Non-contact valve positioner

Abstract

The invention belongs to the technical field of valve positioners, and particularly relates to a non-contact valve positioner which comprises a valve position feedback assembly, a valve control assembly and a central control assembly, and the central control assembly is in communication connection with the valve position feedback assembly and the valve control assembly. The central control assembly comprises a control module, an anti-reverse-connection module, a current-limiting protection module and a current acquisition module, the input end of the anti-reverse-connection module is connected with valve position setting current, the positive output end of the anti-reverse-connection module is connected with the input end of the current-limiting protection module, and the output end of the current-limiting protection module is connected with the positive input end of the current acquisition module; the negative output end of the anti-reverse-connection module is connected with the negative input end of the current acquisition module, and the output end of the current acquisition module is connected with the control module. The reverse connection prevention module and the current-limiting protection module are adopted, so that the functions of wiring fault tolerance and current-limiting protection are achieved, and valve controller faults caused by reverse wiring and surge are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of valve positioners, and in particular relates to a non-contact valve positioner. Background Art

[0002] In automatic control systems, valve positioners are one of the most important accessories for regulating valves and pneumatic actuators, and almost all control valves use valve positioners.

[0003] The traditional valve positioner mainly includes four parts: input, signal processing, output and power supply, and its principle block diagram.

[0004] The digital setting value variable is obtained by analog-to-digital conversion of the valve position setting signal; the valve position change is converted into an electrical signal through a potentiometer, and the digital valve position value variable is obtained by analog-to-digital conversion. The two variables are calculated and processed to obtain the valve position control signal, which controls the electrical converter to make the valve position reach the set point. It relies on digital balance to achieve positioning.

[0005] The input of the traditional valve positioner is a 4-20mA analog current signal, which serves as the power supply and valve position control signal input. When wiring, the positive and negative poles of the analog current signal need to be correctly connected to the positive and negative input terminals of the valve positioner. Once the wiring is wrong, the positioner is easily damaged. At the same time, incorrect control signal input will cause abnormal valve control. Summary of the invention

[0006] The present invention provides a non-contact valve positioner, characterized in that it comprises: a non-contact valve positioner, comprising: a valve position feedback component, a valve control component and a central control component, wherein the central control component is communicatively connected with the valve position feedback component and the valve control component respectively; The valve position feedback component is installed on the valve and is used to generate a valve position signal according to the valve position of the valve. The central control component is used to generate a feedback control signal according to the valve position signal. The valve control component is used to control the valve position of the valve according to the feedback control signal. The central control component includes a control module, an anti-reverse connection module, a current limiting protection module, and a current acquisition module. The input end of the anti-reverse connection module is connected to the valve position setting current, the positive output end of the anti-reverse connection module is connected to the input end of the current limiting protection module, the output end of the current limiting protection module is connected to the positive input end of the current acquisition module, the negative output end of the anti-reverse connection module is connected to the negative input end of the current acquisition module, and the output end of the current acquisition module is connected to the control module.

[0007] Furthermore, the central control component also includes a Bluetooth module and a Hart communication module, and both the Hart communication module and the Bluetooth module are connected to the control module.

[0008] Furthermore, the central control component also includes a digital output module and an analog output module, and both the digital output module and the analog output module are connected to the control module.

[0009] Furthermore, the central control component also includes a display screen and function buttons, and the display screen and function buttons are both communicatively connected to the control module.

[0010] Furthermore, the valve position feedback component includes: a position feedback magnetic strip, a magnetic detection module and a magnetic conductor, the position feedback magnetic strip is installed on the valve, a accommodating space is formed in the magnetic conductor, the position feedback magnetic strip is inserted into the accommodating space, the magnetic conductor is used to receive the magnetism of the position feedback magnetic strip, the magnetic detection module is communicatively connected to the control module, and the magnetic detection module can detect the magnetism of the magnetic conductor to generate a valve position signal.

[0011] Furthermore, the anti-reverse connection module is a bridge rectifier circuit, and the current limiting protection module is a current limiting circuit.

[0012] Furthermore, the valve control assembly includes: an electrical controller and a pneumatic amplifier, the electrical converter is connected to the control module, the pneumatic amplifier is communicatively connected to the electrical converter, and the pneumatic amplifier is connected to the air supply end of the valve.

