Pneumatic stop valve

Abstract

The invention discloses a pneumatic stop valve, belongs to the technical field of valves, and solves the problems that when the pneumatic stop valve acts once per minute at the temperature of 380 DEG C, a valve rod is oxidized and collapsed due to high-temperature filler, the valve rod is abraded by catalyst particles, the valve rod is slightly bent by 0.08 mm due to the pressure difference of 0.5 MPa, sealing and hiding of the valve rod are invalid, and closing lags. Comprising a valve body, a support installed on the valve body through a valve cover, a corrugated pipe fixedly connected into the support, a pneumatic actuator fixedly connected to the upper end of the support and a valve rod, the valve rod is connected into the corrugated pipe in a sliding mode, and the upper end of the valve rod is in transmission connection with the movable end of the pneumatic actuator. All the structures keep efficient sealing, the displacement direction of all the structures is limited, meanwhile, the displacement and strain data of the valve rod are monitored, the bending amount is calculated through multi-source data fusion for position compensation, and meanwhile the pneumatic execution module is controlled to complete S-curve optimized valve opening and closing actions.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and in particular to a pneumatic stop valve. Background Art

[0002] A pneumatic globe valve is a control device consisting of a pneumatic actuator and a globe valve body. Compressed air drives the actuator, causing the valve core to rise and fall along the axis of the valve seat, effectively shutting off or connecting the pipeline medium. Its core relies on the tight fit between the valve core and the valve seat to ensure a tight seal, reliable shutoff, and fast response. It is widely used in the chemical, energy, and other fields, suitable for remote control and high-frequency switching scenarios, and can effectively control the flow of media such as liquids, gases, and steam.

[0003] In the catalyst riser of the catalytic cracking unit of a refinery, the pneumatic stop valve is a key emergency shut-off component for high-temperature, high-frequency media containing abrasive catalyst powder. Due to its pneumatic lifting valve stem structure being exposed to harsh working conditions, it may fail.

[0004] High temperature causes the flexible graphite packing to oxidize and form invisible internal collapsed micro-gaps. The high-frequency opening and closing action once per minute accelerates the attenuation of the packing compression force by 20%. At the same time, catalyst particles with a particle size of 5-20μm invade the stuffing box and grind out axial scratches of more than 10μm on the surface of the valve stem.

[0005] What is more serious is that the 0.5MPa pressure difference that the pneumatic stop valve withstands at the moment of closing causes the valve stem to bend slightly. These progressive damages work together to increase the friction coefficient of the packing, resulting in the thrust margin of the pneumatic actuator being completely offset.

[0006] When the pressure fluctuation of the device triggered an emergency shutdown, the pneumatic stop valve could not be completely sealed due to the closure delay, and the high-temperature hydrocarbon-containing catalyst powder leaked from the tiny opening gap. It spontaneously combusted when it encountered air and ignited the residual hydrogen leaked from the stuffing box maintenance, causing a flash explosion accident.

[0007] Therefore, a pneumatic stop valve is proposed to solve or alleviate the above problems. Summary of the Invention

[0008] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a pneumatic stop valve.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions: A pneumatic stop valve comprises a valve body, a bracket mounted on the valve body through a valve cover, a bellows fixedly connected in the bracket, a pneumatic actuator fixedly connected to the upper end of the bracket, and a valve stem, wherein the valve stem is slidably connected in the bellows, and the upper end of the valve stem is transmission-connected to the movable end of the pneumatic actuator, the lower end of the valve stem is fixedly connected to a valve core located in the valve body, the pneumatic actuator is connected to an air pump through an air circuit, the pneumatic execution module is connected to the air circuit, and further comprises a pneumatic execution system, the pneumatic execution system is electrically connected to the pneumatic actuator and the pneumatic execution module, the pneumatic execution system monitors the valve stem displacement and strain data in real time, and the pneumatic execution system calculates the bending amount and performs position compensation through multi-source data fusion, while completing S-curve optimized valve opening and closing actions and performing packing wear prediction and valve stem fatigue analysis to trigger maintenance warnings.

[0010] Preferably, the pneumatic execution system includes a power management module, a main controller module, a valve position monitoring module, a strain detection module, a piezoelectric compensation module, and a safety protection module. The power management module supplies power to each module. The displacement signal output end of the valve position monitoring module is connected to the first analog-to-digital conversion interface of the main controller module, the strain signal output end of the strain detection module is connected to the second analog-to-digital conversion interface of the main controller module, the control signal input end of the piezoelectric compensation module is connected to the digital-to-analog conversion output end of the main controller module, the control signal input end of the pneumatic execution module is connected to the pulse width modulation output end of the main controller module, the monitoring signal input end of the safety protection module is connected to the alarm output end of the valve position monitoring module and the alarm output end of the strain detection module, and the protection action output end of the safety protection module is connected to the emergency cut-off circuit of the pneumatic execution module.

[0011] Preferably, the main controller module includes an STM32H743 microcontroller, a Spartan-6 field programmable gate array, an IS61WV51216 static memory, an MCP2551 controller area network transceiver, and a 25MHz crystal oscillator. The serial peripheral interface clock pin of the STM32H743 microcontroller is connected to the clock input of the AD7794 analog-to-digital converter in the strain detection module, the serial peripheral interface master input and slave output pin of the STM32H743 microcontroller are connected to the data output of the AD7794 analog-to-digital converter in the strain detection module, the serial peripheral interface master output and slave input pin of the STM32H743 microcontroller are connected to the data input of the AD7794 analog-to-digital converter in the strain detection module, the first digital-to-analog conversion output pin of the STM32H743 microcontroller is connected to the non-inverting input of the PA94 high-voltage operational amplifier in the piezoelectric compensation module, and the first input and output pin of the Spartan-6 field programmable gate array is connected to the ADS127L01 analog in the valve position monitoring module. The clock input end of the analog-to-digital converter is connected to the clock input end of the analog-to-digital converter of the Spartan-6 field programmable gate array, the second input and output pin of the Spartan-6 field programmable gate array is connected to the data output end of the analog-to-digital converter of the ADS127L01 in the valve position monitoring module, the third input and output pin of the Spartan-6 field programmable gate array is connected to the data input end of the analog-to-digital converter of the ADS127L01 in the valve position monitoring module, the first pulse width modulation output pin of the Spartan-6 field programmable gate array is connected to the first input end of the L298N motor driver in the pneumatic actuator module, the address bus pin of the IS61WV51216 static memory is connected to the address bus pin of the STM32H743 microcontroller, the transmit data pin of the MCP2551 controller local area network transceiver is connected to the serial communication transmit pin of the STM32H743 microcontroller, the first oscillation pin of the 25MHz crystal oscillator is connected to the oscillator input end of the STM32H743 microcontroller, and the second oscillation pin of the 25MHz crystal oscillator is connected to the oscillator output end of the STM32H743 microcontroller.

