Retarding diagnosis method for actuator with valve positioner

Abstract

The invention discloses a retardation diagnosis method for an actuator with a valve positioner, and the main design concept of the invention is as follows: after a test platform is built, a new unused target pneumatic diaphragm valve with the valve positioner is connected to the test platform, and the test is started; test data are obtained and transmitted to an upper computer to be stored as original data corresponding to the target pneumatic diaphragm valve, and the test data comprise different actual opening values and the interval duration for executing the adjacent opening values; after the target pneumatic diaphragm valve is actually used, if a retardation phenomenon occurs, the target pneumatic diaphragm valve is re-connected to the test platform for retest; and performing comparative analysis on the obtained review data and the original data, and outputting an analysis report. According to the method, the problem of the abnormal valve positioner can be quickly diagnosed, and the method is suitable for retardation diagnosis of different types of valve positioners which are frequently used in the industry.

Description

Technical Field

[0001] The invention relates to the technical field of valve control, and in particular to a method for diagnosing blockage of an actuator with a valve positioner. Background Art

[0002] The actuator is one of the terminal equipment in the production control process of tobacco enterprises. It receives control signals to control the production process in high temperature, high pressure, corrosion and vibration environments. The actuator can be a control valve, damper, stepper motor or frequency converter, etc. In order to ensure the control accuracy, a valve positioner is needed to control the valve position of the actuator in certain specific occasions. It can increase the output power of the actuator and reduce the lag of the adjustment signal; it can speed up the movement speed of the valve stem and improve the linearity of the valve; it can overcome the friction of the valve stem and eliminate the influence of unbalanced force to ensure accurate positioning; it can realize the interchange of air-open and air-close; it can improve and correct the flow characteristics of the control valve; it can realize direct or rotary control.

[0003] A control valve is a type of actuator. It is a valve used for fluid control. From simple stop valves to various valves in extremely complex control systems, there are many varieties and specifications. It can be used to control air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media, etc. The valve positioner is the main accessory of the control valve. According to the structure and working principle, it can be divided into pneumatic valve positioner, electric valve positioner and intelligent valve positioner. The valve positioner takes the valve stem displacement signal as the input feedback measurement signal and the output signal of the controller as the setting signal and compares them. If there is a deviation between the two, the output signal of the actuator is changed to make the actuator move to establish a one-to-one correspondence between the valve stem displacement and the output signal of the controller, and achieve balance through microprocessor control. Therefore, the valve positioner constitutes a feedback control system with the valve stem displacement as the measurement signal and the controller output as the setting signal.

[0004] At present, there are many valve positioners and actuators used in the industry, and their specifications and signals are also many, including analog valve positioners, digital valve positioners, HART valve positioners, PROFIBUS valve positioners, etc. Their structure is mainly composed of a displacement sensor system proportional to resistance, an analog i / P converter with an air capacity enhancer, and electronic components including a microcontroller. In production, they mainly control the linear stroke pneumatic diaphragm valve (for controlling water and steam, etc.) and the angular stroke pneumatic ball valve (for controlling the damper) in the actuator.

[0005] In the high temperature and high pressure medium environment of manufacturing, actuator problems often occur, such as actuator blockage, increased friction of valve stem after long-term operation, zero drift, actuator aging and rusting, and large medium resistance. Once the above problems occur, they will affect the control accuracy in tobacco and cigarette production, and thus affect the quality of the terminal products. Summary of the invention

[0006] In view of the above, the present invention aims to provide a method for diagnosing actuator blockage with a valve positioner to solve the specific problem of how to diagnose the actuator through the valve positioner.