[0013] Furthermore, the pneumatic amplifier is a single-acting pneumatic amplifier or a double-acting pneumatic amplifier.

[0014] Furthermore, the air source input end and the air source output end of the pneumatic amplifier are both provided with a pressure gauge and an air pressure sensor, and the air pressure sensors are both connected to the control module.

[0015] Furthermore, the current acquisition module includes a current amplifier and a sampling resistor, the negative input end of the current amplifier is connected to one end of the sampling resistor and the negative output end of the anti-reverse connection module, and the other end of the sampling resistor is connected to the signal ground and the positive input end of the current amplifier.

[0016] Beneficial effects of the present invention: The present invention adopts an anti-reverse connection module and a current limiting protection module to play the wiring fault tolerance and current limiting protection functions, avoiding valve controller failure caused by reverse wiring and surge. The present invention adopts high-precision non-contact position feedback technology. It has fast response speed, high positioning accuracy, excellent control linearity, and good stability, and is suitable for industrial process control in different environments. The present invention has a human-machine operation interface, and the large-screen display provides users with more configuration functions, and also has HART and Bluetooth communication functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural block diagram of the present invention.

[0018] Figure 2 It is a schematic diagram of the overall structure of the present invention.

[0019] Figure 3 It is a schematic diagram of the decomposition structure of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. The described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0021] In the technical solution of the present invention, Figure 1 1 is a structural block diagram of a specific structure of a non-contact valve positioner according to the present invention, such as Figure 1 As shown, the present invention includes: A valve position feedback component 2, a valve control component 3 and a central control component 1, wherein the central control component 1 is communicatively connected with the valve position feedback component 2 and the valve control component 3 respectively; The valve position feedback component 2 is installed on the valve and is used to generate a valve position signal according to the valve position of the valve. The signal is a feedback signal of the valve position. The central control component 1 is used to generate a feedback control signal according to the valve position signal. Specifically, the input end of the central control component 1 is connected to a 4-20mA valve position setting signal, and then the valve control amount is determined by PID calculation according to the valve position setting signal and the valve position signal to generate a corresponding feedback control signal. This technology is a conventional technical means in this field, so it will not be repeated here. The valve control component 3 is used to control the valve position of the valve according to the feedback control signal.

[0022] The central control component 1 includes a control module 11, an anti-reverse connection module 12, a current limiting protection module 13, and a current acquisition module 14. The input end of the anti-reverse connection module 12 is connected to the valve position setting current, the positive output end of the anti-reverse connection module 12 is connected to the input end of the current limiting protection module 13, the output end of the current limiting protection module 13 is connected to the positive input end of the current acquisition module 14, the negative output end of the anti-reverse connection module 12 is connected to the negative input end of the current acquisition module 14, and the output end of the current acquisition module 14 is connected to the control module 11. The control module 11 is a microcontroller such as an MCU.

[0023] Among them, the anti-reverse connection module 12 is a bridge rectifier circuit. By setting the bridge rectifier circuit, the current direction of the output is fixed no matter how the input end is connected, thereby achieving anti-reverse connection fault tolerance. When the device is connected to a 4mA~20mA power signal, the locator can still work normally when the positive and negative poles are reversed.

[0024] The current limiting protection module 13 is a current limiting circuit, which plays a role of current limiting protection. The device has the current limiting protection module 13, and when connected to a constant voltage source of VDC≤24V, the positioner can still work normally.

[0025] The current acquisition module 14 specifically includes: a current amplifier 141 and a sampling resistor, wherein the negative input end of the current amplifier 141 is connected to one end of the sampling resistor and the negative output end of the anti-reverse connection module 12, and the other end of the sampling resistor is connected to the signal ground and the positive input end of the current amplifier. The sampling resistor samples the current output by the anti-reverse connection module 12 to the bridge rectifier, and then amplifies the sampled current through the current amplifier to achieve a 4-20mA current input, which can be used as a power supply or as a signal to convert 4-20mA to 0%~100%FS.