[0012] Preferably, the valve position monitoring module includes a first LVDT sensor, a second LVDT sensor, an OPA2188 operational amplifier, a 10kHz signal source, a first INA188 instrumentation amplifier, a second INA188 instrumentation amplifier, an ADS127L01 analog-to-digital converter, an ADG1409 multiplexer, a PT100 temperature sensor, and a REF5050 voltage reference. The positive pole of the primary coil of the first LVDT sensor is connected to the output end of the OPA2188 operational amplifier, the negative pole of the primary coil of the first LVDT sensor is grounded, the positive pole of the secondary coil of the first LVDT sensor is connected to the non-inverting input end of the first INA188 instrumentation amplifier, and the first LVDT The negative pole of the secondary coil of the sensor is connected to the inverting input terminal of the first INA188 instrumentation amplifier, the positive pole of the primary coil of the second LVDT sensor is connected to the output terminal of the OPA2188 operational amplifier, the negative pole of the primary coil of the second LVDT sensor is grounded, the positive pole of the secondary coil of the second LVDT sensor is connected to the non-inverting input terminal of the second INA188 instrumentation amplifier, the negative pole of the secondary coil of the second LVDT sensor is connected to the inverting input terminal of the second INA188 instrumentation amplifier, the non-inverting input terminal of the OPA2188 operational amplifier is connected to the output terminal of the 10kHz signal source, and the inverting input terminal of the OPA2188 operational amplifier is connected to its output terminal through the first resistor. A second resistor is connected between the two gain terminals of the first INA188 instrumentation amplifier, and the output terminal of the first INA188 instrumentation amplifier is connected to the input terminal of the ADG1409 multiplexer through a first low-pass filter. A third resistor is connected between the two gain terminals of the second INA188 instrumentation amplifier, and the output terminal of the second INA188 instrumentation amplifier is connected to the input terminal of the ADG1409 multiplexer through a second low-pass filter. The data terminal of the ADS127L01 analog-to-digital converter is connected to the ADG1409 multiplexer, and the clock terminal, output terminal, and data terminal of the ADS127L01 analog-to-digital converter are all connected to the Spartan-6 field The input and output ends of the field programmable gate array, the alarm interface of the ADS127L01 analog-to-digital converter is connected to the inverting input end of the LM339 comparator in the security protection module, the data output end of the ADG1409 multiplexer is connected to the first analog positive input end of the ADS127L01 analog-to-digital converter, the channel selection input end of the ADG1409 multiplexer is connected to the fourth input and output pin of the Spartan-6 field programmable gate array in the main controller module, the input end of the PT100 temperature sensor is connected to the output end of the REF5050 voltage reference, and the output end of the PT100 temperature sensor is connected to the input end of the STM32H743 microcontroller in the main controller module.

[0013] Preferably, the strain detection module includes a first strain gauge, a second strain gauge, a third strain gauge, a fourth strain gauge, a REF200 dual current source, a first INA128 instrumentation amplifier, a second INA128 instrumentation amplifier, an AD7794 analog-to-digital converter, and an LM35 temperature sensor. The first end of the first strain gauge is connected to the first output end of the REF200 dual current source, the second end of the first strain gauge is connected to the non-inverting input end of the first INA128 instrumentation amplifier, the first end of the second strain gauge is connected to the inverting input end of the first INA128 instrumentation amplifier, the second end of the second strain gauge is grounded, the first end of the third strain gauge is connected to the first output end of the REF200 dual current source, the second end of the third strain gauge is connected to the non-inverting input end of the second INA128 instrumentation amplifier, and the first end of the fourth strain gauge is connected to the second INA128 instrumentation amplifier. The inverting input terminal of the device is connected to the inverting input terminal of the device, the second terminal of the fourth strain gauge is grounded, the second output terminal of the REF200 dual current source is connected to the first output terminal thereof, the ground terminal of the REF200 dual current source is grounded, the two gain terminals of the first INA128 instrumentation amplifier are connected to the fourth resistor, the two gain terminals of the second INA128 instrumentation amplifier are connected to the fifth resistor, the output terminals of the first INA128 instrumentation amplifier and the second INA128 instrumentation amplifier are connected to the input terminals of the AD7794 analog-to-digital converter, the output terminal of the LM35 temperature sensor is connected to the input terminal of the AD7794 analog-to-digital converter, the clock terminal, output terminal, and data terminal of the AD7794 analog-to-digital converter are all connected to the STM32H743 microcontroller in the main controller module, and the alarm terminal of the AD7794 analog-to-digital converter is connected to the non-inverting input terminal of the LM339 comparator in the safety protection module.

[0014] Preferably, the piezoelectric compensation module includes a PA94 high-voltage operational amplifier, a first MOS transistor, a second MOS transistor, a piezoelectric ceramic actuator, an ACS712 current sensor, a first 1N4007 protection diode, and a second 1N4007 protection diode. The non-inverting input terminal of the PA94 high-voltage operational amplifier is connected to the output terminal of the STM32H743 microcontroller in the main controller module through a sixth resistor, the inverting input terminal of the PA94 high-voltage operational amplifier is grounded through a seventh resistor, and the output terminal of the PA94 high-voltage operational amplifier is connected to the gates of the first MOS transistor and the second MOS transistor through an eighth resistor. The drain of the first MOS transistor is connected to electricity, and the source of the first MOS transistor is connected to the input of the piezoelectric ceramic actuator and the ACS712 current sensor. The piezoelectric ceramic actuator is mounted on a pneumatic actuator, and its output terminal is connected to the active end of the piezoelectric ceramic actuator.

[0015] Preferably, the pneumatic actuator module includes an L298N motor driver, a pneumatic servo valve, a 6639S potentiometer, a limit switch, and a freewheeling diode. The pneumatic servo valve is connected to the air path. The input end of the L298N motor driver is connected to the first pulse width modulation output pin of the Spartan-6 field programmable gate array in the main controller module through a tenth resistor. The output end of the L298N motor driver is connected to the first coil end of the pneumatic servo valve. The first coil end of the pneumatic servo valve is connected to the first output end of the L298N motor driver. The second line of the pneumatic servo valve is connected to the first coil end of the pneumatic servo valve. The coil end is connected to the second output end of the L298N motor driver, the sliding end of the 6639S potentiometer is connected to the third analog-to-digital conversion input pin of the STM32H743 microcontroller in the main controller module, the first fixed end of the 6639S potentiometer is connected to electricity, the second fixed end of the 6639S potentiometer is grounded, the normally open end of the limit switch is connected to the general input and output pin of the STM32H743 microcontroller in the main controller module, the anode of the freewheeling diode is connected to the second coil end of the pneumatic servo valve, and the cathode of the freewheeling diode is connected to the first coil end of the pneumatic servo valve.

