Temperature-varying liquid flow adjustable control system and method

Abstract

The invention relates to an adjustable control system and method for liquid flow changing along with temperature. The system comprises an infrared laser thermometer used for detecting the surface temperature of strip steel in real time, a controller internally provided with a temperature-flow control strategy, a pneumatic electric control ball valve controlled by the controller, and a mechanical self-adjusting flow nozzle device. The nozzle device is provided with an inner sleeve capable of axially sliding and a fixed outer sleeve, and is driven by an internal spring and pressure, so that the overlapping area of the water spraying holes can be automatically changed, and the stepless fine adjustment of tail end flow is realized. According to the method, through temperature feedback closed-loop control, the opening degree of the valve and the state of the nozzle are adjusted in a linkage mode, and dynamic and accurate cooling compensation is carried out on the local high-temperature or residual water area of the strip steel surface after laminar cooling. The problem that the strip steel temperature is not uniform due to cooling water residues is effectively solved, the strip shape quality, the mechanical property consistency and the product yield are remarkably improved, the system structure is simple, and existing production line transformation is facilitated.

Description

A temperature-dependent adjustable liquid flow rate control system and method Technical Field

[0001] This invention relates to the field of hot-rolled strip steel technology, and more particularly to a temperature-dependent adjustable liquid flow rate control system and method. Background Technology

[0002] In the hot-rolled strip production process of metallurgical enterprises, uneven temperature control of the steel plate is the direct cause of uneven internal stress, especially the temperature control of the steel plate after finishing mill rolling. Uneven temperature of the steel plate after finishing mill rolling in hot rolling mill will have the following adverse consequences on product quality, production efficiency and subsequent processes:

[0003] 1. Uneven mechanical properties of strip steel. Temperature is a key factor affecting the microstructure and properties of steel after rolling. Strip steel in areas with higher temperatures will experience lower strength and reduced toughness during cooling; while strip steel in areas with lower temperatures will experience higher hardness and insufficient plasticity. Ultimately, this results in excessive differences in mechanical properties such as yield strength, tensile strength, and elongation in different parts of the strip steel, which cannot meet the performance consistency requirements for subsequent processing or use.

[0004] 2. Increased strip shape defects and uneven temperature lead to different degrees of thermal expansion and contraction in different areas of the strip. Locally high-temperature areas shrink more during cooling after finishing rolling, easily resulting in wavy shapes; while areas with lower temperatures may experience uneven distribution of rolling force, leading to strip shape problems such as warping and lateral bending. In severe cases, this can cause uneven stress on the strip during subsequent coiling, resulting in loose coils or tower shapes, increasing the difficulty of uncoiling.

[0005] 3. Surface quality issues: If the cooling rate is insufficient in high-temperature areas, the iron oxide scale may be too thick or unevenly distributed, making it difficult to completely remove in subsequent pickling, resulting in residual pits or spots on the surface; while in local low-temperature areas, due to the high deformation resistance during rolling, the strip surface is prone to defects such as scratches and indentations.

[0006] Furthermore, temperature fluctuations can cause localized overheating of the strip steel, disrupting the continuity of the surface metal and leading to cracks or bulges. This reduces the efficiency of subsequent processes. When strip steel with uneven temperatures enters subsequent processes such as cold rolling and galvanizing, the unstable performance and shape increase processing difficulty and lower product qualification rates. Ultimately, these performance, shape, and surface quality issues will cause the strip steel to fail to meet standard requirements, necessitating downgrading or scrapping, directly impacting the company's production efficiency and product competitiveness. Especially for high-precision products such as silicon steel sheets, special military-grade sheets, automotive sheets, and appliance sheets, uneven temperature can cause entire batches to be scrapped due to excessive performance fluctuations, significantly increasing production costs for companies.

[0007] In the hot rolling process, the temperature of the steel plate needs to be strictly controlled not only in the heating furnace and roughing mill, but also after the finishing mill has finished rolling. The overall temperature is controlled by the laminar flow water through a digital model. However, when the steel plate is passed through the water at high speed, a large amount of cooling water often remains on the surface of the steel plate. Especially for the extreme steel plate, it cannot be discharged in time, which causes uneven surface temperature of the steel plate, resulting in uneven internal stress of the steel plate. This leads to defects such as warping, waviness, and lateral bending, resulting in a large number of unqualified products.

