Strip steel cold rolling adaptive hydraulic station constant pressure control system

Abstract

The utility model discloses a cold rolled strip steel adaptive hydraulic station constant voltage control system, including display, hydraulic oil tank, hydraulic element, the display electric connection has PLC controller, and PLC controller electric connection has the spare pump of work frequency and two servo pumps, and the output of work frequency spare pump and two servo pumps is connected with the oil supply pipe, and work frequency spare pump, servo pump, oil supply pipe connection pressure sensor, flow sensor, and hydraulic oil tank is linked with work frequency spare pump and servo pump, and hydraulic oil tank is connected with the breather valve, and hydraulic element is connected with the oil supply pipe, and the temperature sensor is connected between hydraulic element and the oil supply pipe, and the outlet of hydraulic element is connected with the hydraulic oil tank through the heat exchanger, through to the dynamic power adjustment of servo pump, realizes the dynamic pressure regulation of hydraulic oil, makes hydraulic system can real -time adjustment output pressure according to actual demand, reduces the energy consumption loss that causes by the backflow of surplus hydraulic oil through the pilot type overflow valve, reaches the purpose that energy -conserving and consumption -reducing.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic station technology, specifically to a constant pressure control system for an adaptive hydraulic station for cold rolling of strip steel. Background Technology

[0002] In the field of steel rolling mills, the hydraulic system is the core power unit. Currently, mainstream hydraulic stations generally adopt a traditional configuration based on the total rated pressure demand of the equipment, relying on constant-speed hydraulic pump sets operating at industrial frequency. Such hydraulic systems have the following shortcomings: the pump sets operate at full power continuously after startup, while the equipment pressure demand fluctuates dynamically in actual production, but the hydraulic system continuously outputs excess pressure. The excess oil pressure flows back through the pilot-operated relief valve, resulting in significant energy loss and low energy efficiency. Utility Model Content

[0003] The purpose of this invention is to provide a constant pressure control system for an adaptive hydraulic station in cold rolling of strip steel, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a constant pressure control system for an adaptive hydraulic station in cold rolling of strip steel, including a display, which provides a visual interface for easy viewing of the control system. The display is electrically connected to a PLC controller, which is electrically connected to a power frequency standby pump and two servo pumps. The output ports of the power frequency standby pump and the two servo pumps are connected to oil supply pipes. The power frequency standby pump, the servo pumps, and the oil supply pipes are connected to pressure sensors and flow sensors. The PLC controller changes the power of the servo pump based on the pressure and flow of the hydraulic oil, avoiding the servo pump from running at high power all the time, which can save energy. The hydraulic oil tank is connected to the power frequency standby pump and the servo pump. The hydraulic oil tank is also connected to a breather valve to maintain the air pressure balance of the hydraulic oil tank. The hydraulic component is connected to the oil supply pipe, and a temperature sensor is connected between the hydraulic component and the oil supply pipe. The outlet of the hydraulic component is connected to the hydraulic oil tank through a heat exchanger to realize the circulation of hydraulic oil. The heat exchanger reduces the temperature of the hydraulic oil, which can reduce pressure fluctuations caused by the temperature of the hydraulic oil.

[0005] Furthermore, a servo controller is connected between the servo pump and the PLC controller, and a start switch is connected between the power frequency backup pump and the PLC controller. The two servo controllers serve as backups for each other. When one of the servo controllers fails, the system can automatically switch to the power frequency backup pump and issue an alarm signal.

[0006] Furthermore, the power frequency standby pump and the servo pump are connected to an oil filter, which is located inside the hydraulic oil tank. This reduces the amount of impurities entering the hydraulic components and prevents wear and leakage of the hydraulic components.

[0007] Furthermore, the hydraulic oil tank is also connected to a temperature sensor, and the hydraulic oil tank is equipped with a level radar, which can monitor the level and temperature of the hydraulic oil.

