Hot rolling DHCR planning and compiling method with blank insertion

Abstract

The invention discloses a hot rolling DHCR plan compilation method with blank insertion. The method comprises the following steps that S1, steelmaking plan data and DHCR plan process constants are obtained; s2, a DHCR plan is compiled; s3, adjusting the feeding rhythm of the DHCR plan during execution; s4, regulating and controlling the starting time of the DHCR plan; and S5, issuing a processing DHCR plan. On the basis of considering the production rhythm of steelmaking and hot rolling, the whole-process processing method from planning to issuing management is provided for planning and implementation of the DHCR plan, and the success rate of planning of the DHCR plan is increased to the maximum extent.

Description

Technical Field

[0001] This invention relates to the technology of production planning and control in steel enterprises in the field of automation information, and more specifically, to a method for compiling a hot-rolled DHCR plan with insert billets. Background Technology

[0002] Hot rolling plans can generally be divided into three types based on the slab material state and furnace charging mode: physical CCR plan, virtual HCR plan, and virtual DHCR plan. Unlike CCR plans, which are based on physical slabs, HCR and DHCR both use virtual slabs as planning materials and aim to increase the furnace charging temperature. However, HCR can only start furnace charging after all slabs have been produced, and its energy-saving effect is not as significant as DHCR. Implementing DHCR scheduling involves three key factors: the steelmaking tapping plan, which determines the slab tapping sequence; the continuous casting tapping and rolling line production rhythm; and the inventory of physical slabs that can be planned. The DHCR slab production time and rhythm are determined by the steelmaking process, while the heating furnace feeding and rolling line rhythm are determined by the heating furnace drawing rhythm and the rolling line rolling rhythm. When the rolling rhythm is faster than the DHCR slab production rhythm, pre-prepared hot slabs need to be inserted to compensate for the insufficient continuous casting tapping feeding. Therefore, when scheduling and optimizing DCHR, special attention should be paid to matching the production rhythm of steelmaking and rolling lines, and an appropriate amount of billet should be prepared in advance to prevent the DHCR slab supply from being interrupted.

[0003] Generally, when DHCR slabs are fed by a single continuous casting machine and hot rolling is operating at full capacity, the hot rolling capacity exceeds the continuous casting output capacity. In this case, it is necessary to prepare slab inserts to compensate for the insufficient hot billet supply rhythm in steelmaking. Most DHCR plan execution failures are due to the inability to match appropriate slab inserts. The formation of a slab insert plan is a crucial step in DHCR planning, and the timing and batch size of slab inserts are constrained by various factors. Achieving and successfully implementing DCHR (Distributed Direct Flow Ratio) planning is far more difficult than CCR (Constant Flow Ratio) planning, and its success rate is also much lower.

[0004] Currently, there are generally two approaches to scheduling hot-rolled DHCR plans, depending on the matching of steelmaking and rolling rhythms: First, when the steelmaking rhythm is faster than the rolling rhythm, there is no need to consider billet insertion, and the planning is largely similar to the actual CCR plan; Second, when the steelmaking rhythm cannot keep up with the rolling rhythm, billet insertion needs to be considered, and an appropriate amount of billets needs to be prepared in advance to compensate for the rhythm imbalance.

[0005] Due to limitations in production contract specifications and the characteristics of hot rolling line process design, DHCR (High-Demand Rolling) planning often requires billet insertion to compensate for insufficient hot billet supply during steelmaking. Furthermore, even when the steelmaking pace exceeds the rolling pace and DHCR supply is sufficient, some billets still need to be prepared to handle unforeseen circumstances and prevent DHCR slab supply interruptions caused by abnormal continuous casting tapping. Therefore, billet insertion planning is a crucial aspect of DHCR planning. In manual operation, this is generally achieved by sacrificing some billet charging temperature to prepare a sufficient quantity of billets, ensuring the normal logistics of the DHCR plan.

[0006] In summary, the DCHR (Distributed Cash Flow Reduction) plan is a type of plan with significant energy-saving and consumption-reducing effects in hot rolling scheduling. When the continuous casting tapping rhythm does not match the hot rolling rhythm, the DHCR (Deep Cash Flow Reduction) plan requires offline physical hot billet insertion to balance the steelmaking and hot rolling logistics rhythms. Due to the complex process management involved in DHCR plan preparation, plan issuance, DHCR plan start time, and the cross-interaction of online and offline logistics, the success rate of DCHR plan implementation is relatively low. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for compiling a hot-rolled DHCR (High-Degree Rolling Rate) plan with insert billets. Based on consideration of the steelmaking and hot-rolling production rhythm, this invention proposes a full-process handling method from plan compilation to issuance and management for DHCR plan compilation and implementation, thereby maximizing the success rate of DHCR plan compilation.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A method for compiling a hot-rolled DHCR plan with a billet insert includes the following steps:

[0010] S1, obtain steelmaking plan data and DHCR plan process constants;

[0011] S2, develop the DHCR plan;

[0012] S3, Adjust the material supply rhythm during the execution of the DHCR plan;

[0013] S4, adjusts the start time of the DHCR plan;

[0014] S5, issue and process the DHCR plan.

[0015] Preferably, the steelmaking plan data includes steelmaking plan number, CAST number, LOT number, tapping mark, heat number, DHCR mark, start injection time, virtual slab number, contract number, rolling width, rolling thickness, hardness, tapping temperature, and planned cutting time.

[0016] The DHCR planned process constants include DHCR slab roller conveyor time, heating furnace charging rhythm, steel tapping rhythm, DHCR planned minimum number of slabs, DHCR planned minimum number of DHCR slabs, maximum allowable error value for slabs of the same width, and maximum rolling kilometers of the same width.

[0017] Preferably, step S2 specifically includes the following steps:

[0018] S21, Obtain a valid continuous DHCR slab sequence;

[0019] S22, a complete rolling plan is formed based on the DHCR slab sequence.

