阅读说明：本技术 一种利用常规冷却实现两段冷却的层冷控制方法 (Layer cooling control method for realizing two-stage cooling by utilizing conventional cooling ) 是由 邢伟 王继军 张波 秦红波 邝霜 李晓刚 闫新杰 李士交 王钟萱 于 2021-08-06 设计创作，主要内容包括：本发明涉及一种利用常规冷却实现两段冷却的层冷控制方法,属于热轧方法技术领域。本发明的技术方案是：以当前生产带钢的钢种、冷却策略和目标卷取温度为索引,计算空冷段水阀关闭数量,确定当前生产带钢的上下集管不喷水区域,保证不喷水区域只有空冷一种冷却方式。本发明的有益效果是：可以有效的提高卷取温度的控制精度,不需要增加新的设备和工具,对现有的控制方法和模型进行改造就可以实现两段冷却模式。(The invention relates to a laminar cooling control method for realizing two-stage cooling by utilizing conventional cooling, belonging to the technical field of hot rolling methods. The technical scheme of the invention is as follows: and taking the steel grade, the cooling strategy and the target coiling temperature of the currently produced strip steel as indexes, calculating the closing number of water valves of the air cooling section, determining the water non-spraying area of the upper and lower collecting pipes of the currently produced strip steel, and ensuring that the water non-spraying area only has one cooling mode of air cooling. The invention has the beneficial effects that: the control precision of the coiling temperature can be effectively improved, new equipment and tools do not need to be added, and the two-section cooling mode can be realized by modifying the existing control method and model.)

1. A laminar cooling control method for realizing two-stage cooling by using conventional cooling is characterized by comprising the following steps:

(1) establishing a corresponding relation of the water non-spraying areas of the upper header and the lower header according to the steel type of the strip steel, the cooling strategy, the target thickness layer and the target coiling temperature layer;

(2) taking the steel grade, the cooling strategy and the target coiling temperature of the currently produced strip steel as indexes, calculating the closing number of water valves of the air cooling section, and determining the water non-spraying areas of the upper and lower collecting pipes of the currently produced strip steel, wherein the water non-spraying areas of the upper and lower collecting pipes are realized by setting the water valves of the air cooling section into fault valves;

(3) when the strip steel is tracked and positioned at the position of the crop shear, the number of the water non-spraying collecting pipes is calculated by automatically triggering a program, so that the starting and stopping ranges of the water non-spraying areas are determined, the water non-spraying areas are automatically passed through in the layer cooling model calculation process, the target coiling temperature is reached through other collecting pipes, and the water non-spraying areas are ensured to be only cooled by air in a cooling mode;

(4) when switching to regular cooling, the state before the field failure valve is automatically restored.

2. The laminar cooling control method for realizing two-stage cooling by using conventional cooling according to claim 1, characterized in that: in the step (1), the steel type of the strip steel is a combination of letters and numbers with the length of no more than 10 characters, the combination is specified according to the grade of the steel type, or determined according to different chemical components, or determined according to the requirements of customers, and the number of steel types is 1-200;

the cooling strategy comprises front section cooling, rear section cooling and sparse cooling, and the number of the front section cooling, the rear section cooling and the sparse cooling is 1-5;

the target coiling temperature layers are rolling strip steel coiling temperature target values, and the number of the rolling strip steel coiling temperature target values is 1-8;

the target thickness layer refers to the target thickness value of the rolled strip steel finished product, and the number of the target thickness layers is 1-10.

3. The laminar cooling control method for realizing two-stage cooling by using conventional cooling according to claim 2, characterized in that: the cooling strategy is formulated according to customer requirements, idx _ M is defined as a cooling strategy code, the value range of the idx _ M is [1, 5], and different idx _ M values represent different cooling strategies;

the target coiling temperature layer is respectively formulated according to the target coiling temperature of the strip steel, the parameter idx _ T is a target coiling temperature index, the value range of the target coiling temperature index is [1, 8], and different numbers represent different coiling temperature ranges;

the target thickness layer is established according to the target thickness of the strip steel, the parameter idx _ H is used as a target thickness index, the value range is [1, 10], and different numbers represent different thickness ranges of the strip steel.

