JP2013151021A - Method for determining rolling procedure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for determining rolling procedures, by which rolling can be completed most quickly as a whole without generating the shortage of cooling water and the delay in draining.SOLUTION: An optimization problem is formulated (step S4) by a prescribed objective function and prescribed constraint conditions including one that a water consumption does not exceed a water feeding capacity and a draining capacity of a plate rolling equipment. A mixed integer planning problem is solved (step S5) by applying the formulated optimization problem to the mixed integer planning problem and an extraction order of base materials from a heating furnace and an execution order of rolling in a rolling apparatus are obtained so that rolling completion time may be the minimum.

Description

  The present invention relates to a rolling method determination method for determining a material extraction order from a heating furnace and a rolling execution order in a rolling device for a plurality of types of materials.

  Some plate factories enable rolling and cooling of multiple types of materials. FIG. 20 is a schematic diagram showing an equipment layout of the plank factory. In the plate factory, two continuous heating furnaces 101 and 102, one rolling mill 110 and a water cooling device 120 are arranged from the upstream.

  Each of the two continuous heating furnaces 101 and 102 is configured so that materials (slabs) can be arranged in two rows. Thereby, a total of 4 rows (4 types) of materials can be arranged in the two continuous heating furnaces 101 and 102. Each continuous heating furnace 101, 102 is provided with a walking beam that moves independently in each row, and the material in each row is independently conveyed to the extraction side by this walking beam. The four rows of materials positioned on the most extraction side of the continuous heating furnaces 101 and 102 are extracted in an arbitrary order by the extractor.

  In the thick plate factory, the material extracted from the continuous heating furnaces 101 and 102 is conveyed to the rolling mill 110. The rolling mill 110 is configured such that the roll can be rotated forward and reversely, and the material conveyed to the rolling mill is reverse-rolled by the rolling mill 110. The material is built into a predetermined dimension by this reverse rolling. In addition, in the thick plate factory, the rolling process is performed by one rolling mill 110, but by rolling by one rolling mill 110 in this way, there is an advantage that the scale of equipment in the factory can be reduced.

  Further, in the thick plate factory, there are standby spaces on the front surface (upstream) and rear surface (downstream) of the rolling mill 110 where materials can be waited. Thereby, one raw material under rolling can be made to wait in a waiting space, and the next raw material can be rolled with the rolling mill 110. Thus, the raw material rolled by the rolling mill 110 is cooled as needed by the water cooling device 120 downstream of the rolling mill 110.

  In such a thick plate factory, a raw material is reverse-rolled by a rolling mill 110 to produce a product having a predetermined size. As described above, various products are produced, but the number of passes of the rolling mill 110 and the rolling time are different for each material. Here, the rolling process can be divided into two processes, ie, a forming / bending process and a thicknessing process. Some materials do not require a molding / de-widthing process.

  In addition, in the thicknessing process, the temperature may be adjusted in order to build the material of the product. “Temperature control” refers to waiting on the front and rear surfaces of the rolling mill 110 in the vicinity of the final pass and performing rolling after reaching a predetermined temperature range, and is also referred to as “controlled rolling”. Further, the temperature adjustment may be performed a plurality of times, and the number of temperature adjustments varies depending on the material. The number of temperature adjustments is, for example, 0 to 4 times. Moreover, temperature control may be performed by air cooling or by using the water cooling device 120.

  Processes such as rolling and temperature control as described above are combined according to the material, and the material is created as a predetermined product. This is called a “rolling schedule” or “pass schedule”. And since contents, such as rolling and temperature control, differ with materials, a pass schedule also changes with kinds of materials. FIG. 21 is a schematic diagram illustrating an example of a pass schedule of a certain material. In the case of this material, the pass schedule is in the order of forming / developing rolling process A1, air cooling process A2, thickening rolling process (before temperature control) A3, temperature adjusting process A4, and thickening rolling process (after temperature control) A5. It consists of As described above, the rolling processes such as the forming / developing process A1 and the thicknessing process A3, A5 are separated in the cooling process.

