A digital method for judging the quality of slab

Abstract

The present invention relates to a digital method for slab quality determination criteria, establishing a determination system for slab quality criteria, and compiling the steps of the determination system: extracting the characteristics of quality events corresponding to the slab quality determination criteria, where the quality events include corresponding grades, influence ranges, and frequencies; using the concept of event elements to define the occurrence conditions of quality events, and the event elements are shared among different quality determination criteria; the event elements are divided into logical event elements and range event elements; data sorting. The advantages of the present invention are: it is used to construct a slab quality determination system, which can realize the digitization of slab quality determination criteria, and can conveniently isolate the slab quality determination system from the slab quality determination criteria. Quality management personnel use the quality determination system to maintain the determination criteria, enabling the developed on-line slab quality determination system to be developed and promoted as an independent product; it is convenient for system users to keep the product determination criteria confidential.

Description

Technical Field

[0001] The present invention relates to the technical field of continuous casting slab quality determination models, and particularly to a digital method for slab quality determination criteria. Background Art

[0002] In order to reduce energy consumption, steel enterprises are constantly raising the requirements for the hot charging and direct charging rates of slabs. The online quality rating of slabs has become a necessary condition for slab continuous casting production. The online cleaning of slabs has also put forward higher requirements for the online rating of slabs, and it is necessary to determine the online cleaning method and cleaning level according to the defects of the slabs. The online rating of slabs is an inevitable requirement for enterprises to improve the refined management of steel product quality. With the increasing market competition pressure, users require steel product manufacturers to improve product quality, especially to ensure the stability of product quality. This requires enterprises to effectively identify defective materials and achieve effective processing in the first time.

[0003] In the prior art, the publication number is CN112077273A, and the invention patent name is "A slab quality determination and evaluation system and method with variable casting speed". Only the change in casting speed is involved in the slab quality rating, and it is not an online rating. It can only guarantee to give the slab quality rating within 10 minutes after the slab is cut offline.

[0004] The publication number is CN105629921A, and the invention patent name is "A quality defect determination and secondary treatment method for continuous casting slabs after cutting". It is not an online rating, and the rating standard does not have the function of being dynamically modified through the HMI interface.

[0005] In 2021, the journal "Continuous Casting" published "Research and Practice on the Online Prediction System of CISC Casting Quality". It can be seen from this that CISC has also achieved online rating and rule editing of slabs, but its rule editing has not reached the level of a judgment rule maintenance platform. Summary of the Invention

[0006] The purpose of the present invention is to provide a digital method for slab quality determination criteria, enabling users to input slab quality determination criteria into the slab online rating system. During continuous casting production, the slab online rating can determine the quality of slabs according to the primary signals during the continuous casting process.

[0007] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0008] A digital method for slab quality determination criteria, establishing a determination system for slab quality standards, and the compilation of the determination system specifically includes the following steps:

[0009] S1. Extract the characteristics of quality events corresponding to the slab quality judgment criteria. The quality events include the corresponding grades, influence ranges, and frequencies.

[0010] S2. Use the concept of event elements to define the occurrence conditions of quality events. The event elements are shared among different quality judgment criteria.

[0011] S3. The event elements are divided into logical event elements and range event elements:

[0012] The definition of logical event elements contains multiple groups of conditions. Each group of conditions is a logical definition of an event element. When defining an event element, data items, event elements, event element parameters, and operators are used.

[0013] The range event element is that when the corresponding data item triggers a quality event within a specified range, the trigger condition is that when the data item changes, the corresponding logical event element is triggered.

[0014] S4. Data sorting:

[0015] Some of the continuous casting process data collected cannot be directly used for event element definition and need to be processed before use.

[0016] The data processing based on the logical relationship between data is defined through the point value relationship.

[0017] The processing of a single data item by time period is defined through the interval relationship.

[0018] In step S1, the judgment criteria include multiple quality events. Each quality event corresponds to a highest quality grade. The quality events include an influence range. The types of influence ranges include the full length of the casting stream, the number of slab blocks, the start of the heat, and the end of the heat. The frequency types supported by the quality events are:

[0019] Within each slab: The minimum number of occurrences of the quality events included in the slab.

[0020] Within a specific length: The minimum number of occurrences of the quality events within a certain casting stream length.

[0021] In step S3, for logical event elements, the definition types include end, start, start / end, and replacement. For event elements where start is the same as end, the start / end type is used for definition. When using the replacement type to define an event element, if the calculated result is true, the event element is considered to start; if the calculated result is false, the event element is considered to end.

