A complex order optimization method based on laminar flow operation

Abstract

This invention relates to a method for optimizing complex orders based on laminar flow operation, belonging to the field of metallurgical process engineering technology. It solves the problems of multiple process path intersections, excessive random waiting, and long delays caused by the contradiction between complex small-order production and large-scale mainstream production in existing technologies. The method includes: optimizing complex orders by merging small orders with similar composition, temperature, and processes into one furnace; grouping small orders with similar cross-sectional specifications and matching their cross-sectional specifications with the continuous casting machine; and batching small orders with the same rolling specifications; determining refining and rolling methods; and organizing production according to a laminar flow operation mode, with pretreatment, converter, refining, and continuous casting sequentially set as A, B, C, and D, and the equipment combination A for each flow... x -B w -C y -D z The index difference between adjacent process equipment numbers does not exceed 1, equipment from different processes is not reused, and process running time is controlled according to a quasi-equal rhythm mode; production is carried out according to this mode and orders are closed. This invention shortens the delay time.

Description

Technical Field

[0001] This invention relates to the field of metallurgical process engineering technology, and in particular to a method for optimizing complex orders based on laminar flow operation. Background Technology

[0002] In the steel manufacturing process, the transformation of ferrous materials can be viewed as a "flow," such as the long process of "hot metal pretreatment - converter - refining - continuous casting," or the short process of "raw materials - electric furnace - refining - continuous casting." For steel companies, accepting large-volume orders helps ensure high production line operating rates and stable production processes, thereby reducing manufacturing costs.

[0003] However, in the current market environment, steel companies are increasingly accepting complex orders with small batches and diverse product varieties. When multiple production paths in the steelmaking section are operating simultaneously, if the traditional large-scale production organization model is still used, each small order will select a different process path due to its unique steel grade and specification requirements. This can easily lead to overlapping process paths, logistical conflicts, equipment waiting times, and frequent order insertions. This not only increases additional transportation costs and energy dissipation and prolongs the time between processes, but also adversely affects the stability of product quality, posing technical challenges to achieving intelligent manufacturing.

[0004] When multiple paths are produced simultaneously, scheduling methods based primarily on human experience are limited by computing power and struggle to identify the optimal path combination in a short time. This often forces random waiting, leading to reduced process efficiency. Current technologies lack a systematic approach to organizing complex, small orders into an orderly and efficient production model to resolve the contradiction between this and the large-scale, mainstream production characteristics of steel enterprises. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a complex order optimization method based on laminar flow operation to solve the problems of multiple process production path intersections, numerous random waiting phenomena, and long delay times caused by the contradiction between the complex small-order production of steel manufacturing processes and the large-scale mass production characteristics of steel enterprises.

[0006] The objective of this invention is mainly achieved through the following technical solutions: This invention provides a method for optimizing complex orders based on laminar flow operation, comprising the following steps: S1: Optimize complex orders; S2: Determine the refining and rolling methods for the order optimized by S1, where the refining method includes LF single refining, RH single refining or LF+RH double refining, and the rolling method includes hot rolling or cold rolling. S3: Organize production according to laminar flow operation mode; S4. Steelmaking is carried out in accordance with the laminar flow operation mode determined in S3. After the steel products are put into storage or delivered, the order is completed and the order is closed. In step S3, the laminar flow operation mode is as follows: the pretreatment span, converter span, refining span, and continuous casting span in the steel manufacturing process are sequentially designated as A, B, C, and D. Assume there are m pretreatment devices, numbered A1, A2, ..., A... m There are t converter machines, numbered B1, B2, ..., B t There are p refining units, numbered C1, C2, ..., C p There are q continuous casting machines, numbered D1, D2, ..., D q ; A flow is defined as a complete process path starting from pretreatment, through converter, refining to continuous casting, and its equipment combination is denoted as A. x -B w -C y -D z Where x, w, y, and z are the subscripts of the equipment number, x≤m, w≤t, y≤p, and z≤q; When there are N production lines producing at the same time, N≥1, for each flow's equipment combination, the subscript difference of the equipment number of adjacent processes satisfies: |xw|≤1, |wy|≤1, |yz|≤1, and the same equipment cannot be reused between different flows; When N=1, there is no crossover between the flows; When N≥2, production is organized according to the principle that the intersection of multiple production line paths is zero. The intersection of paths being zero means that there is no unplanned waiting due to path conflict between any two simultaneously running flows.

[0007] Further, step S1 includes: S11: Complex orders are screened according to steel type, specifications, and order quantity, and then prioritized according to the principles of prioritizing those with closer delivery dates and prioritizing high-quality customers. S12: Combine small orders with the same or similar ingredients, temperatures, and processes into one batch; S13: Group small orders with the same or similar cross-sectional specifications and ensure that the cross-sectional specifications are fixedly matched with the continuous casting machine; S14: Combine small orders with the same rolling specifications into one batch.

