Control system and control method for valve position signal of intelligent valve positioner

Abstract

The invention relates to the technical field of valve position control, in particular to an intelligent valve positioner valve position signal control system and method.The system comprises a three-out-of-middle module A. The three-out-of-middle module A is connected with a microprocessor, receives and processes a valve position given signal and sends the processed valve position given signal to the microprocessor; the microprocessor is connected with the three-out-of-middle module B and the valve position opening degree control module, the three-out-of-middle module B is connected with the valve position measuring module, the valve position measuring module obtains valve position feedback signals through measurement and transmits the valve position feedback signals to the three-out-of-middle module B, and the valve position opening degree control module receives instruction signals of the microprocessor to control the opening degree of the pneumatic adjusting valve. According to the invention, by arranging three paths of redundant valve position given signals and valve position feedback signals, the major risk of abnormal valve control caused by single fault of the valve position given signals and the valve position feedback signals of the pneumatic control valve in the prior art is solved, the fault signals can be automatically identified and eliminated, and the operation reliability and stability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of valve position control, and in particular to a control system and a control method for a valve position signal of an intelligent valve positioner. Background Art

[0002] A pneumatic control valve primarily consists of a valve body, valve core, valve stem, actuator, and intelligent valve positioner. The intelligent valve positioner is an auxiliary component of the pneumatic control valve actuator, used to precisely control the position of the valve stem. The pneumatic control valve operates by utilizing the driving force generated by the actuator to drive the valve core within the valve body via the valve stem, thereby changing the cross-sectional area through which the fluid flows and regulating parameters such as fluid flow, pressure, and temperature. When the control system issues a valve position reference signal, the intelligent valve positioner on the actuator drives the valve stem upward or downward based on the signal, thereby changing the opening of the pneumatic control valve. When the opening increases, the cross-sectional area through which the fluid flows increases, increasing the flow rate; when the opening decreases, the cross-sectional area through which the fluid flows decreases, reducing the flow rate.

[0003] As a key accessory for pneumatic control valve actuators, intelligent valve positioners play an important role in ensuring stable operation of pneumatic control valves by improving their reliability. In existing technologies, intelligent valve positioners receive a valve position reference signal from the control system and a valve position feedback signal from the valve stem position sensor. A microprocessor processes and analyzes these signals, calculates the required valve opening, and then outputs a corresponding air pressure signal to drive the valve stem and valve core to adjust the pneumatic control valve opening. Current intelligent valve positioners can only receive one valve position reference signal and one valve position feedback signal. Loss of either the valve position reference signal or the valve position feedback signal can cause the pneumatic control valve to lose control and control functionality. Summary of the Invention

[0004] The present invention provides a control system and a control method for a valve position signal of an intelligent valve positioner, which are used to solve the problem in the prior art that the intelligent valve positioner has a single signal source and there is a risk of loss of control of the pneumatic regulating valve.

[0005] The technical solutions of the present invention are as follows:

[0006] The present invention proposes a control system for the valve position signal of an intelligent valve positioner, which includes a microprocessor, a three-centering module A, a three-centering module B, a valve position measurement module and a valve position opening control module. The three-centering module A is connected to the microprocessor, receives and processes a valve position given signal, and sends the processed valve position given signal to the microprocessor; the microprocessor is connected to the three-centering module B and the valve position opening control module, the three-centering module B is connected to the valve position measurement module, the valve position measurement module measures and obtains a valve position feedback signal and transmits it to the three-centering module B, the three-centering module B processes the valve position feedback signal, and sends the processed valve position feedback signal to the microprocessor; the valve position opening control module receives the command signal from the microprocessor to control the opening of the pneumatic control valve.

[0007] In some embodiments, the valve position measurement module includes three position sensors and three valve position connecting rods. The three position sensors are respectively arranged on the three valve position connecting rods. The three valve position connecting rods are connected to the valve body of the pneumatic control valve. The position sensor measures the displacement of the corresponding valve position connecting rod and converts it into a valve position feedback signal. The three position sensors transmit the three-way valve position feedback signals to the three-centering module B.

[0008] In some embodiments, the three-centering module A receives and processes three-way valve position setting signals.

[0009] In some embodiments, the three-median module A medians the three valve position given signals and performs redundancy removal after a signal failure, and the three-median module B medians the three valve position feedback signals and performs redundancy removal after a signal failure.

