A steel plate heat treatment furnace post water cooling device and a control method thereof

Abstract

The application provides a steel plate heat treatment furnace post water cooling device and a control method thereof. The steel plate heat treatment furnace post water cooling device comprises a first air blowing device, a water cooling device and a second air blowing device arranged in sequence along the outlet direction of the heat treatment furnace. The first air blowing device and the second air blowing device each comprise a plurality of nozzles for blowing gas to the steel plate on the conveying roller. The water cooling device comprises a plurality of spray pipes arranged along the length direction of the conveying roller, and each spray pipe is provided with a plurality of nozzles for spraying cooling water to the steel plate. The steel plate heat treatment furnace post water cooling device has high cooling efficiency and controllable target cooling temperature.

Description

Technical Field

[0001] This invention relates to the field of heat treatment technology, and in particular to a water-cooling device and control method for the heat treatment furnace of steel plates. Background Technology

[0002] With the continuous development of steel materials, the production efficiency and product quality requirements of medium and heavy plate heat treatment lines are constantly increasing. In traditional medium and heavy plate heat treatment processes, such as normalizing, tempering, and tempering, the steel plates exiting the furnace require long periods of natural cooling. Due to insufficient cooling bed area or inadequate conveyor roller length, this severely affects the production rhythm and output of heat treatment. Furthermore, natural cooling often fails to improve the mechanical properties of the steel plates, such as the yield strength after normalizing. These long periods of natural cooling in traditional processes not only extend the production cycle but also increase energy consumption and maintenance costs, becoming one of the key factors restricting the production efficiency of medium and heavy plates.

[0003] CN102586565B discloses a rapid cooling method after a heat treatment furnace for medium and heavy plates. This method uses gas injection to initially cool the steel plate, followed by contact cooling for further cooling. The method includes a gas cooling mechanism and a roller cooling mechanism sequentially positioned after the heat treatment furnace. The gas cooling mechanism includes rollers for conveying the steel plate and cooling nozzles for spraying cooling gas onto the steel plate during conveying. The roller cooling mechanism includes several water-cooled conveyor rollers for heat exchange with the steel plate during conveying. While this method improves the overall heat transfer coefficient of the steel plate surface compared to natural cooling, it still cannot meet the requirements for rapid cooling after normalizing.

[0004] To improve heat exchange efficiency and cooling uniformity, there is an urgent need to develop a novel rapid cooling device after the heat treatment furnace for steel plates. This device can achieve rapid cooling, improve heat exchange efficiency, and enhance the uniformity and shape of steel plates. It utilizes economical cooling water as the cooling medium and optimizes the flow path and pressure control of the cooling water to reduce vapor film formation, thereby achieving more efficient heat exchange across different temperature ranges. This innovation will help improve the overall efficiency and product quality of medium and heavy plate heat treatment lines, meeting the demands of modern steel production for high-efficiency and high-quality manufacturing. Summary of the Invention

[0005] The main objective of this invention is to provide a water-cooling device and its control method after a heat treatment furnace for steel plates, which aims to improve the cooling efficiency of steel plates.

[0006] To achieve the above objectives, the present invention provides a water-cooling device after a steel plate heat treatment furnace, comprising a first air-blowing device, a water-cooling device, and a second air-blowing device arranged sequentially along the outlet direction of the heat treatment furnace, wherein... Both the first and second air blowing devices include multiple nozzles for blowing gas onto the steel plate on the conveyor rollers, and the water cooling device includes multiple spray pipes arranged along the length of the conveyor rollers, with multiple nozzles installed on each spray pipe for spraying cooling water onto the steel plate.

[0007] Preferably, the water cooling device includes a water spray cooling device and a high-density cooling device, with the water spray cooling device located near the first air blowing device.