[0007] The technical solution adopted by the present invention is as follows:

[0008] The present invention provides a method for diagnosing blockage of an actuator with a valve positioner, which includes:

[0009] A test platform is constructed, the test platform comprising: a power module connected to a power supply, a PLC, a digital output module connected to the PLC, an analog input module, an analog output module, a switch, a DP / PA coupler, a touch screen equipped with a test interactive interface, a PC at least used for configuring the PLC and used as a host computer, a solenoid valve connected to a compressed air source, and a pneumatic diaphragm valve with a valve positioner; wherein the switch is respectively connected to the PC, the touch screen, the PLC, and the DP / PA coupler by electrical signals, the digital output module is connected to the solenoid valve by electrical signals, the solenoid valve is connected to the pneumatic diaphragm valve with the valve positioner by air path, and the DP / PA coupler is used to be connected to a field bus type valve positioner by electrical signals, the analog input module and the analog output module are used to be connected to an analog type valve positioner by electrical signals, and the power module is at least used to supply power to the PLC, the touch screen, and the DP / PA coupler;

[0010] Connecting an unused new target pneumatic diaphragm valve with a valve positioner to the test platform and starting the test;

[0011] Acquire test data and transmit the test data to the PC to save as original data corresponding to the target pneumatic diaphragm valve, wherein the test data includes different actual opening values ​​and the interval time between executing adjacent opening values;

[0012] After the target pneumatic diaphragm valve is actually used, if a blocking phenomenon occurs, the target pneumatic diaphragm valve is reconnected to the test platform for retesting;

[0013] The obtained retest data is compared and analyzed with the original data, and an analysis report is output.

[0014] In at least one possible implementation, the testing or retesting process includes at least:

[0015] The preset value of the valve opening is set in advance in sequence according to a number of equal steps;

[0016] After the pneumatic diaphragm valve to be tested is connected to the test platform, the pneumatic diaphragm valve under test is triggered to execute each of the opening preset values ​​in sequence, and the measured opening value in the test and the time value from the previous opening preset value to the current opening preset value are read.

[0017] In at least one possible implementation, the process of constructing the original data or the retest data at least includes:

[0018] Using the PC to perform a drawing analysis, including using the measured opening value as the horizontal axis and the time value as the vertical axis;

[0019] Using the drawing analysis and comparison results, a self-learning system for pneumatic diaphragm valves with valve positioners is established.

[0020] In at least one possible implementation manner, the same test conditions and test operation sequence are used in the retest process and the previous test process of the target pneumatic membrane valve.

[0021] In at least one possible implementation, during the test or retest process, preset test programs of non-current test types are shielded according to different valve positioner types, and the valve positioner types include at least: analog valve positioner and fieldbus valve positioner.

[0022] In at least one possible implementation, the test interaction interface in the touch screen includes at least: a test start and stop button, a valve opening setting value input area, and a valve actual opening display area.

[0023] Compared with the prior art, the main design concept of the present invention is that after the test platform is built, an unused new target pneumatic diaphragm valve with a valve positioner is connected to the test platform and the test is started; the test data is obtained and transmitted to the host computer to be saved as the original data corresponding to the target pneumatic diaphragm valve, wherein the test data includes different actual opening values ​​and the interval time of executing adjacent opening values; after the target pneumatic diaphragm valve is actually used, if a blocking phenomenon occurs, the target pneumatic diaphragm valve is reconnected to the test platform for retesting; the obtained retest data is compared and analyzed with the original data, and an analysis report is output. The present invention can quickly diagnose the problem of an abnormal valve positioner, and is suitable for the blockage diagnosis of different types of valve positioners commonly used in the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described below with reference to the accompanying drawings, in which:

[0025] Figure 1A schematic diagram of the architecture of an actuator blockage diagnosis and testing platform with a valve positioner provided in an embodiment of the present invention;

[0026] Figure 2 A schematic flow chart of a method for diagnosing actuator blockage with a valve positioner provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0028] The present invention provides an embodiment of a method for diagnosing blockage of an actuator with a valve positioner, specifically, comprising:

[0029] Build a test platform, the test platform is as follows Figure 1 Schematically, it includes: a power module connected to a power supply, a PLC (such as Siemens 1200PLC), a digital output module connected to the PLC (CPU), an analog input module, an analog output module, a switch, a DP / PA coupler, a touch screen equipped with a test interactive interface, a PC at least used to configure the PLC and used as a host computer, a solenoid valve connected to a compressed air source (through an air source triplet) and a pneumatic diaphragm valve with a valve positioner (different types can be selected); wherein the switch is respectively connected to the PC, the touch screen, the PLC, and the DP / PA coupler by electrical signals, the digital output module is connected to the solenoid valve by electrical signals, the solenoid valve is connected to the pneumatic diaphragm valve with a valve positioner by air path, and the DP / PA coupler is used to be connected to a field bus type valve positioner by electrical signals, the analog input module and the analog output module are used to be connected to an analog valve positioner by electrical signals, and the power module is at least used to supply power to the PLC, the touch screen, and the DP / PA coupler;

[0030] Connecting an unused new target pneumatic diaphragm valve with a valve positioner to the test platform and starting the test;

[0031] Acquire test data and transmit the test data to the PC to save it as original data corresponding to the target pneumatic diaphragm valve (which can also be understood as standard data or ideal data), wherein the test data includes different actual opening values ​​and the interval time between executing adjacent opening values;

[0032] After the target pneumatic diaphragm valve is actually used, if a blocking phenomenon occurs, the target pneumatic diaphragm valve after use is reconnected to the test platform for retesting (preferably using the same conditions and the same operation sequence for testing);

[0033] The obtained retest data (which can also be understood as the data to be diagnosed, the fault data) is compared and analyzed with the original data, and an analysis report is output. Thus, the maintenance personnel can repair the faulty parts with less severe blocking problems according to the analysis report, and replace the faulty parts with severe blocking problems.

[0034] The following four points can be added to the above diagnostic test methods:

[0035] First, the testing or retesting process shall at least include:

[0036] The preset value of the valve opening is set in advance in sequence according to a number of equal steps;

[0037] After the pneumatic diaphragm valve to be tested is connected to the test platform, the pneumatic diaphragm valve under test is triggered to execute each of the opening preset values ​​in sequence, and the measured opening value in the test and the time value from the previous opening preset value to the current opening preset value are read.

[0038] Second, the process of constructing original data or retest data at least includes:

[0039] Using the PC to perform a drawing analysis, including using the measured opening value as the horizontal axis and the time value as the vertical axis;

[0040] Furthermore, a self-learning system for pneumatic diaphragm valves with valve positioners is established using the drawing analysis and comparison results.

[0041] Third, since the test platform designed by this method can be used for various types of valve positioners, during the actual test or retest process, according to the different types of valve positioners, the preset test programs of non-current test types are shielded. As mentioned above, the valve positioner types include at least: analog valve positioners and fieldbus valve positioners.

[0042] Finally, regarding the touch screen in the aforementioned test platform, it can be supplemented as follows: the test interactive interface described therein includes at least: a test start and stop button, a valve opening setting value input area, and a valve actual opening display area.

[0043] In addition, those skilled in the art can understand that the above-mentioned embodiment based on the test platform can also be expanded to the production line. Of course, it is understandable that it is necessary to design a test sub-screen on the HMI interface at the production site, design a test subroutine in the actual PLC of the production line, call the program during testing in the organization block OB1, shield the program during production, and design a self-learning system with a pneumatic diaphragm valve with a valve positioner on the central control host computer. The test method is basically the same as the aforementioned test platform, and there is no need to elaborate here. However, it should be pointed out that during online testing, the new and old pneumatic diaphragm valves with valve positioners must be tested under the same conditions to ensure reliable test results.

[0044] Based on the above embodiments, the following further describes the specific examples:

[0045] Step 1: First, design a test platform. This platform includes a set of air switches, a DC24 power supply module, a set of Siemens S7-300 PLC (or Siemens 1200PLC), a digital input module, a digital output module, an analog input module and an analog output module assembled and connected through a guide rail, a set of small switches, a set of DP / PA couplers, a Siemens touch screen, a laptop, a compressed air generator (or introduce compressed air from the workshop), a compressed air three-component pressure reducing valve, and a FESTO solenoid valve. Finally, use wires, network cables, and compressed air pipes to connect the above devices to form a standard test bench.