[0008] Further, step S3 includes: S31: Define the laminar flow operation mode and set the constraint that the path intersection point is zero; S32: Control the running time of each process on each path according to the quasi-rhythm mode to achieve time synchronization between the preceding and following processes; S33, Distribute paths according to temperature guidance.

[0009] Furthermore, the principle of organizing production according to the principle of zero intersection points of multiple production line paths includes: ensuring that the transportation areas of different flows do not overlap through the layout of the workshop; and when transportation intersections are unavoidable, assigning specific orders to specific production lines.

[0010] Further, step S13 is as follows: steel grades with a cross-sectional specification greater than 1400mm are defined as wide-section steel grades, and steel grades with a cross-sectional specification less than 1400mm are defined as narrow-section steel grades. Wide-section steel grades are matched with wide-section continuous casting machines, and narrow-section steel grades are matched with narrow-section continuous casting machines. During group casting, based on the maximum rolling section, similar sections with a width difference within ±100mm are combined into a furnace with the same billet section, and then pressed to the specified width by a width-fixing machine.

[0011] Furthermore, the aforementioned quasi-equal rhythm mode refers to the coordinated operation cycles of each process in the same flow, including pretreatment, converter, refining, and continuous casting, so that the completion times of the preceding and following processes match each other, and the operation cycles of each process are basically equal or in an integer multiple relationship.

[0012] Furthermore, the temperature-oriented allocation path includes: preferentially allocating molten iron with a temperature above 1400°C to the RH refining path which is sensitive to temperature drop, and allocating molten iron with a temperature below 1400°C to the LF refining path which has heating capabilities.

[0013] Furthermore, when the number of simultaneously operating streams N≥2, N streams are selected from m pretreatment equipment, t converter equipment, p refining equipment, and q continuous casting equipment for simultaneous production. Each stream requires selecting one equipment from each of the four spans, and different streams cannot reuse the same equipment. Let i represent the sequence number of the currently selected stream. Then, the number of all possible equipment combination schemes is given by the following formula:

[0014] Where N is the number of streams running simultaneously; i = 0, 1, 2, ..., N-1; The actual usable laminar flow operation combination must also meet the condition that the subscript difference between the equipment numbers of the adjacent processes does not exceed 1; The number of continuous casting machines operating simultaneously, N, does not exceed the number of continuous casting machines, q, i.e., N≤q.

[0015] Furthermore, when organizing production according to the laminar flow operation mode, first select one device A in the pretreatment section. x Then, based on the condition that the index difference between adjacent process equipment numbers does not exceed 1, converter equipment B is selected sequentially. w Refining equipment C y Continuous casting equipment D zTo form a flow. Furthermore, the method is applicable to both long and short processes in steel manufacturing, wherein the long process includes hot metal pretreatment, converter steelmaking, refining, and continuous casting, and the short process includes raw materials, electric furnace, refining, and continuous casting.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. This invention optimizes the grouping, casting, and batching of orders, transforming complex small orders into large-scale, batch production, reducing frequent switching and path intersections caused by order fragmentation. By defining a laminar flow operation mode and forcing multiple production line paths to have zero intersection points, combined with quasi-equal rhythm control, it ensures that there are no unplanned waits between any two simultaneously running flows due to path conflicts, achieving time synchronization between preceding and subsequent processes. This effectively reduces process production path intersections and random waiting phenomena, shortens the transfer time between processes, reduces energy dissipation during operation, improves product quality stability, and enhances the steel enterprise's production responsiveness and market competitiveness in the face of complex small orders. Furthermore, the production organization path is simple, and the operating rules are easy to accurately describe by the model, facilitating intelligent control.

[0017] 2. This invention optimizes the grouping, casting, and batching of orders, transforming fragmented, complex small orders into large-scale, batch production. This reduces the frequent switching of equipment parameters and process paths caused by the wide variety of order types and specifications, lowers material consumption and equipment wear in the steelmaking process, increases single-furnace output and continuous casting operation rate, spreads smelting costs, reduces the disruption to the normal production order of complex small orders, and improves the steel mill's production responsiveness and market share in the face of complex small orders.

[0018] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0019] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0020] Figure 1 This is a schematic diagram of the method logic of the present invention; Figure 2 This is a functional layout diagram of the laminar flow operation mode in the method of the present invention; Figure 3This is a schematic diagram of the order process path space division under the laminar flow operation mode of Example 1; Figure 4 This is a comparison chart of the process delay times for Example 1 and Comparative Example 1. Detailed Implementation