[0008] Preferably, the water spray cooling device and the high-density cooling device are provided with multiple spray pipes on both the upper and lower sides of the conveyor roller. The spray pipes on the upper and lower sides of the water spray cooling device and the high-density cooling device are staggered. The nozzles of the water spray cooling device are used to generate atomized water droplets and spray them onto the upper and lower surfaces of the steel plate at an angle of 20-30° with the running direction of the steel plate. The nozzles of the high-density cooling device are used to generate columnar jets and spray them onto the upper and lower surfaces of the steel plate in a vertical direction.

[0009] Preferably, the nozzles installed above the spray pipe of the water spray cooling device in the width direction are arranged with denser nozzles in the middle and sparser nozzles on both sides.

[0010] Preferably, the water cooling device after the steel plate heat treatment furnace further includes a water-blocking device located between the high-density cooling device, the water spray cooling device, and the second air blowing device. The water-blocking device is used to prevent cooling water on the steel plate surface from flowing towards the front and rear areas.

[0011] Preferably, the water-blocking device includes a water-blocking roller located above the conveyor roller table, and a drive mechanism for driving the water-blocking roller to move vertically to adjust the roller gap between the water-blocking roller and the conveyor roller table.

[0012] Preferably, the driving mechanism includes a screw jack located on both sides of the water-blocking roller and connected to its rotating shaft, and the output shaft of the screw jack is connected to the lifting gear motor through a coupling; the nozzle of the first air blowing device blows in the direction of the steel plate running, and the nozzle of the second air blowing device blows in the direction of the steel plate running.

[0013] Preferably, the water cooling device after the steel plate heat treatment furnace further includes a housing covering the outside of the first air blowing device. The housing includes two side plates located on both sides of the conveyor roller, a top plate connecting the top ends of the two side plates, and a water accumulation trough connecting the bottom ends of the two side plates. The top plate and the side plates are connected by inclined plates, and the first air blowing device is mounted between the two side plates.

[0014] Preferably, the present invention also proposes a control method for the water cooling device after the steel plate heat treatment furnace described above, comprising the following steps: The cooling mode is determined based on the size of the steel plate to be cooled. Cooling modes include continuous cooling mode and oscillating cooling mode. The production parameters of the water cooling unit are calculated based on the cooling mode, steel plate inlet temperature, chemical composition, and target temperature. Adjust the conveyor roller speed, water flow rate of the upper nozzle of the water spray cooling device, water output ratio of the upper and lower nozzles of the water spray cooling device, water flow rate of the upper nozzle of the high-density cooling device, water output ratio of the upper and lower nozzles of the high-density cooling device, and cooling time according to production parameters.

[0015] Preferably, the step of calculating the production parameters of the water-cooling device based on the cooling mode, steel plate inlet temperature, chemical composition, and target temperature specifically includes: The cooling water volume of each nozzle of the water cooling device is calculated based on the target temperature using the steel plate temperature calculation module and the surface heat transfer coefficient calculation module. Simulation calculation is then performed based on the calculated cooling water volume of each nozzle to obtain the temperature of the steel plate after cooling. The cooling water volume of each nozzle of the water cooling device is continuously adjusted based on the difference between the temperature of the steel plate after cooling and the target temperature to obtain the final cooling water volume parameters of each nozzle. In continuous cooling mode, the cooling time is calculated based on the length of the water cooling device and the speed of the roller conveyor.