[0008] Existing patent publication CN102553950A proposes a segmented laminar flow cooling system and a dual closed-loop control method for thin strip continuous casting. Its core technology lies in dividing the cooling zone into multiple manifold zones and using nozzles of different diameters. A complex online feedforward and feedback model is used to dynamically calculate and switch the manifold groups in different zones. While this scheme theoretically improves control accuracy, its system structure is complex, requiring large-scale zoning modifications to the existing cooling zone, resulting in high implementation costs. Furthermore, its control granularity remains at the manifold group switching level, unable to continuously and finely adjust the cooling intensity of specific local areas. CN103861879A discloses an online cooling device for medium-thick plates and its pressure-flow coupling control method. This scheme focuses on the stability of the water supply system. By establishing a relationship model between valve opening, pump frequency, flow rate, and pressure, a PID algorithm is used to achieve decoupling and high-precision stable control of the water supply platform pressure and the main pipe flow rate. However, this method mainly optimizes the upstream power supply link of the cooling system to ensure stable pressure and flow rate entering each manifold. It does not address, nor can it resolve, the downstream problem of uneven distribution, residue, and accumulation of cooling water on the strip surface due to hydrodynamic issues after it exits the manifold nozzles—a problem that is precisely the main direct cause of temperature unevenness. CN102397887A provides a method for suppressing temperature fluctuations at the tail end of the strip, which compensates by rapidly sampling the tail temperature and quickly opening and closing a small number of manifolds in the fine-tuning section. This method is highly targeted and has a certain effect on suppressing temperature deviation at the tail end after strip casting. However, its adjustment mechanism is essentially discrete and on / off; the response logic is a pulse-like intervention based on delayed temperature detection, allowing for point-to-point adjustments or pauses, and cannot achieve smooth, continuous, and on-demand proportional adjustment. This method is essentially powerless against the random temperature unevenness caused by water residue that exists over a large area in the front of the strip.

[0009] In summary, existing technologies either have overly complex systems that are difficult to modify, focus on the upstream system rather than the end effect, or employ discrete and coarse-grained adjustment methods. Their common limitation lies in the lack of a simple and effective means to directly, sensitively, and continuously respond to real-time temperature field changes on the strip surface and to perform fine, stepless, on-site adjustment of the cooling water flow rate sprayed onto that specific area. Therefore, there is an urgent need for a relatively simple control system and method that can be directly installed on existing production lines and achieve point-to-point fine-grained flow compensation. Summary of the Invention

[0010] To address the aforementioned technical problems, a control system and method for adjustable liquid flow rate that varies with temperature are provided.

[0011] The technical means adopted in this invention are as follows: A temperature-dependent adjustable liquid flow control system, comprising: a temperature detection unit installed downstream of a laminar flow cooling device for real-time non-contact measurement of the temperature distribution on the strip surface after laminar flow cooling; a control unit whose signal input terminal is connected to the temperature detection unit for receiving the temperature signal from the strip surface, and which has a built-in cooling water flow control strategy based on a preset target strip winding temperature and different temperature ranges; and a flow regulation execution unit comprising a pneumatic-electric ball valve, the control terminal of which is connected to the signal output terminal of the control unit, and its inlet pipe connected to... The outlet pipe is connected to the high-pressure water supply system and the outlet pipe is connected to the end spray device. The end spray unit is a mechanical self-adjusting flow nozzle device, which includes an axially sliding inner sleeve and a fixed outer sleeve. The inner sleeve has multiple first through holes on its wall, and the outer sleeve has multiple nozzles on its wall. An elastic element is provided between the inner sleeve and the outer sleeve. When the cooling water pressure flowing through the pneumatic-electric ball valve acts on the inner sleeve, it can drive the inner sleeve to compress the elastic element and generate axial displacement, thereby changing the relative overlap area between the first through holes and the nozzles, and thus realizing stepless adjustment of the spray flow.

[0012] Furthermore, the temperature detection unit is an infrared laser thermometer, which is installed at a height of 8 to 12 meters above the end roller conveyor of the laminar flow cooling zone, and 3 to 8 meters away from the last set of laminar flow cooling manifolds along the running direction of the strip.

[0013] Further, the control strategies built in the control unit at least include a piecewise linear control logic based on the actually measured temperature of the strip surface: when the actually measured temperature T is in the first interval: 450°C < T ≤ 550°C, output a control instruction to adjust the opening of the pneumatic electro-control ball valve to 90% to 98% of the rated opening; when the actually measured temperature T is in the second interval: 550°C < T ≤ 600°C, output a control instruction to adjust the opening of the pneumatic electro-control ball valve to 70% to 80% of the rated opening; when the actually measured temperature T is in the third interval: 600°C < T ≤ 650°C, output a control instruction to adjust the opening of the pneumatic electro-control ball valve to 50% to 60% of the rated opening; when the actually measured temperature T is in the fourth interval: 650°C < T ≤ 700°C, output a control instruction to adjust the opening of the pneumatic electro-control ball valve to 30% to 40% of the rated opening; when the actually measured temperature T is greater than 700°C, output a control instruction to adjust the opening of the pneumatic electro-control ball valve to 10% of the rated opening.