[0021] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0022] This invention provides a method for optimizing complex orders based on laminar flow operation. This method is applicable to long and / or short processes in steel manufacturing, where the long process includes hot metal pretreatment, converter steelmaking, refining, and continuous casting, and the short process includes raw materials, electric furnace, refining, and continuous casting; it includes the following steps: S1: Optimize complex orders; Specifically, step S1 includes: S11: Complex orders are screened according to steel type, specifications, and order quantity, and then prioritized according to the principles of prioritizing those with closer delivery dates and prioritizing high-quality customers. S12: Combine small orders with the same or similar ingredients, temperatures, and processes into one batch; Specifically, the composition, temperature, and process information are determined based on the steel grade and corresponding process specifications of the order. "Same or similar composition" means that the difference in the content of key alloying elements between the two steel grades is within the allowable fluctuation range of the steelmaking process, and can be achieved by using the same charging system and alloy addition scheme. "Same or similar temperature" means that the difference in the target temperature of the two orders in the same key process is within the normal temperature control accuracy range of that process, requiring no adjustment of the heating or cooling plan. "Same or similar process" means that the two orders have the same key process path. For example, when the target carbon content limit of the two steel grades differs by no more than 0.02%, and the difference in the content of other key alloying elements is within the process adjustment capability range, they can be considered to have similar compositions; when the target temperature of the two orders at the refining station differs by no more than ±10℃, they can be considered to have similar temperatures.

[0023] S13: Group small orders with the same or similar cross-sectional specifications and ensure that the cross-sectional specifications are fixedly matched with the continuous casting machine; Specifically, steel grades with a cross-sectional dimension greater than 1400mm are defined as wide-section steel grades, and steel grades with a cross-sectional dimension less than 1400mm are defined as narrow-section steel grades. Wide-section steel grades are matched with wide-section continuous casting machines, and narrow-section steel grades are matched with narrow-section continuous casting machines. During group casting, based on the maximum rolled cross-section, similar cross-sections with a width difference within ±100mm are combined into a heat of the same billet cross-section, and subsequently pressed to the specified width using a width-fixing machine.

[0024] S14: Combine small orders with the same rolling specifications into one batch.

[0025] It should be noted that the overall optimization described in step S1 includes the following steps: In S11, order screening and priority classification are used to achieve centralized production scheduling for orders with similar delivery dates; in S12, orders with similar composition, temperature, and process are merged into one furnace to achieve furnace group optimization, aiming to increase single furnace output and reduce smelting costs; in S13, orders with similar cross-sections are merged for group casting and fixed matching continuous casting machines to achieve group casting optimization, aiming to reduce cross-section changing time and increase continuous casting operation rate; and in S14, orders with the same specifications are merged for batch rolling to achieve rolling optimization, aiming to reduce roll changing and debugging costs.

[0026] S2: Determine the refining and rolling methods for the order optimized by S1, where the refining method includes LF single refining, RH single refining or LF+RH double refining, and the rolling method includes hot rolling or cold rolling. It should be noted that the determination of the refining and rolling methods described in S2 is based on the steel grade and quality requirements corresponding to the order optimized in S1, and is matched according to the steel company's preset process specifications. Specifically: Regarding the refining method, for steel grades such as ordinary structural steel and low alloy steel with lower requirements for compositional precision and cleanliness, LF single refining is used; for steel grades that require strict control of hydrogen content, carbon content, or fine-tuning of alloy composition (such as IF steel, pipeline steel, electrical steel, etc.), RH single refining is used; for steel grades such as high-strength steel and duplex steel with higher requirements for compositional precision and cleanliness, LF+RH double refining is used. Regarding the rolling method, for orders with a large final product thickness and no requirement for cold working performance, hot rolling is used; for orders with a thinner final product thickness, higher requirements for surface quality and dimensional accuracy, and requiring further cold working, cold rolling is used. The above correspondence between refining and rolling methods can be adjusted according to the actual process capabilities and product positioning of each steel company, and those skilled in the art can make conventional selections based on the steel grade and quality requirements.

[0027] S3: Organize production according to laminar flow operation mode; Specifically, step S3 includes: S31: Define the laminar flow operation mode and set the constraint that the path intersection point is zero; Specifically, the pretreatment bay, converter bay, refining bay, and continuous casting bay in the steel manufacturing process are sequentially designated as A, B, C, and D; for those with m Let A span be the equipment in each process, and let the pretreatment equipment be numbered A1. 、 A2 、 A3……A m ,have t The equipment in the B-span of each process is numbered B1. 、B2 、 B3……B t ,have p The C-span of the equipment in each process step, and the refining equipment are numbered C1 respectively. 、 C2 、 C3……C p ,have q The D-span of the equipment in each process is numbered D1. 、 D2 、 D3……D q In actual production, the number N of the flow (production line) running simultaneously is determined by the number of continuous casting machines q, that is, a maximum of q flow lines can run at the same time, and N≤q.

[0028] A flow is defined as a complete process path starting from pretreatment, through converter, refining to continuous casting, and its equipment combination is denoted as A. x - B w - C y - D z Where x, w, y, and z are the corresponding device indexes (1≤x≤m, 1≤w≤t, 1≤y≤p, 1≤z≤q). To ensure that different flows do not intersect spatially, the difference in device indexes between adjacent processes must satisfy: |xw|≤1, |wy|≤1, |yz|≤1. This constraint ensures that devices in adjacent processes within the same flow are spatially adjacent or close together, thus avoiding path intersections caused by excessively large device spans.