[0020] Preferably, step S21 specifically includes the following steps:

[0021] S211, Set the time period for the DHCR plan, starting from the current time T. start When time T end ;

[0022] S212, Filter out steelmaking furnace plans that do not meet the conditions from the steelmaking plan;

[0023] S213, For the remaining furnace plans, sort them according to the injection start time of each furnace to form a planned furnace sequence: L1, L2, ...Ln;

[0024] S214, based on the planned furnace sequence of step S213 and the planned cutting time sequence of slabs within each furnace, the planned output sequence of DHCR slabs is obtained:

[0025] S11,S12,...,S1q1,S21,S22,...S2q2,...,Sn1,Sn2,...Snq n Where Sij (i = 1, ..., n, j = 1, ..., qi) is the j-th DHCR slab in the i-th furnace Li;

[0026] S215, the planned output sequence of DHCR slabs from step S214 is grouped sequentially to obtain the grouping sequence: B1,...,Bm.

[0027] Preferably, step S22 specifically includes:

[0028] Sequentially select planning block Bj (j=1,...,m) from the group sequence B1,...,Bm. Match the hot ironing roller transition material at the head of Bj and splice the CCR cold billet plan at the tail: Pj=R j1 +Bj+R j2 .

[0029] Preferably, in step S212, filtering out steelmaking furnace plans that do not meet the conditions includes:

[0030] 1) The start time of the furnace injection is not in [T] start ,T end Within the time frame;

[0031] 2) The furnace loading mode is not DHCR;

[0032] If any of the above conditions are met, the item will be removed.

[0033] Preferably, in step S215, the sequential grouping of the planned output sequence of DHCR slabs must meet the following conditions:

[0034] 1) Same CAST number

[0035] 2) All slabs in Bi have the same tapping mark.

[0036] 3)|Bi|≥DhcrSizeMin

[0037] 4)|Wi-Wj|≤ΔW, Si, Sj∈Bi

[0038] 5)|Ti-Ti+1|≤ΔTmin, Si, Si+1∈Bi

[0039] Where |Bi| represents the number of elements in set Bi; Wi and Wj are the rolling widths of slabs Si and Sj in group Bi, respectively; ΔW is a process constant used to define the maximum allowable error value for any two slabs to have the same width; Ti and Ti+1 are the production times of adjacent slabs Si and Si+1 in group Bi, respectively; ΔTmin is the DHCR plan process constant, which is generally matched with the charging rhythm of the heating furnace; DhcrSizeMin is the minimum number of DHCR slabs required by the DHCR plan.

[0040] Preferably, step S22 further includes:

[0041] Find the first Pk (1≤m) that satisfies the following condition:

[0042] |Pk|=|R k1 |+|Bk|+|R k2 |≥PlanSizeMin

[0043] Among them, R k1 For use as a transition material for ironing rollers; Bk is the main body of the DHCR project; R k2 To continue the physical CCR plan section following the DHCR plan segment Bk, and to compensate for the insufficient number of slabs in the DHCR plan; PlanSizeMin is the minimum number of slabs required by the DHCR plan.

[0044] If the above Pk exists, then the DHCR plan Pk has been output; otherwise, the DHCR plan compilation has failed, indicating that the current DHCR plan prerequisites are not met and a qualified DHCR plan cannot be compiled.

[0045] Preferably, step S3 specifically includes:

[0046] The DHCR program includes P1+P2+P3;

[0047] Among them, P1 is the physical blank of the planned hot rolling roller material and its transition material; P2 is the main part of DHCR, a virtual blank; P3 is the physical supplementary blank for the insufficient part of the DHCR blank.

[0048] When the main part of the DHCR plan is being executed, the heating furnace is fed entirely from the direct hot billets of the DHCR plan section.

[0049] When the DHCR slab supply rhythm in steelmaking continuous casting does not match the steel charging rhythm in the heating furnace, the DHCR supply method needs to be adjusted:

[0050] When the DHCR feeding rhythm is greater than the furnace charging rhythm, any excess DHCR slabs that cannot be charged in time will be taken off the line and then reconnected at the end of the DHCR line.

[0051] When the DHCR feeding rhythm is less than the furnace charging rhythm, it is necessary to prepare the replenishment material in advance for the DHCR plan, i.e., the billet insertion plan.

[0052] Preferably, the blanking plan specifically includes:

[0053] P2 = P21 + P22

[0054] Among them, P21 is a buffer plan slab used as a billet insert to compensate for the mismatch between the production rhythm of continuous casting and hot rolling; P22 is the main part of the DHCR plan.

[0055] When the number of slabs in the DHCR plan is insufficient, offline hot billets are used as insert billets. The offline physical slabs used as insert billets need to meet the following conditions:

[0056] 1) The specifications are the same as those of the DHCR planned billet;

[0057] 2) The steel grade is the same as that of the DHCR planned billet;

[0058] 3) The temperature difference between the DHCR loading temperature and the DHCR loading temperature shall not exceed ΔT;

[0059] When the billet output rate of continuous casting in steelmaking is slower than the charging rate of hot rolling furnace, the executed DHCR plan will be insufficient due to insufficient material supply, and a billet insertion plan needs to be prepared at this time.

[0060] During the execution of DHCR, some offline hot billets are inserted into the DHCR planned slab at intervals according to actual needs to make up for insufficient material supply.

[0061] Preferably, the size Nb of the blanking plan is determined by the following formula:

[0062] Nb=(Nd / Vr-Nd / Vc)*Vr+Nh(2.1)

[0063] Where Vr and Vc are the billet output rhythms of hot rolling and continuous casting, respectively; Nd is the size of P2 in the DHCR plan; and Nh is the number of hot billets used as inserts offline.

[0064] Preferably, step S4 specifically includes:

[0065] If there are n preceding plans to be executed, with a production order of P1, ..., Pn, and the number of unloaded slabs corresponding to each plan is N1, ..., Nn respectively; then the total time taken from the current plan to the loading of the last slab of the last preceding plan is:

[0066] T sum0 =∑(Nj / Vr)(1.1)

[0067] Where Vr represents the hot rolling rhythm;

[0068] If the number of actual slabs in the transition material section of the DHCR plan is N0, and the number of inserts for balancing the rolling rhythm is Nb; when the first DHCR planned slab S0 can continue the production of the preceding planned slabs, and all planned slabs before S0 are produced, the time required is:

[0069] T sum =T sum0 +(N0+Nb) / Vr(1.2)

[0070] To ensure that the first DHCR planned billet S0 can be produced consecutively, the planned production time t0 of this billet should satisfy the following relationship:

[0071] T sum -Vf≤t0+T tran ≤T sum +Vf(1.3)

[0072] Where Vf represents the charging rhythm of the hot-rolled heating furnace slab; T tran The transportation time for slabs to be directly conveyed from the cutting production line to the furnace loading waiting position via conveyor rollers;

[0073] When relations (1.1) to (1.3) are not satisfied, the preceding plans and the current DHCR need to be adjusted to ensure that relation (1.2) is satisfied.