[0010] In some embodiments, the valve position opening control module includes an intake valve, an exhaust valve and an actuator, the intake valve and the exhaust valve are connected to a microprocessor, the actuator is connected to the intake valve and the exhaust valve, the above-mentioned actuator is connected to three valve position connecting rods, the intake valve and the exhaust valve receive the command signal of the microprocessor and control the air source pressure entering the actuator, and the actuator drives the three valve position connecting rods to change the opening of the pneumatic regulating valve.

[0011] The present invention proposes a method for controlling a valve position signal of an intelligent valve positioner, the method comprising:

[0012] The three-way median module A receives three-way valve position given signals, takes the median value of the three-way valve position given signals and performs redundancy processing after signal failure, and then transmits the median value to the microprocessor;

[0013] The three-way centering module B receives the three-way valve position feedback signals from the three position sensors, and performs median processing on the three-way valve position feedback signals and performs redundancy removal after signal failure, and then transmits them to the microprocessor;

[0014] The microprocessor receives the processed valve position setting signal and valve position feedback signal, calculates the valve opening that needs to be adjusted according to the deviation between the valve position setting signal and the valve position feedback signal, and outputs the command signal to the intake valve and exhaust valve;

[0015] The intake valve and exhaust valve control the air source pressure entering the actuator. The actuator drives the three valve position connecting rods to drive the valve core in the valve body to move and change the opening of the valve core.

[0016] In some embodiments, in the method, the three-median module A medians the three valve position given signals and performs redundancy reduction processing after a signal failure. The signal failure refers to the signal being 10% lower than the lower limit of the valve position range of the intelligent valve positioner or 10% higher than the upper limit of the valve position range of the intelligent valve positioner.

[0017] In some embodiments, the method comprises the following steps: when one of the three valve position given signals fails, the three median module A selects a signal with a median value among the three given signals and outputs the signal; and the three median module A issues an alarm;

[0018] When two of the three valve position setting signals fail, the three-way centering module A selects the one that does not exceed the limit to output, and the three-way centering module A issues an alarm;

[0019] When three of the three-way valve position setting signals fail, the three-way centering module A uses the valve position setting signal at the moment before the failure, the microprocessor output command signal remains unchanged, and the three-way centering module A issues an alarm;

[0020] When the fault signal is not abnormal, the three-centering module A centers the three valve position given signals and outputs the centered valve position given signal. If the absolute value of the deviation between any one of the three valve position given signals and the other two valve position given signals is greater than 5% of the valve position range of the intelligent valve positioner, the three-centering module A centers the three valve position given signals and outputs the centered valve position given signal and issues an alarm.

[0021] In some embodiments, the method comprises the following steps: when one of the three valve position feedback signals fails, the three median module B selects the one with the middle value among the three feedback signals and outputs it, and the three median module B issues an alarm;

[0022] When two of the three valve position feedback signals fail, the three-way centering module B selects the feedback signal output that is within the limit, and the three-way centering module B issues an alarm;

[0023] When three of the three-way valve position feedback signals fail, the three-way centering module B uses the valve position feedback signal at the moment before the failure, the microprocessor output command signal remains unchanged, and the three-way centering module B issues an alarm;

[0024] When the fault signal is not identified as abnormal, the three-centering module B centers the three valve position feedback signals and outputs the centered valve position feedback signal. If the absolute value of the deviation between any one of the three valve position feedback signals and the other two valve position feedback signals is greater than 5% of the valve position range of the intelligent valve positioner, the three-centering module B centers the three valve position feedback signals, outputs the centered valve position feedback signal, and issues an alarm.

[0025] The implementation of the present invention has the following beneficial effects:

[0026] The present invention provides a control system and control method for the valve position signal of an intelligent valve positioner. By providing three redundant valve position setting signals and valve position feedback signals, the present invention addresses the significant risk of valve control abnormality caused by a single failure of the valve position setting signal and valve position feedback signal of a pneumatic control valve. The present invention can automatically identify and eliminate fault signals, thereby improving operational reliability and stability. The device structure of the present invention is simple, requiring no significant modification to the pneumatic control valve body structure, and is relatively low in cost. The present invention does not require modification of the interface between the upstream control system and the intelligent valve positioner and can be used in new construction projects as well as for equipment modification in existing projects, ensuring wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a control system for valve position signals of an intelligent valve positioner proposed in an embodiment of the present invention;

