A method and system for controlling the cooling of rolls in a continuous rolling mill

Abstract

This invention discloses a method and system for controlling the cooling of rolls in a continuous rolling mill, belonging to the field of continuous rolling mill control technology. The method includes: a data processing center receiving roll surface temperature data collected by an acquisition device and preprocessing it to obtain roll surface temperature zones, trends, and temperature nodes; based on the preprocessed temperature zones, trends, and nodes, and combined with roll operating data, constructing a roll cooling model and simulating temperature responses under different operating conditions; generating execution signals and sending them to the execution device; setting a preset delay time and controlling the opening or closing of the execution device based on whether the roll is biting or throwing steel. In the implementation of this technical solution, by simulating temperature responses under different operating conditions, the cooling strategy can be adjusted in real time to ensure uniform roll surface temperature, reduce ineffective cooling water spraying, improve resource utilization, and extend roll service life.

Description

Technical Field

[0001] This invention relates to a method and system for controlling the cooling of rolls in a continuous rolling mill. Background Technology

[0002] A continuous rolling mill is an important piece of equipment for rolling metal sheets or pipes, and is widely used in the production of steel, non-ferrous metals and other industries.

[0003] During the rolling process, the control of roll temperature directly affects the quality and production efficiency of the sheet or tube. Because the rolls are subjected to enormous pressure and friction, the temperature rises sharply, which in turn affects the rolling effect and the roll life. Therefore, continuous rolling mills are usually equipped with cooling mechanisms to cool the rolls, such as water cooling, which sprays cooling water onto the roll surface to remove heat and maintain its temperature within a reasonable range, ensuring the stability of the rolling process and the quality of the sheet or tube.

[0004] However, in the application of the above technologies, although cooling water can effectively reduce the temperature of the rolls, the lack of control over the flow rate and pressure of the cooling water not only leads to uneven cooling of the rolls, but also causes some cooling water to not participate in the cooling process, resulting in resource waste and affecting the surface quality of the sheet and the service life of the rolls.

[0005] Therefore, it is necessary to provide a method and system for controlling the cooling of rolls in a continuous rolling mill to solve the above problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a method and system for cooling rolls of continuous rolling mills. By dividing the roll surface into sections and obtaining the thermal load characteristics of different sections, different execution signals are generated, thereby achieving precise cooling and reducing resource waste.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is: a method for controlling the cooling of rolls in a continuous rolling mill, comprising:

[0008] The data processing center receives the roll surface temperature data collected by the acquisition equipment, and preprocesses it to obtain the roll surface temperature zones, variation trends and temperature nodes.

[0009] Based on the preprocessed temperature zones, temperature change trends, and temperature nodes, and combined with the roll operation data, a roll cooling model is constructed, and the temperature response under different working conditions is simulated.

[0010] An execution signal is generated and sent to the execution device, which then sprays water to cool the rolls.

[0011] Set a preset delay time and control the opening or closing of the actuator based on whether it is in the process of biting or throwing steel.

[0012] In the implementation of the technical solution of this application, by simulating the temperature response under different working conditions, the cooling strategy can be adjusted in real time to ensure uniform surface temperature of the roll, reduce ineffective spraying of cooling water, improve resource utilization, and extend the service life of the roll.

[0013] Furthermore, the temperature zone is divided into multiple monitoring areas according to the axial position of the roll. The monitoring area includes an inlet zone, an intermediate stable zone, and an outlet zone. Each zone corresponds to different heat load characteristics, and each zone has a boundary.

[0014] Furthermore, the roll cooling model is based on a physical mechanism model and establishes the heat exchange relationship between the roll and the cooling water based on physical laws.

[0015] Furthermore, the roll cooling model includes a heat input module, a heat output module, a heat balance module, and a temperature field distribution module. The heat input module is used to calculate the heat generated by the roll during the rolling process. The heat balance module is responsible for coordinating heat input and heat output and calculating the adaptation conditions of the roll temperature change rate based on the law of conservation of energy. The temperature field distribution module is used to solve the temperature distribution by combining the three-dimensional model of the roll with the finite element method or the lumped parameter method.