[0074] Preferably, methods for adjusting previous plans and current DHCR include:

[0075] 1) t0>T sum +Vf–T tran

[0076] This situation indicates that DHCR slab production is lagging behind and cannot meet the planned continuity requirements. Therefore, it is necessary to insert several physical slabs into the previous plan to compensate for the delays in the continuity plan. The number of physical slabs to be inserted is:

[0077] X = Ceil((t0-T) sum -Vf+T tran ) / Vr)(1.4)

[0078] 2)t0 <T sum +Vf–T tran

[0079] This situation indicates that DHCR slab production is ahead of schedule and cannot meet the planned follow-up requirements. Therefore, it is necessary to delete a number of physical slabs from the previous plan to compensate for the schedule change. The number of physical slabs to be deleted is:

[0080] X = Ceil((T) sum -Vf+T tran -t0) / Vr)(1.5)

[0081] After deleting the N1 slab, the condition expression (1.3) still cannot be satisfied. The problem is solved by increasing the number of DHCR inserts. The increased number of inserts is also calculated by expression (1.5).

[0082] Here, Ceil(Y) represents rounding up to the nearest integer in Y.

[0083] Preferably, step S5 specifically includes:

[0084] The DHCR plan P includes P = P1 + P21 + P22 + P3;

[0085] Among them, P1 and P3 are physical CCR plans; P21 is the virtual slab DHCR insertion plan; P22 is the virtual slab DHCR plan;

[0086] The DHCR plan is issued in the following order: P21, P22, P1, P3. The execution order of the DHCR plan is: P1, P21+P23, P3.

[0087] The hot-rolled DHCR planning method provided by this invention has the following advantages:

[0088] 1) Based on the steelmaking plan, a virtual slab scheduling plan for DHCR scheduling can be performed. As long as it exists, the model system can always find and schedule it into an optimized DHCR plan, avoiding potential omissions and deficiencies in the manual operation mode.

[0089] 2) This invention has a positive impact on standardizing the hot rolling DHCR scheduling process, improving the efficiency of planned rolling preparation and rolling plan performance, and reducing the energy consumption of the rolling line heating furnace. Detailed Implementation

[0090] 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.

[0091] DHCR Program Prerequisites Identification

[0092] The DHCR hot rolling plan is based on the DHCR virtual slabs of the steelmaking plan and needs to meet certain conditions. The current DHCR plan prerequisites are determined by the DHCR slab attributes and specification group spacing of the steelmaking plan, the number of DHCR plan slabs, and the first DHCR plan slab cutting time.

[0093] 1) Minimum number of DCHR slabs

[0094] 1.1) The minimum number of heats for the current steelmaking plan with the same width slab steelmaking DHCR plan that has an injection start time is 2;

[0095] 1.2) The minimum number of heats for the DHCR steelmaking plan with the same width slab injection start time is 1, and the number of hot billets of the same specification is at least Nh blocks;

[0096] Nh should satisfy the rhythm matching requirement; as long as one of the above conditions is met, it is sufficient.

[0097] 2) DHCR slab properties and specification group spacing

[0098] Slabs in the same DCHR plan have the same CAST number, the same tapping mark, and the same slab width.

[0099] 3) Cutting time of the first slab in the first DHCR furnace

[0100] T1+T tran ≥T min

[0101] Where T1 is the cutting time of the first DHCR slab in the first DHCR furnace; T tranThe time it takes for slabs to be transported directly from the cutting production line to the furnace loading position via conveyor rollers; T min This is the minimum time reference constant for the DHCR plan, determined by the process conditions of the continuous casting and hot rolling production lines.

[0102] Only when all three conditions mentioned above are met can the DHCR plan be initiated. Otherwise, the virtual slabs with these DHCR attributes will be processed as HCR or CCR plans after production.

[0103] This invention provides a method for compiling a hot-rolled DHCR plan with a billet insert, comprising the following steps:

[0104] S1, Obtain steelmaking plan data and DHCR plan process constants.

[0105] Steelmaking plan data includes steelmaking plan number, CAST number, LOT number, tapping mark, heat number, DHCR mark, start injection time, virtual slab number, contract number, rolling width, rolling thickness, hardness, tapping temperature, and planned cutting time.

[0106] The DHCR planned process constants include DHCR slab roller conveyor time, heating furnace charging rhythm, steel tapping rhythm, DHCR planned minimum number of slabs, DHCR planned minimum number of DHCR slabs, maximum allowable error value for slabs of the same width, and maximum rolling kilometers of the same width.

[0107] S2, develop a DHCR plan, which includes the following steps:

[0108] S21, Obtain a valid continuous DHCR slab sequence, specifically including:

[0109] From all steelmaking heat plans, based on the conditions for compiling DHCR plans, all heats that can be planned for DHCR are selected and sorted according to the planned cutting time of the first slab in each heat, forming a sequence of planned heats for consecutive production: L1, L2, ... Ln.

[0110] Based on the production sequence of the above heats and the planned output time sequence of slabs within each heat, the following DHCR slab planned output sequence can be obtained: S11, S12, ..., S1 q1 S21, S22, ... S2 q2 ,...,Sn1,Sn2,...Sn qn Where, Si j(i=1,...,n,j=1,...,q) i ) is the i-th furnace Li (the furnace has a total of q) i In the block slab), the j-th DHCR slab.

[0111] The above DHCR plan slab sequence is sequentially grouped as follows (without changing the order of the slabs), resulting in the group sequence: B1,...,Bm, where each group satisfies the following condition:

[0112] 1) Same CAST number

[0113] 2) All slabs in Bi have the same tapping mark.

