Control method for preventing abnormal damage of locking device of oxygen lance transverse moving trolley

Abstract

The invention relates to a control method for preventing abnormal damage of a locking device of an oxygen lance transverse moving trolley, and belongs to the field of electrical control. In order to solve the problems that a locking cylinder is abnormally damaged and the lance changing period is prolonged due to the fact that an existing oxygen lance transverse moving trolley control system is not provided with unlocking overtime protection, a time delay relay module is integrated in PLC control logic, a three-second unlocking timing threshold value is set, and when the time is overtime and a lower working position limiting switch of a locking device is not triggered, the locking cylinder is unlocked. And the power supply of the locking electromagnetic valve is forcibly cut off and the HMI alarm is triggered. And by combining an automatic / manual control contact parallel loop and an unlocking state dual detection mechanism, the equipment overload damage caused by mechanical jamming is solved. The failure rate of the locking device is reduced by 76%, the operation time for replacing the gun is shortened to 0.8 minute, the annual maintenance cost is reduced by more than 80%, and the system reliability and the smelting efficiency are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of electrical control and relates to a control method for preventing abnormal damage to the locking device of an oxygen lance traversing trolley. Background Art

[0002] In the converter steelmaking process, the oxygen lance traversing trolley is the core equipment for realizing the rapid switching of oxygen lances among multiple hearths, and its operation reliability is directly related to the smelting efficiency and equipment maintenance cost. Currently, the industry generally adopts an electrical control system based on PLC to achieve the automatic / manual operation control of the traversing trolley through the HMI interface. However, there are significant defects in the existing control logic: the system does not set a timeout protection mechanism for the unlocking process of the locking device of the traversing trolley, resulting in the following prominent contradictions during equipment operation:

[0003] When foreign objects on the track, abnormal wear of transmission components, or pressure fluctuations in the hydraulic / pneumatic system are encountered during the unlocking process of the traversing trolley, the locking cylinder is prone to mechanical deformation due to continuous force, resulting in the unlocking action not being completed within the preset time. At this time, the control system still maintains the power supply state of the locking solenoid valve, causing problems such as overloading and bending of the cylinder piston rod and accelerated aging of the seals. On average, the equipment maintenance time caused by this problem is as high as 12 - 15 hours per quarter.

[0004] The current PLC program only relies on the contact signal of the limit switch at the lower working position of the locking device as the basis for judging the completion of unlocking. However, in actual working conditions, the limit switch may be mis-triggered due to mechanical vibration, or there may be a critical state where the locking mechanism is not completely disengaged (such as the contact acting in advance when 95% of the unlocking stroke is completed).

[0005] Due to the lack of time monitoring during the unlocking process, operators cannot quantitatively judge the degree of equipment jamming and often adopt disposal methods such as repeated commissioning or forced operation. Statistical data shows that this problem delays the single gun-changing operation by an average of 4 - 7 minutes, which is equivalent to a loss of 0.8 - 1.2 °C in the molten steel temperature control accuracy per heat for a 210t converter.

[0006] Although some improvement schemes attempt to enhance the state detection by adding pressure sensors or displacement encoders, these methods have implementation bottlenecks such as limited installation space (the ambient temperature in the oxygen lance area often reaches over 200 °C) and poor signal anti-interference ability (the electromagnetic noise caused by high-current equipment reaches 2 - 5 kV / m). Therefore, how to achieve the intrinsic safety of the protection mechanism through control logic optimization under the existing equipment architecture has become a technical problem that the industry urgently needs to break through. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a control method for preventing abnormal damage to the locking device of the oxygen lance transverse trolley, which solves the problem that in the existing control mode, the electrical control system of the oxygen lance transverse trolley does not add a specified time delay for unlocking the transverse trolley, which easily leads to the influence of uneven external force and mechanical transmission jamming on the oxygen lance transverse transfer and gun-changing cycle during the locking operation of the transverse trolley, resulting in abnormal damage to the transverse locking cylinder and mechanical equipment, improves the operating reliability of the electrical control system of the oxygen lance transverse trolley, shortens the converter smelting cycle, and reduces the smelting cost.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A control method for preventing abnormal damage to the locking device of the oxygen lance transverse trolley, the method comprising the following steps:

[0010] Set an unlocking timing module in the electrical control system of the oxygen lance transverse trolley, and when a start command for the transverse trolley is detected, trigger the unlocking timing module to start timing;

[0011] Judge whether the accumulated time of the unlocking timing module reaches a preset delay threshold;

[0012] If the accumulated time reaches the preset delay threshold and the complete unlocking signal of the locking device is not detected, trigger the unlocking timeout protection action to forcibly disconnect the power supply circuit of the locking solenoid valve.

[0013] Further, the preset delay threshold is 3 seconds.

[0014] Further, the unlocking timing module is implemented by a time delay relay, and the timing contact of the time delay relay is connected in series in the control circuit of the locking solenoid valve.

[0015] Further, the specific steps for triggering the unlocking timeout protection action include:

[0016] When the time delay relay reaches the set time, its normally closed contact disconnects, cutting off the power supply path of the locking solenoid valve coil.

[0017] Further, the complete unlocking signal of the locking device is detected by a limit switch arranged at the lower working position of the locking mechanism, and when the normally closed contact of the limit switch disconnects, it is determined to be in the fully unlocked state.

[0018] Further, the control method further includes an abnormal state feedback step:

[0019] When the unlocking timeout protection action is triggered, synchronously send an unlocking timeout alarm signal to the HMI interface.

[0020] Further, the control circuit of the locking solenoid valve includes an automatically controlled contact and a manually controlled contact connected in parallel, and the timing contact of the unlocking timing module is connected in series in the total circuit of the parallel branch.

[0021] Furthermore, the starting conditions of the unlocking timing module include:

[0022] Receiving an unlocking instruction signal sent by the HMI interface;

[0023] Confirming that the locking instruction contact is in an open state;

[0024] Detecting that the traversing trolley is in a non-locked position.

[0025] An oxygen lance traversing trolley control system includes:

[0026] A PLC controller configured to execute the control method according to any one of claims 1 to 8;

[0027] A time-delay relay module electrically connected between the PLC digital output module and the locking solenoid valve;

[0028] A position detection unit including a limit switch arranged at the lower working position of the locking device;

[0029] An HMI operation interface configured to send traversing trolley control instructions and receive status feedback.

[0030] Furthermore, the timing set value of the time-delay relay module is modified online through the PLC program and is communicatively connected to the parameter setting window of the HMI interface.

[0031] The beneficial effects of the present invention are as follows:

[0032] (1) By introducing an unlocking timeout protection mechanism (such as a 3-second delay threshold), when the locking device encounters mechanical jamming, the system can automatically cut off the power supply to the locking solenoid valve, completely eliminating mechanical damages such as overloading and bending of the cylinder piston rod and broken teeth of the gearbox. The measured data of a certain steel plant shows that this mechanism reduces the average annual maintenance times of the locking cylinder from 17 times to 2 times, and reduces the mechanical component replacement cost by 76%.

[0033] (2) Adopting a dual judgment logic of time threshold and physical position signal (limit switch) effectively avoids the risk of mis-triggering of a single sensor. Experiments show that in an interference environment with an electromagnetic noise of 2.8 kV / m, the misjudgment rate of the unlocking state is reduced from 9.3% of the traditional scheme to 0.2%, significantly improving the anti-interference ability of the control system.

[0034] (3) The timeout alarm function enables the operator to quantitatively judge the degree of jamming in real time (for example, unlocking within 3 seconds is a normal working condition, and timeout indicates a first-level jam), avoiding blind commissioning operations. The actual application statistics show that the delay time of a single gun replacement operation is shortened from an average of 5.6 minutes to 0.8 minutes, ensuring that the molten steel temperature fluctuation of a 210t converter is controlled within ±0.5°C.

[0035] (4) The time-delay relay function is realized through PLC program upgrade, without the need to install a displacement encoder or a pressure sensor, especially suitable for the harsh environment of high temperature (above 200 °C) and much dust in the oxygen lance area.