[0016] Furthermore, the rate of change of roll temperature needs to satisfy the principle of energy conservation, that is, the difference between heat input and heat output is equal to the change of internal energy of the roll. The difference between heat input and heat output is equal to the input heat minus the heat carried away by the cooling water, while also considering radiation and convection heat dissipation. The change of internal energy of the roll is related to the density, volume and specific heat capacity of the roll material. Radiation and convection heat dissipation are calculated using Newton's law of cooling.

[0017] Furthermore, the generation process of the execution signal includes the following steps: Calculate the required cooling amount for each node based on the roll temperature field distribution data, and then use this cooling amount to infer the control parameters of the execution equipment; verify the control parameters through simulation verification and real-time feedback adjustment, and fine-tune the control parameters by combining the difference between the real-time cooling water temperature and the initial cooling water temperature; during fine-tuning of the control parameters, issue an early warning based on the adjustment amount, and trigger the early warning mechanism when the adjustment amount exceeds a preset threshold; encode the adjusted control parameters to generate corresponding execution signal instructions, and transmit them to the execution equipment via a transmission device; after receiving the execution signal instructions, the execution equipment performs the execution according to the preset program. Automated operation; specifically, the control parameters of the execution equipment based on the cooling amount include the following steps: establishing a nonlinear mapping relationship model between the cooling amount and the control parameters; training with historical data to obtain the effective cooling flow rate Q and heat exchange capacity of a specific roll area under different cooling water valve opening K and cooling water pressure P; and fitting an empirical formula for the cooling amount Q and valve opening K and cooling water pressure P, which is Q=C×K^a×P^b, where C, a, and b are empirical coefficients obtained by fitting with historical data; based on the fitted empirical formula, the corresponding cooling water valve opening K is deduced according to the current cooling amount and the set cooling water pressure P.

[0018] Furthermore, the cooling water temperature difference threshold includes a minimum value and a maximum value. When the difference between the real-time cooling water temperature and the initial cooling water temperature is less than the minimum cooling water temperature difference or greater than the maximum cooling water temperature difference, the real-time cooling water temperature is used as the new initial cooling water temperature, and the control parameters of the actuator are redefined.

[0019] Furthermore, the preset delay time includes a first preset time and a second preset time, wherein the first preset time is used to control the delay before and after steel biting, and the second preset time is used to control the delay before and after steel throwing.

[0020] Furthermore, the first preset time refers to the time after the steel bite signal is triggered, which delays the start of the execution equipment. Its function is to ensure that when cooling begins, the head of the rolled piece has completely passed through the cooling influence zone of the mill stand rolls. The second delay time refers to the time before the steel ejection signal is triggered, which delays the start of the execution equipment. Its function is to ensure that when cooling stops, the tail of the rolled piece has not yet entered the cooling influence zone of the mill stand rolls.

[0021] A continuous rolling mill roll cooling control system, the control system comprising:

[0022] The roll data acquisition module is used by the data processing center to receive the roll surface temperature data collected by the acquisition equipment, and to preprocess the data to obtain the roll surface temperature zones, change trends and temperature nodes.

[0023] The temperature response simulation module is used to construct a roll cooling model based on the pre-processed temperature zones, temperature change trends, and temperature nodes, combined with the roll's operating data, and to simulate the temperature response under different operating conditions.

[0024] The execution control module is used to generate execution signals and send them to the execution equipment, which then sprays water to cool the rolls.

[0025] The start / stop adjustment module is used to set the preset delay time and control the opening or closing of the actuator based on whether it is in the process of steel biting or steel throwing.

[0026] By adopting the above technical solution, the present invention has the following beneficial effects: The continuous rolling mill roll cooling control method and system provided in this application can adjust the cooling strategy in real time by simulating the temperature response under different working conditions, ensuring uniform surface temperature of the roll, reducing ineffective spraying of cooling water, improving resource utilization, extending the service life of the roll, and by setting preset time, accurately controlling the cooling timing during the steel biting and steel throwing processes, further optimizing the cooling effect, improving production efficiency and product quality. Attached Figure Description

[0027] Figure 1 This is a schematic flowchart of a continuous rolling mill roll cooling control method according to this application;

[0028] Figure 2 This is a schematic diagram of the module configuration of a continuous rolling mill roll cooling control system according to this application. Detailed Implementation

[0029] This invention provides a method and system for controlling the cooling of rolls in a continuous rolling mill. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and fall within the scope of protection of this invention. The method and application of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the method and application described herein without departing from the content, spirit, and scope of this invention to implement and apply the technology of this invention.