  In the case of such a pass schedule, during the air-cooling process A2 between the end of the forming / waxing rolling process A1 and the start of the thicknessing rolling process A3, further, the temperature between the two thicknessing rolling processes A3, A5. During the adjustment process A4, the material being rolled is in a standby state in standby spaces provided before and after the rolling mill 110. The standby time (cooling time) can generally be changed, and thus the path schedule can be adjusted.

  Further, in the air cooling process after the end of the forming / de-rolling process A1, the air cooling time can be changed. This is because the material has a thickness after the forming / bench rolling process A1, and therefore the temperature hardly changes even if the cooling time is changed. Further, in the temperature adjustment process A4, as described above, the temperature may be adjusted by air cooling, the temperature may be adjusted using a water cooling device, and air cooling and water cooling may be mixed. By changing such air cooling time or changing the cooling contents in the temperature adjustment process A4, the standby time can be adjusted and the pass schedule can be adjusted.

  A specific example of adjusting the path schedule according to the cooling content will be described with reference to FIG. As shown as a change from FIG. 22A to FIG. 22C, the pass schedule can be adjusted by changing the air cooling time of the air cooling process A2 and adjusting the standby time. Moreover, as shown as a change from FIG. 22 (A) to FIG. 22 (B), or a change from FIG. 22 (C) to FIG. 22 (D), as the contents of the temperature adjustment process A4, only water cooling, only air cooling, Alternatively, the path schedule can be adjusted by appropriately selecting three types of contents in which water cooling and air cooling are mixed.

  Also, for example, as shown in FIG. 23 (A), as a double rolling, A material and B material of two types of materials are paired, and B material is rolled during standby of A material during rolling, As shown in FIG. 23 (B), various materials A, B, C, and D are rolled in order as the mosquito rolling, or other materials are rolled in the middle of rolling the material. As shown in FIG. 23 (C), as a collective rolling, while rolling A material in the middle of rolling, rolling of other materials B material, C material, D material is performed together, such a rolling procedure Thus, the idle state can be reduced as much as possible.

  By the way, based on the judgment of the operator (human), the extraction order of the materials from the continuous heating furnaces 101 and 102, the extraction timing thereof, or the rolling procedure is determined. In this case, if materials with the same pass schedule are continuous, it is possible to determine the rolling procedure to some extent, but if materials with various pass schedules are mixed, it is not possible to determine the rolling procedure at the operator's discretion. Is possible.

  Therefore, a method has been proposed in which the rolling completion time of all slabs is targeted, and an optimization problem is formulated to search for the slab extraction order and rolling method (see, for example, Patent Document 1). In this method, the rolling process is called a “job”, and information on rolling is given to each job based on the rolling pass schedule, and a solution that satisfies the rolling restrictions is obtained.

JP 2003-305508 A JP 2009-82985 A

  However, according to the method disclosed in Patent Document 1, a rolling order that continuously uses strong water cooling equipment and OLAC (On-Line Accelerated Cooling) equipment may be created. In this case, since a large amount of water is handled, a shortage of cooling water or a delay in drainage occurs, and in the worst case, the rolling line is stopped.

  This invention is made in view of the above, Comprising: It aims at providing the rolling point determination method which can complete rolling most quickly as a whole, without the lack of cooling water and drainage delay generating.

  In order to solve the above-described problems and achieve the object, the rolling point determination method according to the present invention includes a heating furnace capable of heating a plurality of types of materials and a material extracted from the heating furnace before and after the heating furnace. A material rolled by a thick plate rolling facility provided with a rolling device that rolls while using a standby space and a strong water cooling device that is disposed immediately after the rolling device and cools the material rolled by the rolling device. A rolling procedure determining method for determining the rolling guidelines of the rolling apparatus, based on the rolling schedule of each material to be rolled, the occupation time of the rolling device when rolling, the cooling time between rolling for the same material The upper and lower limit values, the length of the material after the rolling, the restriction of the preceding relationship of rolling in the rolling schedule of the same material, and information including the flow rate information of the cooling water are obtained, and the heating furnace is determined based on the obtained information. Via pressure The objective function is the rolling completion time until the rolling is completed for all the materials to be performed, and it cannot be performed at the same time in the rolling apparatus, the cooling time between each rolling is in the range of the upper and lower limit values, The total length of raw materials during and during the rolling process is less than or equal to the storage length in the standby space, the prior relationship between rolling must satisfy the given constraints, and the amount of water used is the plate rolling The constraint condition of not exceeding the water supply capacity and drainage capacity of the facility is formulated into an optimization problem, and the formulated optimization problem is converted into a mixed integer programming problem so that the rolling completion time is minimized. Further, it is characterized in that the order of extracting the materials from the heating furnace and the order of performing the rolling in the rolling apparatus are determined.