[0029] When organizing production, first select one machine A in the pre-processing section according to order requirements. x Then, based on the above subscript constraint, select converter equipment B in sequence. w (Satisfying |xw|≤1), Refining equipment C y (Satisfying |wy|≤1), continuous casting equipment D z (Satisfying |yz|≤1). In this way, a flow that meets the requirements of laminar flow operation can be formed. When multiple flows are running simultaneously, each flow must independently satisfy its internal subscript constraint, and different flows must not reuse the same equipment (i.e., the same pretreatment, converter, refining or continuous casting equipment cannot be assigned to two different flows at the same time).

[0030] For example, N streams are selected from m pretreatment equipment, t converter equipment, p refining equipment, and q continuous casting equipment for simultaneous production (each stream requires one equipment selected from each of the four spans, and different streams cannot reuse the same equipment). Let i represent the sequence number of the currently selected stream (i = 0, 1, 2, ..., N-1), then the number of all possible equipment combinations is given by the following formula:

[0031] When N=3, if m=3, t=3, p=4, q=3, then the theoretical number of combinations is 864. However, in actual production, the above-mentioned spatial adjacency constraint with a subscript difference not exceeding 1 must also be added. Only combinations that simultaneously satisfy this constraint are actually usable laminar flow operation combinations.

[0032] It should be noted that zero path intersections does not require that the process equipment numbers of each flow must correspond one-to-one (i.e., A1 is not required to be paired with B1, C1, or D1). In other words, the pretreatment equipment of a flow can be combined with any converter equipment, as long as each flow meets its own subscript constraint when selecting equipment, and the equipment between different flows is not duplicated, and the transportation areas of different flows are not overlapped through the workshop layout, it can be guaranteed that there is no unplanned waiting due to path conflicts between any two flows running at the same time. For example, a steel plant has three production lines, numbered A1, B1, C1, D1; A2, B2, C2, D2; and A3, B3, C3, D3. When only two production lines are in operation simultaneously, the following combinations can be chosen: the first flow is A1-B2-C2-D1 (i.e., using A1 for pretreatment, B2 for converter, C2 for refining, and D1 for continuous casting), and the second flow is A3-B3-C3-D3. Calculations show that the subscripts of adjacent equipment in A1-B2-C2-D1 are |1-2|=1, |2-2|=0, and |2-1|=1, satisfying the above constraints. If the plant's layout ensures that the transport paths from A1 to B2, B2 to C2, and C2 to D1 do not intersect with the transport paths from A3 to B3, B3 to C3, and C3 to D3, then this combination belongs to a laminar flow production mode.

[0033] It should be noted that when n=1, the intersection between the flows is not involved; When n≥2, production is organized according to the principle of zero intersection points of multiple production line paths. Zero intersection points means that in production planning and scheduling, through equipment matching and path planning, there are no unplanned waits caused by path conflicts between any two simultaneously running flows. Specific means to achieve zero intersection points include, but are not limited to: spatial separation (ensuring that the transport areas of different flows do not overlap through workshop layout) and fixed equipment matching (fixedly assigning specific orders to specific production lines).

[0034] S32: Control the running time of each process on each path according to the quasi-rhythm mode to achieve time synchronization between the preceding and following processes; Specifically, the aforementioned quasi-equal rhythm mode refers to the coordinated operation cycles of pretreatment, converter, refining, and continuous casting within the same flow, ensuring that the completion times of successive processes match. Specifically, the operation cycles of each process are essentially equal or integer multiples of each other to avoid waiting or backlogs caused by rhythm mismatch. For example, when the converter smelting cycle is 35 minutes, the refining cycle is 35 minutes, and the continuous casting cycle is 35 minutes, a smooth "furnace-to-machine" connection can be achieved; when the continuous casting cycle is 17.5 minutes (i.e., half the converter cycle), a one-furnace-to-two-flow matching method can be used.

[0035] S33. According to the temperature-oriented allocation path: molten iron in a full ladle at high temperature (greater than 1400℃) is preferentially allocated to the RH path which is sensitive to temperature drop, and molten iron at medium and low temperature is allocated to the LF path which has heating capabilities.

[0036] S4. Steelmaking is carried out in accordance with the laminar flow operation mode determined in S3. After the steel products are put into storage or delivered, the order is completed and the order is closed.

[0037] This invention utilizes the following comprehensive technical means: It optimizes complex orders (including screening by steel type, specifications, and order quantity, prioritizing those with near delivery dates and high-quality customers; merging small orders with similar or identical composition, temperature, and processes into one furnace; grouping small orders with similar or identical cross-sectional specifications and ensuring their cross-sectional specifications are fixedly matched with the continuous casting machine; and batching small orders with the same rolling specifications). It determines the refining and rolling methods for the optimized orders, organizes production according to a laminar flow operation mode (setting the pretreatment span, converter span, refining span, and continuous casting span as A, B, C, and D respectively, defining the first to nth flows; when n≥2, production is organized according to the principle that the intersection of multiple production line paths is zero, and the running time of each process on each path is controlled according to a quasi-equal rhythm mode), and finally, steelmaking production is carried out according to this mode and then shut down. The order system has achieved the following beneficial effects: By optimizing the furnace grouping, casting grouping, and batching of orders, complex small orders are transformed into large-scale, batch production, reducing frequent switching and path intersections caused by order fragmentation; by defining a laminar flow operation mode and forcing multiple production line paths to have zero intersection points, combined with quasi-equal rhythm control, there is no unplanned waiting between any two simultaneously running flows due to path conflicts, and the sequential synchronization of upstream and downstream processes is achieved. This effectively reduces process production path intersections and random waiting phenomena, shortens the transfer time between processes, reduces energy dissipation during operation, improves product quality stability, and enhances the steel enterprise's production responsiveness and market competitiveness in the face of complex small orders. Moreover, the production organization path is simple, the operation law is easy to accurately describe by the model, and it is convenient to realize intelligent control.

