A 300t converter RSW hydraulic servo control method

Abstract

The application discloses a kind of 300t converter RSW hydraulic servo control method, it is related to metallurgical industry RSW hydraulic transmission and automatic control technical field, to solve the problems of servo controller component aging, poor precision, large response deviation, influence furnace mouth micro-positive pressure regulation, high maintenance replacement cost;The application includes using PLC controller to replace original servo controller, and using current-driven hydraulic servo valve with consistent installation mode and installation size to replace original voltage type hydraulic servo valve, to avoid signal interference and pressure drop, while modifying PLC analog output module to adapt to the instruction signal of the replaced current-driven hydraulic servo valve;After connecting servo valve and PLC, ensure normal signal transmission, according to control requirements and parameters, write control program, carry out system debugging and optimization, until servo valve and hydraulic cylinder response speed and running stability meet the demand;The application can reduce spare parts procurement cost, and can meet the RSW response and stability requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of RSW hydraulic transmission and automatic control technology in metallurgical industry, in particular to a 300t converter RSW hydraulic servo control method. BACKGROUND

[0002] Currently, the flue gas dust removal and coal gas recovery system of the 300t converter in Ma Steel No.4 Steel Rolling Plant is Oxygen Converter Gas Recovery System, referred to as OG method. The throat adjustment thereof adopts a ring slit washer, referred to as RSW, which is driven and controlled by three lifting hydraulic cylinders, embedded in the dust removal tower, and synchronously throttled to adjust the airflow in the dust removal pipeline. It is the core hydraulic servo closed-loop control system of the converter and the furnace mouth micro-positive pressure adjustment technology. During production, the RSW opening degree is adjusted in time according to the change of the converter blowing flue gas generation amount to maintain the micro-positive pressure of the furnace mouth, which has the advantage of fast response.

[0003] The furnace mouth micro-positive pressure adjustment technology mainly consists of an inner hydraulic servo position control loop and an outer pressure adjustment loop. The furnace mouth pressure is set to micro-positive pressure, which is subtracted from the actual feedback furnace mouth pressure. The position signal output by the pressure PID algorithm is used as the given signal of the servo position control loop. The difference between the given signal and the hydraulic cylinder position feedback signal is calculated, and the voltage signal is calculated and transmitted by the servo controller to control the servo valve. The servo valve controls the hydraulic flow and moves the hydraulic cylinder to the specified position, thereby eliminating the furnace mouth pressure deviation caused by the change of the converter blowing flue gas generation amount and maintaining the constant micro-positive pressure of the furnace mouth.

[0004] The original design adopts a hardware servo controller of foreign patent technology. The servo controller is placed in the field hydraulic valve table to control the servo valve and the servo closed-loop adjustment of the hydraulic cylinder. Since 2007, the servo controller has been in use. The components in the circuit board of the servo controller have aged, the control accuracy has gradually deteriorated, the response deviation has gradually increased, and the micro-positive pressure adjustment of the furnace mouth has been affected. At the same time, the voltage loop signal of the servo controller is disturbed by the electromagnetic environment, and the hydraulic cylinder body controlled by the servo controller often appears irregular and violent shaking, and resonance phenomenon occurs, which causes the fixed end of the oil cylinder to tear, the oil cylinder body to leak oil, and the steel structure platform to open weld, seriously affecting the stable operation of the converter OG. However, since the servo controller model is old and faces production stoppage, the cost of imported spare parts for maintenance and replacement is high. However, the existing servo valve model is Mod:D661-4121E, Type:P30HAWA4NSM2HO. If the original servo controller is not used, it is difficult to effectively and stably control it. Drastic reform is also not conducive to process development and cost control, and may even cause a chain reaction. Therefore, a 300t converter RSW hydraulic servo control method is needed to solve this problem. SUMMARY

[0005] The 300t converter RSW hydraulic servo control method aims to solve the problems of servo controller component aging, poor precision, large response deviation, affecting the furnace mouth micro-positive pressure regulation, and high maintenance and replacement cost.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions: a 300t converter RSW hydraulic servo control method, wherein the servo valve used by the lifting hydraulic cylinder of RSW is a voltage type hydraulic servo valve, the controller thereof is a special servo controller, the original voltage type hydraulic servo valve is replaced by a current driven type hydraulic servo valve with consistent installation method and size, long distance signal transmission interference and pressure drop are avoided, and the PLC analog output module is reformed to adapt to the instruction signal of the replaced current driven type hydraulic servo valve; after the servo valve and the PLC are connected, the signal transmission is ensured to be normal, the control program is written according to the control requirements and parameters, the system is debugged and optimized until the response speed and running stability of the servo valve and the hydraulic cylinder meet the requirements.