  Further, in the above-described invention, the rolling procedure determining method according to the present invention is a rolling procedure for determining a rolling procedure of a material to be rolled by a thick plate rolling facility further provided with an online accelerated cooling device after the strong water cooling device. A determination method, based on a cooling schedule of each material to be accelerated online cooling, a transfer time from the rolling device to the online accelerated cooling device, a processing time in the online accelerated cooling device, and a cooling of the online accelerated cooling device. Further information on online accelerated cooling processing including water flow rate information is obtained, and on the basis of the obtained information, the online accelerated cooling is completed for all materials that are rolled and online accelerated cooled through the heating furnace. Accelerated cooling completion time is the objective function, and it cannot be performed simultaneously in the rolling equipment. The cooling time between the rollings is in the range of the upper and lower limit values, the total length of the raw material during and during the rolling process is less than or equal to the storage length in the waiting space, and the prior relationship between the rolling is given Restrictions must be satisfied, online accelerated cooling times should not overlap, and the amount of water used, including the amount of water used in the online accelerated cooling device, should be the water supply capacity and drainage of the plate rolling equipment and the online accelerated cooling device. The constraint that the capacity is not exceeded is formulated into an optimization problem, and the formulated optimization problem is converted into a mixed integer programming problem so that the completion time of the online accelerated cooling is minimized. The order of material extraction from the furnace and the order of rolling and online accelerated cooling in the rolling device and online accelerated cooling device are determined. The features.

  Further, in the above-described invention, the rolling procedure determining method according to the present invention compares the rolling pitch and the shear pitch between the materials at the completion of the online accelerated cooling process, and the rolling pitch is larger than the shearing pitch. Further, it is characterized by rearranging to a rolling order having a long online accelerated cooling treatment time.

  According to the present invention, the optimization problem is formulated by a predetermined objective function and predetermined constraints including that the amount of water used does not exceed the water supply capacity and drainage capacity of the plate rolling equipment, and this formulated optimization Since the problem is applied to the mixed integer programming problem and the mixed integer programming problem is solved, the material extraction order from the heating furnace and the rolling execution order in the rolling equipment are obtained so that the rolling completion time is minimized. In addition, it is possible to provide a method for determining a rolling procedure that can complete rolling most quickly as a whole without causing a shortage of cooling water or a delay in drainage.

FIG. 1 is a schematic diagram showing an equipment layout of a thick plate factory according to the present embodiment. FIG. 2 is a schematic flowchart showing the processing contents of the control system of the present embodiment. FIG. 3 is a schematic diagram for explaining a predecessor relationship of jobs such that jobs in the same material are in a predetermined order. FIG. 4 is a schematic diagram for explaining an example in which two or more jobs are prohibited from being rolled at the same time. FIG. 5 is a schematic diagram for explaining the prior relationship of jobs such that the time between overlapping material jobs is equal to or less than the lower limit of the switching time. FIG. 6 is a schematic diagram for explaining the prior relationship of jobs such that the total rolling length of the waiting job and the rolling job does not exceed the limit value. FIG. 7 is a schematic diagram for explaining the preceding relationship of jobs such that the number of jobs of different materials that fall between jobs of the same material becomes the limit value. FIG. 8 is a schematic diagram for explaining the prior relationship of a job in which a material rolled first between two materials is always completed first. FIG. 9 is a schematic diagram illustrating an example of an arrangement of jobs when a water cooling pattern is added. FIG. 10 is a schematic diagram showing a case where a water-cooled material is used as an overtaking material. FIG. 11 is a schematic diagram showing an example of use when the water-cooled material is changed to a CR material. FIG. 12 is a schematic diagram for explaining an example of water amount restriction. FIG. 13 is a schematic diagram schematically showing the processing content up to the determination of the rolling procedure. FIG. 14 is a schematic diagram illustrating a configuration example of an optimum rolling point determination system. FIG. 15 is a schematic diagram showing an equipment layout of a plank factory according to a modification of the present embodiment. FIG. 16 is a schematic flowchart showing an example of the entire processing process of one material including the OLAC processing process. FIG. 17 is a time chart showing an example of the rolling order determined in consideration of the amount of water used according to the modification. FIG. 18 is a time chart showing an example of the rolling order determined so that the OLAC processes according to the modification do not overlap. FIG. 19 is a time chart showing an example of the rolling order determined in consideration of the rolling pitch and the shearing pitch according to the modification. FIG. 20 is a schematic diagram showing an equipment layout of a plank factory. FIG. 21 is a schematic diagram showing a material pass schedule. FIG. 22 is a schematic diagram for explaining a cooling process that is variable in the pass schedule. FIG. 23 is a schematic diagram for explaining a rolling procedure of a plurality of materials.

