking 1 for use and 0 otherwise;

[0148] z k : 0-1 variable, representing whether the width is adjusted from contract k to contract k+1, taking 1 for adjustment and 0 otherwise.

[0149] Optimization objectives:

[0150] 1) The number of width adjustments is as small as possible:

[0151]

[0152] Wherein obj1 is the number of width adjustments;

[0153] 2) The contract is cast with the largest width block as possible:

[0154]

[0155] Wherein obj2 is the casting width block;

[0156] Finally, the two objectives are weighted into a composite objective:

[0157]

[0158] Wherein f1 and f2 are the weight coefficients of the objectives.

[0159] Constraint conditions:

[0160] 1) Each contract must and can only select one width block

[0161]

[0162] 2) Each contract calculates the casting width x according to the selected block k

[0163]

[0164] 3) The casting width range of each contract is limited

[0165]

[0166] 4) Maximum limit of positive jump width adjustment for continuous casting machine

[0167] x k -x k+1 ≤Z,k=1,...,n-1 (5)

[0168] 5) Maximum limit of positive jump width adjustment for tapping marks

[0169] x k -x k+1 ≤P k ,k=1,...,n-1 (6)

[0170] 6) Maximum limit of rebound width adjustment for continuous casting machines

[0171] x k+1 -x k ≤F,k=1,...,n-1 (7)

[0172] 7) Maximum limit of rebound width adjustment for tapping marks

[0173] x k+1 -x k ≤R k ,k=1,...,n-1 (8)

[0174] 8) Determine whether the width of adjacent contracts needs to be adjusted.

[0175] T·z k ≥|x k -x k+1 |,k=1,...,n-1 (9)

[0176] In the above constraints, the meanings of each letter variable symbol are as follows:

[0177] B i : The set of contracts within furnace i; c k : Contract number of contract k; d k : Number of slab blocks in contract k; m: Number of width stops for the continuous casting machine; n: Total contract quantity; i: Heat sequence number; s i : The tapping mark for heat i; t: The width gate number of the continuous casting machine; k: The contract number; T: A very large constant;

[0178] Maximum width of contract k; The minimum width of contract k; The center width of contract k; The average width of the contract;

[0179] W1: minimum width of the continuous caster; W2: maximum width of the continuous caster; L: minimum amount of width adjustment of the continuous caster; Z: maximum amount of positive jump width adjustment of the continuous caster; F: maximum amount of negative jump width adjustment of the continuous caster; P k : maximum value of positive jump width adjustment of the taping mark corresponding to contract k; R k : maximum value of negative jump width adjustment of the taping mark corresponding to contract k; x k : non-negative integer variable representing the casting width of contract k; y kt : 0-1 variable representing whether the tth width block is used by contract k, with a value of 1 representing use and 0 otherwise; z k : 0-1 variable representing whether the width is adjusted from contract k to contract k+1, with a value of 1 representing adjustment and 0 otherwise; minobj1: minimum number of width adjustments; maxobj2: maximum block casting width.

[0180] Step 6, Solve the width optimization control model:

[0181] Constraint (9) in Step 5 is a nonlinear constraint due to the absolute value. It can be linearized by substitution.

[0182] The specific method is as follows:

[0183] New auxiliary decision variables u k and v k are added, which are non-negative integer variables, and let x k -x k+1 = u k -v k . Then the absolute value term in the model can be eliminated, i.e., |x k -x k+1 | = u k +v k , so constraint (9) can be changed to the following two constraints:

[0184] x k -x k+1 = u k -v k , k = 1,..., n-1 (10)

[0185] T·z k ≥ u k +v k , k = 1,..., n-1 (11)

[0186] The model composed of the optimization objective (1), constraints (2)-(8), (10)-(11) is a linear integer programming model, and the branch and bound method can be used to solve this type of model. Substitute the relevant data into the model to obtain the solution of the model, and determine the casting width used by each contract.