[0016] The water-cooling device after the heat treatment furnace for steel plates proposed in this invention has the following beneficial effects: 1. By combining a first air-blowing device, a water-cooling device, and a second air-blowing device, one-stop rapid cooling of steel plates after heat treatment furnace is achieved, greatly simplifying the cooling process, improving production efficiency, and overcoming the shortcomings of traditional cooling bed equipment that requires multiple operations. Simultaneously, by increasing the cooling rate of the steel plate, its properties can be further improved, such as increasing yield strength. This one-stop design not only reduces operating steps but also reduces the space occupied by the equipment, making the production process more efficient and compact, thereby reducing production costs. 2. By implementing zoned cooling and precisely controlling the water jet volume of the water-cooling device, refined management of the steel plate surface temperature and water volume is achieved. This ensures that the steel plate maintains good shape stability and dimensional accuracy during the cooling process, which is of great significance for subsequent cutting, welding, and other processing procedures. This precise control not only improves product quality but also reduces the scrap rate caused by poor plate shape, thereby improving overall production efficiency and economic benefits. 3. The water cooling device after the heat treatment furnace of this steel plate has the advantages of simple structure, stable and reliable operation and easy implementation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the water-cooling device after the steel plate heat treatment furnace of the present invention; Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure along the AA direction; Figure 3 for Figure 1 A schematic diagram of the cross-sectional structure along the BB direction; Figure 4 for Figure 1 A schematic diagram of the cross-sectional structure along the CC direction; Figure 5 This is a flowchart illustrating the process of determining key production parameters in the control method of the post-water cooling device of the steel plate heat treatment furnace of the present invention. Figure 6 This is a schematic diagram of the regional discretization of the control method of the post-water cooling device of the steel plate heat treatment furnace of the present invention.

[0018] In the diagram, 1-steel plate, 2.1-first air blowing device, 2.2-second air blowing device, 3-shell, 3.1-top plate, 3.2-sloping plate, 4-conveying roller conveyor, 5-water cooling device, 5.1-upper water spray nozzle, 5.2-lower water spray nozzle, 5.3-upper high-density nozzle, 5.4-lower high-density nozzle, 6-water blocking device, 6.1-water blocking roller, 6.2-lifting gear motor, 6.3-screw jack, 6.4-coupling, 7-heat treatment furnace.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0021] It should be noted that in the description of this invention, the terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] This invention proposes a water-cooling device for the heat treatment furnace of steel plates.

[0023] Reference Figures 1 to 4 In this preferred embodiment, a water-cooling device after a steel plate heat treatment furnace includes a first air-blowing device 2.1, a water-cooling device 5, and a second air-blowing device 2.2 arranged sequentially along the outlet direction of the heat treatment furnace. The first air blowing device 2.1 and the second air blowing device 2.2 both include multiple nozzles for blowing gas onto the steel plate on the conveyor roller 4. The water cooling device 5 includes multiple spray pipes arranged along the length of the conveyor roller 4. Each spray pipe is equipped with multiple nozzles for spraying cooling water onto the steel plate.

[0024] Specifically, in this embodiment, the water cooling device 5 includes a water spray cooling device and a high-density cooling device, with the water spray cooling device positioned near the first air blowing device 2.1. The cooling water volume of the water spray cooling device and the high-density cooling device is adjustable, and the water pressure is 0.4-0.6 MPa.

[0025] Furthermore, the water spray cooling device and the high-density cooling device are equipped with multiple spray pipes on both the upper and lower sides of the conveyor roller 4. The spray pipes on the upper and lower sides of the water spray cooling device and the high-density cooling device are staggered. The nozzles of the water spray cooling device are used to generate atomized water droplets and spray them onto the upper and lower surfaces of the steel plate at an angle of 20-30° with the running direction of the steel plate. The nozzles of the high-density cooling device are used to generate columnar jets to spray vertically onto the upper and lower surfaces of the steel plate.

[0026] Specifically, the water spray cooling device includes an upper water spray nozzle 5.1 and a lower water spray nozzle 5.2, and the high-density cooling device includes an upper high-density nozzle 5.3 and a lower high-density nozzle 5.4. The nozzles of the water spray cooling device are used to atomize the cooling water into tiny water droplets. The water droplets are sprayed obliquely along the direction of the steel plate and are arranged asymmetrically from top to bottom. The nozzles on adjacent spray boxes are staggered to improve the uniformity of cooling across the width of the steel plate.

[0027] The nozzles of the high-density cooling device are used to generate columnar jets that are sprayed vertically onto the upper and lower surfaces of the steel plate, achieving uniform and rapid cooling of the steel plate.