  Hereinafter, an embodiment of a rolling point determination method according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In this embodiment, the present invention is applied to a control system for controlling a rolling process in a thick plate factory. Further, the configuration of the plank factory is basically the same as the conventional one, but in this embodiment, the layout of the plank factory has two units from the upstream as shown in FIG. The continuous heating furnaces 101 and 102, one rolling mill 110 and a strong water cooling device 130 are arranged. The strong water cooling device 130 is used for cooling while rolling with the rolling mill 110 and has a thin scale, and is used for a beautiful surface steel plate. Further, an OLAC facility (not shown) is disposed downstream of the strong water cooling device 130.

  Each of the two continuous heating furnaces 101 and 102 is configured so that the raw materials (slabs) can be arranged in two rows, and accordingly, the two continuous heating furnaces 101 and 102 have a total of four rows (four types). ) Material can be placed. Each continuous heating furnace 101, 102 is provided with a walking beam that moves independently in each row, and the material in each row is independently conveyed to the extraction side by this walking beam. The four rows of materials positioned on the most extraction side of the continuous heating furnaces 101 and 102 are extracted in an arbitrary order by the extractor.

  In the thick plate factory, the material extracted from the continuous heating furnaces 101 and 102 is conveyed to the rolling mill 110. The rolling mill 110 is configured such that the roll can be rotated forward and reversely, and the material conveyed to the rolling mill is reverse-rolled by the rolling mill 110. The material is built into a predetermined dimension by this reverse rolling. Also, in the plate factory, there is a standby space in the front (upstream) of the rolling mill 110 where the material can be waited. By this, one material being rolled is made to wait in the standby space, and the next material is loaded. The rolling machine 110 can perform rolling. Thus, the raw material rolled by the rolling mill 110 is cooled while rolling as necessary by the strong water cooling cooling device 130 immediately after the downstream side of the rolling mill 110.

  The thick plate factory is configured in this way, and the control system determines the rolling procedure indicating the contents of the extraction order of the raw materials from the continuous heating furnaces 101 and 102 and the execution order of rolling in the rolling mill. Next, the procedure for determining the rolling procedure will be described. In the control system, the optimization problem is formulated from the content necessary for determining the rolling procedure, and this is converted or applied to a mathematical solution method such as a mixed integer programming problem. Has been decided. FIG. 2 shows a processing procedure for realizing it.

  First, in step S1, information on the target material is acquired. In subsequent step S2, a pass schedule (rolling schedule) is acquired based on the information on the target material. In step S3, various information is acquired based on the path schedule. That is, if each material (slab) is determined, the path schedule is also determined, and various information is acquired based on the path schedule.

  Here, the various types of information are information acquired regarding a rolling process (hereinafter referred to as a job) included in the pass schedule, and specifically, information having contents as shown below. In the present embodiment, a water cooling pattern related to the strong water cooling system 130 is added as a job, and information for the water cooling pattern is added.

<Information acquired for each job>
A. Occupancy time of rolling mill when executing job B. Upper and lower limits of cooling time between pass schedules for the same material D. Material length after job execution E. Restriction of job precedence relationship in the same material pass schedule Cooling water flow rate information

  In step S4, an optimization problem is formulated based on the above-described various information. In this formulation, as shown below, the objective function is set as the rolling completion time of all jobs, and the constraint conditions are set to conditions as shown in at least a to e.