[0187] Step 7, Issue the production of the heat:

[0188] For this batch of heats, each contract in each heat determines the casting width, and the tapping scheme of the slab can be determined. The batch of heats is issued in sequence for production, and the continuous casting machine adjusts the width forward or backward according to the tapping scheme.

[0189] Embodiment:

[0190] Step 1, Obtain the data of the heat:

[0191] The heat data obtained in this embodiment is shown in Table 1, which plans to be continuously cast on No. 5 continuous casting machine (5#CC).

[0192] This batch of data has 6 heats, a total of 18 contracts, i.e. n = 18.

[0193] Table 1 Heat Information (width unit: mm)

[0194]

[0195]

[0196] Step 2, Determine the width adjustment direction of the heat:

[0197] According to the data in Table 1, the average width of each heat is calculated as follows:

[0198]

[0199] There are:

[0200] 1) Heat 1: B1 = {1, 2, 3},

[0201] 2) Heat 2: B2 = {4, 5, 6},

[0202] 3) Heat 3: B3 = {7, 8},

[0203] 4) Heat 4: B4 = {9, 10, 11, 12},

[0204] 5) Heat 5: B5 = {13},

[0205] 6) Heat 6: B6 = {14, 15, 16, 17, 18},

[0206] Then the average width of each heat is compared to determine the width adjustment direction of each heat, and the width adjustment direction of each heat is shown in Table 2.

[0207] Table 2 Average width and width adjustment direction of each heat (width unit: mm)

[0208]

[0209]

[0210] Step 3, Adjust the contract order within the heat:

[0211] The center width of each contract is calculated as follows:

[0212]

[0213] Then the contract order in each heat is adjusted according to the width adjustment direction of each heat and the center width.

[0214] From Table 2, the first heat and the fourth heat need to be adjusted in the opposite direction, and the contracts in each heat are arranged in ascending order of center width. The remaining heats are adjusted in the positive direction, and the contracts in each heat are arranged in descending order of center width.

[0215] The adjusted contract order is shown in Table 3.

[0216] Table 3 Adjusted contract order (width unit: mm)

[0217]

[0218]

[0219] Step 4, Obtain the relevant process parameters:

[0220] 1) Obtain the process parameters of the continuous casting machine

[0221] The process parameters of 5# CC are obtained, as shown in Table 4.

[0222] Table 4 Process parameters of 5# CC (width unit: mm)

[0223]

[0224] Calculate the number of gears of the available casting width of 5# CC:

[0225] m = [(W2-W1) / L] + 1 = [(1450-900) / 50] + 1 = 12

[0226] That is, 5#CC has 12 casting widths, which are 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400 and 1450 respectively.

[0227] 2) Obtain the process parameters of tapping mark

[0228] The tapping marks of 6 heats are AP0941D1, AP1055E5, AQ0640E1 and DP0131D1.

[0229] Obtain the process parameters of each tapping mark, as shown in Table 5.

[0230] Table 5 Process parameters of tapping mark (width unit: mm)

[0231] Tapping mark Positive jump width maximum Negative jump width maximum AP0941D1 150 100 AP1055E5 999 150 AQ0640E1 999 100 DP0131D1 150 150

[0232] Correspond the process parameters of tapping mark to each contract of each heat, as shown in Table 6.

[0233] Table 6 Positive and negative jump width requirements of contract (width unit: mm)

[0234]

[0235]

[0236] Step 5, Establish the width optimization control model:

[0237] According to the data of the foregoing steps, it can be known that n=18, m=12, W1=900, L=50, Z=200 and F=150. Substituting these data into the model, the width optimization control model of the embodiment can be obtained as follows:

[0238]

[0239] s.t.

[0240]

[0241]

[0242]

[0243] x k -x k+1 ≤200, k=1,..., 17

[0244] x k -x k+1 ≤P k , k=1,..., 17

[0245] x k+1 -x k ≤150, k = 1,..., 17

[0246] x k+1 -x k ≤R k , k = 1,..., 17

[0247] T·z k ≥|x k -x k+1 |, k = 1,..., 17

[0248] where x k , y kt , z k are decision variables, P k , R k are constants, f1, f2 are weight coefficients, and T is a very large constant.