[0014] Further, the control unit also receives the strip thickness information from the upper process computer and executes a thickness priority control logic: when the strip thickness is less than or equal to 3 mm, regardless of the actually measured temperature, preferentially output a control instruction to close the pneumatic electro-control ball valve; when the strip thickness is greater than or equal to 17 mm, regardless of the actually measured temperature, preferentially output a control instruction to adjust the opening of the pneumatic electro-control ball valve to 90% to 98% of the rated opening.

[0015] Further, on the pipelines at the inlet side and the outlet side of the pneumatic electro-control ball valve, manual or electric butterfly valves are respectively installed in series to isolate the pneumatic electro-control ball valve from the water supply system and the end spraying unit during maintenance or repair.

[0016] Further, a flow detection unit is also installed on the inlet pipeline of the pneumatic electro-control ball valve to real-time monitor the instantaneous cooling water flow rate flowing to the end spraying unit. The signal output end of the flow detection unit is connected to the control unit for data recording and monitoring, and a low flow limit alarm threshold is set.

[0017] Further, in the mechanical self-adjusting flow nozzle device of the end spraying unit, one end of the inner sleeve is connected to a water inlet pipeline flange through a thread. The elastic element is a helical compression spring sleeved outside the inner sleeve and abutted between the boss of the inner sleeve and the end of the outer sleeve. The first through holes are circular through holes uniformly distributed along the circumferential and axial directions of the inner sleeve. The nozzle is a conical or fan-shaped nozzle fixed to the outer sleeve wall through a thread.

[0018] Furthermore, at least one annular sealing element is provided between the outer wall of the inner sleeve and the inner wall of the outer sleeve to ensure dynamic sealing when the two slide relative to each other, preventing cooling water from leaking out from the mating area of ​​the first through hole and the nozzle.

[0019] This invention also discloses a temperature-dependent adjustable liquid flow control method using the above-mentioned system, comprising the following steps: Step 1: After the strip passes through the main laminar flow cooling zone, the temperature detection unit collects its surface temperature data in real time; Step 2: The control unit receives the temperature data and preset process parameters, calculates according to the built-in control strategy, and generates a corresponding flow adjustment command; Step 3: The flow adjustment command is sent to the pneumatic-electric ball valve, driving its valve core to change the water pressure and flow rate in the water supply pipeline leading to the end spray unit; Step 4: Cooling water with a set pressure enters the mechanical self-adjusting flow nozzle device of the end spray unit, and the water pressure drives its inner sleeve to slide, changing the effective flow area of ​​the nozzle, and finally forming a supplementary cooling water flow that matches the current surface temperature distribution requirements of the strip, which is uniformly sprayed onto the surface of the strip to achieve dynamic compensation for the non-uniformity of laminar cooling.

[0020] Compared with existing technologies, this invention has the following advantages: 1. The core technical effect of this invention comes from the closed-loop linkage of the temperature detection unit, control unit, flow regulation execution unit, and end spray unit. Specifically, the laser thermometer is used to capture the real temperature distribution on the strip surface after laminar flow cooling in real time. The control unit instantly calculates the areas that need to be strengthened or weakened in cooling and the required cooling dose based on the acquired data and preset process, and converts it into precise valve opening commands. The pneumatic and electro-hydraulic ball valve quickly and accurately adjusts the total water supply energy. Most importantly, the mechanical self-regulating flow nozzle device not only executes the change in total flow rate, but also, through its internal spring-slip sleeve structure, smoothly and without inertia converts the change in upstream pressure into a continuous change in the effective opening area of ​​the nozzle. Ultimately, the water flow pattern and impact force sprayed onto the strip surface can be adaptively adjusted, thereby more effectively dispersing or replenishing local water accumulation areas and achieving precise compensation for temperature unevenness. It effectively suppresses the temperature gradient caused by residual cooling water at the source, greatly improves the uniformity of strip temperature in the transverse and longitudinal directions, thereby directly reducing plate shape defects such as warping and waviness, and ensuring the stability of mechanical properties.

[0021] 2. Unlike existing technologies, this invention uses a pneumatic proportional valve for continuous proportional regulation of macroscopic flow, resulting in faster response and less overshoot. More importantly, the self-adjusting characteristics of the end nozzle device provide a second layer of protection. Even if there are slight deviations in the water pressure entering the nozzle due to fluctuations in pipeline pressure or valve characteristics, the device can maintain good alignment between the output flow and the preset value through the automatic displacement of its internal mechanical structure, enhancing the robustness and control accuracy of the entire system.

[0022] 3. Compared to existing technologies that require complex rezoning and manifold modifications to the entire cooling zone, this invention primarily involves adding an independent detection and compensation device in series downstream of the existing laminar flow cooling unit. The isolation butterfly valves positioned before and after the pneumatic-electric ball valve, along with the flange connection design of the end nozzle device, allow for easy isolation and disassembly for maintenance of the core regulating components, eliminating the need for prolonged downtime and significantly reducing modification and maintenance costs. The online monitoring and alarm functions of the flow meter also enhance the system's monitorability and safety. This modular, low-intrusion design concept makes this technology easily applicable to various existing hot rolling lines.