[0028] In this embodiment, by combining a water spray cooling device and a high-density cooling device, with the water spray cooling device in front and the high-density cooling device behind, the vapor film on the steel plate surface is effectively broken, improving the utilization rate of cooling water and heat exchange efficiency, thus solving the problem of low heat exchange efficiency in existing cooling equipment. This combined design allows cooling water to penetrate the steel plate surface more quickly, avoiding the heat accumulation phenomenon caused by vapor film obstruction in traditional cooling methods, thereby achieving a more uniform and efficient cooling effect.

[0029] Furthermore, the nozzles installed above the spray nozzles of the water spray cooling device in the width direction are arranged with denser nozzles in the middle and sparser nozzles on both sides. This design ensures that the cooling water can evenly cover the surface of the steel plate, avoiding localized overcooling or overheating and improving the cooling quality.

[0030] Furthermore, the water cooling device after the heat treatment furnace of this steel plate also includes a water-blocking device 6 located between the high-density cooling device, the water spray cooling device, and the second air blowing device 2.2. The water-blocking device 6 is used to prevent the cooling water on the surface of the steel plate from flowing to the front and rear areas.

[0031] Specifically, this embodiment presents a specific structure for a water-blocking device 6: the water-blocking device 6 includes a water-blocking roller 6.1 located above the conveyor roller table 4, and a drive mechanism for driving the water-blocking roller 6.1 to move vertically to adjust the roller gap between the water-blocking roller 6.1 and the conveyor roller table 4. The water-blocking roller 6.1 is made of a high-temperature resistant material, and its upper and lower roller gaps can be adjusted within the range of 5-600mm.

[0032] By setting a drive mechanism to adjust the water-blocking device 6, on the one hand, the water-blocking roller 6.1 can adapt to steel plates of different thicknesses, ensuring that the cooling water can be evenly distributed on the surface of the steel plate during the cooling process, avoiding local overcooling or overheating, thereby improving the consistency and stability of product quality, and on the other hand, improving the versatility of this device.

[0033] Specifically, the drive mechanism includes screw jacks 63 located on both sides of the water-blocking roller 6.1 and connected to their rotating shafts. The output shafts of the screw jacks 6.3 are connected to the lifting gear motor 6.2 via couplings. Both output shafts of the lifting gear motor 6.2 are connected to the input shafts of the two screw jacks 6.3 on both sides via couplings, thereby achieving synchronous lifting of both sides of the rotating shaft of the water-blocking roller 6.1.

[0034] Furthermore, the nozzle of the first air blowing device 2.1 blows in the direction of the steel plate running, while the nozzle of the second air blowing device 2.2 blows in the direction of the steel plate running.

[0035] For ultra-thick steel plates (thickness of 80mm and above), it is necessary to control the forward and reverse rotation of the conveyor roller 4 below the high-density cooling device to drive the steel plate to reciprocate on the conveyor roller 4, thereby increasing the cooling time and accelerating the cooling efficiency.

[0036] The water cooling device after the heat treatment furnace of this steel plate also includes a housing 3 covering the outside of the first air blowing device 2.1. The housing 3 includes two side plates located on both sides of the conveyor roller 4, a top plate 3.1 connecting the top ends of the two side plates, and a water accumulation trough connecting the bottom ends of the two side plates. The top plate 3.1 and the side plates are connected by an inclined plate 3.2. The first air blowing device 2.1 is mounted between the two side plates.

[0037] The shell 3 is used to collect and condense water vapor, reducing cooling water consumption; the inclined structure of the inclined plate 3.2 allows condensate to accumulate in the water tank below the side wall channel, thereby preventing water vapor from escaping into the workshop or falling onto the steel plate surface.

[0038] Furthermore, the first air blowing device 2.1, the water cooling device 5, and the second air blowing device 2.2 are equipped with a control system, which is also electrically connected to the drive mechanism.

[0039] The control system automatically sets the roller speed and water volume for each zone based on the steel plate thickness and cooling temperature. It achieves precise control over the steel plate shape through zoned cooling, water-to-water ratio, and water volume crowning. The control system can also automatically adjust the lifting height of the water-retaining roller 6.1 according to the steel plate thickness, enabling adaptive cooling for steel plates of different thicknesses. The intelligent design of the control system allows for automatic adjustment of various parameters according to different process requirements, improving production efficiency and product quality.