[0008] Furthermore, the power frequency backup pump and servo pump are connected to the oil supply pipe by a check valve to ensure that the three oil circuits do not interfere with each other, resulting in better system stability.

[0009] Furthermore, a three-stage unloading mechanism is installed between the oil supply pipe and the hydraulic oil tank. When the pressure in the oil supply pipe exceeds the limit, the three-stage unloading mechanism opens to release pressure from the oil supply pipe, thereby avoiding overpressure and preventing the oil supply pipe from rupturing.

[0010] Furthermore, the three-stage unloading mechanism includes a pilot-operated relief valve, a solenoid ball valve, and a mechanical safety valve to ensure that the system can safely unload under excessive pressure conditions.

[0011] Compared with the prior art, the beneficial effects of this utility model are: (1) By dynamically adjusting the power of the servo pump, the hydraulic oil can be dynamically adjusted, so that the hydraulic system can adjust the output pressure in real time according to actual needs, reduce the energy loss caused by excess hydraulic oil flowing back through the pilot relief valve, and achieve the purpose of energy saving and consumption reduction.

[0012] The redundant design addresses issues such as energy waste, large pressure fluctuations, and slow fault response in traditional hydraulic systems.

[0013] (2) During the cold rolling process of strip steel, optimized PID parameter self-tuning technology and dynamic pressure compensation control are adopted to ensure that the system pressure fluctuates stably within the set value range, thereby improving rolling accuracy and product quality.

[0014] (3) The pressure and flow of hydraulic oil can be detected by multiple pressure sensors and flow sensors. Faults can be detected in time and the power frequency backup pump can be started, realizing rapid fault detection and automatic switching of the power frequency backup pump, reducing downtime and improving production efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the system structure of this utility model.

[0016] In the diagram: 1. Display; 2. PLC controller; 3. Servo controller; 4. Servo pump; 5. Hydraulic oil tank; 6. Breather valve; 7. Temperature sensor; 8. Liquid level radar; 9. Oil filter; 10. Start switch; 11. Mains frequency standby pump; 12. Pressure sensor; 13. Flow sensor; 14. Check valve; 15. Pilot-operated relief valve; 16. Solenoid ball valve; 17. Mechanical safety valve; 18. Heat exchanger; 19. Hydraulic components; 20. Oil supply pipe. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Example: Please see Figure 1 This utility model provides a technical solution: a constant pressure control system for an adaptive hydraulic station for cold rolling of strip steel, including a display 1. The operator can set the required pressure of the hydraulic station, select automatic or manual control mode, view fault records and perform energy efficiency analysis on the interface of the display 1, which facilitates the use and maintenance of the system. The display 1 is electrically connected to a PLC controller 2. The PLC controller 2 is connected to a temperature sensor 7, a liquid level radar 8, a pressure sensor 12, a flow sensor 13, a solenoid ball valve 16, a mechanical safety valve 17, and a heat exchanger 18 via a CAN bus, so that the PLC controller 2 can collect data from various sources to fully understand the system's operating status. The PLC controller 2 is electrically connected to a power frequency backup pump 11 and two servo pumps 4. The output ports of the power frequency backup pump 11 and the two servo pumps 4 are connected to an oil supply pipe 20. The power frequency backup pump 11, the servo pumps 4, and the oil supply pipe 20 are connected to a pressure sensor 12 and a flow sensor 13, which can accurately measure the pressure and flow of hydraulic oil at various points and provide accurate data for closed-loop control. Hydraulic oil tank 5 is connected to power frequency standby pump 11 and servo pump 4. Hydraulic oil tank 5 is connected to breather valve 6, which maintains the air pressure balance of hydraulic oil tank 5 and prevents hydraulic oil tank 5 from deforming. Hydraulic component 19 (which can be a rolling mill, a cylinder, a hydraulic motor, etc.) is connected to oil supply pipe 20, and a temperature sensor 7 is connected between hydraulic component 19 and oil supply pipe 20. A pressure sensor 12 and a flow sensor 13 are also installed to detect the pressure, temperature, and flow rate at hydraulic component 19. The outlet of hydraulic component 19 is connected to hydraulic oil tank 5 through heat exchanger 18. Heat exchanger 18 is equipped with temperature sensor 7 to check the temperature of hydraulic oil after cooling.