[0023] 4. The programmable logic control unit of this invention not only processes temperature signals but also integrates priority control logic based on strip thickness. This intelligent strategy, which combines temperature feedback control with rule-based judgment of key process parameters, including thickness, enables the system to flexibly adapt to diverse production needs, from ordinary carbon steel to high-strength steel and from thin to thick specifications, thereby improving the versatility and process adaptability of the method.

[0024] This invention, through practical field application, measures the actual temperature of the steel plate and, based on the required temperatures for different steel grades, purges residual laminar cooling water from the steel surface. An intelligent control unit adjusts the opening of the pneumatic and electro-hydraulic control valves according to temperature changes, and a mechanical self-regulating flow nozzle device effectively adjusts the cooling water flow rate. This ensures uniform surface temperature of the steel plate and effectively reduces internal stress caused by uneven temperature, preventing plate shape defects and directly improving product quality. The required flow rate can be adjusted according to different requirements, ensuring safe and reliable control, convenient maintenance and installation, and meeting safe production requirements. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 is a schematic diagram of a method for adjustable control of liquid flow rate with temperature variation according to the present invention; Figure 2 is a schematic diagram of a mechanical self-adjusting flow nozzle device according to the present invention.

[0027] Figure 3 is a schematic diagram of the system of the present invention.

[0028] In the diagram: 1-Conveyor roller conveyor; 2-Steel plate; 3-Laminar flow cooling; 4-Laser thermometer; 5-PLC control module; 6-Input module; 7-Output module; 8-Pneumatic and electric ball valve; 9-Outlet butterfly valve; 10-Inlet butterfly valve; 11-Mechanical self-adjusting flow nozzle device; 11-1 Connecting flange; 11-2 Inner sleeve of manifold; 11-3 Outer sleeve of manifold; 11-4 Control hole; 11-5 Nozzle; 11-6 Control spring; 12-Flow meter. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0033] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0034] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0035] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0036] In hot rolling mills, temperature control of steel plates is extremely important, especially during the laminar flow cooling process after finishing mill rolling. This invention controls the flow rate of laminar flow back-spray water by detecting the temperature of the steel plate, avoiding the problem of uneven temperature caused by residual water when steel plates of extreme specifications are pierced at high speed. This keeps the surface temperature of the steel plate constant, reduces the uneven internal stress caused by uneven temperature, prevents defects such as warping, waviness, and lateral bending, and improves the forming rate of the steel plate.

[0037] Therefore, this invention discloses a temperature-dependent adjustable liquid flow control system, comprising: a temperature detection unit installed downstream of a laminar flow cooling device for real-time non-contact measurement of the temperature distribution on the strip surface after laminar flow cooling; a control unit whose signal input terminal is connected to the temperature detection unit for receiving the temperature signal from the strip surface and having a built-in cooling water flow control strategy based on a preset target strip winding temperature and different temperature ranges; and a flow regulation execution unit including a pneumatic-electric ball valve, the control terminal of which is connected to the signal output terminal of the control unit, and its inlet pipe connected to... The outlet pipe is connected to the high-pressure water supply system and the outlet pipe is connected to the end spray device. The end spray unit is a mechanical self-adjusting flow nozzle device, which includes an axially sliding inner sleeve and a fixed outer sleeve. The inner sleeve has multiple first through holes on its wall, and the outer sleeve has multiple nozzles on its wall. An elastic element is provided between the inner sleeve and the outer sleeve. When the cooling water pressure flowing through the pneumatic-electric ball valve acts on the inner sleeve, it can drive the inner sleeve to compress the elastic element and generate axial displacement, thereby changing the relative overlap area between the first through holes and the nozzles, and thus realizing stepless adjustment of the spray flow.

[0038] The system, through the linkage of the temperature detection unit, control unit, flow regulation execution unit, and end-spray unit, constitutes a closed-loop flow control system based on real-time temperature feedback of the strip surface. This allows for precise dynamic compensation of the cooling intensity in localized areas of the strip surface after laminar flow cooling. Furthermore, the temperature detection unit is an infrared laser thermometer, installed 8-12 meters above the end roller conveyor of the laminar flow cooling zone and 3-8 meters away from the last set of laminar flow cooling manifolds along the strip's running direction. This ensures its measurement field of view completely covers the strip width and avoids major water vapor interference areas.