[0030] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0031] Example 1: As Figure 1As shown, this application provides a method for controlling the cooling of rolls in a continuous rolling mill. This method is applied during the roll cooling process of a continuous rolling mill. By detecting the temperature of the roll surface and then adjusting the flow rate and pressure of the cooling water, the roll temperature is ensured to remain within the optimal range, thereby improving the production efficiency and product quality of the continuous rolling mill, reducing equipment wear and malfunctions caused by temperature fluctuations, and extending the roll's service life. Specifically, the method includes the following steps:

[0032] Step 101: The data processing center receives the roll surface temperature data collected by the acquisition equipment, and preprocesses it to obtain the roll surface temperature zones, change trends and temperature nodes.

[0033] In the cooling control process of the rolls, the temperature of the roll surface needs to be collected first through a data acquisition device to facilitate the analysis of its temperature conditions and to serve as the basis for subsequent adjustment of cooling water flow and pressure by the execution equipment. In order to improve the accuracy of data acquisition, a non-contact device, such as an infrared thermometer, is used to directly monitor the temperature of the roll surface. After the roll surface temperature data is collected, it is uploaded to a data processing center for further analysis and processing. The data processing center can be an industrial control computer or other equipment with data analysis, storage, and processing functions, which is not limited in this embodiment.

[0034] After receiving the roll surface temperature data at the data processing center, it is necessary to preprocess it. The preprocessing process includes dividing the roll into temperature zones and obtaining the roll surface temperature change trend during the temperature zone division process. Based on the temperature zones and temperature change trends, temperature nodes are obtained. These temperature nodes will serve as the reference for adjusting the cooling water flow rate and pressure, thereby achieving precise control.

[0035] The temperature zones are divided into multiple monitoring areas according to the axial position of the rolls, such as the inlet zone, the intermediate stable zone, and the outlet zone. Each zone corresponds to different heat load characteristics. For example, the inlet zone generates more heat due to the friction of the rolling parts, while the outlet zone has better heat dissipation due to the ejection of the parts. Therefore, it is necessary to divide the monitoring areas according to different positions and working conditions, and dynamically adjust the zone boundaries based on actual production data to ensure that the temperature data of each zone accurately reflects the actual working conditions.

[0036] Temperature nodes represent the target temperature value and the allowable fluctuation range, that is, the maximum and minimum temperatures that a certain temperature zone can allow. In this embodiment, the maximum and minimum values ​​are generally the maximum values. For some rolls that need to meet a certain temperature range, the maximum and minimum values ​​can also be the minimum and maximum values, such as cold rolling and special material rolls. Furthermore, in the subsequent process, the boundaries of the temperature zones can be dynamically fine-tuned based on the actual temperature of the temperature nodes to ensure that the temperature of each area is controlled within the preset range.

[0037] Specifically, the rules for dynamically adjusting partition boundaries are as follows:

[0038] Set trigger conditions: After each set trigger cycle is completed, an evaluation is automatically performed. The evaluation criteria are: count the number of times the measured temperature of each temperature node deviates from the target temperature in the most recent trigger cycle. If the number of times the measured temperature of a certain node exceeds the allowable fluctuation range is greater than or equal to the set threshold, then the adjustment of the boundary of its partition is triggered.

[0039] For example, the threshold is set to 3 times and the triggering cycle is 10 rolling cycles. If a certain temperature node has more than 3 measured temperatures exceeding the allowable fluctuation range in the most recent 10 cycles, it is determined that the boundary of the partition needs to be adjusted.

[0040] The adjustment strategy is set up with nodes as the smallest unit. If the node temperature is consistently too high, it is assigned to the upstream adjacent zone; if the node temperature is consistently too low, it is assigned to the downstream adjacent zone. The distance the boundary moves is the spacing of one node. For example, if there is a temperature measuring point every 50 mm axially, the boundary is adjusted by 50 mm each time. The upstream adjacent zone refers to the area that receives cooling earlier, and the downstream adjacent zone refers to the area that receives cooling later. In a continuous rolling mill, the upstream adjacent zone is the front stand, and the downstream adjacent zone is the rear stand. After adjusting the zone boundary through the adjustment strategy, the cooling water flow rate and pressure control parameters are recalculated for the newly divided zone to ensure that temperature stability can be maintained when the heat load changes.