[0019] In this embodiment, as Figure 1As shown, a servo controller 3 is connected between the servo pump 4 and the PLC controller 2, and a start switch 10 is connected between the power frequency backup pump 11 and the PLC controller 2. The design adopts dual servo controllers 3 as backups for each other. When one of the servo controllers 3 fails, the start switch 10 is turned on, and the system can automatically switch to the power frequency backup pump 11 and issue an alarm signal to ensure the reliability and stability of the system.

[0020] In this embodiment, as Figure 1 As shown, the power frequency backup pump 11 and the servo pump 4 are connected to an oil filter 9. The oil filter 9 is located inside the hydraulic oil tank 5. The oil filter 9 can filter impurities, prevent impurities from clogging the check valve 14 and hydraulic components 19, reduce wear, and improve stability.

[0021] In this embodiment, as Figure 1 As shown, the hydraulic oil tank 5 is also connected to a temperature sensor 7, and the hydraulic oil tank 5 is equipped with a liquid level radar 8, which can monitor the temperature of the hydraulic oil tank 5 and the amount of hydraulic oil. When the amount of hydraulic oil is insufficient, it can be replenished in time.

[0022] In this embodiment, as Figure 1 As shown, a one-way valve 14 is connected between the power frequency backup pump 11 and the servo pump 4 and the oil supply pipe 20 to ensure that the power frequency backup pump 11 and the servo pump 4 deliver hydraulic oil into the oil supply pipe 20 in one direction, and to prevent the hydraulic oil discharged by the power frequency backup pump 11 and the servo pump 4 from affecting each other.

[0023] In this embodiment, a three-stage unloading mechanism is installed between the oil supply pipe 20 and the hydraulic oil tank 5. When the pressure of the oil supply pipe 20 exceeds the limit, the three-stage unloading mechanism opens to release the pressure of the oil supply pipe 20. The oil supply pipe 20 is equipped with a pressure sensor 12 and a flow sensor 13. When the pressure of the oil supply pipe 20 exceeds the limit, it automatically unloads to prevent the oil supply pipe 20 from rupturing.

[0024] In this embodiment, the three-stage unloading mechanism includes a pilot-operated relief valve 15, a solenoid ball valve 16, and a mechanical safety valve 17. The first stage (28MPa) opens the pilot-operated relief valve 15; the second stage (30MPa) triggers the solenoid ball valve 16 to quickly unload; and the third stage (32MPa) activates the mechanical safety valve 17 to ensure that the system can safely unload under excessive pressure.

[0025] Specifically, during operation, the servo controller 3 dynamically adjusts the current of the servo pump 4 (frequency range 0-400Hz) based on the pressure signal fed back by the pressure sensor 12, maintaining the system pressure within the set value ±0.2MPa to ensure system pressure stability. For example, if the set pressure is 25MPa, the actual pressure fluctuation range will be between 24.8-25.2MPa. This accuracy ensures that the rolling mill obtains stable hydraulic power during production, avoiding excessive pressure fluctuations that could affect rolling quality and equipment lifespan.

[0026] Dynamic weight adjustment: Based on fuzzy logic, the PID parameters (Kp proportional gain, Ki integral gain, Kd derivative gain) are adjusted in real time according to the pressure deviation (ΔP) and the rate of change (dP / dt). This dynamic adjustment method prioritizes pressure stability (ΔP≤0.5MPa) while also considering energy consumption optimization, enabling the system to achieve good control performance under different operating conditions. Adaptive learning mechanism: By training a neural network model with historical data, it can predict the optimal combination of PID parameters under different operating conditions, continuously learn and optimize the control strategy, reduce overshoot (≤10%), and improve the system's response speed and stability.