4. The laminar cooling control method for realizing two-stage cooling by using conventional cooling according to claim 1, characterized in that: in the step (3), the water non-spraying area mainly has two parameters: the starting position and the air cooling time of the header pipes without spraying water from the upper part and the lower part; number of header without spraying water N = int (V)_base*T_hold/S_dis) Wherein, V_baseThe threading speed of the strip steel in the last finishing mill; t is_holdIs the air cooling time; s_disIs the spacing between headers, N is the number of headers that do not spray water; and determining the starting position and the ending position of the water non-spraying position according to the ending position = the starting position + N.

5. The laminar cooling control method for realizing two-stage cooling by using conventional cooling according to claim 1, characterized in that: before the fault valve is arranged, the real state of the current fault valve is stored and stored in the shared memory, so that the state of each water valve is not corrected again after the mode is switched, and the production time is not influenced.

Technical Field

The invention relates to a laminar cooling control method for realizing two-stage cooling by utilizing conventional cooling, belonging to the technical field of hot rolling methods.

Background

In the production process of hot rolled strip steel, a laminar cooling device is required to be used for cooling the strip steel after rolling and before coiling, and ideal metallographic structure and mechanical properties are obtained by controlling the coiling temperature and the cooling rate of the strip steel. The sub-cooling zone is defined from the finish rolling outlet pyrometer to the underground crimper inlet pyrometer. The laminar cooling area is divided into a rough cooling area and a fine cooling area. Wherein the 1 st to 15 th groups of headers are rough cooling areas, and the 16 th, 17 th and 18 th groups of headers are fine cooling areas.

The control of the hot rolling coiling temperature completely depends on a layer cooling model, and the current layer cooling control modes are mainly divided into conventional cooling and two-stage cooling. The conventional cooling is also called front-end cooling, the opening position and the number of water valves are determined according to the predetermined cooling rate, and when the actual temperature of the strip steel deviates from the set temperature, the water spray header is increased or decreased from the side of the coiling machine to the downstream direction of the strip steel. The two-stage cooling is that the water valve is opened at a certain speed for cooling, then the air cooling is carried out for a few seconds, and then the water valve is opened for cooling in the second stage. The conventional cooling control coiling temperature has higher precision, and the two-section cooling control precision is slightly poor. A two-stage cooling control mode is adopted for the steel grades of the dual-phase steel category, and the coiling temperature often exceeds the deviation range in the actual production process, so that the requirement of customers is difficult to meet.

Disclosure of Invention

The invention aims to provide a layer cooling control method for realizing two-section cooling by utilizing conventional cooling, which takes the steel grade, the cooling strategy and the target coiling temperature of the current produced strip steel as indexes, determines the water non-spraying area of the upper header and the lower header of the current produced strip steel, ensures that the water non-spraying area only has one cooling mode of air cooling, can effectively improve the control precision of the coiling temperature, does not need to add new equipment and tools, can realize two-section cooling mode by modifying the existing control method and model, and effectively solves the problems in the background technology.

The technical scheme of the invention is as follows: a layer cooling control method for realizing two-stage cooling by using conventional cooling, comprising the following steps of:

(1) establishing a corresponding relation of the water non-spraying areas of the upper header and the lower header according to the steel type of the strip steel, the cooling strategy, the target thickness layer and the target coiling temperature layer;

(2) taking the steel grade, the cooling strategy and the target coiling temperature of the currently produced strip steel as indexes, calculating the closing number of water valves of the air cooling section, and determining the water non-spraying areas of the upper and lower collecting pipes of the currently produced strip steel, wherein the water non-spraying areas of the upper and lower collecting pipes are realized by setting the water valves of the air cooling section into fault valves;

(3) when the strip steel is tracked and positioned at the position of the crop shear, the number of the water non-spraying collecting pipes is calculated by automatically triggering a program, so that the starting and stopping ranges of the water non-spraying areas are determined, the water non-spraying areas are automatically passed through in the layer cooling model calculation process, the target coiling temperature is reached through other collecting pipes, and the water non-spraying areas are ensured to be only cooled by air in a cooling mode;

(4) when switching to regular cooling, the state before the field failure valve is automatically restored.