[0039] Further, the control strategies built in the control unit at least include a piecewise linear control logic based on the actually measured temperature of the strip surface: when the actually measured temperature T is in the first interval: 450°C < T ≤ 550°C, output a control instruction to adjust the opening degree of the pneumatic electric control ball valve to 90% to 98% of the rated opening degree; when the actually measured temperature T is in the second interval: 550°C < T ≤ 600°C, output a control instruction to adjust the opening degree of the pneumatic electric control ball valve to 70% to 80% of the rated opening degree; when the actually measured temperature T is in the third interval: 600°C < T ≤ 650°C, output a control instruction to adjust the opening degree of the pneumatic electric control ball valve to 50% to 60% of the rated opening degree; when the actually measured temperature T is in the fourth interval: 650°C < T ≤ 700°C, output a control instruction to adjust the opening degree of the pneumatic electric control ball valve to 30% to 40% of the rated opening degree; when the actually measured temperature T is greater than 700°C, output a control instruction to adjust the opening degree of the pneumatic electric control ball valve to 10% of the rated opening degree.

[0040] Further, the control unit also receives the strip thickness information from the upper process computer and executes a thickness priority control logic: when the strip thickness is less than or equal to 3 mm, regardless of the actually measured temperature, preferentially output a control instruction to close the pneumatic electric control ball valve; when the strip thickness is greater than or equal to 17 mm, regardless of the actually measured temperature, preferentially output a control instruction to adjust the opening degree of the pneumatic electric control ball valve to 90% to 98% of the rated opening degree. [[ID=??]]

[0041] Further, on the pipelines at the inlet side and the outlet side of the pneumatic electric control ball valve, manual or electric butterfly valves are respectively installed in series to isolate the pneumatic electric control ball valve from the water supply system and the end spraying unit during maintenance or repair.

[0042] Further, a flow detection unit is also installed on the inlet pipeline of the pneumatic electric control ball valve to real-time monitor the instantaneous cooling water flow rate flowing to the end spraying unit. The signal output end of the flow detection unit is connected to the control unit for data recording and monitoring, and a low flow limit alarm threshold is set.

[0043] Further, in the mechanical self-adjusting flow nozzle device of the end spraying unit, one end of the inner sleeve is threadedly connected to a flange of the inlet pipeline. The elastic element is a helical compression spring sleeved outside the inner sleeve and abutted between the boss of the inner sleeve and the end of the outer sleeve. The first through hole is a circular through hole uniformly distributed along the circumferential and axial directions of the inner sleeve. The nozzle is a conical or fan-shaped nozzle fixedly installed on the wall of the outer sleeve by threads.

[0044] Furthermore, at least one annular sealing element is provided between the outer wall of the inner sleeve and the inner wall of the outer sleeve to ensure dynamic sealing when the two slide relative to each other, preventing cooling water from leaking out from the mating area of ​​the first through hole and the nozzle.

[0045] This invention also discloses a temperature-dependent adjustable liquid flow control method using the above-mentioned system, comprising the following steps: Step 1: After the strip passes through the main laminar flow cooling zone, the temperature detection unit collects its surface temperature data in real time; Step 2: The control unit receives the temperature data and preset process parameters, calculates according to the built-in control strategy, and generates a corresponding flow adjustment command; Step 3: The flow adjustment command is sent to the pneumatic-electric ball valve, driving its valve core to change the water pressure and flow rate in the water supply pipeline leading to the end spray unit; Step 4: Cooling water with a set pressure enters the mechanical self-adjusting flow nozzle device of the end spray unit, and the water pressure drives its inner sleeve to slide, changing the effective flow area of ​​the nozzle, and finally forming a supplementary cooling water flow that matches the current surface temperature distribution requirements of the strip, which is uniformly sprayed onto the surface of the strip to achieve dynamic compensation for the non-uniformity of laminar cooling.

[0046] Example 1, as shown in Figures 1-3, illustrates a specific structure for a temperature-dependent adjustable liquid flow control system. This system includes: a conveyor roller 1, a steel plate 2, a laminar flow cooling system 3, a laser thermometer 4, a PLC control module 5, an input module 6, an output module 7, a pneumatic / electric ball valve 8, an outlet butterfly valve 9, an inlet butterfly valve 10, a mechanical self-adjusting flow nozzle device 11, and a flow meter 12. The conveyor roller 1 safely transports the steel plate 2 to the next process. The laminar flow cooling system 3 cools the steel plate 2. The laser thermometer 4 is installed 10 meters diagonally above the steel plate, protecting it from high-temperature radiation and facilitating inspection and maintenance. The temperature detected by the laser thermometer 4 is connected to the input module 6, and the secondary model control is also connected to the input module 6. The input module 6 transmits all data to the PLC control module 5. The PLC control module 5 calculates the control commands through the output module 7. The water is transmitted to the pneumatic-electric ball valve 8, which performs precise flow control of the cooling water according to the instructions. To facilitate maintenance and testing, an outlet butterfly valve 9 and an inlet butterfly valve 10 are installed before and after the pneumatic-electric ball valve 8. The outlet butterfly valve 9 delivers the cooling water through the pipeline to the mechanical self-regulating flow nozzle device 11. The flow meter 12 is installed before the inlet butterfly valve 10 for testing.