[0016] Preferably, the safety protection module includes an LM339 comparator, a MAX6814 timer, a relay, and an SRV05-4 transient voltage suppression diode array. The input pin of the MAX6814 timer is connected to the general input and output pin of the STM32H743 microcontroller in the main controller module, the output pin of the MAX6814 timer is connected to the reset pin of the STM32H743 microcontroller in the main controller module, the positive pole of the coil of the relay is connected to the first output end of the LM339 comparator, the common end of the relay is connected to electricity, the normally open end of the relay is connected to the loop of the pneumatic execution module, one end of the SRV05-4 transient voltage suppression diode array is grounded, and the other end of the SRV05-4 transient voltage suppression diode array is used to connect to all external interface signal lines.

[0017] Preferably, the pneumatic actuator includes a cylinder body fixedly connected and communicated with the upper end of the bracket, a cylinder head fixedly connected to the cylinder body, and a piston slidably connected in the cylinder body, the cylinder body is provided with an air inlet, the cylinder head is provided with an air outlet, the air inlet is connected to the air pump through an air path, the upper end of the valve stem is fixedly connected to the piston, and an indicator rod that can pass through the cylinder head is provided above the piston, the piezoelectric ceramic actuator in the piezoelectric compensation module is fixedly connected to the cylinder head and is transmission-connected to the upper end of the indicator rod, and the outer ring of the indicator rod is provided with a spring that contacts the inner top surface of the cylinder head and the top surface of the piston.

[0018] The present invention has the following beneficial effects: In the present invention, each structure maintains efficient sealing and limits the displacement direction of each structure, while monitoring the valve stem displacement and strain data, calculating the bending amount through multi-source data fusion to perform position compensation, and controlling the pneumatic execution module to complete the valve opening and closing action of S-curve optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 This is a structural block diagram of the pneumatic execution system in the present invention.

[0021] 1. Valve body; 2. Hexagonal movable nut; 3. Valve core sealing gasket; 4. Valve core; 5. Bellows; 6. Sealing gasket; 7. Valve cover; 8. Bracket; 9. First O-ring; 10. Bushing; 11. Cylinder body; 12. Second O-ring; 13. Piston; 14. Cylinder head; 15. Third O-ring; 16. Indicator rod; 17. Spring; 18. Hexagonal nut; 19. Elastic washer; 20. Flat washer; 21. Fourth O-ring; 22. Power management module; 23. Main controller module; 24. Valve position monitoring module; 25. Strain detection module; 26. Piezoelectric compensation module; 27. Pneumatic actuator module; 28. Safety protection module. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0025] In the description of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use, or are the orientation or position relationship commonly understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] Furthermore, the terms “first,” “second,” “third,” etc., are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0028] A pneumatic stop valve, such as Figure 1 As shown, it includes a valve body 1, a bracket 8 installed on the valve body 1 through a valve cover 7, a bellows 5 fixedly connected to the bracket 8, a pneumatic actuator fixedly connected to the upper end of the bracket 8, and a valve stem. The valve stem is slidably connected in the bellows 5, and the upper end of the valve stem is transmission-connected to the movable end of the pneumatic actuator. The lower end of the valve stem is fixedly connected to the valve core 4 located in the valve body 1. The pneumatic actuator is connected to an air pump through an air path. The pneumatic actuator module 27 is connected to the air path. The pneumatic actuator includes a cylinder body 11 fixedly connected and communicated with the upper end of the bracket 8, a pneumatic actuator 27 fixedly connected to the air path. The cylinder head 14 on the cylinder body 11 and the piston 13 slidably connected to the cylinder body 11, the cylinder body 11 is provided with an air inlet, the cylinder head 14 is provided with an air outlet, the air inlet is connected to the air pump through the air path, the upper end of the valve stem is fixedly connected to the piston 13, and an indicator rod 16 that can pass through the cylinder head 14 is provided above the piston 13. The piezoelectric ceramic actuator in the piezoelectric compensation module 26 is fixedly connected to the cylinder head 14 and is in transmission connection with the upper end of the indicator rod 16. The outer ring of the indicator rod 16 is provided with a contact with the inner top surface of the cylinder head 14 and the top surface of the piston 13. The outer sides of the inlet and outlet on both sides of the valve body 1 are provided with a rotatable hexagonal movable nut 2, the bottom of the valve core 4 is fixedly connected to the valve core sealing gasket 3, the valve cover 7 and the valve body 1 are filled with a sealing gasket 6, a first O-ring 9 is provided between the outer ring of the bracket 8 and the cylinder body 11, and between the inner ring of the bracket 8 and the valve stem, a sleeve 10 for sliding the valve stem is installed in the bracket 8, an annular groove is provided on the outer ring of the piston 13, and a second O-ring 12 that can conflict with the inner ring of the cylinder body 11 is embedded in the annular groove, and the indicator rod 16 passes through the outer ring of the cylinder head 14. The third O-ring 15 is fixedly connected to the ring, the upper end of the valve stem passes through the piston 13, and the outer ring of the valve stem is fixedly connected to the fourth O-ring 21 that interferes with the point where it passes through the piston 13. The outer ring of the end of the valve stem after passing through the piston 13 is provided with an external thread, and a hexagonal nut 18 is threaded on the external thread. The outer ring of the valve stem is provided with an elastic washer 19 and a flat washer 20 clamped between the piston 13 and the hexagonal nut 18. The indicator rod 16 is welded to the end of the hexagonal nut 18 away from the piston 13. The length of the end of the valve stem after passing through the piston 13 is less than the thickness of the hexagonal nut 18.

[0029] like Figure 2As shown, it also includes a pneumatic execution system, which is electrically connected to the pneumatic actuator and the pneumatic execution module 27. The pneumatic execution system monitors the valve stem displacement and strain data in real time, and the pneumatic execution system calculates the bending amount and performs position compensation through multi-source data fusion. At the same time, it completes the valve opening and closing action of S curve optimization and performs packing wear prediction and valve stem fatigue analysis to trigger maintenance warning. The pneumatic execution system includes a power management module 22, a main controller module 23, a valve position monitoring module 24, a strain detection module 25, a piezoelectric compensation module 26, and a safety protection module 28. The power management module 22 supplies power to each module, and the displacement signal of the valve position monitoring module 24 is The output end is connected to the first analog-to-digital conversion interface of the main controller module 23, the strain signal output end of the strain detection module 25 is connected to the second analog-to-digital conversion interface of the main controller module 23, the control signal input end of the piezoelectric compensation module 26 is connected to the digital-to-analog conversion output end of the main controller module 23, the control signal input end of the pneumatic execution module 27 is connected to the pulse width modulation output end of the main controller module 23, the monitoring signal input end of the safety protection module 28 is connected to the alarm output end of the valve position monitoring module 24 and the alarm output end of the strain detection module 25, and the protection action output end of the safety protection module 28 is connected to the emergency cut-off circuit of the pneumatic execution module 27.