In the step (1), the steel type of the strip steel is a combination of letters and numbers with the length of no more than 10 characters, the combination is specified according to the grade of the steel type, or determined according to different chemical components, or determined according to the requirements of customers, and the number of steel types is 1-200;

the cooling strategy comprises front section cooling, rear section cooling and sparse cooling, and the number of the front section cooling, the rear section cooling and the sparse cooling is 1-5;

the target coiling temperature layers are rolling strip steel coiling temperature target values, and the number of the rolling strip steel coiling temperature target values is 1-8;

the target thickness layer refers to the target thickness value of the rolled strip steel finished product, and the number of the target thickness layers is 1-10.

The cooling strategy is formulated according to customer requirements, idx _ M is defined as a cooling strategy code, the value range of the idx _ M is [1, 5], and different idx _ M values represent different cooling strategies;

the target coiling temperature layer is respectively formulated according to the target coiling temperature of the strip steel, the parameter idx _ T is a target coiling temperature index, the value range of the target coiling temperature index is [1, 8], and different numbers represent different coiling temperature ranges;

the target thickness layer is established according to the target thickness of the strip steel, the parameter idx _ H is used as a target thickness index, the value range is [1, 10], and different numbers represent different thickness ranges of the strip steel.

In the step (3), the water non-spraying area mainly has two parameters: the starting position and the air cooling time of the header pipes without spraying water from the upper part and the lower part; the number of headers without spraying water N = int (Vbase × Thold/Sdis), wherein Vbase is the threading speed of the strip steel in the last finishing mill; thold is the air cooling time; sdis is the spacing between headers, N is the number of headers that are not sprayed with water; and determining the starting position and the ending position of the water non-spraying position according to the ending position = the starting position + N.

Before the fault valve is arranged, the real state of the current fault valve is stored and stored in the shared memory, so that the state of each water valve is not corrected again after the mode is switched, and the production time is not influenced.

The invention has the beneficial effects that: the steel grade, the cooling strategy and the target coiling temperature of the currently produced strip steel are used as indexes, the water non-spraying area of the upper header pipe and the lower header pipe of the currently produced strip steel is determined, the water non-spraying area is ensured to be only one cooling mode of air cooling, the control precision of the coiling temperature can be effectively improved, new equipment and tools do not need to be added, and the two-section cooling mode can be realized by transforming the existing control method and model.

Drawings

FIG. 1 is a flow chart of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions of the embodiments of the present invention with reference to the drawings of the embodiments, and it is obvious that the described embodiments are a small part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative work based on the embodiments of the present invention belong to the protection scope of the present invention.

A layer cooling control method for realizing two-stage cooling by using conventional cooling, comprising the following steps of:

(1) establishing a corresponding relation of the water non-spraying areas of the upper header and the lower header according to the steel type of the strip steel, the cooling strategy, the target thickness layer and the target coiling temperature layer;

(2) taking the steel grade, the cooling strategy and the target coiling temperature of the currently produced strip steel as indexes, calculating the closing number of water valves of the air cooling section, and determining the water non-spraying areas of the upper and lower collecting pipes of the currently produced strip steel, wherein the water non-spraying areas of the upper and lower collecting pipes are realized by setting the water valves of the air cooling section into fault valves;

(3) when the strip steel is tracked and positioned at the position of the crop shear, the number of the water non-spraying collecting pipes is calculated by automatically triggering a program, so that the starting and stopping ranges of the water non-spraying areas are determined, the water non-spraying areas are automatically passed through in the layer cooling model calculation process, the target coiling temperature is reached through other collecting pipes, and the water non-spraying areas are ensured to be only cooled by air in a cooling mode;

(4) when switching to regular cooling, the state before the field failure valve is automatically restored.

In the step (1), the steel type of the strip steel is a combination of letters and numbers with the length of no more than 10 characters, the combination is specified according to the grade of the steel type, or determined according to different chemical components, or determined according to the requirements of customers, and the number of steel types is 1-200;

the cooling strategy comprises front section cooling, rear section cooling and sparse cooling, and the number of the front section cooling, the rear section cooling and the sparse cooling is 1-5;

the target coiling temperature layers are rolling strip steel coiling temperature target values, and the number of the rolling strip steel coiling temperature target values is 1-8;

the target thickness layer refers to the target thickness value of the rolled strip steel finished product, and the number of the target thickness layers is 1-10.