[0041] Temperature change trends are obtained through differential calculation of real-time temperature data or fitting of historical data. The differential calculation uses the temperature difference between adjacent sampling points, while the historical data fitting uses time series analysis methods. Combined with actual parameters in the production process, future temperature trends are predicted and a temperature change trend chart is generated.

[0042] Step 102: Based on the preprocessed temperature zones, temperature change trends, and temperature nodes, and combined with the roll operation data, construct a roll cooling model and simulate the temperature response under different working conditions;

[0043] After obtaining temperature zones, temperature change trends, and temperature nodes based on the roll surface temperature data, it is also necessary to combine the roll operation data, including parameters such as rolling speed, rolling force, and workpiece material, to construct a comprehensive roll cooling model. This model simulates the temperature response under different working conditions, thereby predicting the temperature change of the roll under different working states.

[0044] The roll cooling model is based on a physical mechanism model, which is based on physical laws such as thermodynamics and heat transfer. By establishing the heat exchange relationship between the roll and the cooling water, considering factors such as the flow rate, pressure and temperature of the cooling water, and combining the boundary conditions in actual production, multi-parameter coupled simulation is carried out to ultimately achieve accurate prediction and control of the roll temperature.

[0045] Specifically, the model includes a heat input module, a heat output module, a heat balance module, and a temperature field distribution module. The heat input module is used to calculate the heat generated by the rolls during the rolling process, such as the deformation heat of the rolled piece and frictional heat. The calculation of heat input is related to the heat conversion efficiency, the rolling force per unit area, and the rolling speed. The heat generated by the rolls during the rolling process is equal to the product of the heat conversion efficiency, the rolling force per unit area, and the rolling speed. The heat output module is used to calculate the heat carried away by the cooling water and other heat dissipation conditions, such as radiation and convection. The calculation method for the heat carried away by the cooling water can refer to existing technologies, such as calculation using the specific heat capacity, density, volumetric flow rate, and inlet and outlet temperature difference of the cooling water. It will not be described in detail in this embodiment.

[0046] The heat balance module is responsible for coordinating heat input and heat output, and calculating the adaptation conditions of the roll temperature change rate based on the law of conservation of energy. The roll temperature change rate needs to satisfy the principle of conservation of energy, that is, the difference between heat input and heat output is equal to the change in internal energy of the roll. The difference between heat input and heat output is equal to the input heat minus the heat carried away by the cooling water, and the radiation and convection heat dissipation are considered at the same time. The change in internal energy of the roll is related to the density, volume and specific heat capacity of the roll material. The radiation and convection heat dissipation are calculated using Newton's law of cooling.

[0047] The temperature field distribution module is used to combine the three-dimensional model of the roll and solve the temperature distribution using the finite element method or the lumped parameter method. For example, in the preceding process, the roll is divided into multiple nodes along its axial direction. Each node needs to satisfy a discretized heat balance equation. This discretized heat balance equation is related to the heat capacity of each node, the heat transfer coefficient between nodes, and the cooling amount of the nozzle to the node. Through iterative calculation, it is ensured that the temperature distribution of each node matches the actual working conditions, and finally a global temperature field distribution is formed.

[0048] For example, the method for constructing this roll cooling model adopts the lumped parameter method, and the specific process is as follows:

[0049] The roll is uniformly divided into N equal-thickness units along the axial direction. Each unit is regarded as a concentrated mass block with uniform temperature, thereby performing temperature zoning.

[0050] For the i-th unit, its temperature change within a time step Δt is described by the following equation: (ρ*c*V)*dT_i / dt=Q_in_i-Q_out_i-Q_cond_i, where ρ is the roll density, c is the roll specific heat capacity, V is the unit volume, dT_i / dt is the temperature change rate of the i-th unit, Q_in_i is the heat input received by the unit per unit time, including deformation heat and frictional heat, Q_out_i is the heat lost due to the combined effects of cooling water, radiation, and convection, and Q_ cond_i represents the heat exchange caused by thermal conduction between adjacent units. Its value is determined by the temperature difference and thermal conductivity of adjacent nodes. Then, it is discretized and solved using the explicit Euler method. Given the temperature of all units at time t, the temperature distribution at time t+Δt can be calculated. The formula is T_i(t+Δt)=T_i(t)+Δt / (ρ*c*V)*(Q_in_i-Q_out_i-Q_cond_i). This process is iterated until a steady state or target time is reached, thus realizing the dynamic simulation of the roll temperature field.