[0030] The main controller module 23 includes an STM32H743 microcontroller, a Spartan-6 field programmable gate array, an IS61WV51216 static memory, an MCP2551 controller area network transceiver, and a 25MHz crystal oscillator. The serial peripheral interface clock pin of the STM32H743 microcontroller is connected to the clock input of the AD7794 analog-to-digital converter in the strain detection module 25. The serial peripheral interface master input and slave output pins of the STM32H743 microcontroller are connected to the data output of the AD7794 analog-to-digital converter in the strain detection module 25. The serial peripheral interface master output and slave input pins of the STM32H743 microcontroller are connected to the data input of the AD7794 analog-to-digital converter in the strain detection module 25. The first digital-to-analog conversion output pin of the STM32H743 microcontroller is connected to the non-inverting input of the PA94 high-voltage operational amplifier in the piezoelectric compensation module 26. The first input and output pins of the Spartan-6 field programmable gate array are connected to the ADS127L0 in the valve position monitoring module 24. 1 is connected to the clock input end of the analog-to-digital converter, the second input-output pin of the Spartan-6 field programmable gate array is connected to the data output end of the ADS127L01 analog-to-digital converter in the valve position monitoring module 24, the third input-output pin of the Spartan-6 field programmable gate array is connected to the data input end of the ADS127L01 analog-to-digital converter in the valve position monitoring module 24, the first pulse width modulation output pin of the Spartan-6 field programmable gate array is connected to the first input end of the L298N motor driver in the pneumatic actuator module 27, the address bus pin of the IS61WV51216 static memory is connected to the address bus pin of the STM32H743 microcontroller, the transmit data pin of the MCP2551 controller area network transceiver is connected to the serial communication transmit pin of the STM32H743 microcontroller, the first oscillation pin of the 25MHz crystal oscillator is connected to the oscillator input end of the STM32H743 microcontroller, and the second oscillation pin of the 25MHz crystal oscillator is connected to the oscillator output end of the STM32H743 microcontroller.

[0031] The valve position monitoring module 24 includes a first LVDT sensor, a second LVDT sensor, an OPA2188 operational amplifier, a 10kHz signal source, a first INA188 instrumentation amplifier, a second INA188 instrumentation amplifier, an ADS127L01 analog-to-digital converter, an ADG1409 multiplexer, a PT100 temperature sensor, and a REF5050 voltage reference. The positive pole of the primary coil of the first LVDT sensor is connected to the output end of the OPA2188 operational amplifier, the negative pole of the primary coil of the first LVDT sensor is grounded, the positive pole of the secondary coil of the first LVDT sensor is connected to the non-inverting input end of the first INA188 instrumentation amplifier, and the first LVDT sensor is connected to the positive pole of the secondary coil of the first LVDT sensor. The negative pole of the secondary coil of the sensor is connected to the inverting input terminal of the first INA188 instrumentation amplifier, the positive pole of the primary coil of the second LVDT sensor is connected to the output terminal of the OPA2188 operational amplifier, the negative pole of the primary coil of the second LVDT sensor is grounded, the positive pole of the secondary coil of the second LVDT sensor is connected to the non-inverting input terminal of the second INA188 instrumentation amplifier, the negative pole of the secondary coil of the second LVDT sensor is connected to the inverting input terminal of the second INA188 instrumentation amplifier, the non-inverting input terminal of the OPA2188 operational amplifier is connected to the output terminal of the 10kHz signal source, the inverting input terminal of the OPA2188 operational amplifier is connected to its output terminal through the first resistor, and the first INA1 A second resistor is connected between the two gain terminals of the INA188 instrumentation amplifier, the output terminal of the first INA188 instrumentation amplifier is connected to the input terminal of the ADG1409 multiplexer through a first low-pass filter, a third resistor is connected between the two gain terminals of the second INA188 instrumentation amplifier, the output terminal of the second INA188 instrumentation amplifier is connected to the input terminal of the ADG1409 multiplexer through a second low-pass filter, the data terminal of the ADS127L01 analog-to-digital converter is connected to the ADG1409 multiplexer, and the clock terminal, output terminal, and data terminal of the ADS127L01 analog-to-digital converter are all connected to the Spartan-6 field programmable gate array in the main controller module 23. The input and output ends of the column, the alarm interface of the ADS127L01 analog-to-digital converter is connected to the inverting input end of the LM339 comparator in the security protection module 28, the data output end of the ADG1409 multiplexer is connected to the first analog positive input end of the ADS127L01 analog-to-digital converter, the channel selection input end of the ADG1409 multiplexer is connected to the fourth input and output pin of the Spartan-6 field programmable gate array in the main controller module 23, the input end of the PT100 temperature sensor is connected to the output end of the REF5050 voltage reference, and the output end of the PT100 temperature sensor is connected to the input end of the STM32H743 microcontroller in the main controller module 23.

[0032] The strain detection module 25 includes a first strain gauge, a second strain gauge, a third strain gauge, a fourth strain gauge, a REF200 dual current source, a first INA128 instrumentation amplifier, a second INA128 instrumentation amplifier, an AD7794 analog-to-digital converter, and an LM35 temperature sensor. The first end of the first strain gauge is connected to the first output end of the REF200 dual current source, the second end of the first strain gauge is connected to the non-inverting input end of the first INA128 instrumentation amplifier, the first end of the second strain gauge is connected to the inverting input end of the first INA128 instrumentation amplifier, the second end of the second strain gauge is grounded, the first end of the third strain gauge is connected to the first output end of the REF200 dual current source, the second end of the third strain gauge is connected to the non-inverting input end of the second INA128 instrumentation amplifier, and the first end of the fourth strain gauge is connected to the inverting input end of the second INA128 instrumentation amplifier. The inverting input terminal, the second terminal of the fourth strain gauge is grounded, the second output terminal of the REF200 dual current source is connected to its first output terminal, the ground terminal of the REF200 dual current source is grounded, the two gain terminals of the first INA128 instrumentation amplifier are connected to the fourth resistor, the two gain terminals of the second INA128 instrumentation amplifier are connected to the fifth resistor, the output terminals of the first INA128 instrumentation amplifier and the second INA128 instrumentation amplifier are connected to the input terminal of the AD7794 analog-to-digital converter, the output terminal of the LM35 temperature sensor is connected to the input terminal of the AD7794 analog-to-digital converter, the clock terminal, output terminal and data terminal of the AD7794 analog-to-digital converter are all connected to the STM32H743 microcontroller in the main controller module 23, and the alarm terminal of the AD7794 analog-to-digital converter is connected to the non-inverting input terminal of the LM339 comparator in the safety protection module 28.