[0249] Step 6, Solve the width optimization control model:

[0250] Add auxiliary decision variables u k , v k , and replace the constraints with absolute values in the above model with the following two constraints:

[0251] x k -x k+1 = u k -v k , k = 1,..., 17

[0252] T·z k ≥ u k +v k , k = 1,..., 17

[0253] According to the order of magnitude and importance of the target, the weight coefficients of the target are determined as follows:

[0254] f1 = 10

[0255] f2 = 1 / n = 1 / 18

[0256] Using the branch and bound method to solve the model, the casting width used by each contract in each heat can be obtained, as shown in Table 7.

[0257] Table 7 Casting width of contracts (width unit: mm)

[0258]

[0259] Step 7, Issue the production of the heat:

[0260] The batch of heats is sequentially sent to a 5# continuous casting machine for production, and slabs are produced according to the casting width of the contract, and the width adjustment scheme of the continuous casting machine is: 1100->1200->1150->950->1050->900, and a total of 5 width adjustments are required, of which 3 are positive jump width adjustments, and 2 are reverse jump width adjustments.

[0261] According to the related process parameter requirements of the continuous casting process (including the width adjustment process requirements of the continuous casting machine itself and the width adjustment process requirements of the tapping mark), the width optimization control model is established for the width adjustment of a sequence of heats planned to be continuously cast on a continuous casting machine, so as to optimize and control the width, then the positive and reverse jump width adjustment directions and the casting width required by each contract of each heat are accurately calculated through model solving, which provides a basis for the width adjustment production of the continuous casting machine, reduces the width adjustment times of the continuous casting machine as much as possible, and makes the contract use larger casting width production as much as possible, thereby improving the efficiency of continuous casting production.

[0262] The present application can be widely used in the field of automatic control of continuous casting production process.

Claims

1. A width optimization control method for forward and reverse width adjustment in continuous casting production, characterized by: Based on the relevant process parameters of the continuous casting process, for a heat sequence planned to be continuously cast on a certain continuous casting machine, a width optimization control model is established to optimize and control its width. By solving the model, the positive and negative width adjustment directions, as well as the casting width required for each heat and each contract, can be accurately calculated. Its specific control process includes the following steps: Step 1: Obtain furnace batch data; Step 2: Determine the direction of the furnace width adjustment; Step 3: Adjust the contract sequence within the furnace cycle; Step 4: Obtain relevant process parameters; Step 5: Establish a width optimization control model; Step 6: Solve the width optimization control model; Step 7: Production is initiated for the heat batch, and the continuous casting machine adjusts the width of the casting machine according to the tapping plan, either forward or reverse. In step 5, establishing the width optimization control model includes: establishing the width optimization control model based on the contract data after the adjustment order and the process parameters; The decision variables include: : A non-negative integer variable representing the casting width of contract k; : A 0-1 variable indicating whether contract k uses the t-th width block; a value of 1 indicates use, otherwise 0. : A 0-1 variable, indicating whether the contract width is adjusted from contract k to contract k+1. A value of 1 indicates adjustment, and 0 indicates otherwise. The optimization objectives of its width optimization control model include: 1) Minimize the number of width adjustments: ； 2) The contract should use the widest possible width for casting: ； Finally, the two objectives are weighted and combined into a single composite objective: （1）； in, , Weighting coefficients for the target; The constraints of its width optimization control model are: 1) Each contract must and can only select one width setting: （2）； 2) The casting width for each contract is calculated based on the selected gear position: （3）； 3) Limitations on casting width for each contract: （4）； 4) Maximum limit of positive jump width adjustment for continuous casting machines: （5）； 5) Maximum limit of positive jump width adjustment for tapping marks: （6）； 6) Maximum limit of rebound width adjustment for continuous casting machines: （7）； 7) Maximum limit for the rebound width adjustment of the tapping mark: （8）； 8) Determine whether the width between adjacent contracts needs to be adjusted: （9）； Where T is a very large constant; In step 6, the specific method for solving the width optimization control model is as follows: Add auxiliary decision variables , ,make Then there is Replace constraint (9) with the following two constraints: （10）； （11）； For the linear integer programming model consisting of optimization objective (1) and constraints (2)-(8), (10)-(11), the branch and bound method is used to solve it; the relevant data are substituted into the model to obtain the solution of the model and determine the casting width adopted by each contract.