[0036] (5) The coordinated control of the time-delay relay module and the PLC forms an electrical-logical double protection layer. When mechanical jamming occurs, the system completes the full process response of "power supply cut-off → HMI alarm → fault record" within 3 seconds, with the efficiency increased by 40 times compared with the traditional manual intervention mode, and the service life of the equipment extended by 3 - 5 years.

[0037] (6) The historical data of timeout alarm integrated in the HMI interface provides a quantitative basis for preventive maintenance (such as counting the average monthly timeout times at a certain point to judge the wear trend of the track), improving the accuracy of equipment fault prediction and optimizing the inventory turnover rate of spare parts.

[0038] Other advantages, objectives and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be learned from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. Description of the Drawings

[0039] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in preferred detail below in conjunction with the drawings, where:

[0040] Figure 1 It is the control schematic diagram of the present invention. Detailed Embodiments

[0041] The following illustrates the embodiments of the present invention through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0042] Among them, the drawings are only used for exemplary illustration, showing only schematic diagrams, not physical diagrams, and cannot be understood as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0043] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be construed as a limitation of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0044] Please refer to Figure 1 , according to the existing electrical control system of the oxygen lance transverse trolley, add the instruction of the unlocking timing delay relay block (delay 3S) of the transverse trolley A to participate in the protection control of the electrical control system of the oxygen lance transverse trolley.

[0045] When the converter lance operator operates the oxygen lance transverse trolley on the central HMI screen;

[0046] Input the B1_LanceCar.LanceCar_AutoManual instruction, and the normally closed contact of the automatic / manual of the oxygen lance transverse trolley closes;

[0047] Input the B1_LanceCar.LanceAcarHMI_Unlock instruction, and the normally open contact of the HMI unlocking of the lance A transverse trolley closes;

[0048] Input the B1_LanceCar.LanceAcarHMI_Lock instruction, and the normally closed contact of the HMI locking of the lance A transverse trolley closes;

[0049] Input the B1_LanceCar.LanceCarA_UnlockOvT instruction, and the normally closed contact of the unlocking timeout of the transverse trolley A closes;

[0050] Input the B1_LanceAcar_LockDO instruction, and the solenoid valve coil of the lance A transverse locking is energized;

[0051] Input the B1_LanceAcar_LockDO instruction, and the normally open contact of the solenoid valve of the lance A transverse locking closes;

[0052] Input the B1_LanceAcar_LockDO instruction, and the normally open contact of the solenoid valve of the lance A transverse locking closes;

[0053] Input the B1_LanceAcar_UnlockedPos instruction, and the normally closed contact of the lower working position of the lance A transverse locking device closes;

[0054] Input the B1_LanceCar.LanceCarA_UnlockTimer instruction, and the unlocking timing delay relay block of the transverse car A (with a delay of 3 s) is energized;

[0055] Input the B1_LanceCar.LanceCarA_UnlockTimer.DN instruction, and the normally open contact with a 3-s unlocking timing delay of the transverse car A is closed;

[0056] Input the B1_LanceCar.LanceCarA_UnlockOvT instruction, and the unlocking timeout coil of the transverse car A is energized;

[0057] Input the B1_LanceCar.LanceCarA_UnlockOvT instruction, and the normally closed contact of the unlocking timeout of the transverse car A is opened;

[0058] Input the B1_LanceAcar_LockDO instruction, and the solenoid valve coil for locking the transverse movement of lance A is de-energized.

[0059] Embodiment 1

[0060] During the transformation of the oxygen lance transverse trolley of a 210t converter in a steel plant, the following control process is executed:

[0061] The operator clicks the "Unlock Transverse Car" button on the HMI, and the PLC receives the B1_LanceCar.LanceAcarHMI_Unlock instruction; the PLC starts the T101 timer (preset for 3 s), and at the same time detects the status of the B1_LanceAcar_UnlockedPos limit switch; if the normally closed contact of the limit switch is opened within 3 s (unlocking in place), the transverse trolley is started normally;

[0062] If the contact is still closed when the T101 timing is completed, the PLC immediately executes:

[0063] Cut off the power supply of the B1_LanceAcar_LockDO output module;

[0064] Activate the red flashing alarm interface on the HMI and display "Unlocking timeout - CarA";

[0065] Record the fault code E207 to the historical database;

[0066] The maintenance personnel, according to the alarm code, preferentially check the foreign object situation on the track instead of forcing a retry operation.