[0040] The working process of the water cooling device after the heat treatment furnace of this steel plate is as follows: The steel plate is conveyed from the heat treatment furnace outlet via conveyor roller 4. Airflow is sprayed from the nozzles of the first air blowing device 2.1, thus blocking the cooling water on the steel plate surface and preventing it from flowing back into the heat treatment furnace. Subsequently, when the steel plate is transported to the water cooling device 5 area, the upper and lower nozzles of the water spray cooling device spray atomized tiny water droplets. The water droplets are sprayed obliquely along the direction of the steel plate to further cool it. Then, the steel plate enters the high-density cooling device. The nozzles of the high-density cooling device generate columnar jets that spray vertically onto the upper and lower surfaces of the steel plate, achieving uniform and rapid cooling. Water-blocking rollers 6.1 are installed at both the outlet and inlet of the high-density cooling device to prevent the cooling water on the steel plate surface from flowing towards the front and rear areas. Finally, the steel plate enters the area of ​​the second air blowing device 2.2, where the nozzles of the second air blowing device 2.2 blow away the cooling water from the steel plate surface.

[0041] The water-cooling device after the heat treatment furnace for steel plates proposed in this embodiment has the following beneficial effects: 1. By combining the first air-blowing device 2.1, the water-cooling device 5, and the second air-blowing device 2.2, one-stop rapid cooling of the steel plate after the heat treatment furnace is achieved, greatly simplifying the cooling process, improving production efficiency, and overcoming the shortcomings of traditional cooling bed equipment that requires multiple operations. Simultaneously, by increasing the cooling rate of the steel plate, its properties can be further improved, such as increasing its yield strength. This one-stop design not only reduces operating steps but also reduces the space occupied by the equipment, making the production process more efficient and compact, thereby reducing production costs. 2. By implementing zoned cooling and precisely controlling the spray volume of the water-cooling device 5, refined management of the steel plate surface temperature and water volume is achieved. This ensures that the steel plate maintains good shape stability and dimensional accuracy during the cooling process, which is of great significance for subsequent cutting, welding, and other processing procedures. This precise control not only improves product quality but also reduces the scrap rate caused by poor plate shape, thereby improving overall production efficiency and economic benefits. 3. The water cooling device after the heat treatment furnace of this steel plate has the advantages of simple structure, stable and reliable operation and easy implementation.

[0042] The present invention also proposes a control method for a water-cooling device after a steel plate heat treatment furnace.

[0043] In this preferred embodiment, a method for controlling a water-cooling device after a steel plate heat treatment furnace includes the following steps: The cooling mode is determined based on the size of the steel plate to be cooled. Cooling modes include continuous cooling mode and oscillating cooling mode. The production parameters of the water cooling unit 5 are calculated based on the cooling mode, steel plate inlet temperature, chemical composition, and target temperature. Adjust the following parameters according to production parameters: conveyor roller speed, water flow rate of the upper nozzle of the water spray cooling device, water output ratio of the upper and lower nozzles of the water spray cooling device, water flow rate of the upper nozzle of the high-density cooling device, water output ratio of the upper and lower nozzles of the high-density cooling device, and cooling time.

[0044] Specifically, the steps for calculating the production parameters of the water-cooling unit based on the cooling mode, steel plate inlet temperature, chemical composition, and target temperature include: The cooling water volume of each nozzle of the water cooling device 5 is calculated based on the target temperature through the steel plate temperature calculation module and the surface heat transfer coefficient calculation module. The calculated cooling water volume of each nozzle is then used for simulation calculation to obtain the temperature of the steel plate after cooling. Based on the difference between the temperature of the steel plate after cooling and the target temperature, the cooling water volume of each nozzle of the water cooling device 5 is continuously adjusted to obtain the final cooling water volume parameters of each nozzle. In continuous cooling mode, the cooling time is calculated based on the length of the water cooling device 5 and the speed of the conveyor roller 4.