[0026] In one embodiment of the present invention, the central control component 1 also includes a Bluetooth module 19 and a Hart communication module 110, and the Hart communication module 110 and the Bluetooth module 19 are both connected to the control module 11. The Hart communication module 110 supports the Hart protocol, provides a data communication interface for the DCS system, and is connected to the GsLink software for configuration, debugging and diagnosis. The Bluetooth module 19 supports Bluetooth communication. When the positioner is in debugging mode, the input current is adjusted to above 8mA, the Bluetooth communication function can be turned on, and communication with the hand operator or other detection equipment can be carried out. Debugging is performed according to the percentage of the valve position opening, which brings convenience to users in detection, maintenance and debugging; especially in the early stage of installation and debugging, it can be debugged directly through the intelligent terminal, which can not only reduce the cost of debugging equipment, but also speed up the debugging process. Among them, the power supply end of the Hart communication module 110 is connected to the output end of the current limiting circuit, and Hart can still maintain normal communication in the reverse state.

[0027] In one embodiment of the present invention, the central control component 1 further includes a digital output module 15 and an analog output module 16, and the digital output module 15 and the analog output module 16 are both connected to the control module 11. The digital output module 15 and the analog output module 16 perform analog output and digital output according to the control module 11, wherein the digital output module 15 and the analog output module 16 are conventional technical means in the art, and thus will not be described in detail herein.

[0028] In one embodiment of the present invention, the central control component 1 further includes a display screen 17 and a function button 18, and the display screen 17 and the function button 18 are both in communication connection with the control module 11. Specifically, the display screen 17 can display in combination with numbers, graphics, and curves, and a friendly human-computer interaction interface can intuitively understand the parameters of the positioner and the change of the valve position, and the function button 18 provides a human-computer interaction signal to realize the functions of selection and confirmation.

[0029] In one embodiment of the present invention, the valve position feedback component 2 includes: a position feedback magnetic strip 21, a magnetic detection module 22 and a magnet 23, wherein the position feedback magnetic strip 21 is installed on the valve, a containing space is formed in the magnet 23, the position feedback magnetic strip 21 is arranged in the containing space, the magnet 23 is used to receive the magnetism of the position feedback magnetic strip 21, the magnetic detection module 22 is connected to the control module 11 for communication, and the magnetic detection module 22 can detect the magnetism of the magnet 23 to generate a valve position signal. The position feedback magnetic strip 21 is installed on the valve actuator and moves up and down with the valve actuator. During the movement, the magnet 23 continuously receives the magnetism of the position feedback magnetic strip 21, and the magnetic detection module 22 continuously detects the change of the magnetism of the magnet 23 to generate a corresponding valve position signal. The control module 11 determines the current valve opening according to the valve position signal, thereby controlling the valve opening according to a preset program. The magnetic detection module 22 specifically adopts a TMR chip, which is implemented as a TMR2505T chip, and is input into the control module 11 in conjunction with a signal amplifier.

[0030] In one embodiment of the present invention, the valve control assembly 3 includes: an electrical converter 31 and a pneumatic amplifier 32, wherein the electrical converter 31 is connected to the control module 11, the pneumatic amplifier 32 is in communication with the electrical converter 31, and the pneumatic amplifier 32 is connected to the gas supply end of the valve. The electrical converter 31 is an IP converter, which is used to convert the output electrical signal of the valve controller into a pneumatic signal, and the pneumatic amplifier 32 controls the input gas source after receiving the gas signal, thereby realizing the control of the valve position.

[0031] The pneumatic amplifier 32 is a single-acting pneumatic amplifier 32 or a double-acting pneumatic amplifier 32. Whether it is a single-acting amplifier or a double-acting amplifier can be determined according to the actual needs of the valve controller.

[0032] In one embodiment of the present invention, the air source input end and the air source output end of the pneumatic amplifier 32 are both provided with a pressure gauge and an air pressure sensor, and the air pressure sensors are both connected to the control module 11. The pressure gauge can provide an intuitive display of the air inlet and air outlet pressures, and the air pressure sensor detects the pressures of the air inlet and air outlet and feeds them back to the control module 11. When a valve position feedback failure occurs, the control module 11 can realize valve position control through the air source pressure, realize redundant control, and ensure the normal operation of the valve controller.