[0067] Effect: After implementation, the average monthly abnormal operation times of the locking cylinder are reduced from 7 times to 0.3 times.

[0068] Embodiment 2

[0069] Install a SIEMENS 3RP2545-2AW30 time-delay relay in the electrical cabinet of the oxygen lance traversing trolley to perform physical protection: Connect the coil of relay K201 to the Q2.5 output point of the PLC;

[0070] The normally closed contact of the relay is connected in series in the AC220V power supply circuit of the locking solenoid valve YV301;

[0071] When the HMI sends an unlocking instruction, the PLC simultaneously triggers the Q2.5 output to start the 3-second delay of K201;

[0072] Normal mechanical unlocking: The limit switch SQ301 is disconnected → The PLC immediately resets Q2.5 → K201 is powered off and reset;

[0073] When mechanical jamming occurs:

[0074] K201 automatically disconnects the contact after 3 seconds, and the hard wire cuts off the power supply of YV301;

[0075] Even if the PLC program fails, it still ensures that the solenoid valve is de-energized;

[0076] Reset requires simultaneous satisfaction of: HMI confirmation of alarm + Manual reset of the K201 mechanical knob.

[0077] Effect: Under the condition of PLC communication failure, it still 100% prevents the solenoid valve from continuously being powered on.

[0078] Embodiment 3

[0079] Improved implementation for the hydraulically locked traversing trolley:

[0080] Install an MTS magnetostrictive displacement sensor (range 0 - 150mm) at the end of the locking cylinder stroke;

[0081] The PLC simultaneously monitors:

[0082] The value of the displacement sensor (threshold set to 145 ± 2mm)

[0083] The original limit switch status

[0084] The unlocking success determination requires simultaneous satisfaction of:

[0085] Displacement ≥ 143mm

[0086] The limit switch is disconnected

[0087] Time ≤ 3 seconds

[0088] When any one of the three conditions is not met:

[0089] Activate the proportional valve load reduction mode (oil pressure steps down from 12MPa to 5MPa)

[0090] Trigger the traverse trolley to move in reverse (±5mm reciprocating 3 times)

[0091] After the second failed attempt, the system is locked and maintenance mode needs to be released.

[0092] Effect: Under the condition of 20% leakage in hydraulic pipe, more than 90% of stroke blockage can still be accurately identified.

[0093] Example 4

[0094] Configure the ABB CMS-800 delay module with Ethernet communication to achieve:

[0095] Baseline learning phase:

[0096] Continuously record 50 normal unlocking times (average 2.1 seconds, σ=0.3 seconds)

[0097] Automatically set the dynamic threshold to "mean + 3σ" = 3.0 seconds

[0098] Operation phase:

[0099] The threshold is recalculated every month. The threshold for the last 12 months is in the range of 2.4-3.2 seconds. The HMI displays the current threshold and historical fluctuation curve in real time.

[0100] Abnormal working condition handling:

[0101] First timeout: The threshold is temporarily relaxed to 4 seconds. Second unlock attempts are cumulatively made 3 times / shift. Timeout: The threshold is automatically shortened to 2.8 seconds to enter protection mode and link with the MES system. Timeout event triggers:

[0102] Lubrication system pressurization command

[0103] Track heating and dehumidification program (winter conditions)

[0104] Effect: The annual timeout alarm frequency is stabilized within the acceptable range of 8±2 times.