[0114] 3)|Bi|≥DhcrSizeMin

[0115] 4)|Wi-Wj|≤ΔW, Si, Sj∈Bi

[0116] 5)|Ti-Ti+1|≤ΔTmin, Si, Si+1∈Bi

[0117] Where |Bi| represents the number of elements in set Bi; Wi and Wj are the rolling widths of slabs Si and Sj in group Bi, respectively; ΔW is a process constant used to define the maximum allowable error value for any two slabs with the same width; Ti and Ti+1 are the production times of adjacent slabs Si and Si+1 in group Bi, respectively; ΔTmin is the process constant of the DHCR plan; DhcrSizeMin is the minimum number of DHCR slabs required by the DHCR plan. DHCR plans with fewer than this number have little energy-saving significance and are generally abandoned, or HCR plans are considered instead.

[0118] S22, based on the DHCR slab sequence, forms a complete rolling plan, specifically including:

[0119] Sequentially select planning block Bj (j=1,...,m) from the group sequence B1,...,Bm. Match the hot ironing roller transition material at the head of Bj and splice the CCR cold billet plan at the tail: Pj=R j1 +Bj+R j2 Find the first Pk (1≤m) that satisfies the following condition:

[0120] |Pk|=|R k1 |+|Bk|+|R k2 |≥PlanSizeMin

[0121] Among them, R k1 For the transition material of the hot rolling pin (composition of the actual slab); Bk is the main part of the DHCR plan (including the insert plan slab); R k2 To continue the physical CCR plan section following the DHCR plan segment Bk, and to compensate for the insufficient number of slabs in the DHCR plan; PlanSizeMin is the minimum number of slabs required by the DHCR plan (a number less than this is considered an invalid plan due to being too small).

[0122] If the above Pk exists, then the DHCR plan Pk has been output; otherwise, the DHCR plan compilation has failed, indicating that the current DHCR plan prerequisites are not met and a qualified DHCR plan cannot be compiled.

[0123] S3, Adjust the material supply rhythm during the execution of the DHCR plan.

[0124] The DHCR program includes P1+P2+P3;

[0125] Among them, P1 is the physical blank of the planned hot rolling roller material and its transition material; P2 is the main part of DHCR, a virtual blank; P3 is the physical supplementary blank for the insufficient part of the DHCR blank.

[0126] When the main part of the DHCR plan is being executed, the heating furnace is fed entirely from the direct hot billets of the DHCR plan section.

[0127] When the DHCR slab supply rhythm in steelmaking continuous casting does not match the steel charging rhythm in the heating furnace, the DHCR supply method needs to be adjusted:

[0128] When the DHCR feeding rhythm is greater than the furnace charging rhythm, any excess DHCR slabs that cannot be charged in time will be taken off the line and then reconnected at the end of the DHCR line.

[0129] When the DHCR feeding rhythm is less than the furnace charging rhythm, it is necessary to prepare the replenishment material in advance for the DHCR plan, i.e., the billet insertion plan.

[0130] The blanking plan comes from the first part of the DHCR plan, and P2 of the DHCR plan is divided into two parts:

[0131] P2 = P21 + P22

[0132] Among them, P21 is a buffer plan slab used as a billet insert to compensate for the mismatch between the production rhythm of continuous casting and hot rolling; P22 is the main part of the DHCR plan.

[0133] When the number of slabs in the DHCR plan is insufficient, offline hot billets are used as insert billets. The offline physical slabs used as insert billets need to meet the following conditions:

[0134] 1) The specifications are the same as those of the DHCR planned billet;

[0135] 2) The steel grade is the same as that of the DHCR planned billet;

[0136] 3) The temperature difference between the DHCR loading temperature and the DHCR loading temperature shall not exceed ΔT;

[0137] When the billet output rhythm of continuous casting in steelmaking is slower than the charging rhythm of the hot rolling furnace (hot rolling rhythm), the executed DHCR plan will be insufficient due to insufficient material supply, and a billet insertion plan needs to be prepared at this time.

[0138] During the execution of DHCR, some offline hot billets are inserted into the DHCR planned slab at intervals according to actual needs to make up for insufficient material supply.

[0139] The size Nb of the blanking plan is determined by the following formula:

[0140] Nb=(Nd / Vr-Nd / Vc)*Vr+Nh(2.1)

[0141] Where Vr and Vc are the billet output rhythms of hot rolling and continuous casting, respectively; Nd is the size of P2 in the DHCR plan (including insert billets); and Nh is the number of hot billets used as insert billets offline.

[0142] S4, Adjust the start time of the DHCR program.

[0143] The start-up time of the DHCR program depends on the amount of billet prepared (Nb) to balance the rolling rhythm. Since the first DHCR slab (S0) is directly fed into the heating furnace via the transport rollers during DHCR program implementation, assuming the production time of slab S0 is t0, the following calculation outlines a reasonable start-up time for the DHCR program, or the conditions that need to be met.

[0144] Ideally, after the last slab of the previous plan begins to be loaded into the furnace, the first DHCR plan slab S0 will arrive at the furnace preparation position just within the next slab loading cycle.

[0145] If there are n preceding DHCR plans to be executed, with a production order of P1, ..., Pn, and the number of unloaded slabs corresponding to each plan is N1, ..., Nn respectively; then the total time taken from the current plan until the last slab of the last preceding plan is loaded into the furnace is:

[0146] T sum0 =∑(Nj / Vr)(1.1)

[0147] Where Vr represents the hot rolling rhythm;

[0148] If the number of actual slabs in the transition material section of the DHCR plan is N0, and the number of inserts for balancing the rolling rhythm is Nb; when the first DHCR planned slab S0 can continue the production of the preceding planned slabs, and all planned slabs before S0 are produced, the time required is:

[0149] T sum =T sum0 +(N0+Nb) / Vr(1.2)

[0150] To ensure that the first DHCR planned billet S0 can be produced consecutively, the planned production time t0 of this billet should satisfy the following relationship:

[0151] T sum -Vf≤t0+T tran ≤T sum +Vf(1.3)