[0033] The piezoelectric compensation module 26 includes a PA94 high-voltage operational amplifier, a first MOS transistor, a second MOS transistor, a piezoelectric ceramic actuator, an ACS712 current sensor, a first 1N4007 protection diode, and a second 1N4007 protection diode. The non-inverting input of the PA94 high-voltage operational amplifier is connected to the output of the STM32H743 microcontroller in the main controller module 23 through a sixth resistor. The inverting input of the PA94 high-voltage operational amplifier is grounded through a seventh resistor. The output of the PA94 high-voltage operational amplifier is connected to the gates of the first and second MOS transistors through an eighth resistor. The drain of the first MOS transistor is connected to electricity, and the source of the first MOS transistor is connected to the input of the piezoelectric ceramic actuator and the ACS712 current sensor. The input end is connected to the piezoelectric ceramic actuator and the input end of the ACS712 current sensor. The output end of the ACS712 current sensor is connected to the STM32H743 microcontroller in the main controller module 23 through the ninth resistor. The anode of the first 1N4007 protection diode is connected to the source of the first MOS tube, the cathode of the first 1N4007 protection diode is connected to the drain of the first MOS tube, the anode of the second 1N4007 protection diode is connected to the drain of the second MOS tube, and the cathode of the second 1N4007 protection diode is connected to the source of the second MOS tube. The piezoelectric ceramic actuator is mounted on the pneumatic actuator, and its output end is transmission-connected to the movable end of the pneumatic actuator.

[0034] The pneumatic actuator module 27 includes an L298N motor driver, a pneumatic servo valve, a 6639S potentiometer, a limit switch, and a freewheeling diode. The pneumatic servo valve is connected to the air path. The input end of the L298N motor driver is connected to the first pulse width modulation output pin of the Spartan-6 field programmable gate array in the main controller module 23 through a tenth resistor. The output end of the L298N motor driver is connected to the first coil end of the pneumatic servo valve. The first coil end of the pneumatic servo valve is connected to the first output end of the L298N motor driver. The second coil end of the pneumatic servo valve is connected to the first coil end of the L298N motor driver. Connect the second output terminal of the L298N motor driver, the sliding end of the 6639S potentiometer is connected to the third analog-to-digital conversion input pin of the STM32H743 microcontroller in the main controller module 23, the first fixed end of the 6639S potentiometer is connected to power, the second fixed end of the 6639S potentiometer is grounded, the normally open end of the limit switch is connected to the general input and output pin of the STM32H743 microcontroller in the main controller module 23, the anode of the freewheeling diode is connected to the second coil end of the pneumatic servo valve, and the cathode of the freewheeling diode is connected to the first coil end of the pneumatic servo valve.

[0035] The safety protection module 28 includes an LM339 comparator, a MAX6814 timer, a relay, and an SRV05-4 transient voltage suppression diode array. The input pin of the MAX6814 timer is connected to the general input and output pin of the STM32H743 microcontroller in the main controller module 23, and the output pin of the MAX6814 timer is connected to the reset pin of the STM32H743 microcontroller in the main controller module 23. The positive pole of the relay coil is connected to the first output terminal of the LM339 comparator, the common terminal of the relay is connected to power, and the normally open terminal of the relay is connected to the circuit of the pneumatic actuator module 27. One end of the SRV05-4 transient voltage suppression diode array is grounded, and the other end of the SRV05-4 transient voltage suppression diode array is used to connect to all external interface signal lines.

[0036] The power supply module includes an LM2596 switching regulator, a first LT3080 linear regulator, a second LT3080 linear regulator, an ADuM5000 isolated power supply, a first filter capacitor and a second filter capacitor. The voltage input terminal of the LM2596 switching regulator is connected to the positive electrode of the 24V power supply, the voltage output terminal of the LM2596 switching regulator is connected to the voltage input terminal of the first LT3080 regulator and the second LT3080 linear regulator, the ground terminal of the LM2596 switching regulator is grounded, the voltage output terminal of the first LT3080 linear regulator outputs a 5V voltage, the ground terminal of the first LT3080 linear regulator is grounded, and the ground terminal of the second LT3080 is grounded. The voltage output terminal of the 0 linear regulator outputs a 3.3V voltage, the ground terminal of the second LT3080 linear regulator is grounded, the primary side voltage input terminal of the ADuM5000 isolated power supply is connected to the voltage output terminal of the first LT3080 regulator, the secondary side positive voltage output terminal of the ADuM5000 isolated power supply outputs +15V, the secondary side negative voltage output terminal of the ADuM5000 isolated power supply outputs -15V, the primary side ground terminal of the ADuM5000 isolated power supply is grounded, the first filter capacitor is connected between the voltage output terminal of the LM2596 switching regulator and ground, and the second filter capacitor is connected between the voltage output terminal of the first LT3080 regulator and ground.

[0037] When the pneumatic actuator system is working, The main controller module 23 performs initialization tests on the power supply, sensors, and actuators, verifies that the voltage value of the 3.3V rail is between 3.1V and 3.5V, the voltage value of the 5V rail is between 4.7V and 5.3V, and the voltage value of the + / -15V rail is between 14V and 16V. It calculates the average value of the sampled data at multiple positions as the LVDT zero position, verifies that the absolute value of the strain gauge bridge output voltage is less than 5 millivolts, confirms that the valve is in a safe initial position, completes the safety protection system self-test, and enters the ready state. The valve position monitoring module 24 and the strain detection module 25 collect data and perform temperature compensation. The arithmetic mean of the position data of the two LVDT sensors is calculated as the valve stem position. The strain value is calculated based on the instrument amplifier output voltage, amplifier gain, excitation voltage and strain gauge sensitivity coefficient. The position and strain data are temperature compensated using the temperature compensation coefficient. The compensation amount is proportional to the difference between the current temperature and the calibration temperature. The position data is filtered using a first-order low-pass filter algorithm. The current filter output value is equal to the current sample value multiplied by the filter coefficient plus the previous filter output value multiplied by one minus the filter coefficient. The main controller module 23 calculates the real-time bending amount based on multi-source data fusion, and calculates the strain-based bending amount based on the compensated strain value, valve stem length, and diameter. The bending amount is proportional to the strain, proportional to the square of the length, and inversely proportional to the diameter. The position difference-based bending amount is calculated based on the absolute difference between the two LVDT position data, the valve stem length, and the LVDT spacing. The bending amount is proportional to the position difference and length, and inversely proportional to the LVDT spacing. The theoretical bending amount is calculated based on the pressure difference, the effective area of ​​the valve core 4, the valve stem length, the elastic modulus after temperature correction, and the section inertia moment. The elastic modulus decays exponentially with temperature, and the theoretical bending amount is proportional to the cube of the pressure difference, area, and length, and inversely proportional to the elastic modulus and section inertia moment. The three bending amounts are weighted and summed to obtain the final bending amount, and the sum of the weight coefficients is one. The piezoelectric compensation module 26 performs bending compensation and hysteresis compensation. It uses a proportional-integral-differential algorithm to calculate the bending compensation amount. The compensation amount is a linear combination of the proportional, integral, and differential terms of the bending amount. Based on the previous output voltage and voltage change, a hysteresis model is applied to perform nonlinear correction on the compensation amount. The compensation voltage is limited to a preset minimum and maximum value. The piezoelectric ceramic drive current is monitored to ensure that it does not exceed the maximum allowable current. The pneumatic actuator module 27 performs S-curve optimized valve movement and generates an S-shaped velocity curve, which includes three stages: uniform acceleration, uniform velocity, and uniform deceleration. The pulse width modulation signal of the pneumatic actuator is generated based on the proportional control of the position deviation and the velocity deviation. At the end of the valve closing, the velocity decreases according to the exponential decay law to verify that the deviation between the actual closing position and the target position is less than the allowable error. The safety protection module 28 monitors key parameters in real time and triggers protection. It monitors the valve closing time to ensure that it is less than the maximum allowable closing time of two seconds, monitors the bending change rate to ensure that it is less than the maximum allowable change rate of 0.01 mm per second, calculates the high-frequency vibration energy, and determines it as a leak when it exceeds the threshold. It implements a graded response based on the temperature: normal operation when the temperature is below 150 degrees Celsius, reduced operating frequency when the temperature is between 150 and 180 degrees Celsius, and emergency shutdown when the temperature is 180 degrees Celsius or above; The main controller module 23 calculates packing wear and valve stem fatigue, calculates packing wear based on the integral of the absolute value of friction and the square of the bending amount over time, predicts the remaining life based on the current wear amount and wear rate, and evaluates valve stem fatigue damage based on the power accumulation sum of the ratio of the strain amplitude to the fatigue limit strain. A maintenance alarm is triggered when the wear amount exceeds 80% of the maximum allowable wear amount or the fatigue damage accumulation value exceeds 1; The main controller module 23 records the operation data and uploads it to the host computer, records periodic operation data such as time, position, bending amount, temperature, pressure difference and compensation voltage, stores key event data such as valve action, alarm and maintenance events, transmits real-time data to the host computer through the controller LAN bus, and automatically generates daily operation reports and maintenance recommendation reports.