The cooling strategy is formulated according to customer requirements, idx _ M is defined as a cooling strategy code, the value range of the idx _ M is [1, 5], and different idx _ M values represent different cooling strategies;

the target coiling temperature layer is respectively formulated according to the target coiling temperature of the strip steel, the parameter idx _ T is a target coiling temperature index, the value range of the target coiling temperature index is [1, 8], and different numbers represent different coiling temperature ranges;

the target thickness layer is established according to the target thickness of the strip steel, the parameter idx _ H is used as a target thickness index, the value range is [1, 10], and different numbers represent different thickness ranges of the strip steel.

In the step (3), the water non-spraying area mainly has two parameters: the starting position and the air cooling time of the header pipes without spraying water from the upper part and the lower part; the number of headers without spraying water N = int (Vbase × Thold/Sdis), wherein Vbase is the threading speed of the strip steel in the last finishing mill; thold is the air cooling time; sdis is the spacing between headers, N is the number of headers that are not sprayed with water; and determining the starting position and the ending position of the water non-spraying position according to the ending position = the starting position + N.

Before the fault valve is arranged, the real state of the current fault valve is stored and stored in the shared memory, so that the state of each water valve is not corrected again after the mode is switched, and the production time is not influenced.

In practical application, a laminar cooling device is arranged in a laminar cooling area on a hot-rolled strip steel production line, and the laminar cooling area is divided into a rough cooling area and a fine cooling area. Wherein the 1 st to 15 th groups of headers are rough cooling areas, and the 16 th, 17 th and 18 th groups of headers are fine cooling areas. The invention comprises the following steps:

acquiring attribute information of the currently rolled strip steel;

according to belted steel kind, cooling strategy, target thickness level, target coiling temperature level do not spray the corresponding relation that sets up with X kind upper and lower collector pipe, determine the setting that matches with the attribute information of current rolling belted steel in X kind upper and lower collector pipe does not spray the water setting, include: and determining the settings which are simultaneously matched with the steel type of the current rolled strip steel, the cooling strategy, the target thickness level and the target coiling temperature level from the X types of the water-spraying-free settings of the upper header and the lower header according to the corresponding relation between the strip steel attribute and the water-spraying-free mode of the upper header and the lower header.

The water-spraying-free arrangement of the upper and lower water pipes is characterized in that the starting position and the air cooling time of the water-spraying-free arrangement of the upper and lower collecting pipes are determined. The set of the water non-spraying positions of the upper header and the lower header is determined by the formula, namely the formula for the water non-spraying of the upper header and the lower header is as follows: n = int (Vbase Thold/Sdis), wherein the strip threading speed of the Vbase rolled piece in the last finishing mill; thold air cooling time; sdis, the spacing between headers, N does not spray the number of headers. Thus, the start position and the end position (start position + N) of the water-spraying-free position can be determined.

The method is characterized in that a water valve is opened in a water collecting pipe, and the water valve is opened in a water collecting pipe in a normal state.

The upper and lower headers do not spray water for collection, namely, water is not sprayed from a certain header to a certain header, the upper and lower headers are synchronous, and the non-synchronization can be realized unless special requirements exist.

The non-spraying collection of the upper and lower headers is achieved by providing the headers as failed valves which normally cannot be opened or closed due to failure of the solenoid or pneumatic valves controlling the headers. And in the model calculation process, the manifold with the marked fault valve is automatically eliminated, and the manifold with the normal state is selected to be appropriately opened. Thereby leading the strip steel to reach the target temperature required by the customer.

Alternatively, the start and end positions of the header fault valve settings may also be obtained from PDI (Primary data entry Table) data, which is more privileged.

If the opening position and the ending position of the upper and lower header fault valves exist in the PDI data, setting is carried out according to the PDI data, otherwise, the starting position and the air cooling time of the fault valve of the strip steel are matched according to the steel grade and the specification, and the starting and stopping positions of the fault valve are calculated by the program by using the formula.

The setting of the defective valve needs to be completed before the rolled product enters the crop shear, and since the model is the last calculation at this location, the defective valve is set prior to the model calculation. And after the strip steel is detected by the coiling inlet pyrometer, the automatically arranged fault valve is restored to the original state.