[0152] Where Vf represents the charging rhythm of the hot-rolled heating furnace slab; T tran The transportation time for slabs to be directly conveyed from the cutting production line to the furnace loading waiting position via conveyor rollers;

[0153] When relations (1.1) to (1.3) are not satisfied, adjustments need to be made to the preceding plan and the current DHCR to ensure that relation (1.2) holds. The adjustment methods depend on the condition that the value of t0 satisfies relation (1.3), and mainly include the following cases:

[0154] 1) t0>T sum +Vf–T tran

[0155] This situation indicates that DHCR slab production is lagging behind and cannot meet the planned continuity requirements. Therefore, several physical slabs need to be inserted into the previous plan (including the transitional material portion of the current DHCR plan) to compensate for the delays in the continuity plan. The number of physical slabs to be inserted is:

[0156] X = Ceil((t0-T) sum -Vf+T tran ) / Vr)(1.4)

[0157] 2)t0 <T sum +Vf–T tran

[0158] This situation indicates that DHCR slab production is ahead of schedule and cannot meet the planned follow-up requirements. Therefore, it is necessary to delete a number of slabs from the previous plan (including the transitional material portion of the current DHCR plan) to compensate for the schedule change. The number of slabs to be deleted is:

[0159] X = Ceil((T) sum -Vf+T tran -t0) / Vr)(1.5)

[0160] Even after deleting the N1 slab, the condition expression (1.3) still cannot be satisfied. The solution is to increase the number of DHCR inserts. The increased number of inserts is also calculated using expression (1.5). Of course, the number of inserts Nb in a DHCR plan should not exceed a certain amount; otherwise, the DHCR plan loses its energy-saving significance, and it would be better to downgrade the plan to an HCR plan.

[0161] Here, Ceil(Y) represents rounding up to the nearest integer in Y.

[0162] S5, issue and process DHCR plan

[0163] In some hot-rolling production processes, unlike the CCR logical plan which can be issued as a complete plan, the DHCR plan needs to be split into multiple plans for issuance. The main reason is that the plans issued by the manufacturing management system do not allow physical slabs and virtual slabs to be issued together.

[0164] To facilitate the distribution and management of DHCR plans, the DHCR plan P includes P = P1 + P21 + P22 + P3;

[0165] Among them, P1 and P3 are physical CCR plans; P21 is the virtual slab DHCR insertion plan; P22 is the virtual slab DHCR plan;

[0166] The DHCR plan is issued in the following order: P21, P22, P1, P3. The execution order of the DHCR plan is: P1, P21+P23, P3.

[0167] Example

[0168] This embodiment further illustrates the method for compiling a hot-rolled DHCR plan using the hot-rolled steel enterprise DHCR planning process, including the following steps:

[0169] S1, Obtain steelmaking plan data and DHCR plan process constants.

[0170] Steelmaking plan data: steelmaking plan number, CAST number, LOT number, tapping mark, furnace number, DHCR mark, start injection time, virtual slab number, contract number, rolling width, rolling thickness, hardness, tapping temperature, and planned cutting time.

[0171] DHCR planned process constants: DHCR slab roll conveyor time, heating furnace charging rhythm (rolling rhythm), steel tapping rhythm, DHCR planned minimum number of slabs, DHCR planned minimum number of DHCR slabs, maximum allowable error value for slabs of the same width, and maximum rolling kilometers (number of pieces) for slabs of the same width.

[0172] S2, Develop the DHCR plan

[0173] S21, Obtain a valid continuous DHCR slab sequence.

[0174] Set the DHCR plan time period: from the current time T start When time T end Depending on the needs, the DHCR (Dual Activity Response) planning period is generally 4 to 8 hours. Beyond 8 hours, due to the drastic changes in steelmaking schedules, the likelihood of implementing the prepared DHCR plan is low; therefore, DHCR plans outside of 8 hours are generally not considered.

[0175] Filter out steelmaking heat plans that do not meet the criteria from the steelmaking plan:

[0176] 1) The start time of the furnace injection is not in [T] start ,T end Within the time frame

[0177] 2) The furnace loading mode is not DHCR

[0178] If any of the above conditions are met, the application will be rejected. The remaining heat plans will be processed as follows:

[0179] The planned furnace sequence is formed by sorting the furnaces according to the start time of each furnace injection: L1, L2, ... Ln.

[0180] Clearly, all these heats consist entirely of DHCR slabs. Based on the production sequence of the aforementioned heats and the planned cutting time sequence of the slabs within each heat, the planned output sequence of DHCR slabs can be obtained as follows: S11, S12, ..., S1 q1 S21, S22, ... S2 q2 ,...,Sn1,Sn2,...Sn qn Where Sij(i=1,...,n,j=1,...,q) i ) is the i-th furnace Li (the furnace has a total of q) i In the block slab), the j-th DHCR slab.

[0181] The above DHCR plan slab sequence is sequentially grouped as follows (without changing the order of the slabs), resulting in the grouping sequence: B1,...,Bm, satisfying the following conditions:

[0182] 1) Same CAST number

[0183] 2) All slabs in Bi have the same tapping mark.

[0184] 3)|Bi|≥DhcrSizeMin

[0185] 4)|Wi-Wj|≤ΔW, Si, Sj∈Bi

[0186] 5)|Ti-Ti+1|≤ΔTmin, Si, Si+1∈Bi

[0187] Where |Bi| represents the number of elements in set Bi; Wi and Wj are the rolling widths of slabs Si and Sj in group Bi, respectively; ΔW is a process constant used to define the maximum allowable error value for any two slabs to have the same width, generally taken as 50mm; Ti and Ti+1 are the production times of adjacent slabs Si and Si+1 in group Bi, respectively; ΔTmin is the DHCR plan process constant, generally matched with the charging rhythm of the heating furnace; DhcrSizeMin is the minimum number of DHCR slabs required by the DHCR plan. DHCR plans with fewer than this number have little energy-saving significance and are generally abandoned, or HCR plans are considered instead. Generally, at least two heats with approximately 25 slabs can be considered as needed. If there is offline billet insertion, it can be reduced to one heat as appropriate.