[0038] More specific: When the pneumatic stop valve is working, the air pump supplies air to the air inlet of the cylinder body 11 through the air path, and the spring 17 pushes the piston 13 to adjust the position of the piston 13 in the cylinder body 11, thereby driving the valve stem. The O-rings in various places ensure its sealing performance and are not prone to leakage. The setting of the sleeve 10 plays a guiding role for the valve stem, thereby reducing the deformation problem of the valve stem.

[0039] In addition, the pneumatic actuator system will cooperate in monitoring the valve stem. The LM2596 switching regulator of the power management module 22 converts the 24V input voltage into a 12V reference voltage. Its voltage input terminal receives an external power supply and supplies power to the LT3080 linear regulator through the voltage output terminal of pin 2. The voltage output terminal of the first LT3080 linear regulator outputs a 5V voltage to power the sensor network, and the voltage output terminal of the second LT3080 linear regulator outputs a 3.3V voltage to provide the core power supply for the main controller module 23. At the same time, after the primary side voltage input terminal of the ADuM5000 isolated power supply receives a 5V voltage, its secondary side positive voltage output terminal and secondary side negative voltage output terminal respectively generate ±15V isolation voltages for use by the high-voltage circuit.

[0040] The positive poles of the primary coils of the first and second LVDT sensors in the valve position monitoring module 24 receive the 10kHz sinusoidal excitation signal output by the OPA2188 operational amplifier, and the positive poles and negative poles of the secondary coils are connected to the non-inverting input and inverting input of the INA188 instrumentation amplifier, respectively, to convert the valve stem displacement into a differential voltage signal. The signal is filtered out of high-frequency noise by a low-pass filter composed of a 100kΩ resistor and a 0.1μF capacitor and then sent to the first channel input of the ADG1409 multiplexer. The data output of the ADG1409 multiplexer is connected to the first analog positive input of the ADS127L01 analog-to-digital converter. The channel selection is controlled by the Spartan-6 field programmable gate array through the input and output pins. Finally, the 24-bit displacement data is transmitted to the Spartan-6 field programmable gate array through the serial clock input, data output, and data input. At the same time, the signal output end of the PT100 temperature sensor transmits the temperature data to the first analog-to-digital conversion input pin of the STM32H743 microcontroller, and the reference voltage output end of the REF5050 voltage reference source provides stable excitation for the PT100; the four Vishay K-Alloy high-temperature strain gauges of the strain detection module 25 form a full-bridge circuit, and the positive input end of the power supply of the REF200 dual current source receives a 5V voltage and outputs a 1mA constant current excitation from its first output end. The millivolt-level signal output by the strain gauge is amplified by the INA128 instrumentation amplifier and transmitted from its output end to the first analog positive input end of the AD7794 analog-to-digital converter. The voltage output end of the LM35 temperature sensor is connected to the second analog positive input end of the AD7794 to achieve temperature compensation. The AD7794 analog-to-digital converter transmits the strain data in real time to the STM32H743 microcontroller through the serial peripheral interface.

[0041] The STM32H743 microcontroller of the main controller module 23 processes multi-source data based on a fusion algorithm and calculates the valve stem deformation under the action of thermal-mechanical coupling using the material creep model E=206e9·e^(-0.0023(T-25)). When a micro-bend of 0.08mm is detected, its first digital-to-analog conversion output pin outputs a compensation signal corrected by the Preisach hysteresis model. This signal is transmitted to the non-inverting input terminal of the piezoelectric compensation module 26PA94 high-voltage operational amplifier through the tenth resistor. The output terminal of the PA94 high-voltage operational amplifier drives the first MOS transistor and the second MOS transistor. The drain of the first MOS transistor is connected to an 80V high-voltage power supply, and the source is connected to the power output node to generate an adjustable voltage of ±80V, so that the piezoelectric ceramic actuator applies axial thrust within 380μs to correct the valve stem bending. The current detection positive electrode of the ACS712 current sensor monitors the output node current in real time, and its voltage output terminal feeds back the current data to the second analog-to-digital conversion input pin of the microcontroller.

[0042] The first input of the L298N motor driver of the pneumatic actuator module 27 receives an S-curve PWM signal generated by the first pulse width modulation output pin of the Spartan-6 field programmable gate array. The first and second outputs of the L298N motor driver drive the coil of the Festo pneumatic servo valve, causing the valve core 4 to move along a third-order acceleration trajectory. The valve core 4 is uniformly accelerated to 120 mm / s in the first 50 ms, operates at a constant speed during the middle stroke, and then decreases exponentially to 5 mm / s in the final 30 ms according to v_end = v_max·e^(-0.1(Pos_end-Pos). The sliding end of the 6639S potentiometer provides real-time feedback of the valve position to the third analog-to-digital conversion input pin of the STM32H743 microcontroller, forming a closed-loop control. When the valve is fully closed, the limit switch triggers a normally open signal to forcibly cut off the drive. A freewheeling diode is connected across the servo valve coil to absorb the 120V back electromotive force during shutdown.

[0043] The LM339 comparator of the safety protection module 28 compares the valve position and the strain alarm signal in real time through the first inverting input terminal and the first non-inverting input terminal. When it detects that the closing time is greater than 2s or the bending change rate is greater than 0.01mm / s, its first output terminal triggers the relay to cut off the gas supply. The input pin of the MAX6814 timer continuously receives the signal of the STM32H743 microcontroller. When there is no response after 300ms, its output pin directly resets the main controller module 23.