[0038] Example 1 This embodiment describes the application of the complex order optimization method based on laminar flow operation of the present invention in a steel plant for one month. The steel plant's equipment configuration includes: three KR desulfurization stations (KR1-KR3), three converters (BOF1-BOF3), four refining furnaces (including LF1-LF2 and RH1-RH2), and three continuous casting machines (CC1-CC3).

[0039] The specific steps include: S1: Optimize complex orders; S11: Complex orders are screened according to steel type, specifications, and order quantity, and then prioritized according to the principles of prioritizing those with closer delivery dates and prioritizing high-quality customers. Specifically, the orders received in August 2025 will be sorted according to the above principles, involving a total of 174 steel grades and 2,643 heats.

[0040] S12: Combine small orders with the same or similar ingredients, temperatures, and processes into one batch; Specifically, high-strength IF steel grades with similar compositions, such as H220Y, H260Y, TS210P1, and TS250P1, will be considered together in the furnace grouping scheme.

[0041] S13: Group small orders with the same or similar cross-sectional specifications and ensure that the cross-sectional specifications are fixedly matched with the continuous casting machine; Specifically, steel grades with a cross-sectional area greater than 1400mm are defined as wide-section steel grades, and steel grades with a cross-sectional area less than 1400mm are defined as narrow-section steel grades. Wide-section steel grades are matched with wide-section continuous casting machines (Casting Machines 1 and 2), and narrow-section steel grades are matched with narrow-section continuous casting machines (Casting Machine 3). During group casting, based on the maximum rolled cross-section, similar cross-sections with a width difference within ±100mm are combined into a heat with the same billet cross-section, and then pressed to the specified width using a width-fixing machine. For example, heats with a cross-sectional width of 1400-1600mm are preferentially assigned to CC1 and CC2, and heats with a cross-sectional width less than 1400mm are preferentially assigned to CC3.

[0042] S14: Combine small orders with the same rolling specifications into one batch.

[0043] Specifically, multiple small orders of the same hot-rolled specifications will be combined into one batch for rolling.

[0044] S2: Determine the refining and rolling methods for the order optimized by S1, where the refining method includes LF single refining, RH single refining or LF+RH double refining, and the rolling method includes hot rolling or cold rolling. Based on the characteristics of the steel, SPHC, MRT, and high-strength IF steels are refined using RH single refining, Q235B and 22MnB5 are refined using LF single refining, and high-strength steels above 780MPa and duplex steels are refined using LF+RH double refining.

[0045] S3: Organize production according to laminar flow operation mode; Specifically, step S3 includes: S31: Define the laminar flow operation mode and set the constraint that the path intersection point is zero; According to the method of this invention, the pretreatment span, converter span, refining span, and continuous casting span are sequentially designated as A, B, C, and D. Specifically, there are m=3 pretreatment units, numbered A1-A3 corresponding to KR1-KR3; t=3 converter units, numbered B1-B3 corresponding to BOF1-BOF3; p=4 refining units, numbered C1-C4 corresponding to LF1, LF2, RH1, and RH2 respectively; and q=3 continuous casting units, numbered D1-D3 corresponding to CC1-CC3.

[0046] A flow is defined as a complete process path starting from pretreatment, through converter, refining to continuous casting, and its equipment combination is denoted as A. x -B w -C y -D z (1≤x≤3, 1≤w≤3, 1≤y≤4, 1≤z≤3). To ensure that different flows do not intersect in space, the subscript difference of the equipment numbers of adjacent processes must satisfy: |xw|≤1, |wy|≤1, |yz|≤1.

[0047] When organizing production, the pretreatment equipment is first selected based on order requirements, and then the converter, refining, and continuous casting equipment are selected sequentially according to the aforementioned subscript constraints. When multiple processes are running simultaneously, each process must independently meet its internal subscript constraints, and different processes must not reuse the same equipment.

[0048] According to the schematic diagram of the order process path space division under the laminar flow operation mode in this embodiment (e.g.) Figure 3 As shown), the following three sets of equipment combinations are selected as three flows running simultaneously. Each combination satisfies the lower standard deviation constraint and the equipment is unique: First stream: A1-B1-C1-D1, i.e., KR1-BOF1-LF1-CC1; Subscript difference: |1-1|=0, |1-1|=0, |1-1|=0.