[0188] S22, forming a complete rolling plan based on the DHCR slab sequence.

[0189] Sequentially select planning block Bj (j=1,...,m) from the group sequence B1,...,Bm. Match the hot ironing roller transition material at the head of Bj and splice the CCR cold billet plan at the tail: Pj=R j1 +Bj+R j2 Find the first Pk (1≤m) that satisfies the following condition:

[0190] |Pk|=|R k1 |+|Bk|+|R k2 |≥PlanSizeMin

[0191] Among them, R k1 For the transition material of the hot rolling pin (composition of the actual slab); Bk is the main part of the DHCR plan (including the insert plan slab); R k2 To continue the physical CCR plan section following the DHCR plan segment Bk and to compensate for the insufficient number of slabs in the DHCR plan; PlanSizeMin is the minimum number of slabs required by the DHCR plan (a number less than this will be considered an invalid plan due to its small size). Setting this value too high will make plan preparation difficult, while setting it too low will result in low roll utilization and increase the production and manufacturing costs of plan execution. It can be set to around 35 to 40 as needed.

[0192] If the above Pk exists, then the DHCR plan Pk has been output; otherwise, the DHCR plan compilation failed, indicating that the current DHCR plan preconditions are not met and a qualified DHCR plan cannot be compiled.

[0193] S3, Adjust the material supply rhythm during the execution of the DHCR plan.

[0194] During the execution of the DHCR (High-Demand Container Loading) program, the heating furnace feed consists entirely of directly delivered hot billets from the DHCR program segment. When the DHCR billet supply rhythm in steelmaking continuous casting does not match the heating furnace charging rhythm, the DHCR feeding method needs adjustment. When the DHCR feeding rhythm exceeds the furnace charging rhythm, excess DHCR billets that cannot be charged in time are immediately removed from the line and subsequently added back to the DHCR line at the end. When the DHCR feeding rhythm is less than the furnace charging rhythm, a reserve material for replenishment, known as a billet insertion plan, needs to be prepared in advance for the DHCR program. The billet insertion plan originates from the earlier part of the DHCR program, where the billets from this part of the DHCR program are removed from the line in advance as reserve material.

[0195] The DHCR main body P2 of the DHCR program is divided into two parts:

[0196] P2 = P21 + P22

[0197] Here, P21 is a buffer plan slab used to compensate for the mismatch between the continuous casting and hot rolling production rhythms; P22 is the main part of the DHCR plan. The values ​​of P21 and P22 are given by the following calculation formula (2.1).

[0198] Because a portion of the DHCR main body is removed for the insert billet plan, resulting in insufficient DHCR plan slab quantity for P22 (not meeting the minimum number of DHCR blocks), the number of blocks in P21 should be appropriately reduced. The remaining quantity can also be used as insert billets using offline hot-rolled billets. The offline physical slabs used as insert billets must meet the following conditions:

[0199] 1) The specifications are the same as those of the DHCR planned billet;

[0200] 2) The steel grade is the same as that of the DHCR planned billet;

[0201] 3) The temperature difference between the DHCR loading temperature and the DHCR loading temperature shall not exceed ΔT;

[0202] When the continuous casting billet output pace is slower than the hot rolling furnace charging pace (hot rolling pace), the executed DHCR plan suffers from insufficient material supply. In this case, a billet insertion plan needs to be prepared. During the DHCR execution process, some offline hot billets are intermittently inserted into the DHCR plan slabs as needed to compensate for the insufficient material supply. The size Nb of the billet insertion plan is determined by the following formula:

[0203] Nb=(Nd / Vc-Nd / Vr)*Vc+Nh(2.1)

[0204] Where Vr and Vc are the billet output rhythms of hot rolling and continuous casting, respectively; Nd is the size of DHCR plan P2 (including insert billets); and Nh is the number of hot billets used as insert billets offline.

[0205] For a given total number of DCHR slabs, a smaller billet insertion plan results in better energy savings. However, an excessively small insertion plan can lead to an empty furnace due to insufficient insertion quantity. Therefore, in practice, a slightly larger insertion quantity is always added to prevent insufficient insertion quantity caused by DHCR logistics fluctuations.

[0206] S4, Adjust the start time of the DHCR program.

[0207] The timing of the first virtual slab produced under the DHCR program is crucial; producing it too early or too late will cause problems. If it's too early, there will be insufficient supply of subsequent DHCR slabs, resulting in an empty furnace; if it's too late, subsequent DHCR slabs will not be loaded into the furnace in time and will be taken off the line, resulting in wasted energy.

[0208] The timing of the DHCR program's initiation depends on the amount of blank preparation (Nb) required to balance the rolling rhythm, as well as the time needed for the preceding DHCR program to be completed.

[0209] Since the first DHCR slab S0 is directly fed into the heating furnace via the conveyor rollers during the DHCR program, without leaving the production line, and assuming the production time of slab S0 is t0, the following calculation outlines the reasonable start-up time for the DHCR program, or the conditions that need to be met.

[0210] Ideally, after the last slab of the previous plan begins to be loaded into the furnace, the first DHCR plan slab S0 will arrive at the furnace preparation position just within the next slab loading cycle.

[0211] Assume there are n preceding plans to be executed, with a production order of P1, ..., Pn, and the number of unloaded slabs corresponding to each plan are N1, ..., Nn, respectively. Then, the total time required to load all slabs from the current plan to the last slab of the last preceding plan is:

[0212] T sum0 =∑(Nj / Vr)(2.1)

[0213] Wherein, Vr (blocks / min) is the hot rolling rhythm.

[0214] Assuming that in the DHCR plan, the number of actual slabs in the transition material section is N0, and the number of inserts balancing the rolling rhythm is Nb. When the first DHCR planned slab S0 can continue production from the preceding planned slabs, and all planned slabs before S0 are produced, the time required is:

[0215] T sum =T sum0 +(N0+Nb) / Vr(2.2)

[0216] To ensure that the first DHCR planned billet S0 can be produced consecutively, the planned cutting time t0 of this billet should satisfy the following relationship:

[0217] T sum -Vf≤t0≤T sum +Vf(2.3)

[0218] Wherein, Vf is the charging rhythm of hot-rolled heating furnace slabs, which can be calculated based on historical performance data.