[0044] As a result, the entire system determines whether the seal has failed through high-frequency vibration energy analysis, and uses the wear integral model Wear=∫|0.15×compaction force|dt+∫Bend 2 dt accumulates packing loss and triggers a maintenance alarm when the wear exceeds the 80% threshold, ultimately shortening the closing time and extending the seal life, solving the closing lag problem caused by high-temperature packing collapse, particle erosion, and pressure differential bending.

[0045] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A pneumatic stop valve, characterized in that: The invention comprises a valve body (1), a bracket (8) mounted on the valve body (1) through a valve cover (7), a bellows (5) fixedly connected in the bracket (8), a pneumatic actuator fixedly connected to the upper end of the bracket (8), and a valve stem, wherein the valve stem is slidably connected in the bellows (5), and the upper end of the valve stem is transmission-connected to the movable end of the pneumatic actuator, the lower end of the valve stem is fixedly connected to a valve core (4) located in the valve body (1), the pneumatic actuator is connected to an air pump through an air path, the pneumatic actuator module (27) is connected to the air path, and further comprises a pneumatic actuator system, the pneumatic actuator system is electrically connected to the pneumatic actuator and the pneumatic actuator module (27), the pneumatic actuator system monitors the displacement and strain data of the valve stem in real time, and the pneumatic actuator system calculates the bending amount and performs position compensation by multi-source data fusion, and simultaneously completes the valve opening and closing action of S curve optimization and performs packing wear prediction and valve stem fatigue analysis to trigger maintenance warning.

2. A pneumatic stop valve according to claim 1, characterized in that: The pneumatic execution system comprises a power management module (22), a main controller module (23), a valve position monitoring module (24), a strain detection module (25), a piezoelectric compensation module (26), and a safety protection module (28). The power management module (22) supplies power to each module. The displacement signal output end of the valve position monitoring module (24) is connected to the first analog-to-digital conversion interface of the main controller module (23). The strain signal output end of the strain detection module (25) is connected to the second analog-to-digital conversion interface of the main controller module (23). The control signal input end of the piezoelectric compensation module (26) is connected to the digital-to-analog conversion output end of the main controller module (23). The control signal input end of the pneumatic execution module (27) is connected to the pulse width modulation output end of the main controller module (23). The monitoring signal input end of the safety protection module (28) is connected to the alarm output end of the valve position monitoring module (24) and the alarm output end of the strain detection module (25). The protection action output end of the safety protection module (28) is connected to the emergency cut-off circuit of the pneumatic execution module (27).

3. A pneumatic stop valve according to claim 2, characterized in that: The main controller module (23) includes an STM32H743 microcontroller, a Spartan-6 field programmable gate array, an IS61WV51216 static memory, an MCP2551 controller area network transceiver, and a 25MHz crystal oscillator. The serial peripheral interface clock pin of the STM32H743 microcontroller is connected to the clock input end of the AD7794 analog-to-digital converter in the strain detection module (25). The serial peripheral interface master input and slave output pins of the STM32H743 microcontroller are connected to the strain detection module (25). 5) The data output end of the AD7794 analog-to-digital converter, the main output slave input pin of the serial peripheral interface of the STM32H743 microcontroller is connected to the data input end of the AD7794 analog-to-digital converter in the strain detection module (25), the first digital-to-analog conversion output pin of the STM32H743 microcontroller is connected to the non-inverting input end of the PA94 high-voltage operational amplifier in the piezoelectric compensation module (26), and the first input-output pin of the Spartan-6 field programmable gate array is connected to the ADS127 in the valve position monitoring module (24). The clock input end of the L01 analog-to-digital converter, the second input-output pin of the Spartan-6 field programmable gate array is connected to the data output end of the ADS127L01 analog-to-digital converter in the valve position monitoring module (24), the third input-output pin of the Spartan-6 field programmable gate array is connected to the data input end of the ADS127L01 analog-to-digital converter in the valve position monitoring module (24), and the first pulse width modulation output pin of the Spartan-6 field programmable gate array is connected to the L298N in the pneumatic execution module (27). The first input end of the motor driver, the address bus pin of the IS61WV51216 static memory is connected to the address bus pin of the STM32H743 microcontroller, the transmit data pin of the MCP2551 controller local area network transceiver is connected to the serial communication transmit pin of the STM32H743 microcontroller, the first oscillation pin of the 25MHz crystal oscillator is connected to the oscillator input end of the STM32H743 microcontroller, and the second oscillation pin of the 25MHz crystal oscillator is connected to the oscillator output end of the STM32H743 microcontroller.

4. A pneumatic stop valve according to claim 2, characterized in that: The valve position monitoring module (24) includes a first LVDT sensor, a second LVDT sensor, an OPA2188 operational amplifier, a 10kHz signal source, a first INA188 instrumentation amplifier, a second INA188 instrumentation amplifier, an ADS127L01 analog-to-digital converter, an ADG1409 multiplexer, a PT100 temperature sensor, and a REF5050 voltage reference. The positive pole of the primary coil of the first LVDT sensor is connected to the output end of the OPA2188 operational amplifier, the negative pole of the primary coil of the first LVDT sensor is grounded, the positive pole of the secondary coil of the first LVDT sensor is connected to the non-inverting input end of the first INA188 instrumentation amplifier, and the positive pole of the secondary coil of the first LVDT sensor is connected to the non-inverting input end of the first INA188 instrumentation amplifier. The negative pole of the secondary coil is connected to the inverting input terminal of the first INA188 instrumentation amplifier, the positive pole of the primary coil of the second LVDT sensor is connected to the output terminal of the OPA2188 operational amplifier, the negative pole of the primary coil of the second LVDT sensor is grounded, the positive pole of the secondary coil of the second LVDT sensor is connected to the non-inverting input terminal of the second INA188 instrumentation amplifier, the negative pole of the secondary coil of the second LVDT sensor is connected to the inverting input terminal of the second INA188 instrumentation amplifier, the non-inverting input terminal of the OPA2188 operational amplifier is connected to the output terminal of the 10kHz signal source, the inverting input terminal of the OPA2188 operational amplifier is connected to its output terminal through a first resistor, and the first INA18 A second resistor is connected between the two gain terminals of the 8 instrumentation amplifier, the output terminal of the first INA188 instrumentation amplifier is connected to the input terminal of the ADG1409 multiplexer through a first low-pass filter, a third resistor is connected between the two gain terminals of the second INA188 instrumentation amplifier, the output terminal of the second INA188 instrumentation amplifier is connected to the input terminal of the ADG1409 multiplexer through a second low-pass filter, the data terminal of the ADS127L01 analog-to-digital converter is connected to the ADG1409 multiplexer, and the clock terminal, output terminal and data terminal of the ADS127L01 analog-to-digital converter are all connected to the input terminal of the Spartan-6 field programmable gate array in the main controller module (23). The alarm interface of the ADS127L01 analog-to-digital converter is connected to the inverting input terminal of the LM339 comparator in the security protection module (28), the data output terminal of the ADG1409 multiplexer is connected to the first analog positive input terminal of the ADS127L01 analog-to-digital converter, the channel selection input terminal of the ADG1409 multiplexer is connected to the fourth input-output pin of the Spartan-6 field programmable gate array in the main controller module (23), the input terminal of the PT100 temperature sensor is connected to the output terminal of the REF5050 voltage reference, and the output terminal of the PT100 temperature sensor is connected to the input terminal of the STM32H743 microcontroller in the main controller module (23).