If the next rolled piece and the current rolled piece have the same fault valve setting, the program automatically maintains the fault valve setting condition until the next rolled piece and the current rolled piece are different in setting, and the setting state of the next rolled piece is switched to before the next rolled piece enters the crop shear.

And for the manifold valve with abnormal action, the manifold valve is set as a fault valve after field verification. Regardless of the cooling mode employed, it will always maintain a failed valve.

For a normal valve, when two stages of cooling are achieved with conventional cooling, if it is in the upper and lower header no-water-spray collection, it will be set as a failed valve. When the cooling mode is switched to normal cooling, the valve is also automatically switched to a normal valve. This function is achieved primarily in such a way that the two cooling modes do not influence each other.

Alternatively, if the operator deems the automatically set failed valve to be unsuitable for manual intervention, the operator's setting will ultimately be the final result, since the operator's authority is highest.

An automatic/manual mode selection button is added on an operation picture, and the automatic mode is selected to automatically receive the setting of a fault valve; selection of the manual mode will end up with the operator selected failed valve.

Example 1: the specific process of the production method of the hot rolled strip for TKDC bundling is as follows.

Step 1: air-cooled segment index Idx: the steel type TKDC is a steel type 3, and the cooling strategy code idx _ M is a front section cooling 1; the target thickness of 3.2mm is the thickness layer 3; the target coiling temperature is 470 ℃ which is the temperature level 5, the opening position of the air cooling section corresponding to the read air cooling section index Idx is the 7 th water valve V7, the air cooling temperature is 720 ℃, and the air cooling time is 4.5 s.

Step 2: reading the state of the field water valve, wherein the 12 th water valve V12 of the upper header on the field primary picture HMI is a fault valve.

And step 3: and the rolling speed of the strip steel is calculated in the second stage to be 8.3m/s, the opening position of the air cooling section corresponding to the air cooling section index Idx is read to be a 7 th water valve V7, the air cooling temperature is 720 ℃, and the air cooling time is 4.5 s. Calculating the closing number N = int (V) of water valves in the air cooling section_base*T_hold/S_dis) Int (8.3 × 4.5/1.2) = 31.

And 4, step 4: and finishing the setting of the fault valves V7-V38 of the air cooling section before the rolled piece enters the head cutting shear according to the tracking information of the strip steel. And after the coiling inlet pyrometer detects that no strip steel exists, the automatically arranged fault valve is restored to the original state, and the setting of the fault valve is cancelled.

And 5: according to the reading of the state of the water valve on site in the step 2, the 12 th water valve V12 of the upper header on the primary picture HMI on site is set as a failure valve.

Example 2: the specific process of the production method of the Q550C hot rolled strip is as follows.

Step 1: air-cooled segment index Idx: the steel grade Q550C is steel grade 12, and the cooling strategy code idx _ M is front section cooling 1; the target thickness of 6.0mm is the thickness layer 6; the target coiling temperature is 550 ℃ and is the temperature level 6, the opening position of the air cooling section corresponding to the corresponding read air cooling section index Idx is the 8 th water valve V8, the air cooling temperature is 700 ℃, and the air cooling time is 3 s.

Step 2: read on site water valve status the 20 th water valve V20 of the upper header on the on site primary view HMI is a failed valve.

And step 3: and the rolling speed of the strip steel is calculated in the second stage to be 7.1m/s, the opening position of the air cooling section corresponding to the air cooling section index Idx is read to be the 8 th water valve V8, the air cooling temperature is 700 ℃, and the air cooling time is 3 s. Calculating the closing number N = int (V) of water valves in the air cooling section_base*T_hold/S_dis) Int (7.1 × 3/1.2) = 17.

And 4, step 4: and finishing the setting of the fault valves V8-V25 of the air cooling section before the rolled piece enters the head cutting shear according to the tracking information of the strip steel. And after the coiling inlet pyrometer detects that no strip steel exists, the automatically arranged fault valve is restored to the original state, and the setting of the fault valve is cancelled.

And 5: according to the on-site water valve status reading in the step 2, the 20 th water valve V20 of the upper header on the on-site primary picture HMI is set as a failure valve.