[0219] When the above relationship is not satisfied, adjustments need to be made to the preceding plan and the current DHCR to ensure that relationship (2.3) holds. The adjustment methods depend on the condition that the t0 value satisfies relationship (2.3), and mainly include several cases:

[0220] 1) t0>T sum +Vf

[0221] This situation indicates that DHCR slab production is lagging and cannot meet the planned follow-up requirements. Therefore, it is necessary to insert several physical slabs into the previous plan (including the transitional material portion of the current DHCR plan) to compensate for the delays in the follow-up plan. The number of physical slabs to be inserted is:

[0222] X = Ceil((t0-T) sum -Vf) / Vr)(2.4)

[0223] 2)t0 <T sum -Vf

[0224] This situation indicates that DHCR slab production is ahead of schedule and cannot meet the planned follow-up requirements. Therefore, it is necessary to delete several physical slabs from the previous plan (including the transitional material portion of the current DHCR plan) to compensate for the schedule change. The number of physical slabs to be deleted is:

[0225] X = Ceil((T) sum -Vf-t0) / Vr)(2.5)

[0226] Even after deleting the N1 slab, the relationship (2.3) still cannot be satisfied. This can be resolved by increasing the number of DHCR inserts. The increased number of inserts is also calculated using the relationship (1.5). Of course, the number of inserts Nb in a DHCR plan should not exceed a certain amount; otherwise, the DHCR plan loses its energy-saving significance. In this case, the plan is generally downgraded to an HCR plan.

[0227] Here, Ceil(Y) represents rounding up to the nearest integer in Y.

[0228] S5, issue and process DHCR plan

[0229] In some hot-rolling production processes, unlike the CCR plan which can be issued as a complete plan, the DHCR plan needs to be split into multiple plans. The main reason is that the plans issued by the manufacturing management system do not allow for the simultaneous issuance of physical and virtual slabs.

[0230] To facilitate the distribution and management of DHCR plans, a typical DHCR plan can be divided into four sub-plans: P = P1 + P21 + P22 + P3. Here, P1 and P3 are the physical CCR plans; P21 is the DHCR plan for virtual slabs; and P22 is the DHCR plan for virtual slabs. The distribution order is: P21, P22, P1, P3, and the execution order is: P1, P21 + P23, P3.

[0231] 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 compiling a hot-rolled DHCR plan with a billet insert, characterized in that, Includes the following steps: S1, obtain steelmaking plan data and DHCR plan process constants; S2, develop the DHCR plan; S3, Adjust the material supply rhythm during the execution of the DHCR plan; S4, adjusts the start time of the DHCR plan; S5, issue and process the DHCR plan.

2. The method for compiling a hot-rolled DHCR plan with a billet according to claim 1, characterized in that: The steelmaking plan data includes steelmaking plan number, CAST number, LOT number, tapping mark, heat number, DHCR mark, start injection time, virtual slab number, contract number, rolling width, rolling thickness, hardness, tapping temperature, and planned cutting time. The DHCR planned process constants include DHCR slab roller conveyor time, heating furnace charging rhythm, steel tapping rhythm, DHCR planned minimum number of slabs, DHCR planned minimum number of DHCR slabs, maximum allowable error value for slabs of the same width, and maximum rolling kilometers of the same width.

3. The method for compiling a hot-rolled DHCR plan with a billet according to claim 1, characterized in that, Step S2 specifically includes the following steps: S21, Obtain a valid continuous DHCR slab sequence; S22, a complete rolling plan is formed based on the DHCR slab sequence.

4. The method for compiling a hot-rolled DHCR plan with a billet according to claim 3, characterized in that, Step S21 specifically includes the following steps: S211, Set the time period for the DHCR plan, starting from the current time T. start When time T end ; S212, Filter out steelmaking furnace plans that do not meet the conditions from the steelmaking plan; S213, For the remaining furnace plans, sort them according to the injection start time of each furnace to form a planned furnace sequence: L1, L2, ...Ln; S214, based on the planned furnace sequence of step S213 and the planned cutting time sequence of slabs within each furnace, the planned output sequence of DHCR slabs is obtained: S11,S12,...,S1q1,S21,S22,...S2q2,...,Sn1,Sn2,...Snq n Where Sij (i = 1, ..., n, j = 1, ..., qi) is the j-th DHCR slab in the i-th furnace Li; S215, the planned output sequence of DHCR slabs from step S214 is grouped sequentially to obtain the grouping sequence: B1,...,Bm.

5. The method for compiling a hot-rolled DHCR plan with a billet according to claim 4, characterized in that, Step S22 specifically includes: Sequentially select planning block Bj (j=1,...,m) from the group sequence B1,...,Bm. Match the hot ironing roller transition material at the head of Bj and splice the CCR cold billet plan at the tail: Pj=R j1 +Bj+R j2 .

6. The method for compiling a hot-rolled DHCR plan with a billet according to claim 4, characterized in that, In step S212, filtering out steelmaking furnace plans that do not meet the conditions includes: 1) The start time of the furnace injection is not in [T] start ,T end Within the time frame; 2) The furnace loading mode is not DHCR; If any of the above conditions are met, the item will be removed.

7. The method for compiling a hot-rolled DHCR plan with a billet according to claim 4, characterized in that, In step S215, the grouping of the planned output sequence of DHCR slabs must meet the following conditions: 1) Same CAST number 2) All slabs in Bi have the same tapping mark. 3) |Bi| ≥ DhcrSizeMin 4)|Wi-Wj|≤ΔW, Si, Sj∈Bi 5)|Ti-Ti+1|≤ΔTmin, Si, Si+1∈Bi Where |Bi| represents the number of elements in set Bi; Wi and Wj are the rolling widths of slabs Si and Sj in group Bi, respectively; ΔW is a process constant used to define the maximum allowable error value for any two slabs to have the same width, generally taken as 50mm; Ti and Ti+1 are the production times of adjacent slabs Si and Si+1 in group Bi, respectively; ΔTmin is the DHCR plan process constant, generally matched with the charging rhythm of the heating furnace; DhcrSizeMin is the minimum number of DHCR slabs required by the DHCR plan.