[0045] Cooling time refers to the time from when the head of the steel plate enters the front section of the water-cooling device to when the head of the steel plate exits the rear section of the water-cooling device. Target temperature refers to the planned cooling temperature of the steel plate.

[0046] The oscillating cooling mode refers to the conveyor roller 4 below the high-density cooling device rotating forward and backward alternately, thereby driving the steel plate to move back and forth within the cooling zone of the high-density cooling device, thus increasing the cooling time. The continuous cooling mode refers to the conveyor roller 4 continuously rotating forward or backward, thereby driving the steel plate to move forward through the cooling zone of the high-density cooling device, without the back-and-forth repetitive process.

[0047] The specific control method and process are as follows.

[0048] The control system automatically calculates the production parameters of the water cooling unit 5 based on the dimensions (especially thickness), inlet temperature, and target temperature of the steel plate to be cooled. These parameters include cooling mode, roller speed, water flow rate at the top of the water spray cooling unit, water-to-water ratio at the top and bottom of the water spray cooling unit, water flow rate at the top of the high-density cooling unit, water-to-bottom ratio at the top and bottom of the high-density cooling unit, and oscillating cooling time. The specific process is as follows: Figure 5 As shown.

[0049] STEP 1 Cooling Mode Selection The control system determines the cooling mode based on the table below.

[0050]

[0051] In other words, when the steel plate thickness is between 5mm and 20mm, it is not necessary to activate the high-density cooling device. With the help of the water spray cooling device, the steel plate can reach the target temperature by selecting the appropriate roller speed and water flow rate. When the steel plate thickness is between 20mm and 80mm, the water spray cooling device and the high-density cooling device work simultaneously. With the help of selecting the appropriate roller speed and water flow rate, the steel plate can reach the target temperature. When the steel plate thickness is greater than or equal to 80mm, the system activates the oscillating cooling mode. In this mode, the water spray device is not working, and the high-density cooling device is working. The steel plate is conveyed by the rollers and passes back and forth through the area covered by the high-density cooling device until the final cooling temperature requirement is met.

[0052] STEP2 Roller Conveyor Speed ​​Calculation In continuous cooling mode, the roller speed V is calculated using the simplified method TV=C: Where T is the steel plate thickness in mm; V is the roller speed in m / min; and C is a constant in mm·m / min, with a value ranging from 200 to 300.

[0053] Taking C=300 as an example, when the steel plate thickness T is 20mm, the roller speed V=C / T=300÷20=15 m / min In the oscillating cooling mode, the roller speed is constant. The furnace exit speed of this invention is set to 10-20 m / min, and the forward and reverse rotation speeds of the conveyor rollers are set to 2-5 m / min.

[0054] STEP3 Cooling Water Flow Calculation In continuous cooling mode, the control system calls upon its built-in steel plate temperature calculation module and surface heat transfer coefficient calculation module to continuously adjust the cooling water volume W in each upper zone. i Then, the temperature of the steel plate during the entire cooling process is simulated and calculated until the steel plate temperature meets the target temperature requirement at the end of the cooling process. At this time, the cooling water volume of each nozzle is saved.

[0055] In swing cooling mode, the control system automatically sets the water volume of each zone to kWh. i,max Where k is a coefficient, typically ranging from 0.85 to 0.95, W i,max This represents the maximum water volume in zone i.

[0056] STEP4 Calculation of Water Supply and Drainage Ratio To control the shape of the steel plate, the control system employs an upper and lower water ratio control, meaning the water flow rate to the upper and lower surfaces of the steel plate is at a fixed ratio. The upper and lower water ratio of the nozzle in this invention ranges from 1:1.2 to 1.5, and the final value was confirmed based on the debugging results.

[0057] STEP5 Cooling Time Calculation In continuous cooling mode, the cooling time τ is calculated as L / V. In the formula, L is the total length of the cooling device (including the total length of the first air blowing device 2.1, the water cooling device 5, and the second air blowing device 2.2), in meters; V is the speed of the roller conveyor, in meters per minute.