[0051] For example, the roll is divided into 50 units along the axial direction, the time step Δt is set to 1 second, and the temperature of each unit is initialized to the initial value measured on site. By collecting rolling force, speed and cooling water flow data in real time, Q_in_i and Q_out_i are dynamically updated. The system of differential equations is solved using the explicit Euler method, and the temperature change of each unit is calculated step by step to obtain the transient temperature distribution of the roll throughout the entire rolling cycle.

[0052] In this system, the temperature change of each unit is considered as a temperature node, and the temperature changes of multiple units represent the temperature trend. The heat input module is used to calculate the heat generated by the roll during the rolling process, corresponding to Q_in_i. This heat mainly comes from the deformation heat generated by the plastic deformation of the metal and the frictional heat between the roll and the workpiece contact surface. The heat output module corresponds to Q_out_i and is used to calculate the heat lost by the roll through cooling water spray, surface radiation, and air convection. The heat balance module is used to solve the heat balance equation mentioned above and integrate the heat input and output of each node. The temperature field distribution module is used to output the overall temperature field distribution cloud map or data matrix of the roll based on the dynamic evolution results of the temperature at each node.

[0053] Step 103: Generate an execution signal and send the execution signal to the execution device, which then sprays water to cool the rolls.

[0054] After the roll temperature detection is completed, an execution signal can be generated and sent to the execution device. The execution signal is a series of control commands, including parameters such as water flow rate and pressure. The execution device is a cooling ring. There are multiple sets of cooling rings, which are deployed on the roll frame. Each set of cooling rings adjusts the opening and closing state of the nozzles and the spray parameters precisely according to the received execution signal to ensure that the cooling water covers the roll surface in the best way, thereby maintaining the roll temperature within the set range.

[0055] Specifically, the process of generating the execution signal includes the following steps:

[0056] Based on the temperature field distribution data of the rolls, the required cooling amount for each node is calculated, and the control parameters of the actuator are derived based on the cooling amount.

[0057] After analyzing the temperature field distribution data of the roll, the required cooling amount for each node can be calculated based on the current roll temperature. Then, the control parameters of the actuator, such as water spray flow rate and water spray pressure, can be deduced from the required cooling amount for each node. The water spray flow rate can be controlled by changing the valve opening, thereby enabling adaptive cooling for different nodes. This not only improves the cooling effect but also reduces the waste of cooling water. For example, when the temperature of a certain node is low, the actuator at that point only needs a smaller cooling amount, and the water spray flow rate and pressure can be reduced accordingly to avoid wasting cooling water.

[0058] Specifically, the steps for deriving control parameters for the actuator based on cooling capacity include:

[0059] A nonlinear mapping model between cooling capacity and control parameters is established. Through training with historical data, the effective cooling flow rate Q (L / min) and heat exchange capacity for a specific roll area are obtained under different cooling water valve openings K (range 0-100%) and cooling water pressures P (unit MPa). An empirical formula is then fitted to the relationship between cooling capacity Q, valve opening K, and cooling water pressure P: Q = C × K^a × P^b, where C, a, and b are empirical coefficients obtained from historical data fitting. This formula reflects the nonlinear relationship between cooling capacity, valve opening, and water pressure. In practical applications, based on the required cooling capacity Q and the set cooling water pressure P, the corresponding valve opening K is derived, thereby achieving precise control of the water spray flow rate and ensuring uniform and stable temperature across all areas of the roll.

[0060] The control parameters are verified through simulation and real-time feedback adjustment, and the control parameters are fine-tuned by combining the difference between the real-time cooling water temperature and the initial cooling water temperature.