8. The method for compiling a hot-rolled DHCR plan with a billet according to claim 5, characterized in that, Step S22 further includes: Find the first Pk (1≤m) that satisfies the following condition: |Pk|=|R k1 |+|Bk|+|R k2 |≥PlanSizeMin Among them, R k1 For use as a transition material for ironing rollers; Bk is the main body of the DHCR project; R k2 To continue the physical CCR plan section following the DHCR plan segment Bk, and to compensate for the insufficient number of slabs in the DHCR plan; PlanSizeMin is the minimum number of slabs required by the DHCR plan. If the above Pk exists, then the DHCR plan Pk has been output; otherwise, the DHCR plan compilation has failed, indicating that the current DHCR plan prerequisites are not met and a qualified DHCR plan cannot be compiled.

9. The method for compiling a hot-rolled DHCR plan with a billet according to claim 1, characterized in that, Step S3 specifically includes: The DHCR program includes P1+P2+P3; Among them, P1 is the physical blank of the planned hot rolling roller material and its transition material; P2 is the main part of DHCR, a virtual blank; P3 is the physical supplementary blank for the insufficient part of the DHCR blank. When the main part of the DHCR plan is being executed, the heating furnace is fed entirely from the direct hot billets of the DHCR plan section. When the DHCR slab supply rhythm in steelmaking continuous casting does not match the steel charging rhythm in the heating furnace, the DHCR supply method needs to be adjusted: When the DHCR feeding rhythm is greater than the furnace charging rhythm, any excess DHCR slabs that cannot be charged in time will be taken off the line and then reconnected at the end of the DHCR line. When the DHCR feeding rhythm is less than the furnace charging rhythm, it is necessary to prepare the replenishment material in advance for the DHCR plan, i.e., the billet insertion plan.

10. The method for compiling a hot-rolled DHCR plan with a billet according to claim 9, characterized in that, The blanking plan specifically includes: P2 = P21 + P22 Among them, P21 is a buffer plan slab used as a billet insert to compensate for the mismatch between the production rhythm of continuous casting and hot rolling; P22 is the main part of the DHCR plan. When the number of slabs in the DHCR plan is insufficient, offline hot billets are used as insert billets. The offline physical slabs used as insert billets need to meet the following conditions: 1) The specifications are the same as those of the DHCR planned billet; 2) The steel grade is the same as that of the DHCR planned billet; 3) The temperature difference between the DHCR loading temperature and the DHCR loading temperature shall not exceed ΔT; When the billet output rate of continuous casting in steelmaking is slower than the charging rate of hot rolling furnace, the executed DHCR plan will be insufficient due to insufficient material supply, and a billet insertion plan needs to be prepared at this time. During the execution of DHCR, some offline hot billets are inserted into the DHCR planned slab at intervals according to actual needs to make up for insufficient material supply.

11. The method for compiling a hot-rolled DHCR plan with a billet according to claim 10, characterized in that, The size Nb of the blanking plan is determined by the following formula: Nb=(Nd / Vr-Nd / Vc)*Vr+Nh(2.1) Where Vr and Vc are the billet output rhythms of hot rolling and continuous casting, respectively; Nd is the size of P2 in the DHCR plan; and Nh is the number of hot billets used as inserts offline.

12. The method for compiling a hot-rolled DHCR plan with a billet according to claim 1, characterized in that, Step S4 specifically includes: If there are n preceding DHCR plans to be executed, with a production order of P1, ..., Pn, and the number of unloaded slabs corresponding to each plan is N1, ..., Nn respectively; then the total time taken from the current plan until the last slab of the last preceding plan is loaded into the furnace is: T sum0 =∑(Nj / Vr)(1.1) Where Vr represents the hot rolling rhythm; If the number of actual slabs in the transition material section of the DHCR plan is N0, and the number of inserts for balancing the rolling rhythm is Nb; when the first DHCR planned slab S0 can continue the production of the preceding planned slabs, and all planned slabs before S0 are produced, the time required is: T sum =T sum0 +(N0+Nb) / Vr(1.2) To ensure that the first DHCR planned billet S0 can be produced consecutively, the planned production time t0 of this billet should satisfy the following relationship: T sum -Vf≤t0+T tran ≤T sum +Vf(1.3) Where Vf represents the charging rhythm of the hot-rolled heating furnace slab; T tran The transportation time for slabs to be directly conveyed from the cutting production line to the furnace loading waiting position via conveyor rollers; When relations (1.1) to (1.3) are not satisfied, the preceding plans and the current DHCR need to be adjusted to ensure that relation (1.2) is satisfied.

13. The method for compiling a hot-rolled DHCR plan with a billet according to claim 12, characterized in that, The specific methods for adjusting previous plans and the current DHCR include: 1)t0>T sum +Vf–T tran This situation indicates that DHCR slab production is lagging behind and cannot meet the planned continuity requirements. Therefore, it is necessary to insert several physical slabs into the previous plan to compensate for the delays in the continuity plan. The number of physical slabs to be inserted is: X=Ceil((t0-T sum -Vf+T tran ) / Vr)(1.4) 2)t0<T sum +Vf–T tran This situation indicates that DHCR slab production is ahead of schedule and cannot meet the planned follow-up requirements. Therefore, it is necessary to delete a number of physical slabs from the previous plan to compensate for the schedule change. The number of physical slabs to be deleted is: X=Ceil((T sum -Vf+T tran -t0) / Vr)(1.5) After deleting the N1 slab, the condition expression (1.3) still cannot be satisfied. The problem is solved by increasing the number of DHCR inserts. The increased number of inserts is also calculated by expression (1.5).

14. The method for compiling a hot-rolled DHCR plan with a billet according to claim 1, characterized in that, Step S5 specifically includes: The DHCR plan P includes P = P1 + P21 + P22 + P3; Among them, P1 and P3 are physical CCR plans; P21 is the virtual slab DHCR insertion plan; P22 is the virtual slab DHCR plan; The DHCR plan is issued in the following order: P21, P22, P1, P3. The execution order of the DHCR plan is: P1, P21+P23, P3.