[0028] Description of the drawings: 1. Microprocessor; 2. Air source; 3. Inlet valve; 4. Exhaust valve; 5. Actuator; 6. Position sensor A; 7. Valve position connecting rod A; 8. Valve body; 9. Three-centering module A; 10. Three-centering module B; 11. Position sensor B; 12. Valve position connecting rod B; 13. Position sensor C; 14. Valve position connecting rod C. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] like Figure 1As shown, the present invention proposes a control system for valve position signals of an intelligent valve positioner, which includes a microprocessor 1, an air source 2, an intake valve 3, an exhaust valve 4, an actuator 5, three position sensors, three valve position connecting rods, a three-centering module A9 and a three-centering module B10. All of the above components are integrated into the intelligent positioner.

[0031] Three-way centering module A9 is connected to microprocessor 1 and receives redundant three-way valve position reference signals from the upstream system. These signals are used to control the position of the three-way valve position connecting rods in this system. Three-way centering module A9 receives these three-way valve position reference signals, medians them, and performs redundancy processing in the event of a signal failure before transmitting them to microprocessor 1.

[0032] The three-centering module B10 is connected to the microprocessor 1. The three-centering module B10 is connected to three position sensors. The three position sensors are respectively arranged on the three valve position connecting rods, among which the position sensor A6 is arranged on the valve position connecting rod A7, the position sensor B11 is arranged on the valve position connecting rod B12, and the position sensor C13 is arranged on the valve position connecting rod C14. The position sensors are used to measure the displacement of the corresponding valve position connecting rods and convert them into valve position feedback signals. The position sensor A6, the position sensor B11 and the position sensor C13 respectively transmit the three-way valve position feedback signals to the three-centering module B10. The three-centering module B10 receives the three-way valve position feedback signals, medians them, and performs redundancy processing after signal failure, and then transmits them to the microprocessor 1.

[0033] Microprocessor 1 is connected to intake valve 3 and exhaust valve 4, which are connected to actuator 5. Actuator 5 is connected to three valve position connecting rods, which are connected to valve body 8. Microprocessor 1 performs closed-loop PID calculations on the valve position reference signal and valve position feedback signal received after three-way signal redundancy processing. Based on the deviation between the valve position reference signal and the valve position feedback signal, it calculates the valve opening that needs to be adjusted and outputs command signals to intake valve 3 and exhaust valve 4. Intake valve 3 and exhaust valve 4 control the pressure of air source 2 entering actuator 5. Actuator 5 drives the three valve position connecting rods of the pneumatic control valve to drive the valve core in valve body 8 to move, changing the valve core opening to meet process requirements.

[0034] The present invention proposes a method for controlling a valve position signal of an intelligent valve positioner, the method comprising:

[0035] The three-way median module A9 receives three valve position reference signals from the upstream system. After median processing and redundancy processing in the event of a signal failure, the module transmits the signal to microprocessor 1. A signal failure occurs when the signal falls below the lower limit of the intelligent valve positioner's range by 10% or exceeds the upper limit by 10%.

[0036] The three-median module A9 medians the three valve position given signals and performs redundancy processing after a signal failure. Specifically, when one of the three valve position given signals fails, the failure is manifested as one signal being too large or too small, and being 10% lower than the lower limit of the range or 10% higher than the upper limit of the range. The three-median module A9 selects the given signal with the middle value among the three signals and outputs it, thereby automatically eliminating the fault signal. The three-median module A9 also issues an alarm.

[0037] When two of the three valve position given signals fail, the fault manifests as the two signals being too large or too small, and both signals are 10% lower than the lower limit of the range or 10% higher than the upper limit of the range. The three-centering module A9 selects the given signal output that does not exceed the limit, and the three-centering module A9 issues an alarm.

[0038] When three of the three valve position setting signals fail, the failure is manifested as the three signals being too large or too small, and all three signals are 10% lower than the lower limit of the range or 10% higher than the upper limit of the range. The three-centering module A9 uses the valve position setting signal at the moment before the failure, the output command signal of the microprocessor 1 remains unchanged, and the three-centering module A9 issues an alarm.