[0047] In this embodiment, the secondary model control refers to the laminar flow cooling setting model located in the process control computer. This model calculates the target coiling temperature and required cooling strategy for the steel plate based on the steel grade, specifications, and final rolling temperature. The PLC control unit communicates with the process computer via industrial Ethernet and receives the target temperature and the measured thickness of the steel plate. The PLC uses the difference between the measured temperature and the target temperature as the primary adjustment basis, while also referring to the thickness H to execute the aforementioned priority logic.

[0048] This invention collects the surface temperature of the steel plate at a rate of 0.01 s / n using a non-contact measurement (laser thermometer), transmits the data via single-mode fiber optic cable, and feeds it back to the primary PLC control. The primary PLC control sends instructions set by the secondary model control to the control unit according to the instructions. The control unit adjusts the flow regulation execution unit. The adjusted flow rate is fed back to the primary PLC control via a flow meter. The primary PLC control uses the data from the temperature detection unit and the flow meter to more accurately regulate the flow rate and achieve the required temperature control of the steel plate.

[0049] The mechanical self-regulating flow nozzle device 11, as shown in Figure 2, includes a connecting flange 11-1, a manifold inner sleeve 11-2, a manifold outer sleeve 11-3, control holes 11-4, nozzles 11-5, and a control spring 11-6. The inlet of the connecting flange 11-1 is connected to the pressurized cooling water, and the outlet of the connecting flange 11-1 is threadedly connected to the manifold inner sleeve 11-2. The control holes 11-4 are evenly distributed on the manifold inner sleeve 11-2, and these holes are evenly distributed along the axial direction. The manifold outer sleeve 11-3 is threadedly connected to the evenly distributed nozzles 11-5. The control holes 11-4 and the nozzles 11-5 intersect in displacement. The manifold inner sleeve 11-2 is installed inside the manifold outer sleeve 11-3, and its inner diameter is slightly larger than the outer diameter of the manifold inner sleeve 11-2 to form a sliding fit. Multiple standard nozzles 11-5 (corresponding to the number of control holes in the inner sleeve) are welded on the pipe wall of the manifold outer sleeve 11-3. The control spring 11-6 is placed in the gap between the unconnected flange end of the manifold inner sleeve 11-2 and the end of the manifold outer sleeve 11-3.

[0050] An O-ring is installed between the outer wall of the inner manifold sleeve and the inner wall of the outer manifold sleeve to ensure a seal during sliding contact. The control hole is a circular through hole, and the nozzle is a hollow tubular structure. As the inner sleeve slides, the centerline of the control hole and the centerline of the nozzle gradually change from being completely offset to partially overlapping and then to completely coinciding. The flow rate is adjusted by controlling the overlap area.

[0051] Specifically, the mechanical self-adjusting flow nozzle device 11 includes an inner manifold sleeve 11-2, an outer manifold sleeve 11-3, and a control spring 11-6. Both the inner manifold sleeve 11-2 and the outer manifold sleeve 11-3 are tubular structures. The inner manifold sleeve 11-2 is slidably connected inside the outer manifold sleeve 11-3. Multiple control holes 11-4 are uniformly opened axially on the wall of the inner manifold sleeve 11-2. Multiple nozzles are correspondingly installed axially on the outer manifold sleeve 11-3. A control spring 11-6 is provided between one end of the inner manifold sleeve 11-2 and the outer manifold sleeve 11-3. The compression of the control spring 11-6 changes with the fluid pressure inside the inner manifold sleeve 11-2, thereby driving a relative axial displacement between the inner manifold sleeve 11-2 and the outer manifold sleeve 11-3 to continuously adjust the communication area between each control hole 11-4 and the corresponding nozzle.

[0052] The compression of the control spring 11-6 can be controlled by adjusting the pressure of the cooling water according to different requirements, thereby achieving flexible adjustment of the nozzle flow rate. The flow control method is safe and reliable, and the mechanical self-adjusting flow nozzle device is easy to maintain and install, ensuring that safe production requirements are met. By controlling the water and surface temperature on the steel plate through changes in the cooling water flow rate, the problem of uneven stress and warping defects caused by temperature fluctuations across the entire plate surface during high-speed water piercing of steel plates of extreme specifications is solved. At the same time, the forming rate of the product is greatly improved, thereby improving the plate shape quality of the product and meeting customer requirements.

[0053] The other end of the manifold inner sleeve 11-2 is connected to the pressure cooling water pipeline via a connecting flange 11-1. The standardized interface ensures reliable connection with the external pressure cooling water pipeline, improves the overall sealing and connection strength, and facilitates system installation and integration.

[0054] The connecting flange 11-1 is threaded to the other end of the manifold inner sleeve 11-2. Specifically, the other end of the manifold inner sleeve 11-2 is provided with external threads, and the connecting flange 11-1 is provided with internal threads. This threaded connection structure enables a detachable fastening between the manifold inner sleeve 11-2 and the connecting flange 11-1, facilitating the assembly, maintenance, and replacement of components, while ensuring the sealing reliability of the connection.