[0046] Step 2: Select a set of commonly used models of pneumatic diaphragm valves with valve positioners for connection. Figure 2 As shown. Since there are many ways to classify valve positioners, but they are mainly classified into analog signals and digital signals according to the input signal, they can be divided into ordinary valve positioners and fieldbus electrical valve positioners. Ordinary valve positioners are generally divided into pneumatic valve positioners (input signal is analog air pressure 20-100KPa) and analog valve positioners (input signal is current 4-20mA or voltage 1-5V). Fieldbus electrical valve positioners are generally equipped with CPUs and belong to intelligent valve positioners. Their valve stem displacement feedback signals are generally detected by Hall effect displacement method or electromagnetic induction method. Therefore, if you choose an analog valve positioner, connect the AO analog output signal to the valve positioner input signal terminal, and connect the valve positioner valve stem displacement feedback signal terminal to the AI ​​analog input module. If you choose a fieldbus electrical valve positioner, you can connect it to the PLC through the DP / PA coupler with a network cable.

[0047] Step 3: Use PC or PG to configure PLC. Figure 1As shown. Here, a laptop computer with STEP software (such as but not limited to Siemens 1200PLC) is used to configure the above-mentioned S7-300 PLC, digital input and output modules, analog input and output modules, DP / PA coupler and other devices. If a fieldbus electric valve positioner is selected, the valve positioner must also be connected and configured to the DP / PA coupler through a GSD file.

[0048] Step 4: Design the test operation screen on the Siemens touch screen. Figure 2 As shown. Use Winccflexible software to set the "Test Start" button (data source is M0.1), the "Test End" button (data source is M0.2), the "Valve Opening Setting Value" data input area (data source is MD10, valve opening setting value), the "Valve Actual Opening" data input area (data source is MD20, valve positioner valve stem actual displacement feedback value), etc. Press the "Test Start" button, M0.1 is 1, if not, M0.1 is 0; press the "Test End" button, M0.2 is 1, if not, M0.2 is 0, etc.

[0049] Step 5: Write the test program, such as Figure 2 shown.

[0050] Write program 1: If an analog valve positioner is used, first block program 2, and then use FC106 to convert the valve setting opening value MD10 into the output value of the analog output module (AO), which is the input signal of the valve positioner; use FC105 to convert the actual valve stem displacement feedback signal collected by the analog input module (AI) into the actual opening value of the pneumatic diaphragm and transmit it to MD20.

[0051] Write program 2: If a fieldbus valve positioner is used, first shield the above program 1, and then according to the configuration communication manual of the valve positioner, send the valve positioner enable signal word to PQW + valve positioner configuration Q zone address; send the valve set opening value MD10 to PQD + valve positioner configuration Q zone address; read the actual opening of the valve positioner through PID + valve positioner configuration I zone address and send it to MD20.

[0052] Write program 3: Use the SR statement to assign the normally open point of M0.1 to the S end of SR; use the comparison statement CMP=R (assign MD10 to IN1 and MD20 to IN2) and the normally open point of M0.2 in parallel and assign them to the R end of SR; name the SR output end M5.0.

[0053] Program 4: Use the TONR statement to collect the running time of the pneumatic diaphragm valve with valve positioner from one opening to another. Select the TONR timer and name it T0 (the timer has a variable rate of 1ms and is a retentive timer), assign the M5.0 normally open point to the IN terminal of T0; assign the M0.2 normally open contact to the R terminal of T0; assign T#6000S) to the PT terminal of T0 (this time can be customized); assign MD30 to the ET terminal of T0 (used to collect the running time from one opening to another).

[0054] Program preparation 5: The normally open point of M0.1 is connected in parallel with the normally open point of Q0.1, and then connected in series with the normally closed point of M0.2 and assigned to Q0.1. Q0.1 controls the solenoid valve, which controls the compressed air source to the valve positioner.