[0027] Fault mode switching: When a fault is detected in servo pump 4, the system can automatically switch to the mains frequency backup pump 11 and enable simplified PID control (only the proportional element is retained, Kp=2.5). The rapid fault response mechanism can effectively ensure the basic operation of the system under fault conditions, improving the reliability and safety of the system.

[0028] In this embodiment, the hydraulic component 19 is a rolling mill. Based on the rolling mill speed and rolling force, the pressure demand is predicted, and the displacement of the servo pump 4 is adjusted in advance so that the system can better adapt to changes in the production process and improve the timeliness and accuracy of control.

[0029] The pressure sensor 12 provides closed-loop correction to compensate for pressure fluctuations caused by changes in pipeline resistance, thereby overcoming the shortcomings of feedback control and improving the stability of system pressure.

[0030] Fault mode self-identification Feature database matching: A feature database containing 12 typical faults (such as pipe bursts, pump jamming, and sensor failure) is established. Rapid identification (≤200ms) is achieved by comparing vibration spectrum and pressure waveform. The rapid identification mechanism can detect system faults in a timely manner, buying time for emergency response.

[0031] Tiered alarm Level 1 Alarm (Yellow): When pressure fluctuations exceed the threshold (±0.5MPa), parameter self-tuning is triggered. The early warning mechanism can adjust system parameters in time before a fault occurs, preventing the fault from escalating further.

[0032] Level 2 Alarm (Red): When a critical equipment failure occurs, the system automatically switches to the mains frequency backup pump 11 and locks the faulty pump. This tiered alarm and handling system allows for appropriate measures to be taken based on the severity of the fault, improving system safety and reliability.

[0033] Intelligent pipe burst recognition Pressure gradient detection: When the pressure drops sharply (dP / dt ≥ -5MPa / s) and the flow rate increases abnormally, it is determined to be a pipe rupture, and the corresponding branch valve is closed. The pipe rupture identification method based on pressure gradient and flow rate changes can quickly and accurately detect pipe rupture faults and take corresponding emergency measures to reduce accident losses.

[0034] Feedforward compensation: Frictional resistance is predicted based on the rate of change of rolling force, and the current of servo pump 4 is adjusted in advance. In the event of a tube rupture, this feedforward compensation can further stabilize the system pressure and ensure the safe operation of the system.

[0035] The real-time load demand prediction algorithm uses an LSTM neural network to predict the load demand for the next 10 seconds based on historical rolling data (pressure, flow rate, speed), with an error of ≤5%. The high-precision prediction algorithm enables the system to adjust the operating parameters of servo pump 4 in advance, improving the system's energy efficiency and response speed.

[0036] Dynamic pre-pressure is applied 300ms before the rolls bite the steel, increasing the system pressure to 110% of the set value. This dynamic pre-pressure technology can provide sufficient pressure in advance for the rolling process, reducing pressure fluctuations and improving rolling quality and efficiency.

[0037] Distributed pressure balancing control method Regional pressure coordination: The hydraulic station is divided into multiple control zones, and the pressure in each zone is coordinated via a CAN bus to avoid local overpressure. Traditional hydraulic stations control the pressure in each zone relatively independently, which easily leads to local overpressure. The regional pressure coordination control in this embodiment improves the safety and stability of the system.

[0038] Dynamic flow distribution: The servo pump's displacement is adjusted in real time according to the demand of the oil supply branch pipe, reducing throttling losses. This dynamic flow distribution method can rationally allocate flow according to actual needs, improving system energy efficiency.

[0039] Optimization method for 4-group start-stop sequence of servo pump Dynamic programming is used to calculate the optimal start-stop combination within a 10-second time window, minimizing start-stop losses and idle energy consumption. The dynamic programming method in this embodiment effectively reduces system energy consumption and improves system economy.