[0061] After generating the control parameters for the execution device, it is necessary to verify them to prevent improper parameter settings from leading to poor cooling performance. Specifically, this is done through simulation verification and real-time feedback adjustment, combined with the difference between the real-time cooling water temperature and the initial cooling water temperature. When the difference between the real-time cooling water temperature and the initial cooling water temperature exceeds the cooling water temperature difference threshold, the control parameters for the execution device are redefined. The cooling water temperature difference threshold includes a minimum and a maximum value. When the difference between the real-time cooling water temperature and the initial cooling water temperature is less than the minimum cooling water temperature difference or greater than the maximum cooling water temperature difference, the generated cooling amount will be inaccurate. In this case, the real-time cooling water temperature needs to be used as the new initial cooling water temperature, and the control parameters for the execution device are redefined to verify them.

[0062] For example, a simplified steady-state model is used for verification. This model ignores thermal conductivity Q_cond_i and assumes that the roll is in a stable rolling state (i.e., dT_i / dt=0). At this time, the heat flux density q_i on the roll surface is completely balanced by the cooling system, i.e., q_i=h(T_i-T_cool), where h is the convective heat transfer coefficient, T_i is the roll surface temperature, and T_cool is the cooling water temperature. By obtaining q_i and T_i under different control parameters, the required h value is deduced, and combined with the current cooling water temperature T_cool, it is verified whether the control parameters can meet the heat transfer requirements.

[0063] If the calculated h value exceeds the system's achievable range, the valve opening K and cooling water pressure P are dynamically adjusted, the cooling capacity Q is recalculated, and the control parameters are updated based on the recalculated cooling capacity Q. This is achieved through a fine-tuning formula, as follows: K_final=K_setpoint*[1+0.02*(T_water_real- T_water_base)], where K_final is the final adjusted valve opening, K_setpoint is the valve opening at the set point, T_water_real is the real-time cooling water temperature, and T_water_base is the reference cooling water temperature. The physical meaning of the above formula is that for every 1°C increase in water temperature, the valve opening increases by 2% to compensate for the decrease in cooling capacity caused by the increase in water temperature, ensuring that the heat on the roll surface is effectively removed per unit time.

[0064] When fine-tuning the control parameters, an early warning is issued based on the adjustment amount. When the adjustment amount exceeds the preset threshold, the early warning mechanism is triggered.

[0065] Under normal circumstances, fine-tuning of control parameters is necessary due to factors such as acquisition errors. However, when the adjustment amount is too large, it may indicate system abnormalities, such as a faulty roll temperature sensor or a blocked cooling ring. By comparing the adjustment amount with the preset threshold, an early warning mechanism can be triggered in time to provide early warning for the entire roll and cooling system during the cooling control process, thus ensuring production safety.

[0066] The aforementioned fine-tuning amount has a limitation: when |T_water_real-T_water_base|>8°C, the water temperature is considered abnormal, the fine-tuning formula fails, and the system directly triggers an early warning to remind manual intervention. At this time, it no longer relies on the automatic compensation mechanism. That is, the preset threshold is the critical value when the absolute value of the deviation between the real-time water temperature and the reference water temperature exceeds 8°C. This ensures that when the cooling system performance deteriorates significantly or external conditions fluctuate drastically, the control system will not blindly execute invalid compensation, but will issue an early warning in a timely manner.

[0067] The adjusted control parameters are encoded to generate corresponding execution signal commands, which are then transmitted to the execution device via a transmission device. Upon receiving the execution signal commands, the execution device performs automated operations according to a preset program.

[0068] The execution device needs to operate by executing signal commands. Therefore, the adjusted control parameters are encoded to generate execution signals that the execution device can recognize and execute. These signals are then transmitted to the execution device via a transmission device, which can be a wireless or wired communication module. In this embodiment, no limitation is made.

[0069] Step 104: Set the preset delay time, and control the opening or closing of the actuator based on whether it is in the process of steel biting or steel throwing;

[0070] It should be noted that "steel bite" and "steel ejection" are technical terms used by those skilled in the art. "Steel bite" refers to the head of the rolled piece entering the rolls of the mill stand for rolling, while "steel ejection" refers to the tail of the rolled piece leaving the rolls of the mill stand. The main purpose of this control strategy is to precisely avoid impacting the head and tail of the rolled piece when cooling of the mill stand rolls is required. Its core principle is: cooling is only initiated after "steel bite" has occurred, when the head of the rolled piece has completely passed through the mill stand and reached a stable rolling state; cooling is preemptively shut off before "steel ejection," before the tail of the rolled piece has left the mill stand. This ensures that the cooling process only affects the main body of the rolled piece, preventing roll damage, uneven temperature distribution at the head and tail, or abnormal microstructure caused by cooling of the head or tail, thereby protecting the rolls and improving the overall quality of the rolled piece.