[0007] Preferably, the control requirements and parameters include position, speed and frequency.

[0008] Preferably, the process of connecting the servo valve and the PLC includes configuring the IO port and interface, input and output signal and cylinder sensor signal related to servo control in the programming software of the PLC.

[0009] Preferably, the control program is written for real-time monitoring and control of the running state of the servo system, specifically including position detection, furnace mouth pressure control and hydraulic cylinder position loop control.

[0010] Preferably, the voltage type hydraulic servo valve is Mod:D661-4121E, Type:P30HAWA4NSM2HO, the instruction signal is ±10v, the output signal is 4-20mA, the replaced current driven type hydraulic servo valve is Mod:D661-4121E, Type:P30HAWA4NSX2HO, the instruction signal is ±10mA, and the output signal is 4-20mA; the PLC analog output module is changed to ±10mA.

[0011] Compared with the prior art, the present application has the following advantages:

[0012] 1. The 300t converter RSW hydraulic servo control method uses the existing hydraulic and electrical configuration, realizes the direct control of the servo valve and the hydraulic cylinder by the PLC through the minimum modification, and strips the intermediate control link, i.e. the imported hardware servo controller, which not only reduces the spare part procurement cost, but also meets the rapid response working condition of RSW.

[0013] 2. The 300t converter RSW hydraulic servo control method does not require the purchase of expensive equipment or the redesign of the installation structure during the modification process. It does not damage the original equipment. Since we have full control technology, there is no need to hire foreign personnel at high prices for maintenance, repair, and replacement. At the same time, it is of great significance for the future open source development of technology. Attached Figure Description

[0014] Figure 1 The existing servo controller control schematic;

[0015] Figure 2 This is a schematic diagram of the PLC control principle of the present invention;

[0016] Figure 3 Example 1 of the existing servo controller converter RSW cylinder position feedback trend diagram;

[0017] Figure 4 Example 2 of the existing servo controller converter RSW cylinder position feedback trend diagram;

[0018] Figure 5 This is a partial example of the PLC-controlled converter RSW cylinder position feedback trend diagram of the present invention.

[0019] Figure 6 This is the second example of the PLC-controlled converter RSW cylinder position feedback trend diagram of the present invention. Detailed Implementation

[0020] like Figure 1 As shown, this invention addresses the situation where the servo valve used in the lifting hydraulic cylinder of the RSW is a voltage-type hydraulic servo valve, and its controller is a dedicated servo controller. The modification of this invention encountered many difficulties during the exploration process. Initially, although replacing the servo controller with a PLC was considered, extensive testing failed to meet the requirements for fast response and stability, making the modification impossible. Therefore, it was thought that the problem might be a fault in the valve itself. However, even after replacing the servo valve, stable control by the PLC could not be achieved, causing the modification project to stall. After several meetings and hypothetical discussions, a new feasible direction was finally found: a hydraulic servo control method for a 300t converter RSW. (See reference...) Figure 2 :

[0021] Replace the original servo controller with a PLC controller, and replace the original voltage-type hydraulic servo valve with a current-driven hydraulic servo valve with the same installation method and installation size to avoid signal interference and voltage drop, especially to avoid long-distance transmission interference and voltage attenuation of PLC signals.

[0022] In addition to replacing the PLC and servo valve mentioned above, the PLC analog output module should also be modified to adapt to the command signals of the replaced current-driven hydraulic servo valve.

[0023] We also study and analyze the circuit diagram principle, control algorithm and operating parameters of imported RSW servo controller, its specific control requirements and parameters include position, speed, frequency.

[0024] After the above steps are completed, the servo valve and PLC can be connected to ensure normal signal transmission. Specifically, the IO port and interface related to servo control, input and output signals, and cylinder sensor signals are configured in the programming software of PLC.

[0025] After the connection is completed, the control program can be written, including real-time monitoring of the running state of the servo system and control, including: position detection, furnace opening pressure control, hydraulic cylinder position loop control.

[0026] After the program is written, the system is debugged and optimized until the response speed and running stability of the servo valve and hydraulic cylinder meet the requirements.

[0027] Example:

[0028] The RSW original voltage type hydraulic servo valve of the three 300t converters in Ma Steel No.4 Steel Rolling Plant is Mod:D661-4121E, Type:P30HAWA4NSM2HO, the command signal is ±10v, the output signal is 4-20mA, and it uses 12 imported servo controllers as "neck" devices.