[0058] In swing cooling mode, the control system determines the water flow rate k·W. i,max It calls its built-in steel plate temperature calculation module and surface heat transfer coefficient calculation module, and by continuously accumulating cooling time, it eventually reaches the target temperature.

[0059] STEP 6 Production Parameter Storage, Distribution, and Execution The control system calculates operating parameters such as cooling mode, roller speed, cooling water volume, water-to-water ratio, and oscillation cooling time, and sends them to the execution structure to complete the controlled cooling of the steel plate.

[0060] To improve calculation speed and accuracy, the steel plate temperature calculation module and surface heat transfer coefficient calculation module built into this control system adopt the following basic principles: Steel Plate Temperature Field Calculation Module The heat exchange process of a steel plate is a complex physicochemical change process with typical distributed parameter characteristics and complex boundary conditions. Furthermore, compared to its width and length, the thickness is very small. Therefore, this system simplifies the heat conduction problem of the steel plate into a one-dimensional heat transfer model along the thickness direction, as shown below: Governing equations: (1) Initial conditions: or (2) In the formula, T0 is the temperature value, which indicates that the object has a uniform temperature at the beginning. — is a known function representing the temperature distribution of the object at the initial moment.

[0061] To solve this problem, this system employs explicit finite difference solving, and the solution process is as follows: First, discretize the region. For example... Figure 6 As shown, the thickness of the steel plate is taken as the research object. The origin of the coordinate system is set on the lower surface of the steel plate along the thickness direction, with the thickness direction as the x-axis. The thickness of the steel plate is divided into n equal parts, each with a length of Δx. The time axis is the y-axis, which is also discretized. Node i within the region... Temperature at time recorded .

[0062] Secondly, the difference expression for the second-order partial derivative is determined using the Taylor series expansion method: (3) When λ=0, it is an explicit difference scheme, i.e. (4) The discrete result of the internal nodes is then... (5) in Fo represents the steel temperature at node i at time k+1. Let Fo be the Fourier number (to ensure computational stability, Fo ≤ 0.5). The discretization scheme for the upper and lower surfaces is as follows:

[0063] (6) Where T w1 T represents the temperature of the cooling medium on the upper surface. w2 The temperature of the cooling medium on the lower surface. It is the number of Bishop.

[0064] Given the convection boundary conditions, if the temperature of each node of the steel plate at a certain moment is known, the temperature distribution of the steel plate at any subsequent moment can be obtained by solving the above difference equations simultaneously.

[0065] Steel Plate Surface Heat Transfer Coefficient Calculation Module The surface heat transfer coefficient h of the cooling device j It is related to the water flow density in zone i and zone j and the surface temperature of the steel plate, and can be calculated using Equation 7.

[0066] (7) In the formula h j —The overall heat transfer coefficient of the j-th water cooling system; k i W i —Water flow density from region i to region j; a j b j c j —Coefficient of the j-th water-cooled zone; The above control method achieves the cooling of the steel plate from 900℃ to 600℃, followed by straightening in a warm straightening machine to eliminate shape defects. Throughout the cooling process, the plate shape detection system monitors the steel plate shape in real time to ensure the quality of the plate shape during cooling. When the head of the steel plate leaves the cooling zone of the high-density cooling device, the second air blowing device 2.2 is activated to blow air across the surface of the steel plate, ensuring that there is no residual water on the surface.

[0067] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A water cooling device after a steel plate heat treatment furnace, characterized by, It includes a first air blowing device, a water cooling device, and a second air blowing device arranged sequentially along the outlet direction of the heat treatment furnace, wherein, Both the first and second air blowing devices include multiple nozzles for blowing gas onto the steel plate on the conveyor rollers, and the water cooling device includes multiple spray pipes arranged along the length of the conveyor rollers, with multiple nozzles installed on each spray pipe for spraying cooling water onto the steel plate.