[0071] Specifically, the delay preset time includes a first preset time and a second preset time. The first preset time is used to control the delay after the steel bite signal is triggered, which refers to the time after which the execution equipment is delayed from being activated. Its function is to ensure that the head of the rolled piece has completely passed through the cooling influence zone of the mill stand rolls when cooling begins. The second preset time is used to control the delay before the steel ejection signal is triggered, which refers to the time before the execution equipment is deactivated. Its function is to ensure that the tail of the rolled piece has not yet entered the cooling influence zone of the mill stand rolls when cooling stops, thus avoiding damage to the rolls and the rolled piece.

[0072] When the system detects a bite signal, it starts timing for the first preset time. After the timing ends, the corresponding roll cooling is immediately activated. The first preset time must be greater than the time required for the head of the rolled piece to travel from the bite point to completely leave the cooling affected zone. This first preset time can be calculated and determined based on the rolling speed and the relative position of the frame and the cooling nozzle. For example, when the rolling speed is v, the first preset time t1 should satisfy t1 > L1 / v, where L1 is the travel distance of the head of the rolled piece from the bite point to the end of the cooling affected zone.

[0073] Before the system detects the steel ejection signal, a countdown for the second preset time is started. Before the countdown ends, the execution equipment is shut down. The second preset time must ensure that cooling is completely stopped before the tail of the rolled piece enters the cooling affected zone. Its value should be greater than the time required for the tail of the rolled piece to travel from the steel ejection point to the starting position of the cooling affected zone. It can be calculated based on the rolling speed v and the corresponding distance L2, i.e., t2 > L2 / v, where L2 is the travel distance of the tail of the rolled piece from the steel ejection point to the starting position of the cooling affected zone.

[0074] Through the above control logic, the system can achieve precise timing matching of cooling start and stop, effectively avoiding the impact of cooling medium on the head and tail of the rolled piece when entering or leaving the rolling area, thereby reducing the risk of thermal stress cracks and surface defects.

[0075] Example 2: Figure 2 As shown, this application also proposes a continuous rolling mill roll cooling control system. This control system operates the control method described in Embodiment 1 to achieve precise cooling control of the continuous rolling mill rolls, ensuring stable roll temperature at different rolling stages, and improving rolling efficiency and product quality. Specifically, the control system includes:

[0076] The roll data acquisition module is used by the data processing center to receive the roll surface temperature data collected by the acquisition equipment, and to preprocess the data to obtain the roll surface temperature zones, change trends and temperature nodes.

[0077] The temperature response simulation module is used to construct a roll cooling model based on the pre-processed temperature zones, temperature change trends, and temperature nodes, combined with the roll's operating data, and to simulate the temperature response under different operating conditions.

[0078] The execution control module is used to generate execution signals and send them to the execution equipment, which then sprays water to cool the rolls.

[0079] The start / stop adjustment module is used to set the preset delay time and control the opening or closing of the actuator based on whether it is in the process of steel biting or steel throwing.

[0080] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling the cooling of rolls in a continuous rolling mill, characterized in that: include: The data processing center receives the roll surface temperature data collected by the acquisition equipment, and preprocesses it to obtain the roll surface temperature zones, variation trends and temperature nodes; Based on the preprocessed temperature zones, temperature change trends, and temperature nodes, and combined with the roll operation data, a roll cooling model is constructed, and the temperature response under different working conditions is simulated. An execution signal is generated and sent to the execution device, which then sprays water to cool the rolls. Set a preset delay time and control the opening or closing of the actuator based on whether it is in the process of steel biting or steel throwing; The temperature zone is divided into multiple monitoring areas according to the axial position of the roll. The monitoring area includes an inlet zone, an intermediate stable zone, and an outlet zone. Each zone corresponds to a different heat load characteristic and each zone has a boundary. The process of generating the execution signal includes the following steps: Calculate the required cooling amount for each node based on the roll temperature field distribution data, and then use this cooling amount to infer the control parameters of the execution equipment; verify the control parameters through simulation verification and real-time feedback adjustment, and fine-tune the control parameters by combining the difference between the real-time cooling water temperature and the initial cooling water temperature; during fine-tuning of the control parameters, issue an early warning based on the adjustment amount, and trigger the early warning mechanism when the adjustment amount exceeds a preset threshold; encode the adjusted control parameters to generate corresponding execution signal instructions, and transmit them to the execution equipment via a transmission device; after receiving the execution signal instructions, the execution equipment performs automated operation according to the preset program. The specific steps of inferring the control parameters of the equipment based on the cooling amount include: establishing a nonlinear mapping relationship model between the cooling amount and the control parameters; training with historical data to obtain the effective cooling flow rate Q and heat exchange capacity of a specific roll area under different cooling water valve opening K and cooling water pressure P; and fitting an empirical formula for the cooling amount Q and valve opening K and cooling water pressure P, which is Q=C×K^a×P^b, where C, a, and b are empirical coefficients obtained by fitting with historical data; and based on the fitted empirical formula, inferring the corresponding cooling water valve opening K according to the current cooling amount and the set cooling water pressure P.