[0039] When the signal without fault diagnosis is abnormal, the three-centering module A9 centers the three valve position given signals and outputs the centered valve position given signal. If the absolute value of the deviation between any one of the three valve position given signals and the other two valve position given signals is greater than 5% of the valve position range of the intelligent valve positioner, the three-centering module A9 centers the three valve position given signals and outputs the centered valve position given signal and issues an alarm.

[0040] The three-way median module B10 receives three valve position feedback signals from three position sensors. It medians the three signals and performs redundancy processing to prevent signal failures before transmitting them to microprocessor 1. A signal failure occurs when the signal falls below the lower limit of the intelligent valve positioner's range or exceeds the upper limit by 10%.

[0041] The three-median module B10 medians the three valve position feedback signals and performs redundancy processing after a signal failure. Specifically, when one of the three valve position feedback signals fails, the failure is manifested as one signal being too large or too small, and being 10% lower than the lower limit of the range or 10% higher than the upper limit of the range. The three-median module B10 selects the signal output with the middle value among the three valve position feedback signals to automatically eliminate the fault signal and issue an alarm.

[0042] When two of the three valve position feedback signals fail, the fault manifests as the two signals being too large or too small, and both signals being 10% lower than the lower limit or 10% higher than the upper limit, the three-centering module B10 selects the feedback signal that is within the limit and outputs it, and issues an alarm.

[0043] When three of the three valve position feedback signals fail, the failure is manifested as the three signals being too large or too small, and all three signals are 10% lower than the lower limit of the range or 10% higher than the upper limit of the range. The three-centering module B10 uses the valve position feedback signal at the moment before the failure, the microprocessor 1 outputs the command signal unchanged, and an alarm is issued.

[0044] When the signal without fault diagnosis is abnormal, the three-centering module B10 centers the three valve position feedback signals and outputs the centered valve position feedback signal. If the absolute value of the deviation between any one of the three valve position feedback signals and the other two valve position feedback signals is greater than 5% of the valve position range of the intelligent valve positioner, the three-centering module B10 centers the three valve position feedback signals, outputs the centered valve position feedback signal, and issues an alarm.

[0045] The microprocessor 1 receives the processed valve position setting signal and valve position feedback signal, calculates the valve opening that needs to be adjusted according to the deviation between the valve position setting signal and the valve position feedback signal, and outputs the command signal to the intake valve 3 and the exhaust valve 4.

[0046] The inlet valve 3 and the exhaust valve 4 control the pressure of the air source 2 entering the actuator 5. The actuator 5 drives the three valve position connecting rods of the pneumatic control valve to drive the valve core in the valve body 8 to move and change the opening of the valve core.

[0047] The above embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A control system for valve position signals of an intelligent valve positioner, characterized in that: The system comprises a microprocessor (1), a three-centering module A (9), a three-centering module B (10), a valve position measurement module and a valve position opening control module, wherein the three-centering module A (9) is connected to the microprocessor (1), the three-centering module A (9) receives and processes a valve position given signal, and sends the processed valve position given signal to the microprocessor (1); the microprocessor (1) is connected to the three-centering module B (10) and the valve position opening control module, the three-centering module B (10) is connected to the valve position measurement module, the valve position measurement module measures and obtains a valve position feedback signal and transmits it to the three-centering module B (10), the three-centering module B (10) processes the valve position feedback signal, and sends the processed valve position feedback signal to the microprocessor (1); the valve position opening control module receives the instruction signal from the microprocessor (1) to control the opening of the pneumatic control valve.

2. The control system for valve position signal of an intelligent valve positioner according to claim 1, characterized in that: The valve position measurement module includes three position sensors and three valve position connecting rods. The three position sensors are respectively arranged on the three valve position connecting rods. The three valve position connecting rods are connected to the valve body (8) of the pneumatic control valve. The position sensors measure the displacement of the corresponding valve position connecting rods and convert it into a valve position feedback signal. The three position sensors transmit the three-way valve position feedback signal to the three-centering module B (10).

3. The control system for valve position signal of an intelligent valve positioner according to claim 2, characterized in that: The three-centering module A (9) receives three-way valve position setting signals and processes them.

4. The control system for valve position signal of an intelligent valve positioner according to claim 3, characterized in that: The three-median module A (9) medians the three-way valve position given signals and performs redundancy removal processing after a signal failure. The three-median module B (10) medians the three-way valve position feedback signals and performs redundancy removal processing after a signal failure.