[0022] Logical event elements are defined according to the logical event element types, that is, the start conditions and end conditions of the event elements are defined. Logical event element operators include: =, <, <=, >, >=.

[0023] In the event element, the event elements in the same group are in an AND relationship, that is, if a false condition is encountered, the calculation of the group can be terminated;

[0024] If the event element type is End and Start, the event element is assigned a value only when the result is true, and the event element is not processed if the result is false;

[0025] If type is start / end or replace, the result is true or false and the event element is processed.

[0026] In step S3, the data items are used for other data except event meta-parameters, and the data items include primary data items, tertiary data items, calculated data items, and predefined data items;

[0027] The primary data item is the data item corresponding to the primary variable, which is collected through OPC;

[0028] Level 3 data items are data related to the steelmaking process and are received through the steelmaking PES;

[0029] The calculation data items are defined by point value relations and interval relations;

[0030] The predefined data items are data items with specific meanings, such as recording the full length of the casting strand at the location where the quality event occurs, which is the casting strand position at the current moment.

[0031] Predefined data items include primary predefined data items and PES predefined data items. Primary predefined data items require users to specify their corresponding primary data items or calculated data items. PES predefined data items are temporarily solidified in the program and are extracted from the manufacturing standards issued by PES through steel-making marks.

[0032] The impact range may be part of the casting strand outside the location where the quality event occurs that is affected by the quality event, and all slabs within the impact range of the quality event will be downgraded.

[0033] Quality events can also be defined by frequency. For example, a quality event is considered to have occurred only when the number of times the event element corresponding to a slab occurs exceeds a certain number.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. It is used to build a slab quality determination system, which can realize the digitization of slab quality determination standards and can easily isolate the slab quality determination system from the slab quality determination standards. Quality management personnel use the quality determination system to maintain the determination standards, so that the developed slab online quality determination system can be developed and promoted as an independent product;

[0036] 2. Facilitate the system users to keep the product judgment criteria confidential, so that developers do not need to access the specific judgment criteria;

[0037] 3. A slab online quality judgment system can adapt to continuous casting machines with different processes and different continuous casting slab products. Quality management personnel use the quality judgment system to maintain judgment criteria and can define multiple sets of criteria simultaneously;

[0038] 4. The users of the slab online quality judgment system can formulate and adjust the quality judgment criteria by themselves, and can conveniently digitalize the slab quality judgment criteria and maintain them in the slab quality judgment system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the digitalization process of slab quality judgment criteria and the relationships between objects.

[0040] Figure 2 It is a schematic diagram of the structure of slab quality judgment criteria.

[0041] Figure 3 It is a schematic diagram of the structure of event elements.

[0042] Figure 4 It is a schematic diagram of the structure of data items.

[0043] Figure 5 It is a schematic diagram of the OPC structure.

[0044] Figure 6 It is a schematic diagram of the data sorting structure.

[0045] Figure 7 It is the HMI interface of the slab quality online rating system. DETAILED DESCRIPTION OF THE INVENTION

[0046] The present invention will be described in detail below with reference to the accompanying drawings of the specification, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0047] The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments. The methods used in the following embodiments are all conventional methods unless otherwise specified.

[0048]

Embodiment 1

[0049] See Figure 1 , the digitalization process of slab quality judgment criteria and the relationships between objects are as follows:

[0050] Each slab quality rating standard corresponds to one or more major product categories. The quality determination model uses the tapping mark or steel grade to correspond to the major product category and then finds the determination standard. For example, in a certain steel mill, one tapping mark corresponds to one manufacturing standard, and the quality determination standard for the tapping mark used is specified in the manufacturing standard; if this correspondence cannot be guaranteed, it is necessary to directly use the product type to find the determination standard, see Figure 2 . Each determination standard contains multiple quality events, and each quality event corresponds to a highest quality level. Generally, a quality event has an influence range, which refers to that parts of the casting stream other than the location where the quality event occurs are also affected by this quality event. The slabs within the influence range of the quality event need to be downgraded; the types of influence range (location type) can be divided into: the full length of the casting stream, the number of slab blocks, the start of the heat, the end of the heat; some quality events are defined by frequency, for example, the number of occurrences of the event element corresponding to a slab exceeds a certain number before it is considered that the quality event has occurred; the frequency types supported by the system are: within each slab, within a specific length. The occurrence conditions of quality events are defined by event elements.