<Objective function>
Rolling completion time until jobs for all materials rolled through the heating furnace are completed <Restrictions>
a. It cannot be performed simultaneously in the rolling machine b. The cooling time of each job is within the range of upper and lower limits c. The total length of the materials being rolled and waiting is equal to or less than the storage length in the waiting space d. The predecessor relationship between jobs must satisfy the given constraints e. The amount of water used does not exceed the water supply capacity and drainage capacity of the plate rolling equipment.

  Here, “d. The preceding relationship between jobs satisfies a given constraint”, but the preceding relationship of the job is given as follows, for example. First, the prior relationship of jobs is set so that jobs in the same material are in a predetermined order. That is, as shown in FIG. 3, the relationship is such that rolling is performed in the order of rolling a1 (rolling 1), rolling a2 (rolling 2), and rolling a3 (rolling 3). For example, here, the rolling a1 (rolling 1) is forming / increase rolling, the rolling a2 (rolling 2) is the first thickening rolling (thickening rolling before temperature control), and the rolling a3 (rolling 3). ) Is the second thickening rolling (thickness rolling after temperature control).

  Further, the preceding relationship of the jobs is set so that the rolling of two or more jobs does not overlap at the same time. In other words, as shown in FIG. 4, the job of the material a and the job of the material b are prohibited from being performed at the same time. Further, the prior relationship of the jobs is set so that the time between the jobs of the overlapping materials becomes equal to or greater than the lower limit value of the switching time. In other words, as shown in FIG. 5, the relationship is set in consideration of the switching time between jobs of different materials a and b.

  Further, the prior relationship of the jobs is set so that the total rolling length of the waiting job and the rolling job does not exceed the limit value. That is, as shown in FIG. 6, the total rolling length of the standby material a job and the rolling material b job is considered. Further, the prior relationship of the jobs is set such that the number of jobs of different materials that fall between jobs of the same material becomes the limit value. For example, the limit value is set to 2. As a result, as shown in FIG. 7, it is allowed that one job a1 of the other material a and one job c1 of the material c enter between the job b1 and the job b2 of the material b.

  In addition, the prior relationship of the job is set such that the material rolled first between the two materials is always rolled first. As a result, as shown in FIG. 8A, the completion of the job b1 of the other material b, which is performed later, between the job a1 and the job a2 of the material a is prohibited. As shown in FIG. 8B, the job b1 of the other material b is executed and completed after the last job a2 of the material a.

  As for the newly added water cooling pattern, for example, as shown in FIG. 9, in the case of a material c that is a water cooling material, the material has a water cooling pattern that is cooled by a strong water cooling device 130 between the rolling c1 and c2. For example, it is processed at the timing of the lift between the rolling a1 and a2 of the material a.

  The water-cooled material can be used as an overtaking material in overtaking rolling. For example, as shown in FIG. 10, the material b that is a water-cooled material can be overtaken at the timing of the lift between the rolling a1 and a2 of the material a.

  Furthermore, in general, the water-cooled material can be changed to a CR material (controlled rolling material), and as shown in FIG. 11, it can also be used as a lift material (material on the overtaking side) for existing tandem rolling and overtaking rolling. . However, there are also slabs that cannot be changed to CR materials for reasons such as the incorporation of materials.

  Subsequently, in step S5, the optimization problem formulated with the objective function and the constraint conditions as described above is converted into a mixed integer programming problem, and the continuous heating furnaces 101 and 102 are made to minimize the rolling completion time. The material extraction order from the machine and the job execution order in the rolling mill 110 are determined. Through the above processing procedure, the optimization problem is formulated from the various information obtained from the path schedule by the objective function and the constraint conditions, and the formulated optimization problem is applied to the mixed integer programming problem, The rolling procedure is determined as an optimal schedule that minimizes the rolling time.

Thereby, for example, as shown in FIG. 12, the amount of water V used per period T0 is used as the amount of water used per unit time.
V = Q1 * T1 + Q2 * T2
(The flow rate of cooling water to be used is known from “E: Cooling water flow rate information” in the information acquired for each job), and the upper limit usage determined by the capacity and current water level of the water supply and drainage tanks Do not exceed Vlim,
V ≦ Vlim
By giving as constraints, it becomes possible to search for a combination that does not cause cooling water shortage or drainage delay, and it is possible to prevent a reduction in rolling efficiency such as a rolling line stoppage.