[0055] Step 6: Use PLC to read the actual opening value MD20 of the pneumatic diaphragm valve with valve positioner and the corresponding time value MD30 from the previous opening to the current opening. Figure 2 As shown. Before installing a new pneumatic diaphragm valve with a valve positioner, first connect the new pneumatic diaphragm valve with a valve positioner to the test bench and adjust the compressed air pressure reducing valve to the standard air pressure required by the pneumatic diaphragm valve. Then set the valve opening setting value MD10 to 20 (set in the order of valve opening 20°, 40°, 60°, 80°, 100°); press the "test start" button M0.1, the pneumatic diaphragm valve with a valve positioner starts to run, and the timer T0 also starts timing. When the actual opening value MD20 of the diaphragm valve is equal to the set opening setting value MD10, the pneumatic diaphragm valve stops, and T0 also stops running. At this time, the pointer addressing method is used to transmit the value of MD20 to DB1.DBD0, and the time value of MD30 is transmitted to DB2.DBD0. Similarly, according to the above operation sequence, the valve opening setting value MD10 is set to 40°, 60°, 80°, and 100°, and the corresponding opening value MD20 is transmitted to DB1.DBD4, DB1.DBD8, DB1.DBD12, and DB1.DBD16 by pointer addressing; the time value of MD30 is transmitted to DB2.DBD4, DB2.DBD8, DB2.DBD12, and DB2.DBD16 by pointer addressing. Of course, the above opening setting value can be divided into finer or coarser ranges for testing. The above test results are transmitted to the host computer as original data and ideal data. When the pneumatic diaphragm valve with valve positioner has a blocking problem during use, it is first removed and installed on the test bench. The same conditions (such as the same compressed air source pressure) and the same operation sequence (such as the same number of test points) are used for testing and data access, and the above test results are transmitted to the host computer as the required diagnostic data and fault data.

[0056] Step 7: Design a self-learning system on the host computer and transmit the above raw data and fault data to the host computer. The host computer will analyze the data and issue an analysis report after self-learning. Figure 2 As shown. On the test bench, a laptop can be used as a host computer, and software (such as IFIX software, etc.) can be used to perform drawing analysis (opening as the horizontal axis, time as the vertical axis) and data analysis and comparison to design a self-learning system for a pneumatic diaphragm valve with a valve positioner. Then the above raw data and fault data are transmitted to the host computer's self-learning system for a pneumatic diaphragm valve with a valve positioner. After data analysis and self-learning, the information on the blocking location and degree of blocking is issued based on the comparative analysis of the deviation size, and an analysis report is issued. The maintenance personnel will perform part repairs when the deviation is small and the blocking is light, or must replace the part when the deviation is large and the wear is serious.

[0057] Step 8: This test function can also be implemented on the production line. However, the test sub-screen should be designed on the HMI interface at the production site, including the test start and test stop buttons, the "valve opening set value" data input area, the "valve actual opening" data input area, etc. Then design the test subroutine in the PLC of the production line, call the program during the test in the organization block OB1, and shield the program during production. After installing the new pneumatic diaphragm valve with valve positioner, test it and transmit this data as the original data and ideal data to the host computer in the central control room. Design a self-learning system for pneumatic diaphragm valve with valve positioner on the host computer, which can test the same pneumatic diaphragm valve with valve positioner under the same test conditions in the new and old stages (this is very important), and use the self-learning system to compare and diagnose the data tested in the new and old stages and output the analysis report. In this way, when the pneumatic diaphragm valve of the valve positioner is blocked during use, it is tested by the same means and test conditions as when a new pneumatic diaphragm valve with a valve positioner is installed, and the test data (fault data) is transmitted to the self-learning system of the pneumatic diaphragm valve with a valve positioner in the upper computer. After comparing and analyzing the fault data with the original data, an analysis report is output. The maintenance personnel can repair the reported parts according to the analysis report if the blocking problem is relatively minor, and replace the parts with serious blocking problems.