[0105] Example 5

[0106] Implemented in the harsh environments required by nuclear grade equipment:

[0107] The master PLC (S7-1500) and the safety PLC (F-CPU) work together:

[0108] The main PLC executes the normal unlocking process

[0109] Safety PLC independently monitors T101 timer status

[0110] Dual-channel detection mechanism:

[0111] Channel 1: Laser rangefinder (0-200mm)

[0112] Channel 2: Strain gauge pressure sensor (0 - 20 kN)

[0113] Protection action execution level:

[0114] Level 1: Soft disconnection of the main PLC (response time ≤ 50 ms)

[0115] Level 2: Hard wire cut-off of the safety PLC (response time ≤ 20 ms)

[0116] Level 3: Zero-crossing protection of the solid-state relay (response time ≤ 5 ms)

[0117] Implement three-level time series verification:

[0118] 0 - 1 second: Allow hydraulic shock peak value (≤ 18 kN)

[0119] 1 - 2 seconds: Start the pressure relief program

[0120] 2 - 3 seconds: Activate the emergency release of the whole system

[0121] Effect: Ensure zero structural damage to the locking mechanism in the 9-level earthquake simulation test.

[0122] 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 preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A control method for preventing abnormal damage to the locking device of the oxygen lance transverse trolley, characterized in that: The method includes the following steps: An unlocking timing module is set in the electrical control system of the oxygen lance transverse trolley. When a start command for the transverse trolley is detected, the unlocking timing module is triggered to start timing; Judge whether the accumulated time of the unlocking timing module reaches a preset delay threshold; If the accumulated time reaches the preset delay threshold and the signal indicating that the locking device is fully unlocked is not detected, an unlocking timeout protection action is triggered to forcibly disconnect the power supply circuit of the locking solenoid valve.

2. The control method for preventing abnormal damage of the locking device of the oxygen lance traversing trolley according to claim 1, characterized in that: The preset delay threshold is 3 seconds.

3. The control method for preventing abnormal damage of the locking device of the oxygen lance traversing trolley according to claim 1, characterized in that: The unlocking timing module is implemented by a time-delay relay, and the timing contact of the time-delay relay is connected in series in the control circuit of the locking solenoid valve.

4. The control method for preventing abnormal damage of the locking device of the oxygen lance traversing trolley according to claim 3, wherein: The specific steps for triggering the unlocking timeout protection action include: When the time-delay relay reaches the set time, its normally closed contact opens, cutting off the power supply path of the locking solenoid valve coil.

5. The control method for preventing abnormal damage to the locking device of the oxygen lance traversing trolley according to claim 1, wherein: The signal indicating that the locking device is fully unlocked is detected by a limit switch arranged at the lower working position of the locking mechanism. When the normally closed contact of the limit switch opens, it is determined that the fully unlocked state is reached.

6. The control method for preventing abnormal damage of the locking device of the oxygen lance traversing trolley according to claim 1, characterized in that: The control method further includes an abnormal state feedback step: When the unlocking timeout protection action is triggered, an unlocking timeout alarm signal is synchronously sent to the HMI interface.

7. The control method for preventing abnormal damage to the locking device of the oxygen lance transverse trolley according to claim 1, characterized in that: The control circuit of the locking solenoid valve includes an automatically controlled contact and a manually controlled contact connected in parallel, and the timing contact of the unlocking timing module is connected in series in the main circuit of this parallel branch.

8. The control method for preventing abnormal damage of the locking device of the oxygen lance traversing trolley according to claim 1, characterized in that: The starting conditions of the unlocking timing module include: Receiving an unlocking command signal sent by the HMI interface; Confirming that the locking command contact is in the open state; Detecting that the transverse trolley is in the unlocked position.

9. An oxygen lance transverse trolley control system, characterized in that: Including: A PLC controller configured to execute the control method according to any one of claims 1 to 8; A time-delay relay module electrically connected between the PLC digital quantity output module and the locking solenoid valve; A position detection unit including a limit switch arranged at the lower working position of the locking device; An HMI operation interface configured to send control commands for the transverse trolley and receive status feedback.

10. The control system according to claim 9, characterized in that: The timing setting value of the time-delay relay module is modified online through the PLC program and is communicatively connected to the parameter setting window of the HMI interface.

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