[0049] Stream 2: A2-B2-C3-D2, i.e., KR2-BOF2-RH1-CC2; Subscript difference: |2-2|=0, |2-3|=1, |3-2|=1.

[0050] Stream 3: A3-B3-C4-D3, i.e., KR3-BOF3-RH2-CC3; Subscript difference: |3-3|=0, |3-4|=1, |4-3|=1.

[0051] Wide-section orders (section size > 1400mm) are fixedly assigned to flows 1 and 2, while narrow-section orders (section size < 1400mm) are fixedly assigned to flow 3. Spatial separation is achieved through fixed equipment matching, ensuring that there are no unplanned waits between any two flows due to path intersections. It should be noted that the process equipment numbers for each flow are not one-to-one (e.g., flow 1 uses LF1, flow 2 uses RH1, and flow 3 uses RH2), but since all meet the lower standard deviation constraint, the constraint that the path intersection point is zero is still satisfied.

[0052] S32: Control the running time of each process on each path according to the rhythm mode; By adjusting the operation time of each process, the converter smelting cycle, refining cycle, and continuous casting cycle are made to be basically equal (all controlled within the range of 35-40 minutes), thus avoiding waiting or backlog caused by mismatch in rhythm.

[0053] S33: Distribute paths according to temperature guidance; High-temperature molten iron with a temperature above 1400℃ is diverted to the first stream (KR1-BOF1-LF1-CC1) and the second stream (KR2-BOF2-RH1-CC2), with the RH path, which is sensitive to temperature drop, being given priority for high-temperature molten iron; medium- and low-temperature molten iron with a temperature below 1400℃ is diverted to the third stream (KR3-BOF3-RH2-CC3) and allocated to the LF path, which has heating capabilities.

[0054] S4: Steelmaking is carried out according to the laminar flow operation mode determined in S3, and the order is closed upon completion.

[0055] Table 1 shows the optimized process transfer schedule for Example 1.

[0056] Table 1. Process delay schedule for Example 1 (min)

[0057] Example 2 This embodiment is implemented in the same steel manufacturing process as in Embodiment 1. The steel plant equipment configuration is as follows: three KR desulfurization stations (KR1-KR3), three converters (BOF1-BOF3), four refining furnaces (including LF1-LF2 and RH1-RH2), and three continuous casting machines (CC1-CC3).

[0058] This embodiment takes the production of TS210P1 grade phosphorus-added high-strength IF steel as an example. This steel grade is a high value-added steel, and a certain factory's monthly output is only one heat, which is a typical complex small order. Production is arranged according to the complex order optimization method based on laminar flow operation provided by this invention, including: S1: Optimize complex orders; S11: Orders are screened according to steel type, specifications, and order quantity, and then prioritized according to the principles of prioritizing orders with closer delivery dates and prioritizing high-quality customers; The TS210P1 order was grouped together with the H220Y, H260Y, and TS250P1 orders with the same delivery date.

[0059] S12: Combine small orders with the same or similar ingredients, temperatures, and processes into one batch; TS210P1, H220Y, H260Y, and TS250P1 all belong to the high-strength IF steel grade, with similar alloy composition and smelting process, and are considered together in the furnace grouping scheme.

[0060] S13: Cast small orders with the same or similar cross-sectional specifications in groups; The cross-sectional specifications of the above four steel grades are all 1200mm, which is a narrow cross-section (less than 1400mm). They are uniformly matched with narrow cross-section continuous casting machines (No. 3 continuous casting machine CC3). When casting in batches, the maximum rolling cross-section of 1200mm is used as the benchmark. The cross-sections of the four heats are the same and there is no need to adjust the width.

[0061] S14: Combine small orders with the same rolling specifications into one batch; The above-mentioned steel grades are all hot-rolled specifications and are combined into the same rolling batch.

[0062] S2: Determine the refining and rolling methods for the order optimized by S1; Based on the characteristics of the steel grades, TS210P1, H220Y, H260Y, and TS250P1 all adopt RH single refining and are hot rolled.

[0063] S3: Organize production according to laminar flow operation mode; S31: Define the laminar flow operation mode and set the constraint that the path intersection point is zero; According to the method of this invention, the pretreatment span, converter span, refining span, and continuous casting span are sequentially designated as A, B, C, and D. Specifically, there are m=3 pretreatment units, numbered A1-A3 corresponding to KR1-KR3; t=3 converter units, numbered B1-B3 corresponding to BOF1-BOF3; p=4 refining units, numbered C1-C4 corresponding to LF1, LF2, RH1, and RH2 respectively; and q=3 continuous casting units, numbered D1-D3 corresponding to CC1-CC3.

[0064] A flow is defined as a complete process path starting from pretreatment, through converter, refining to continuous casting, and its equipment combination is denoted as A. x -B w -C y -D z(1≤x≤3, 1≤w≤3, 1≤y≤4, 1≤z≤3). To ensure that different flows do not intersect in space, the subscript difference of the equipment numbers of adjacent processes must satisfy: |xw|≤1, |wy|≤1, |yz|≤1.