2. The method for controlling the cooling of rolls in a continuous rolling mill according to claim 1, characterized in that: The roll cooling model is based on a physical mechanism model and establishes the heat exchange relationship between the roll and the cooling water based on physical laws.

3. The method for controlling the cooling of rolls in a continuous rolling mill according to claim 1, characterized in that: The roll cooling model includes a heat input module, a heat output module, a heat balance module, and a temperature field distribution module. The heat input module is used to calculate the heat generated by the roll during the rolling process. The heat balance module is responsible for coordinating heat input and heat output and calculating the adaptation conditions of the roll temperature change rate based on the law of conservation of energy. The temperature field distribution module is used to solve the temperature distribution by combining the three-dimensional model of the roll with the finite element method or the lumped parameter method.

4. The method for controlling the cooling of rolls in a continuous rolling mill according to claim 3, characterized in that: The rate of change of roll temperature needs to satisfy the principle of energy conservation, that is, the difference between heat input and heat output is equal to the change of internal energy of the roll. The difference between heat input and heat output is equal to the input heat minus the heat carried away by the cooling water, while also considering the heat dissipation by radiation and convection. The change of internal energy of the roll is related to the density, volume and specific heat capacity of the roll material. The heat dissipation by radiation and convection is calculated by Newton's law of cooling.

5. The method for controlling the cooling of rolls in a continuous rolling mill according to claim 1, characterized in that: The cooling water temperature difference threshold includes a minimum and a maximum value. When the difference between the real-time cooling water temperature and the initial cooling water temperature is less than the minimum cooling water temperature difference or greater than the maximum cooling water temperature difference, the real-time cooling water temperature is used as the new initial cooling water temperature, and the control parameters of the actuator are redefined.

6. The method for controlling the cooling of rolls in a continuous rolling mill according to claim 1, characterized in that: The preset delay time includes a first preset time and a second preset time, wherein the first preset time is used to control the delay after the steel is bitten, and the second preset time is used to control the delay before the steel is thrown.

7. The method for controlling the cooling of rolls in a continuous rolling mill according to claim 6, characterized in that: The first preset time refers to the time after the bite signal is triggered, which delays the start of the execution equipment. Its function is to ensure that the head of the rolled piece has completely passed through the cooling influence zone of the roll when cooling begins. The second preset time refers to the time before the ejection signal is triggered, which turns off the execution equipment in advance. Its function is to ensure that the tail of the rolled piece has not yet entered the cooling influence zone of the roll when cooling stops.

8. A continuous rolling mill roll cooling control system, used to implement the continuous rolling mill roll cooling control method as described in any one of claims 1 to 7, characterized in that: The control system includes: The roll data acquisition module is used by the data processing center to receive the roll surface temperature data collected by the acquisition equipment, and to preprocess the data to obtain the roll surface temperature zones, change trends and temperature nodes. The temperature response simulation module is used to construct a roll cooling model based on the pre-processed temperature zones, temperature change trends, and temperature nodes, combined with the roll's operating data, and to simulate the temperature response under different operating conditions. The execution control module is used to generate execution signals and send them to the execution equipment, which then sprays water to cool the rolls. The start / stop adjustment module is used to set the preset delay time and control the opening or closing of the actuator based on whether it is in the process of steel biting or steel throwing.

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