2. The water-cooling device after the steel plate heat treatment furnace as described in claim 1, characterized in that, The water cooling device includes a water spray cooling device and a high-density cooling device, with the water spray cooling device located near the first air blowing device.

3. The water-cooling device after the steel plate heat treatment furnace as described in claim 2, characterized in that, The water spray cooling device and the high-density cooling device are equipped with multiple spray pipes on both the upper and lower sides of the conveyor roller. The spray pipes on the upper and lower sides of the water spray cooling device and the high-density cooling device are staggered. The nozzles of the water spray cooling device are used to generate atomized water droplets and spray them onto the upper and lower surfaces of the steel plate at an angle of 20-30° with the running direction of the steel plate. The nozzles of the high-density cooling device are used to generate columnar jets and spray them onto the upper and lower surfaces of the steel plate in a vertical direction.

4. The water-cooling device after the steel plate heat treatment furnace as described in claim 2, characterized in that, The nozzles installed above the spray pipe of the water spray cooling device in the width direction are arranged with denser nozzles in the middle and sparser nozzles on both sides.

5. The water-cooling device after the steel plate heat treatment furnace as described in claim 2, characterized in that, It also includes a water-blocking device located between the high-density cooling device and the water spray cooling device and the second air blowing device, which is used to prevent cooling water from flowing from the steel plate surface to the front and rear areas.

6. The water-cooling device after the steel plate heat treatment furnace as described in claim 5, characterized in that, The water-blocking device includes a water-blocking roller located above the conveyor roller track, and a drive mechanism for driving the water-blocking roller to move vertically to adjust the roller gap between the water-blocking roller and the conveyor roller track.

7. The water-cooling device after the steel plate heat treatment furnace as described in claim 6, characterized in that, The drive mechanism includes a screw jack located on both sides of the water-blocking roller and connected to its rotating shaft. The output shaft of the screw jack is connected to the lifting gear motor via a coupling. The nozzle of the first air blowing device blows in the direction of the steel plate running, and the nozzle of the second air blowing device blows in the direction of the steel plate running.

8. The water-cooling device after the heat treatment furnace for steel plates as described in any one of claims 1 to 7, characterized in that, It also includes a housing that covers the outside of the first air blowing device. The housing includes two side plates located on both sides of the conveyor roller, a top plate connecting the top ends of the two side plates, and a water collection trough connecting the bottom ends of the two side plates. The top plate and the side plates are connected by inclined plates, and the first air blowing device is mounted between the two side plates.

9. A control method for the water-cooling device after the steel plate heat treatment furnace according to any one of claims 1 to 8, characterized in that, Includes the following steps: The cooling mode is determined based on the size of the steel plate to be cooled. Cooling modes include continuous cooling mode and oscillating cooling mode. The production parameters of the water cooling unit are calculated based on the cooling mode, steel plate inlet temperature, chemical composition, and target temperature. Adjust the conveyor roller speed, water flow rate of the upper nozzle of the water spray cooling device, water output ratio of the upper and lower nozzles of the water spray cooling device, water flow rate of the upper nozzle of the high-density cooling device, water output ratio of the upper and lower nozzles of the high-density cooling device, and cooling time according to production parameters.

10. The control method for the water-cooling device after the steel plate heat treatment furnace as described in claim 9, characterized in that, The steps for calculating the production parameters of the water-cooling unit based on the cooling mode, steel plate inlet temperature, chemical composition, and target temperature specifically include: The cooling water volume of each nozzle of the water cooling device is calculated based on the target temperature using the steel plate temperature calculation module and the surface heat transfer coefficient calculation module. Simulation calculation is then performed based on the calculated cooling water volume of each nozzle to obtain the temperature of the steel plate after cooling. The cooling water volume of each nozzle of the water cooling device is continuously adjusted based on the difference between the temperature of the steel plate after cooling and the target temperature to obtain the final cooling water volume parameters of each nozzle. In continuous cooling mode, the cooling time is calculated based on the length of the water cooling device and the speed of the roller conveyor.

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