[0065] When organizing production, the pretreatment equipment is first selected based on order requirements, and then the converter, refining, and continuous casting equipment are selected sequentially according to the aforementioned subscript constraints. When multiple processes are running simultaneously, each process must independently meet its internal subscript constraints, and different processes must not reuse the same equipment.

[0066] According to the schematic diagram of the order process path space division under the laminar flow operation mode in this embodiment (e.g.) Figure 3 As shown), the following three sets of equipment combinations are selected as three flows running simultaneously. Each combination satisfies the lower standard deviation constraint and the equipment is unique: First stream: A1-B1-C1-D1, i.e., KR1-BOF1-LF1-CC1; Subscript difference: |1-1|=0, |1-1|=0, |1-1|=0.

[0067] Stream 2: A2-B2-C3-D2, i.e., KR2-BOF2-RH1-CC2; Subscript difference: |2-2|=0, |2-3|=1, |3-2|=1.

[0068] Stream 3: A3-B3-C4-D3, i.e., KR3-BOF3-RH2-CC3; Subscript difference: |3-3|=0, |3-4|=1, |4-3|=1.

[0069] All the above combinations satisfy the subscript constraint. In this embodiment, TS210P1, H220Y, H260Y, and TS250P1 are all narrow-section orders, so they are assigned to the third flow, i.e., the equipment is matched as KR3-BOF3-RH2-CC3. Through spatial division (separating the narrow-section area from the wide-section area), it is ensured that there are no unplanned waits between the third flow and the first and second flows due to path intersections.

[0070] S32: Control the running time of each process on each path according to the rhythm mode; Adjust the work cycles of KR3, BOF3, RH2, and CC3 in the third flow to make the cycle of each process basically equal (all controlled within the range of 35-40 minutes), so as to achieve mutual matching of the completion time of the preceding and following processes.

[0071] S33: Assign path according to temperature guidance. The molten iron used in this order is all above 1400℃, which is high temperature molten iron. The high temperature molten iron will be dispatched to the RH2 refining path (i.e., RH2 in the third stream) which is sensitive to temperature drop.

[0072] S4. Steelmaking is carried out according to the laminar flow operation mode determined in S3. The order is closed upon completion.

[0073] After optimization, the total delay time for TS210P1 order is 42.1 minutes. The production status of each furnace in the same casting batch is shown in Table 2.

[0074] Table 2. Production details of small orders in the same casting cycle, Example 2

[0075] Comparative Example 1 The production conditions of this comparative example are basically the same as those of Example 1, except that the production schedule was not based on the laminar flow operation mode described in S3 (i.e., the path intersection point was not required to be zero, the control was not based on a precise rhythm, and the path was not allocated according to temperature guidance). The process delay time statistics are shown in Table 3.

[0076] Table 3. Process delay schedule for Comparative Example 1 (in minutes)

[0077] Comparative Example 2 This comparative example is similar to Example 2, also producing TS210P1 orders, but the method of this invention was not used. The difference is: Insert the TS210P1 small order into the regular production order for SPHETi-5 steel grade; The process paths were not divided according to the laminar flow operation mode, and the production path organization was arbitrary. During the production process, the process path for the first batch of SPHETi-5 was divided into KR1-BOF2-RH1-CC1, the process path for the second batch of SPHETi-5 was divided into KR3-BOF2-RH2-CC1, the process path for the third batch of TS210P1 was divided into KR3-BOF1-RH1-CC1, and the process path for the fourth batch of SPHETi-5 was divided into KR3-BOF1-RH2-CC1. The production situation of each batch in the same casting cycle of Comparative Example 2 is shown in Table 4.

[0078] Table 4. Production of small orders in the same casting batch in Comparative Example 2

[0079] The comparison chart of the process delay time between Comparative Example 1 and Example 1 is as follows. Figure 4 From Table 1, Table 3 and... Figure 4As can be seen, compared with the data before optimization (data from August 2024, i.e., Comparative Example 1 without the method of the present invention), the total transfer time of the LF single refining process path in Example 1 (data from August 2025) decreased from 54.82 min to 52.03 min, the RH single refining process path decreased from 65.48 min to 62.01 min, and the LF+RH double refining process path decreased from 64.28 min to 62.44 min.