[0055] The other end of the manifold inner sleeve 11-2 is provided with an axial extension, and the connecting flange 11-1 is threaded to the end of the axial extension. The axial extension provides sufficient travel space for the axial movement of the manifold inner sleeve 11-2, effectively avoiding mechanical interference from the connecting flange 11-1 on the movement of the manifold inner sleeve 11-2 during the adjustment process, and ensuring smooth and reliable adjustment.

[0056] The compression of the control spring 11-6 is controlled by the fluid pressure inside the manifold inner sleeve 11-2. By controlling the compression of the control spring 11-6 through the fluid pressure inside the manifold inner sleeve 11-2, automatic feedback adjustment of the injection flow rate is achieved, enabling the nozzle flow rate to adapt to changes in internal working pressure, thereby improving the stability and intelligence level of the system.

[0057] Each of the nozzles is threadedly connected to the manifold sleeve 11-3.

[0058] The working principle of the mechanical self-adjusting flow nozzle device of the present invention is as follows: When pressurized cooling water enters the inner sleeve 11-2 of the manifold through the connecting flange 11-1, as the cooling water pressure increases and exceeds the spring force of the control spring 11-6, the inner sleeve 11-2 of the manifold moves along the outer sleeve 11-3 of the manifold towards the control spring 11-6. The control holes 11-4 evenly distributed on the inner sleeve 11-2 will gradually align with the inlet of the nozzle 11-5 on the outer sleeve 11-3 of the manifold, and the overlapping flow area of ​​the two will increase accordingly, thereby increasing the outlet flow of the nozzle 11-5. The required flow of the nozzle can be adjusted according to different requirements to meet the needs of on-site use.

[0059] In this embodiment, the method for adjustable control of liquid flow rate with temperature variation is as follows: During the process of transporting steel plate 2 safely to the next process by conveyor roller 1, laminar flow cooling 3 cools steel plate 2. After cooling, the steel plate continues to be rapidly conveyed forward by conveyor roller 1 and rolling mill. In this embodiment, laser thermometer 4 is installed at a distance of 5 meters from the last laminar flow cooling 3 and 10 meters above it, which helps protect laser thermometer 4 from damage by high temperature radiation and facilitates detection and maintenance. The temperature detected by laser thermometer 4 is transmitted to PLC control module 5 through input module 6. At the same time, the secondary model control is also transmitted to PLC through input module 6. The control module 5 incorporates temperature and model control into the PLC control module 5 via program code. Control commands are transmitted to the pneumatic-electric ball valve 8 through the output module 7. The pneumatic-electric ball valve 8 controls the flow rate of cooling water and delivers the cooling water through pipelines to the mechanical self-regulating flow nozzle device 11. The flow meter 12 inputs the measured parameters into the PLC control module 5 for data storage and use. The flow meter 12 sets a minimum flow limit. When the pneumatic-electric ball valve 8 malfunctions and fails to open, the flow meter 12 issues an alarm. The alarm signal is sent to the on-site operator's PC monitor via remote monitoring for maintenance and inspection, preventing quality accidents.

[0060] When cooling water enters the connecting flange 11-1 in Figure 2, it flows into the inner sleeve 11-2 of the manifold. As the cooling water flow rate increases, the water pressure also increases. When the water pressure exceeds the spring force of the control spring 11-6, the inner sleeve 11-2 moves along the outer sleeve 11-3 towards the control spring 11-6. The evenly distributed control holes 11-4 on the inner sleeve 11-2 gradually overlap with the nozzles 11-5, thereby gradually increasing the flow rate of the nozzles 11-5 to meet the on-site requirements. The stiffness coefficient K of the control spring needs to be designed according to the system's working pressure range.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A temperature-dependent liquid flow rate adjustable control system, characterized in that, Comprising: A temperature detection unit, which is installed at the downstream position of the laminar flow cooling device and is used for non-contact measurement of the temperature distribution on the strip surface in real time after laminar flow cooling; a control unit, whose signal input end is connected to the temperature detection unit and is used for receiving the temperature signal of the strip surface, and is built-in with a cooling water flow control strategy formulated according to the preset target coiling temperature of the strip and different temperature intervals; a flow regulation execution unit, which includes a pneumatic and electrically controlled ball valve, the control end of the pneumatic and electrically controlled ball valve is connected to the signal output end of the control unit, its inlet pipeline is connected to the high-pressure water supply system, and the outlet pipeline is connected to the end spraying device; the end spraying unit is a mechanical self-adjusting flow nozzle device, which includes an axially slidable inner sleeve and a fixed outer sleeve, a plurality of first through holes are provided on the wall of the inner sleeve, and a plurality of nozzles are correspondingly arranged on the wall of the outer sleeve, and an elastic element is arranged between the inner sleeve and the outer sleeve; when the cooling water pressure flowing through the pneumatic and electrically controlled ball valve acts on the inner sleeve, it can drive it to compress the elastic element and generate an axial displacement, thereby changing the relative overlapping area between the first through holes and the nozzles, and further realizing stepless adjustment of the spraying flow rate.