[0040] Safety constraints ensure that the available power redundancy is ≥15% at any given time. While ensuring energy saving, the system's safety is fully considered to ensure that the system can still operate normally in case of emergencies.

[0041] Dual-degree-of-freedom control simultaneously adjusts the servo pump's speed (0-3000 rpm) and displacement (0-100 mL / r), achieving wide-range and efficient adjustment. Dual-degree-of-freedom control allows for flexible adjustment according to system requirements, improving system efficiency and adaptability.

[0042] Energy efficiency mapping establishes a three-dimensional map of speed, displacement, and efficiency, enabling real-time selection of the optimal operating point. Through energy efficiency mapping, the system can understand the optimal operating state under different operating conditions in real time and automatically adjust parameters to achieve efficient operation.

[0043] The three-stage unloading mechanism consists of a first stage (28MPa) opening of the pilot-operated relief valve 15, a second stage (30MPa) triggering of the solenoid ball valve 16 for rapid unloading, and a third stage (32MPa) actuation of the mechanical safety valve 17. This multi-stage unloading method can gradually unload according to pressure changes, improving the safety and reliability of unloading.

[0044] The pressure gradient control maintains a slope of 5 MPa / s during the pressure relief process to avoid shock. This embodiment of pressure gradient control effectively protects system equipment.

[0045] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A constant pressure control system for an adaptive hydraulic station in cold rolling of strip steel, characterized in that, include: The display (1) is electrically connected to a PLC controller (2), the PLC controller (2) is electrically connected to a power frequency backup pump (11) and two servo pumps (4), the output ports of the power frequency backup pump (11) and the two servo pumps (4) are connected to an oil supply pipe (20), and the power frequency backup pump (11), servo pumps (4), and oil supply pipe (20) are connected to a pressure sensor (12) and a flow sensor (13). Hydraulic oil tank (5), the hydraulic oil tank (5) is connected to the power frequency standby pump (11) and the servo pump (4), and the hydraulic oil tank (5) is connected to a breather valve (6). Hydraulic component (19) is connected to oil supply pipe (20), and a temperature sensor (7) is connected between hydraulic component (19) and oil supply pipe (20). The outlet of hydraulic component (19) is connected to hydraulic oil tank (5) through heat exchanger (18).

2. The constant pressure control system for an adaptive hydraulic station in cold rolling of strip steel according to claim 1, characterized in that: A servo controller (3) is connected between the servo pump (4) and the PLC controller (2), and a start switch (10) is connected between the power frequency standby pump (11) and the PLC controller (2).

3. The constant pressure control system for an adaptive hydraulic station in cold rolling of strip steel according to claim 1, characterized in that: The power frequency standby pump (11) and the servo pump (4) are connected to an oil filter (9), which is located inside the hydraulic oil tank (5).

4. The constant pressure control system for an adaptive hydraulic station in cold rolling of strip steel according to claim 1, characterized in that: The hydraulic oil tank (5) is also connected to a temperature sensor (7), and the hydraulic oil tank (5) is equipped with a liquid level radar (8).

5. The constant pressure control system for an adaptive hydraulic station in cold rolling of strip steel according to claim 1, characterized in that: A check valve (14) is connected between the power frequency standby pump (11) and the servo pump (4) and the oil supply pipe (20).

6. The constant pressure control system for an adaptive hydraulic station in cold rolling of strip steel according to claim 1, characterized in that: A three-stage unloading mechanism is installed between the oil supply pipe (20) and the hydraulic oil tank (5). When the pressure of the oil supply pipe (20) exceeds the limit, the three-stage unloading mechanism opens to release the pressure of the oil supply pipe (20).

7. The constant pressure control system for an adaptive hydraulic station in cold rolling of strip steel according to claim 6, characterized in that: The three-stage unloading mechanism includes a pilot-operated relief valve (15), a solenoid ball valve (16), and a mechanical safety valve (17).

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