[0058] In summary, the main design concept of the present invention is that after the test platform is built, an unused new target pneumatic diaphragm valve with a valve positioner is connected to the test platform and the test is started; the test data is obtained and the test data is transmitted to the PC to be saved as the original data corresponding to the target pneumatic diaphragm valve, wherein the test data includes different actual opening values ​​and the interval time of executing adjacent opening values; after the target pneumatic diaphragm valve is actually used, if a blocking phenomenon occurs, the target pneumatic diaphragm valve is reconnected to the test platform for retesting; the obtained retest data is compared and analyzed with the original data, and an analysis report is output. The present invention can quickly diagnose the problem of an abnormal valve positioner, and is suitable for the blockage diagnosis of different types of valve positioners commonly used in the industry.

[0059] If the expressions expressing orientation are mentioned in the embodiments of the present invention, they are relative concepts based on the embodiments. In addition, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, wherein a, b, c can be single or multiple.

[0060] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings, but the above is only a preferred embodiment of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched into a variety of equivalent schemes by those skilled in the art without departing from or changing the design ideas and technical effects of the present invention; therefore, the present invention is not limited to the scope of implementation shown in the drawings, and all changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the specification and drawings, should be within the protection scope of the present invention.

Claims

1. A method for diagnosing actuator blockage with a valve positioner, characterized in that: include: A test platform is constructed, the test platform comprising: a power module connected to a power supply, a PLC, a digital output module connected to the PLC, an analog input module, an analog output module, a switch, a DP / PA coupler, a touch screen equipped with a test interactive interface, a PC at least used for configuring the PLC and used as a host computer, a solenoid valve connected to a compressed air source, and a pneumatic diaphragm valve with a valve positioner; wherein the switch is respectively connected to the PC, the touch screen, the PLC, and the DP / PA coupler by electrical signals, the digital output module is connected to the solenoid valve by electrical signals, the solenoid valve is connected to the pneumatic diaphragm valve with the valve positioner by air path, and the DP / PA coupler is used to be connected to a field bus type valve positioner by electrical signals, the analog input module and the analog output module are used to be connected to an analog type valve positioner by electrical signals, and the power module is at least used to supply power to the PLC, the touch screen, and the DP / PA coupler; Connecting an unused new target pneumatic diaphragm valve with a valve positioner to the test platform and starting the test; Acquire test data and transmit the test data to the PC to save as original data corresponding to the target pneumatic diaphragm valve, wherein the test data includes different actual opening values ​​and the interval time between executing adjacent opening values; After the target pneumatic diaphragm valve is actually used, if a blocking phenomenon occurs, the target pneumatic diaphragm valve is reconnected to the test platform for retesting; The obtained retest data is compared and analyzed with the original data, and an analysis report is output.

2. The method for diagnosing actuator blockage with a valve positioner according to claim 1, characterized in that: The testing or retesting process shall include at least: The preset value of the valve opening is set in advance in sequence according to a number of equal steps; After the pneumatic diaphragm valve to be tested is connected to the test platform, the pneumatic diaphragm valve under test is triggered to execute each of the opening preset values ​​in sequence, and the measured opening value in the test and the time value from the previous opening preset value to the current opening preset value are read.

3. The method for diagnosing actuator blockage with a valve positioner according to claim 2, characterized in that: The process of constructing original data or retest data includes at least: Using the PC to perform a drawing analysis, including using the measured opening value as the horizontal axis and the time value as the vertical axis; Using the drawing analysis and comparison results, a self-learning system for pneumatic diaphragm valves with valve positioners is established.

4. The method for diagnosing actuator blockage with a valve positioner according to claim 1, characterized in that: The retest process of the target pneumatic diaphragm valve and the previous test process adopt the same test conditions and test operation sequence.

5. The method for diagnosing actuator blockage with a valve positioner according to claim 1, characterized in that: During the test or retest process, preset test programs of non-current test types are shielded according to different valve positioner types, and the valve positioner types at least include: analog valve positioner and fieldbus valve positioner.

6. The method for diagnosing actuator blockage with a valve positioner according to any one of claims 1 to 5, characterized in that: The test interactive interface in the touch screen at least includes: a test start and stop button, a valve opening setting value input area, and a valve actual opening display area.

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