  Further, the processing content up to the determination of the rolling procedure as described above is as shown in FIG. As shown in FIG. 13, first, the arrangement information of the materials in the furnace is acquired (B1), and the pass schedule is calculated based on the arrangement information in the furnace (B2). Here, the calculation of the path schedule is a calculation for acquiring various kinds of information as shown in the above-described A to E. Then, optimization calculation is performed using the calculation result of the pass schedule and the in-furnace arrangement information as required (B3).

  Here, the acquisition of the in-furnace array information (B1) corresponds to the processing content of step S1 in FIG. 2, and the calculation of the path schedule (B2) corresponds to the processing content of step S2 and step S3 in FIG. The optimization calculation (B3) corresponds to the processing contents of steps S4 and S5 in FIG. As described above, the control system determines the rolling procedure as the optimum schedule. And the calculation for obtaining the rolling procedure is to formulate the objective function and the constraint condition as an optimization problem using the values described using the above-mentioned conditions A to E, and then formulate the optimization problem. Is converted to a mixed integer programming problem to obtain a rolling procedure.

  As a result, the mixed integer programming problem solving method is the optimal method established to find the optimal solution of the scheduling problem, so rolling as the optimal schedule obtained by using the mixed integer programming problem solution The contents of the process can be obtained in real time as an optimal solution of the contents close to the ideal by effectively utilizing the processing capacity of the computer. That is, the content of the rolling procedure is a more realistic content, and is an optimal schedule that can complete the rolling earliest.

  FIG. 14 shows an optimum rolling point determination system as a specific example of the control system. In this optimum rolling point determination system, a computer (mil P / C (mill process computer), hereinafter referred to as a first computer) 1 for managing information about heating, a computer (hereinafter referred to as a rolling order) 2) and a computer (hereinafter referred to as a third computer) 3 for calculating a schedule.

  In such an optimum rolling point determination system, information in the heating furnace is stored in the second computer 2 for determining the rolling order from the first computer 1 for managing information on the raw material and heating of the raw material. The data is transmitted via a LAN (Local Area Network) 4. In addition, information on combination patterns (extraction timing) and the like are transmitted from the second computer 2 to the first computer 1 via the LAN 4 in accordance with the optimum schedule. In the third computer 3, sharing of schedule calculation is realized.

(Modification)
Incidentally, as shown in FIG. 15, the OLAC device 140 is arranged at the rear stage of the rolling equipment including the above-described strong water cooling system 130, and the downstream equipment such as the shearing device 150 is arranged at the subsequent stage. The OLAC device 140 accelerates and cools the thick steel plate after rolling at a specific cooling rate required for the material in a specific temperature range, and then air-cools. Therefore, the OLAC processing time by the OLAC device 140 varies depending on the material and dimensions, and depending on the rolling order of the rolled material, the rolling mill 110 may be stopped, or traffic jams may occur in downstream equipment such as the shearing device 150. is there. Moreover, since the OLAC device 140 uses cooling water together with the strong water cooling device 130, there is a possibility that cooling water shortage or drainage delay may occur as a whole system. For this reason, in this modification, not only the rolling process but also the optimum rolling procedure including the OLAC process is determined.

  FIG. 16 is a schematic flowchart showing an example of the entire processing process of one material including the OLAC processing process. As shown in FIG. 16, in this modification, the entire process including the job J2 in the OLAC process performed after the job J1 in the rolling process is the target for determining the optimum rolling procedure. The job J2 of the OLAC processing process is performed by the OLAC transport J21 and the OLAC apparatus 140 which transport to the OLAC apparatus 140 after the rolling process (rolling J11 → cooling J12 → rolling J13) by the rolling mill 110 including the strong water cooling apparatus 130. An OLAC process J22 is included.

  The second computer 2 shown in FIG. 14 determines not only the rolling order in the rolling process but also the entire rolling order including the OLAC process. Note that the fourth computer 5 that performs job management only for the OLAC process may be connected to the LAN 4 so that the third computer 3 calculates the schedule of the entire process. The 2nd computer 2 concerning a modification gives the information regarding OALC processing to each slab (each material) of a predetermined object, and adds that the OLAC processing time between each material does not overlap in the above-mentioned restriction conditions.