[0051] See Figure 3 , event elements are divided into logical event elements and range event elements. The range event element is the range in which the corresponding data item triggers a quality event; when defining a range event element, data items and event element parameters are required. The definition of a logical event element may contain multiple sets of conditions (tuples), and each one of them is called an event element item. When defining a logical event element, data items, event elements, event element parameters, operators are required, and it is necessary to indicate whether the data items and event elements used are the trigger conditions of the event. The types of event element definitions include: end, start, start / end, replace. The logical event element is defined according to the logical event element type, that is, the start condition and the end condition of the event element need to be defined. The event element where start is end needs to be defined by the start / end type. When defining an event element by the replace type, if the calculated result is true, it is considered that the event element starts; if the calculated result is false, it is considered that the event element ends; logical event element operators include: =, <, <=, >, >=. Relationship between items: The relationship between each item within the same group is an AND relationship, that is, when encountering a false situation, the calculation of this group can end; if the type is end / start, the event element is only assigned a value when the result is true, and if the result is false, the event element is not processed; if the type is not start / end, replace, the event element is processed regardless of whether the result is true or false; Trigger condition: When the data item and the event element change, the corresponding logical event element (the tuple where the trigger condition is located) is triggered.

[0052] See Figure 4, data items are other data used in the process of slab quality determination except parameters. Data items are divided into primary data items, tertiary data items, calculated data items, and predefined data items; whether they are related to the flow: some data items are not related to the casting flow, and some data items are related to the casting flow. In the system, various rule configurations including event meta-definition are without casting flow (for example, quality events cannot be defined by flow). Correspondingly, the data items in the model are stored in arrays (0: not related to flow; 1: 1 flow data; 2: 2 flow data). In the system, only the primary variable address is configured by flow; primary data items: data items directly corresponding to primary variables. Primary variables are collected through OPC. In order to identify each primary data item, the model needs to define the primary data item code. If the data item represented by a code is related to the flow, two addresses need to be configured when defining the primary address; tertiary data items: data related to the molten steel smelting process, which are received through the steelmaking PES. In order to realize the user configuration of quality judgment rules, each third-level data item corresponds to a third-level data item code; calculated data item: a data item calculated by other data items. Calculated data items are defined by point value relationships and interval relationships; point value relationship: defines the calculation relationship between data items, and the data used are all current data; interval relationship: defines the maximum value, minimum value, average value, etc. of a single data item within a period of time or a casting stream; predefined data items: data items that are required for slab quality judgment and cannot be defined by the user. Predefined data items are divided into first-level predefined data items and PES predefined data items; first-level predefined data items: users are required to specify their corresponding first-level data items or calculated data items; PES predefined data items: temporarily solidified in the program, and extracted from the manufacturing standards issued by PES through steel-out marks.

[0053] See Figure 5 OPC is an industry standard for communicating with PLCs; it can also represent the middleware used to communicate with PLCs, and an OPC server needs to be installed. The quality judgment model mainly collects the required data from the first level and does not send data to the first level. Data collection is generally divided into two modes: subscription and active reading; subscription: when the first-level data changes, the OPC server notifies the model system to process the first-level data by calling the callback function; active reading: in addition to the subscription method, the first-level data can also be actively read; when communicating with PLC through OPC, it is necessary to define the first-level variables in OPC. The first-level variables are defined by group, and the PLC address corresponding to the variable needs to be given when defining the first-level variable identifier.

[0054] See Figure 6, data sorting is divided into point-value relationships and interval relationships. The point-value relationship is the calculation relationship between data items, and the data used are all current data. The interval relationship is the maximum value, minimum value, average value, etc. of a single data item within a period of time or a casting stream; Point-value relationship: The definition of the point-value relationship is similar to the definition of the logical event element. Its definition may include multiple sets of conditions, and each of them is called a point-value relationship item. When defining the point-value relationship, data items and operators are required, and it is necessary to indicate whether the data items used are the triggering conditions of the event; Point-value relationship operators include: <, <=, =, +, -, *, / , difference (absolute value), assignment, exclusive OR, jump, >, >=; Relationship between items: The relationship between items in the same group is an AND relationship, that is, when encountering a false situation, the calculation of this group can end; if it is the last item in this group, the corresponding data item is assigned a value; Triggering condition: When the data item changes, the corresponding point-value relationship calculation is triggered (the item group where the triggering condition is located); Interval relationship: When defining the interval relationship, it is necessary to specify the value type and interval type. There is only one definition for each interval relationship; Value type: It is divided into 5 types: change range, difference between two points, maximum value, minimum value, sum, etc.; Interval relationship: It is divided into four interval relationship types: equal division length, equal division time, time window, inflection point.

[0055] The main fields and the associated relationships between tables are shown in Figure 7 , as shown in Table 1.