[0080] As shown in Tables 2 and 4, in Example 2 using the method of the present invention, the total transfer time for the TS210P1 order was 42.1 min. The production status of each furnace in the same casting cycle is shown in Table 2. Compared with 67.1 min before optimization (Comparative Example 2, without the method of the present invention), this time was shortened by 25 min. The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for optimizing complex orders based on laminar flow operation, characterized in that, Includes the following steps: S1: Optimize complex orders; S2: Determine the refining and rolling methods for the order optimized by S1, where the refining method includes LF single refining, RH single refining or LF+RH double refining, and the rolling method includes hot rolling or cold rolling. S3: Organize production according to laminar flow operation mode; S4. Steelmaking is carried out in accordance with the laminar flow operation mode determined in S3. After the steel products are put into storage or delivered, the order is completed and the order is closed. In step S3, the laminar flow operation mode is as follows: the pretreatment span, converter span, refining span, and continuous casting span in the steel manufacturing process are sequentially designated as A, B, C, and D. Assume there are m pretreatment devices, numbered A1, A2, ..., A... m There are t converter machines, numbered B1, B2, ..., B t There are p refining units, numbered C1, C2, ..., C p There are q continuous casting machines, numbered D1, D2, ..., D q ; A flow is defined as a complete process path starting from pretreatment, through converter, refining to continuous casting, and its equipment combination is denoted as A. x -B w -C y -D z Where x, w, y, and z are the subscripts of the equipment number, x≤m, w≤t, y≤p, and z≤q; When there are N production lines producing at the same time, N≥1, for each flow's equipment combination, the subscript difference of the equipment number of adjacent processes satisfies: |xw|≤1, |wy|≤1, |yz|≤1, and the same equipment cannot be reused between different flows; When N=1, there is no crossover between the flows; When N≥2, production is organized according to the principle that the intersection of multiple production line paths is zero. The intersection of paths being zero means that there is no unplanned waiting due to path conflict between any two simultaneously running flows.

2. The complex order optimization method according to claim 1, characterized in that, Step S1 includes: S11: Complex orders are screened according to steel type, specifications, and order quantity, and then prioritized according to the principles of prioritizing those with closer delivery dates and prioritizing high-quality customers. S12: Combine small orders with the same or similar ingredients, temperatures, and processes into one batch; S13: Group small orders with the same or similar cross-sectional specifications and ensure that the cross-sectional specifications are fixedly matched with the continuous casting machine; S14: Combine small orders with the same rolling specifications into one batch.

3. The complex order optimization method according to claim 1, characterized in that, Step S3 includes: S31: Define the laminar flow operation mode and set the constraint that the path intersection point is zero; S32: Control the running time of each process on each path according to the quasi-rhythm mode to achieve time synchronization between the preceding and following processes; S33, Distribute paths according to temperature guidance.

4. The complex order optimization method according to claim 1, characterized in that, The principle of organizing production according to the principle of zero intersection points of multiple production line paths includes: ensuring that the transportation areas of different flows do not overlap through workshop layout; and when transportation intersection is unavoidable, assigning specific orders to specific production lines.

5. The complex order optimization method according to claim 2, characterized in that, Step S13 is as follows: steel grades with a cross-sectional specification greater than 1400mm are defined as wide-section steel grades, and steel grades with a cross-sectional specification less than 1400mm are defined as narrow-section steel grades. Wide-section steel grades are matched with wide-section continuous casting machines, and narrow-section steel grades are matched with narrow-section continuous casting machines. During group casting, based on the maximum rolling section, similar sections with a width difference within ±100mm are combined into a furnace with the same billet section, and then pressed to the specified width by a width-fixing machine.

6. The complex order optimization method according to claim 3, characterized in that, The aforementioned quasi-equal rhythm mode refers to the coordinated operation cycles of pretreatment, converter, refining, and continuous casting processes within the same flow, so that the completion times of the preceding and following processes match each other, and the operation cycles of each process are basically equal or in an integer multiple relationship.

7. The complex order optimization method according to claim 3, characterized in that, The temperature-guided allocation path includes: prioritizing the allocation of molten iron with a temperature above 1400℃ to the RH refining path, which is sensitive to temperature drop, and allocating molten iron with a temperature below 1400℃ to the LF refining path, which has heating capabilities.

8. The complex order optimization method according to claim 1, characterized in that, When the number of concurrently operating streams N≥2, N streams are selected from m pretreatment equipment, t converter equipment, p refining equipment, and q continuous casting equipment for simultaneous production. Each stream requires one equipment selected from each of the four spans, and different streams cannot reuse the same equipment. Let i represent the sequence number of the currently selected stream. Then the number of all possible equipment combination schemes is given by the following formula: Where N is the number of streams running simultaneously; i = 0, 1, 2, ..., N-1; The actual usable laminar flow operation combination must also meet the condition that the subscript difference between the equipment numbers of the adjacent processes does not exceed 1; The number of continuous casting machines operating simultaneously, N, does not exceed the number of continuous casting machines, q, i.e., N≤q.

9. The complex order optimization method according to claim 1, characterized in that, When organizing production according to the laminar flow operation mode, first select one device A in the pretreatment section. x Then, based on the condition that the index difference between adjacent process equipment numbers does not exceed 1, converter equipment B is selected sequentially. w Refining equipment C y Continuous casting equipment D z To form a flow.

10. The complex order optimization method according to claim 1, characterized in that, The method is applicable to both long and short processes in steel manufacturing. The long process includes hot metal pretreatment, converter steelmaking, refining, and continuous casting, while the short process includes raw materials, electric furnace, refining, and continuous casting.

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