  Here, the information related to the OLAC process includes the OLAC transfer time, which is the time for transferring the material to the OLAC apparatus 140 after the completion of rolling, the OLAC process time, which is the accelerated cooling time by the OLAC apparatus 140, and the amount of water used by the OLAC apparatus 140. included. This amount of water used is included in the above-described E: cooling water flow rate information. The OLAC transport time depends on the equipment specifications and material length of the transport device. The OLAC processing time is a variable that depends on product use, material length, and equipment specifications (cooling capacity).

  And the rolling order of each raw material is determined by making the OLAC completion time until the OLAC process by the OLAC apparatus 140 with respect to all the raw materials rolled and OLAC processed through the heating furnaces 101 and 102 complete is an objective function.

For example, as shown in FIG. 17, the amount of water V1 used per period T10 is used as the amount of water used per unit time in the entire system.
V1 = Q11 * T11 + Q12 * T12 + Q13 * T13 + Q14 * T14 + Q15 * T15
(The flow rate of cooling water to be used is known from “E: Cooling water flow rate information” in the information acquired for each job), and the upper limit usage determined by the capacity and current water level of the water supply and drainage tanks Do not exceed Vlim1
V1 ≦ Vlim1
By giving as constraints, it becomes possible to search for a combination that does not cause cooling water shortage or drainage delay, and it is possible to prevent a reduction in rolling efficiency such as a rolling line stoppage.

  Further, the path schedule is determined so as to satisfy the constraint that the OLAC processing time between the materials does not overlap. This is because the OLAC device 140 assumes that the material can be processed only one by one. For example, as shown in FIG. 18, the preceding rolled material a11 and the subsequent rolled material a12 have a path schedule such that the OLAC replacement time tc2 is tc2> 0 so that the OLAC processing times t11, t21 do not overlap. It is determined. Thereby, the material after rolling does not wait in front of the OLAC device 140, and the occurrence of congestion on the rolling line can be suppressed. The OLAC transport time t11 needs to be equal to or longer than the mill replacement time tc1.

  Furthermore, in this modification, the rolling pitch at the completion of the OLAC process of one material is compared with the shearing pitch of the subsequent stage, and when the comparison result is rolling pitch> shearing pitch, that is, when the shearing process is congested. The rolling order is rearranged so that a material having a long OLAC processing time is preferentially rolled first.

  For example, as shown in FIG. 19, when three materials (slabs) a21, a22, a23 are processed, in the upper diagram, the shear pitch between the slabs a22, a23 is the rolling pitch between the slabs a21, a22, a23. Shorter than that. For this reason, as shown in the lower figure, the slab is rolled so that the OLAC processing time is in the long order. That is, the rolling order of slabs a21 → a22 → a23 is rearranged to the rolling order of slabs a22 → a21 → a23. As a result, in the lower rolling order, the completion of the OLAC process for the slab a22 is delayed by a time t3, in particular, compared to the upper rolling order, and accordingly, a time margin is provided for the subsequent shearing process. As a result, the congestion on the shear line can be reduced.

  As shown in FIG. 19, determining the rolling order in consideration of the rolling pitch and the shearing pitch enables leveling of the rolling pitch and the shearing pitch, and rolling in order of the OLAC processing completion time. This is a more preferable rolling order determination process because it allows more time for shearing than the order determination process. In addition, when a rolling pitch is not larger than a shear pitch, it processes in the rolling order that the efficiency of a rolling process becomes the maximum.

  As described above, the optimization problem is formulated by a predetermined objective function and a predetermined constraint condition, and the extraction order of materials as a mixed integer programming problem, and the rolling in the rolling equipment including the rolling equipment or the OLAC apparatus are performed. By unraveling the order, it is possible to determine the material extraction order from the heating furnace and the rolling order for completing the rolling earliest. In particular, it is formulated according to certain constraints including that the amount of water used does not exceed the water supply capacity and drainage capacity of the plate rolling equipment, and this formulated optimization problem is applied to the mixed integer programming problem. And the extraction order of the raw materials from the heating furnace and the order of rolling equipment including the rolling equipment or the rolling equipment including the OLAC equipment are obtained so that the rolling completion time is minimized. Thus, it is possible to prevent a reduction in rolling efficiency such as stopping of the rolling line.