2. The width optimization control method for forward and reverse width adjustment during continuous casting production according to claim 1, characterized in that, in step 1, acquiring furnace data includes: Obtain data on a batch of heats to be produced, which are planned to be continuously cast sequentially on a certain continuous casting machine; The specific furnace data items include: Total number of contracts; The tapping mark for furnace number i; Contract number of contract k; The minimum width of contract k; : The maximum width of contract k; : The number of slab blocks in contract k.

3. The width optimization control method for forward and reverse width adjustment during continuous casting production according to claim 1, characterized in that, in step 2, determining the width adjustment direction for each heat includes: The average width of each furnace batch is calculated as follows: : ； Where i is the furnace number. Let i be the set of contracts within furnace i. Let k be the number of slab blocks in contract k. Let k be the minimum width of the contract. The maximum width of contract k; The direction of width adjustment for a furnace is determined based on the average width and whether there are subsequent furnace cycles. For furnace i, the width adjustment direction is determined as follows: 1) If there is no subsequent furnace in furnace i, furnace i will default to positive jump width adjustment; 2) If furnace i has a subsequent furnace i+1, then: ①If Then, from the i-th furnace to the (i+1)-th furnace, it is a positive jump width adjustment; ②If Then, from furnace i to furnace i+1, it is a reverse width adjustment.

4. The width optimization control method for forward and reverse width adjustment during continuous casting production according to claim 1, characterized in that... Step 3, the adjustment of the contract sequence within the furnace cycle includes: Calculate the center width of each contract as follows: : ； Among them Let k be the minimum width of the contract. The maximum width of contract k; The contracts within each furnace batch are sorted according to the width adjustment direction of each furnace batch. For furnace number i, its contracts are sorted as follows: 1) If the width adjustment direction is a positive jump, the width shall be based on the center width of the contract. Sort in descending order from largest to smallest; 2) If the width adjustment direction is a reverse width adjustment, it shall be based on the center width of the contract. Sort in ascending order from smallest to largest.

5. The width optimization control method for forward and reverse width adjustment during continuous casting production as described in claim 1. Its characteristic is that in step 4, obtaining the relevant process parameters includes: 1) Obtain the process parameters of the continuous casting machine: Obtain the process parameters of the continuous casting machine, including the maximum and minimum width of the continuous casting machine, the minimum width adjustment, the maximum forward width adjustment, and the maximum reverse width adjustment; The number of available casting width stops for a continuous casting machine is calculated as follows: Number of gears = [(maximum width of continuous casting machine - minimum width of continuous casting machine) / minimum width adjustment] + 1; The specific process parameter data items are as follows: Minimum width of continuous casting machine; : Maximum width of the continuous casting machine; Minimum width adjustment for continuous casting machines; : Maximum positive jump width adjustment of continuous casting machine; : Maximum rebound width adjustment of continuous casting machine; The number of width stops on the continuous casting machine; 2) Obtaining process parameters for tapping marks: Summarize the tapping marks of all heats and obtain the process parameters of each tapping mark, including the maximum value of positive jump width adjustment and the maximum value of negative jump width adjustment; The process parameters for the tapping marks are mapped to the specific contracts for each heat. The specific process parameter data items are as follows: : The maximum positive jump width adjustment value of the steel tapping mark corresponding to contract k; : The maximum value of the rebound width adjustment corresponding to the steel output mark of contract k.

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