[0033] like Figure 2 and Figure 3 As shown, Figure 2 and Figure 3 A structural diagram of a non-contact valve positioner is provided, wherein a magnetic detection module, a magnetizer, a valve control component 3 and a central control component 1 are all installed in a shell, and a groove at the bottom is a housing space for the magnetizer 23. It should be noted that the central control component is a circuit component and is welded on a circuit board.

[0034] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A non-contact valve positioner, characterized in that: include: A valve position feedback component (2), a valve control component (3) and a central control component (1), wherein the central control component (1) is communicatively connected to the valve position feedback component (2) and the valve control component (3) respectively; The valve position feedback component (2) is installed on the valve and is used to generate a valve position signal according to the valve position of the valve, the central control component (1) is used to generate a feedback control signal according to the valve position signal, and the valve control component (3) is used to control the valve position of the valve according to the feedback control signal; The central control component (1) comprises a control module (11), an anti-reverse connection module (12), a current limiting protection module (13), and a current acquisition module (14); the input end of the anti-reverse connection module (12) is connected to the valve position setting current, the positive output end of the anti-reverse connection module (12) is connected to the input end of the current limiting protection module (13), and the output end of the current limiting protection module (13) is connected to the positive input end of the current acquisition module (14); The negative output end of the anti-reverse connection module (12) is connected to the negative input end of the current acquisition module (14), and the output end of the current acquisition module (14) is connected to the control module (11).

2. The non-contact valve positioner according to claim 1, characterized in that: The central control component (1) further comprises a Bluetooth module (19) and a Hart communication module (110), and the Hart communication module (110) and the Bluetooth module (19) are both connected to the control module (11).

3. The non-contact valve positioner according to claim 1, characterized in that: The central control component (1) further comprises a digital quantity output module (15) and an analog quantity output module (16), wherein the digital quantity output module (15) and the analog quantity output module (16) are both connected to the control module (11).

4. The non-contact valve positioner according to claim 1, characterized in that: The central control component (1) further comprises a display screen (17) and function buttons (18), and the display screen (17) and function buttons (18) are both communicatively connected to the control module (11).

5. The non-contact valve positioner according to claim 1, characterized in that: The valve position feedback component (2) comprises: a position feedback magnetic strip (21), a magnetic detection module (22) and a magnetic conductor (23); the position feedback magnetic strip (21) is mounted on the valve; a containing space is formed in the magnetic conductor (23); the position feedback magnetic strip (21) is inserted into the containing space; the magnetic conductor (23) is used to receive the magnetism of the position feedback magnetic strip (21); the magnetic detection module (22) is communicatively connected to the control module (11); and the magnetic detection module (22) is capable of detecting the magnetism of the magnetic conductor (23) to generate a valve position signal.

6. The non-contact valve positioner according to claim 1, characterized in that: The anti-reverse connection module (12) is a bridge rectifier circuit, and the current limiting protection module (13) is a current limiting circuit.

7. The non-contact valve positioner according to claim 1, characterized in that: The valve control assembly (3) comprises: an electrical converter (31) and a pneumatic amplifier (32); the electrical converter (31) is connected to the control module (11); the pneumatic amplifier (32) is communicatively connected to the electrical converter (31); and the pneumatic amplifier (32) is connected to the gas supply end of the valve.

8. The non-contact valve positioner according to claim 6, characterized in that: The pneumatic amplifier (32) is a single-acting pneumatic amplifier (32) or a double-acting pneumatic amplifier (32).

9. The non-contact valve positioner according to claim 6, characterized in that: The air source input end and the air source output end of the pneumatic amplifier (32) are both provided with a pressure gauge and an air pressure sensor, and the air pressure sensors are both connected to the control module (11).

10. The non-contact valve positioner according to claim 1, characterized in that: The current acquisition module (14) comprises a current amplifier (141) and a sampling resistor, wherein a negative input end of the current amplifier (141) is connected to one end of the sampling resistor and a negative output end of the anti-reverse connection module (12), and the other end of the sampling resistor is connected to a signal ground and a positive input end of the current amplifier.

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