5. The control system for valve position signal of an intelligent valve positioner according to claim 4, characterized in that: The valve position opening control module includes an intake valve (3), an exhaust valve (4) and an actuator (5), wherein the intake valve (3) and the exhaust valve (4) are connected to the microprocessor (1), the actuator (5) is connected to the intake valve (3) and the exhaust valve (4), and the actuator (5) is connected to three valve position connecting rods. The intake valve (3) and the exhaust valve (4) receive a command signal from the microprocessor (1) and control the pressure of the air source (2) entering the actuator (5), and the actuator (5) drives the three valve position connecting rods to change the opening of the pneumatic regulating valve.

6. The method for controlling the valve position signal of an intelligent valve positioner according to claim 5, characterized in that: The method comprises: The three-way median module A (9) receives three-way valve position setting signals, and the three-way median module A (9) medians the three-way valve position setting signals and performs redundancy processing after signal failure, and then transmits the median to the microprocessor (1); The three-way median module B (10) receives three-way valve position feedback signals from three position sensors, performs median processing on the three-way valve position feedback signals and performs redundancy removal processing after signal failure, and then transmits the signals to the microprocessor (1); The microprocessor (1) receives the processed valve position setting signal and valve position feedback signal, calculates the valve opening that needs to be adjusted according to the deviation between the valve position setting signal and the valve position feedback signal, and outputs a command signal to transmit to the intake valve (3) and the exhaust valve (4); The inlet valve (3) and the exhaust valve (4) control the pressure of the air source (2) entering the actuator (5), and the actuator (5) drives three valve position connecting rods to drive the valve core in the valve body (8) to move, thereby changing the opening of the valve core.

7. The method for controlling the valve position signal of an intelligent valve positioner according to claim 6, characterized in that: In the method, the three-median module A (9) medians the three-way valve position given signals and performs redundancy removal after a signal failure, wherein the signal failure refers to a signal that is 10% lower than the lower limit of the intelligent valve positioner valve position range or 10% higher than the upper limit of the intelligent valve positioner valve position range.

8. The method for controlling the valve position signal of an intelligent valve positioner according to claim 7, characterized in that: The method comprises the following steps: when one of the three valve position given signals fails, the three-medium module A (9) selects a signal with a middle value among the three given signals and outputs it, and the three-medium module A (9) issues an alarm; When two of the three valve position setting signals fail, the three-centering module A (9) selects the one setting signal that does not exceed the limit to output, and the three-centering module A (9) issues an alarm; When three of the three valve position setting signals fail, the three-centering module A (9) uses the valve position setting signal at the moment before the failure, the microprocessor (1) outputs a command signal that remains unchanged, and the three-centering module A (9) issues an alarm; When the fault signal is not judged to be abnormal, the three-way centering module A (9) centers the three-way valve position given signals and outputs the valve position given signal after the centering. If the absolute value of the deviation between any one of the three-way valve position given signals and the other two valve position given signals is greater than 5% of the valve position range of the intelligent valve positioner, the three-way centering module A (9) centers the three-way valve position given signals, outputs the valve position given signal after the centering and issues an alarm.

9. The method for controlling the valve position signal of an intelligent valve positioner according to claim 7, characterized in that: The method comprises the following steps: when one of the three valve position feedback signals fails, the three-median module B (10) selects a signal with a median value among the three feedback signals and outputs the signal; and the three-median module B (10) issues an alarm; When two of the three valve position feedback signals fail, the three-centering module B (10) selects the one feedback signal that does not exceed the limit to output, and the three-centering module B (10) issues an alarm; When three of the three valve position feedback signals fail, the three-centering module B (10) uses the valve position feedback signal at the moment before the failure, the microprocessor (1) outputs a command signal that remains unchanged, and the three-centering module B (10) issues an alarm; When the fault signal is not judged to be abnormal, the three-way valve position feedback signal is averaged and the averaged valve position feedback signal is output. If the absolute value of the deviation between any one of the three-way valve position feedback signal and the other two valve position feedback signals is greater than 5% of the valve position range of the intelligent valve positioner, the three-way valve position feedback signal is averaged, the three-way valve position feedback signal is output, and an alarm is issued.

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