2. The temperature-dependent adjustable liquid flow control system according to claim 1, characterized in that, The temperature detection unit is an infrared laser thermometer, and its installation position is 8-12 meters above the end roller table of the laminar flow cooling zone and 3-8 meters away from the last set of laminar flow cooling headers along the strip running direction.

3. The temperature-dependent adjustable liquid flow control system according to claim 1, characterized in that, The control strategy built in the control unit at least includes a piecewise linear control logic based on the measured temperature on the strip surface: when the measured temperature T is in the first interval: 450°C < T ≤ 550°C, output a control command to adjust the opening of the pneumatic and electrically controlled ball valve to 90% to 98% of the rated opening; when the measured temperature T is in the second interval: 550°C < T ≤ 600°C, output a control command to adjust the opening of the pneumatic and electrically controlled ball valve to 70% to 80% of the rated opening; when the measured temperature T is in the third interval: 600°C < T ≤ 650°C, output a control command to adjust the opening of the pneumatic and electrically controlled ball valve to 50% to 60% of the rated opening; when the measured temperature T is in the fourth interval: 650°C < T ≤ 700°C, output a control command to adjust the opening of the pneumatic and electrically controlled ball valve to 30% to 40% of the rated opening; when the measured temperature T is greater than 700°C, output a control command to adjust the opening of the pneumatic and electrically controlled ball valve to 10% of the rated opening.

4. The temperature-dependent adjustable liquid flow control system according to claim 1, characterized in that, The control unit also receives the strip thickness information from the upper process computer and executes a thickness priority control logic: when the strip thickness is less than or equal to 3 mm, regardless of the measured temperature, a control command is preferentially output to close the pneumatic and electrically controlled ball valve; when the strip thickness is greater than or equal to 17 mm, regardless of the measured temperature, a control command is preferentially output to adjust the opening of the pneumatic and electrically controlled ball valve to 90% to 98% of the rated opening.

5. The temperature-dependent adjustable liquid flow rate control system according to claim 1, characterized in that, On the pipelines on the inlet side and the outlet side of the pneumatic and electrically controlled ball valve, a manual or electric butterfly valve is respectively installed in series for isolating the pneumatic and electrically controlled ball valve from the water supply system and the end spraying unit during maintenance or repair.

6. The temperature-dependent adjustable liquid flow control system according to claim 1, characterized in that, A flow detection unit is also installed on the inlet pipe of the pneumatic and electrically controlled ball valve to monitor the instantaneous flow rate of cooling water flowing to the end spray unit in real time. The signal output terminal of the flow detection unit is connected to the control unit for data recording and monitoring, and a low flow alarm threshold is set.

7. The temperature-dependent adjustable liquid flow control system according to claim 1, characterized in that, In the mechanical self-adjusting flow nozzle device of the terminal injection unit, one end of the inner sleeve is connected to a water inlet flange by a thread, the elastic element is a helical compression spring sleeved on the outside of the inner sleeve and abutting between the inner sleeve boss and the end of the outer sleeve, the first through hole is a circular through hole evenly distributed along the circumference and axial direction of the inner sleeve, and the nozzle is a conical or fan-shaped nozzle fixed to the wall of the outer sleeve by a thread.

8. The temperature-dependent adjustable liquid flow control system according to claim 1, characterized in that, At least one annular sealing element is provided between the outer wall of the inner sleeve and the inner wall of the outer sleeve to ensure dynamic sealing when the two slide relative to each other, and to prevent cooling water from leaking from outside the mating area of ​​the first through hole and the nozzle.

9. A method for temperature-dependent adjustable liquid flow control using the system according to any one of claims 1 to 8, comprising the following steps: Step 1: After the strip passes through the main laminar flow cooling zone, its surface temperature data is collected in real time by the temperature detection unit. Step 2: The control unit receives the temperature data and preset process parameters, calculates based on the built-in control strategy, and generates a corresponding flow regulation command. Step 3: The flow regulation command is sent to the pneumatic-electric ball valve, driving its valve core to change the water pressure and flow rate in the water supply pipeline leading to the end-spray unit. Step 4: Cooling water with a set pressure enters the mechanical self-regulating flow nozzle device of the end-spray unit. The water pressure drives the inner sleeve to slide, changing the effective flow area of ​​the nozzle, ultimately forming a supplementary cooling water flow that matches the current surface temperature distribution requirements of the strip, uniformly spraying it onto the strip surface to achieve dynamic compensation for the unevenness of laminar flow cooling.

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