5. The pneumatic stop valve according to claim 2, characterized in that: The strain detection module (25) includes a first strain gauge, a second strain gauge, a third strain gauge, a fourth strain gauge, a REF200 dual-channel current source, a first INA128 instrumentation amplifier, a second INA128 instrumentation amplifier, an AD7794 analog-to-digital converter, and an LM35 temperature sensor, wherein the first end of the first strain gauge is connected to the first output end of the REF200 dual-channel current source, the second end of the first strain gauge is connected to the non-inverting input end of the first INA128 instrumentation amplifier, the first end of the second strain gauge is connected to the inverting input end of the first INA128 instrumentation amplifier, the second end of the second strain gauge is grounded, the first end of the third strain gauge is connected to the first output end of the REF200 dual-channel current source, the second end of the third strain gauge is connected to the non-inverting input end of the second INA128 instrumentation amplifier, and the first end of the fourth strain gauge is connected to the inverting input end of the second INA128 instrumentation amplifier. The input end, the second end of the fourth strain gauge is grounded, the second output end of the REF200 dual current source is connected to its first output end, the ground end of the REF200 dual current source is grounded, the two gain ends of the first INA128 instrumentation amplifier are connected to the fourth resistor, the two gain ends of the second INA128 instrumentation amplifier are connected to the fifth resistor, the output ends of the first INA128 instrumentation amplifier and the second INA128 instrumentation amplifier are connected to the input end of the AD7794 analog-to-digital converter, the output end of the LM35 temperature sensor is connected to the input end of the AD7794 analog-to-digital converter, the clock end, the output end and the data end of the AD7794 analog-to-digital converter are all connected to the STM32H743 microcontroller in the main controller module (23), and the alarm end of the AD7794 analog-to-digital converter is connected to the non-inverting input end of the LM339 comparator in the safety protection module (28).

6. The pneumatic stop valve according to claim 2, characterized in that: The piezoelectric compensation module (26) includes a PA94 high-voltage operational amplifier, a first MOS tube, a second MOS tube, a piezoelectric ceramic actuator, an ACS712 current sensor, a first 1N4007 protection diode, and a second 1N4007 protection diode. The non-inverting input terminal of the PA94 high-voltage operational amplifier is connected to the output terminal of the STM32H743 microcontroller in the main controller module (23) through a sixth resistor. The inverting input terminal of the PA94 high-voltage operational amplifier is grounded through a seventh resistor. The output terminal of the PA94 high-voltage operational amplifier is connected to the gates of the first MOS tube and the second MOS tube through an eighth resistor. The drain of the first MOS tube is connected to electricity, and the source of the first MOS tube is connected to the input of the piezoelectric ceramic actuator and the ACS712 current sensor. The source of the second MOS tube is grounded, the drain of the second MOS tube is connected to the input end of the piezoelectric ceramic actuator and the ACS712 current sensor, the output end of the ACS712 current sensor is connected to the STM32H743 microcontroller in the main controller module (23) through a ninth resistor, the anode of the first 1N4007 protection diode is connected to the source of the first MOS tube, the cathode of the first 1N4007 protection diode is connected to the drain of the first MOS tube, the anode of the second 1N4007 protection diode is connected to the drain of the second MOS tube, the cathode of the second 1N4007 protection diode is connected to the source of the second MOS tube, the piezoelectric ceramic actuator is mounted on the pneumatic actuator, and its output end is connected to the active end of the pneumatic actuator.

7. The pneumatic stop valve according to claim 2, characterized in that: The pneumatic execution module (27) includes an L298N motor driver, a pneumatic servo valve, a 6639S potentiometer, a limit switch, and a freewheeling diode. The pneumatic servo valve is connected to the air path. The input end of the L298N motor driver is connected to the first pulse width modulation output pin of the Spartan-6 field programmable gate array in the main controller module (23) through a tenth resistor. The output end of the L298N motor driver is connected to the first coil end of the pneumatic servo valve. The first coil end of the pneumatic servo valve is connected to the first output end of the L298N motor driver. The second coil end of the pneumatic servo valve is connected to the first output end of the L298N motor driver. The second output terminal of the L298N motor driver is connected, the sliding end of the 6639S potentiometer is connected to the third analog-to-digital conversion input pin of the STM32H743 microcontroller in the main controller module (23), the first fixed end of the 6639S potentiometer is connected to electricity, the second fixed end of the 6639S potentiometer is grounded, the normally open end of the limit switch is connected to the general input and output pin of the STM32H743 microcontroller in the main controller module (23), the anode of the freewheeling diode is connected to the second coil end of the pneumatic servo valve, and the cathode of the freewheeling diode is connected to the first coil end of the pneumatic servo valve.

8. The pneumatic stop valve according to claim 2, characterized in that: The safety protection module (28) includes an LM339 comparator, a MAX6814 timer, a relay, and an SRV05-4 transient voltage suppression diode array. The input pin of the MAX6814 timer is connected to the general input and output pin of the STM32H743 microcontroller in the main controller module (23), the output pin of the MAX6814 timer is connected to the reset pin of the STM32H743 microcontroller in the main controller module (23), the positive pole of the coil of the relay is connected to the first output end of the LM339 comparator, the common end of the relay is connected to electricity, the normally open end of the relay is connected to the circuit of the pneumatic execution module (27), one end of the SRV05-4 transient voltage suppression diode array is grounded, and the other end of the SRV05-4 transient voltage suppression diode array is used to connect to all external interface signal lines.

9. The pneumatic stop valve according to claim 2, characterized in that: The pneumatic actuator comprises a cylinder body (11) fixedly connected to and communicated with the upper end of the bracket (8), a cylinder head (14) fixedly connected to the cylinder body (11), and a piston (13) slidably connected in the cylinder body (11), the cylinder body (11) is provided with an air inlet, the cylinder head (14) is provided with an air outlet, the air inlet is connected to the air pump through an air path, the upper end of the valve stem is fixedly connected to the piston (13), and an indicator rod (16) that can pass through the cylinder head (14) is provided above the piston (13), the piezoelectric ceramic actuator in the piezoelectric compensation module (26) is fixedly connected to the cylinder head (14) and is transmission-connected to the upper end of the indicator rod (16), and the outer ring of the indicator rod (16) is provided with a spring (17) that contacts the inner top surface of the cylinder head (14) and the top surface of the piston (13).

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