[0056] Table 1: Main data structure for digitizing the slab quality judgment standard

[0057]

[0058]

[0059]

[0060]

[0061]

[0062] The present invention is used to construct a slab quality determination system, which can digitize the slab quality determination criteria and can conveniently isolate the slab quality determination system from the slab quality determination criteria. Quality management personnel use the quality determination system to maintain the determination criteria, enabling the developed on-line slab quality determination system to be developed and promoted as an independent product; it is convenient for system users to keep the product determination criteria confidential, so that developers do not need to contact the specific determination criteria; one set of on-line slab quality determination system can adapt to continuous casting machines with different processes and different continuous casting slab products. Quality management personnel use the quality determination system to maintain the determination criteria and can define multiple sets of criteria simultaneously; users of the on-line slab quality determination system can formulate and adjust the quality determination criteria by themselves, and can conveniently digitize the slab quality determination criteria and maintain them in the slab quality determination system.

Claims

1. A digitized method for determining slab quality standards, characterized in that: Establish a determination system for slab quality standards. The preparation of the determination system specifically includes the following steps: S1. Extract the characteristics of quality events corresponding to the slab quality judgment standard. The quality events include the corresponding level, impact range, and frequency; S2. Use the concept of event element to define the occurrence conditions of quality events. Event element is shared in different quality judgment standards. S3. Event elements are divided into logical event elements and scope event elements: The definition of a logical event element includes multiple groups of conditions, each group of conditions is an event element logic definition, and the event element is defined using data items, event elements, event element parameters, and operators; The range event element is a quality event triggered when the corresponding data item is within the specified range. The triggering condition is the data item. When the data item changes, the corresponding logic event element is triggered; S4. Data sorting: Some of the collected continuous casting process data cannot be directly used for event meta-definition and need to be processed before use; Data processing based on the logical relationship between data is defined by point value relationship; The processing of single data by time period is defined by interval relationship.

2. A digitized method for determining slab quality standards according to claim 1, characterized in that: In step S1, the judgment criteria include multiple quality events, each quality event corresponds to a highest quality level, and the quality event includes an impact range. The types of impact ranges include the full length of the casting strand, the number of slabs, the start of the furnace, and the end of the furnace. The frequency types supported by the quality event are: In each slab: the minimum number of occurrences of quality events contained in the slab; Within a specific length: The minimum number of quality events that occur within a certain casting strand length.

3. A digitized method for determining slab quality standards according to claim 1, characterized in that: In step S3, the logic event element has definition types including end, start, start / end, and replacement. The event element that starts and ends is defined by the start / end type. When the event element is defined by the replacement type, if the calculation result is true, the event element is considered to have started; if the calculation result is false, the event element is considered to have ended. The logic event element is defined according to the logic event element type, that is, the start condition of the event element and the end condition of the event element are defined; Logical event meta-operators include: =, <, <=, >, >=.

4. A digitized method for determining slab quality standards according to claim 3, characterized in that: In the event elements, the event elements in the same group are in an AND relationship, that is, if a false condition is encountered, the calculation of the group can be terminated; If the event element type is End and Start, the event element is assigned a value only when the result is true, and the event element is not processed if the result is false; If type is start / end or replace, the result is true or false and the event element is processed.

5. A digitized method for determining slab quality standards according to claim 1, characterized in that: In step S3, the data items are used for other data except event meta-parameters, and the data items include primary data items, tertiary data items, calculated data items, and predefined data items; The primary data item is the data item corresponding to the primary variable, which is collected through OPC; Level 3 data items are data related to the steelmaking process and are received through the steelmaking PES; The calculation data items are defined by point value relations and interval relations; A predefined data item is a data item with a specific meaning.

6. A digitized method for determining slab quality standards according to claim 5, characterized in that: The predefined data items include primary predefined data items and PES predefined data items. The primary predefined data items require the user to specify their corresponding primary data items or calculation data items. The PES predefined data items are temporarily solidified in the program and are extracted from the manufacturing standards issued by PES through steel tapping marks.

7. A digitized method for determining slab quality standards according to claim 2, characterized in that: The impact range refers to the part of the casting strand outside the location where the quality event occurs that is affected by the quality event, and the slabs within the impact range of the quality event will be downgraded.

8. A digitized method for determining slab quality standards according to claim 2, characterized in that: The quality event is defined by frequency, and the quality event is considered to have occurred only when the number of times the event element corresponding to a slab occurs exceeds a certain number.

9. A digitized method for determining slab quality standards according to claim 5, characterized in that: The predefined data item refers to the full length of the strand recording the location where the quality event occurs, that is, the strand position at the current moment.

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