[0029] The replaced current-driven hydraulic servo valve is Mod:D661-4121E, Type:P30HAWA4NSX2HO, the command signal is ±10mA, and the feedback signal is 4-20mA; to match the new servo valve, the PLC analog output module is changed from the original 4-20mA to ±10mA.

[0030] After the replacement of the hardware equipment is completed, the circuit diagram principle, control algorithm and operating parameters of the imported RSW servo controller are studied and analyzed, the PLC programming software control parameters are set, the control requirements of the servo system are determined according to the actual requirements, including position, speed, frequency, and the corresponding control parameters are set.

[0031] The servo valve and PLC are connected to ensure normal signal transmission. Configure IO port and interface: configure the IO port and interface related to servo control, input and output signals, and cylinder sensor signals in the programming software of PLC.

[0032] Using the programming software of PLC, according to the control requirements and parameters, the corresponding program logic and PID algorithm are written, including real-time monitoring and control: through the PLC program, the running state of the servo system is monitored and controlled in real time, including RSW position and furnace opening pressure detection, furnace opening pressure control, hydraulic servo position loop control.

[0033] After completing the program writing, system debugging and optimization are carried out, the pressure regulation outer loop proportional parameter is 1, the integral parameter is 2; the servo position control inner loop proportional parameter is 15, the integral parameter is 0, so as to ensure the fast response and stable operation of the servo system.

[0034] Figure 3 And Figure 4 In order to improve the existing servo controller converter RSW oil cylinder position feedback trend chart, the white circle part in the middle indicates the position feedback of the three oil cylinders, and it can be seen from the figure that the oil cylinder appears irregular and violent shaking, the steel structure in the working field will produce resonance phenomenon, which seriously affects the stable operation of the converter OG.

[0035] Figure 5 And Figure 6 The PLC control converter RSW oil cylinder position feedback trend chart after the transformation of the application is shown in the figure, and there is no obvious shaking phenomenon, and the operation is stable and the response is normal.

[0036] In this embodiment, by using the existing hydraulic and electrical configuration, through the minimum transformation, the PLC directly controls the servo valve and the hydraulic cylinder, and the intermediate control link is stripped, and the rapid response of the RSW is met; the imported controller hardware is completely replaced in function, the stable control of the furnace opening micro-positive pressure is ensured; a large amount of spare parts cost is saved in economy, the unit price of the imported controller is 28.91 million, the total amount of three converter installed machines is 12, a total of 28.91*12=346.92 million is saved, and there is no need to invite foreign personnel to maintain, repair and replace at high cost, and the development of open source technology in the future is of great significance.

[0037] The above is only a preferred embodiment of the application, but the protection scope of the application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be limited by the protection scope defined by the claims.

[0038] The details of the application not described are the known technology of the person skilled in the art.

Claims

1. A 300t converter RSW hydraulic servo control method, wherein the servo valve adopted by the lifting hydraulic cylinder of the RSW is an electric voltage type hydraulic servo valve, and the controller thereof is a special servo controller, characterized in that: The original servo controller is replaced by a PLC controller, and a current-driven hydraulic servo valve with consistent installation mode and installation size is used to replace the original voltage-driven hydraulic servo valve, so as to avoid signal interference and pressure drop, and the PLC analog output module is reformed to adapt to the instruction signal of the replaced current-driven hydraulic servo valve; after the servo valve and the PLC are connected, the signal transmission is ensured to be normal, the control program is written according to the control requirements and parameters, the system is debugged and optimized, and until the response speed and running stability of the servo valve and the hydraulic cylinder meet the requirements; The process of connecting the servo valve and the PLC comprises: configuring IO ports and interfaces, input and output signals, and cylinder sensor signals related to servo control in the programming software of the PLC; The control program comprises: real-time monitoring and control of the running state of the servo system, specifically comprising: position detection, furnace opening pressure control, and hydraulic cylinder position loop control; The voltage-driven hydraulic servo valve is of Mod:D661-4121E, Type:P30HAWA4NSM2HO, the instruction signal is ±10v, the feedback signal is 4-20mA, the replaced current-driven hydraulic servo valve is of Mod:D661-4121E, Type:P30HAWA4NSX2HO, the instruction signal is ±10mA, and the feedback signal is 4-20mA; the PLC analog output module is changed to ±10mA.

2. The hydraulic servo control method for 300t converter RSW according to claim 1, characterized in that: The control requirements and parameters comprise position, speed, and frequency.

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