  In addition, if the slab extraction order (rolling order) and the rolling method are determined, the amount of water used at that time can be determined, so that the water level of the water supply tank and the drain tank can be controlled by feedforward control. Further, as described above, by defining the water-cooled material as a slab that can be changed to various rolling methods, it is possible to combine various slab extraction orders and rolling methods. This can be expected to have the effect that when the rolling efficiency is adjusted by a combination of the extraction order and the rolling method, the water cooling material widens the adjustment range, and a flexible combination can be created.

  Furthermore, when the rolling pitch is larger than the shearing pitch, the shearing time can be reduced by rearranging the rolling order in which the OLAC processing time is long, so that the shearing time can be suppressed.

101, 102 Heating furnace 110 Rolling mill 130 Strong water cooling device 140 OLAC device 150 Shearing device

Claims (3)

A heating furnace capable of heating a plurality of types of materials, a rolling device that rolls the materials extracted from the heating furnace using a standby space provided before and after the material, and the rolling device disposed immediately after the rolling device. A rolling point determination method for determining a rolling point of a material rolled by a thick plate rolling facility equipped with a strong water cooling device for cooling the material rolled by the apparatus,
Based on the rolling schedule of each material to be rolled, the occupation time of the rolling device when performing rolling, the upper and lower limit values of the cooling time between rolling for the same material, the length of the material after the rolling, Obtain information including restrictions on the preceding relationship of rolling in the rolling schedule of the same material, and information on the flow rate of cooling water,
Based on the obtained information, the rolling completion time until the rolling of all the materials rolled through the heating furnace is completed as an objective function, and cannot be performed simultaneously in the rolling apparatus, between each rolling The cooling time is within the range of the upper and lower limit values, the total length of the raw material during and during the rolling process is less than or equal to the storage length in the standby space, and the preceding relationship between the rolling satisfies the given constraints. And the constraint condition that the amount of water used must not exceed the water supply capacity and drainage capacity of the plate rolling equipment is formulated into an optimization problem,
Convert the formulated optimization problem into a mixed integer programming problem, and determine the material extraction order from the heating furnace and the rolling execution order in the rolling device so that the rolling completion time is minimized. A rolling point determination method characterized by: A rolling point determination method for determining a rolling point of a material to be rolled by a thick plate rolling facility further provided with an online accelerated cooling device at a subsequent stage of the strong water cooling device,
Based on the cooling schedule of each material to be accelerated online cooling, including the transfer time from the rolling device to the online accelerated cooling device, the processing time in the online accelerated cooling device, and the flow rate information of the cooling water of the online accelerated cooling device Seeking more information about online accelerated cooling,
Based on the obtained information, the objective function is the on-line accelerated cooling completion time until the on-line accelerated cooling is completed for all the materials that are rolled and on-line accelerated cooling through the heating furnace, and are simultaneously overlapped in the rolling apparatus. That the cooling time between each rolling is in the range of the upper and lower limit values, that the total length of the raw material during and during the rolling process is less than or equal to the storage length in the standby space, the prior relationship between rolling Must satisfy the given constraints, the online accelerated cooling time does not overlap, and the amount of water used, including the amount of water used for the online accelerated cooling device, is the same for the plate rolling equipment and the online accelerated cooling device. The constraint condition of not exceeding the water supply capacity and drainage capacity is formulated into an optimization problem,
The formulated optimization problem is converted into a mixed integer programming problem, and the extraction order of the material from the heating furnace, the rolling device, and the online accelerated cooling device so as to minimize the completion time of the online accelerated cooling The method for determining a rolling procedure according to claim 1, wherein an execution order of the rolling and online accelerated cooling is determined.   A comparison is made between the rolling pitch and the shear pitch between the respective materials at the completion of the online accelerated cooling treatment, and when the rolling pitch is larger than the shear pitch, the rolling order is changed to a long online accelerated cooling treatment time. The rolling point determination method according to claim 2.

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