RU2525043C1 - Method for permanent monitoring of pipeline valve control circuit integrity and scheme for its implementation - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: method for permanent monitoring of pipeline valve control circuit integrity involves monitoring mode, control mode, selection of a control circuit, generation of a signal on circuit integrity and electric control command and carrying out of valve control. Monitoring is performed by measuring the voltage at the ends of the normally open contact of a control relay for a solenoid valve by means of the telemetering module of a teleautomatic controller. Circuit integrity signal is generated by the comparison of the above voltage with the voltage value for the controller pickup threshold stored in the controller memory. Description is also given to a permanent monitoring scheme for the pipeline valve control circuit integrity.

EFFECT: carrying out of permanent monitoring of valve control circuit integrity and simultaneous control of the valve along with improved reliability of the control scheme.

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Description

The proposed method and scheme relate to the field of automation of control of pneumohydraulic actuators of safety or shutoff valves (hereinafter referred to as taps) installed on pipelines. The scheme is applicable to cranes controlled by a linear telemechanics system (LTM) or an automated process control system (ACS TP) of main and field pipelines: gas pipelines and product pipelines (hereinafter referred to as pipelines), provides constant, automatic control of the integrity of the crane electric circuits, allows simultaneously control the integrity of control circuits and control the crane.

Cranes are installed on pipelines in order to cut off the emergency section, to stop the transport of the product and to localize the emergency section.

Cranes are mainly equipped with two types of control:

- autonomous control - the crane is controlled automatically, by means of an emergency shut-off machine (AAZK) and an electro-pneumatic control unit (BUEP) by pneumatic or hydraulic signals for monitoring the technological parameters of product transportation [1] D.F. Gurevich, O.N. Zarinsky , Yu.K. Kuzmin. Handbook of fittings for gas and oil pipelines. Leningrad: "Nedra", Leningrad Branch, 1988. Chapter 9, pp. 388-412; [2] Technical documentation. A detection system for an emergency machine with separation of closure media with digital adjustment for liquids and high pressure gas pipelines, operating at low temperatures. Via Gandini 4, 27058 Voghera (Pavia) Italy Tel. + 39-0383.343311 Telefax + 39-0383.62289-366105. 2012];

- remote control - the crane is controlled by a linear telemechanics system. In this mode, the crane is controlled by an electrical signal that forms a linear telemechanics controller. An electrical signal is supplied to the solenoid valve located in the BUEP. In turn, the solenoid valve generates a pneumatic valve control signal.

The well-known telemechanics system "Highway-1" [3]. Technical description and operating instructions ZIO.239.006 TO Blocks BK. Telemechanics "Highway-1". VNPO "Soyuzgazavtomatika", SKB "Gazpriboravtomatika" 1988] is equipped with crane control units BK-22 ÷ BK-25, which are designed to form electrical control commands for cranes and to automatically control the integrity of control circuits. In it, the control device is a high-resistance winding of relay K1 of the BK-22 unit, shown in Fig 1. High-resistance winding I of relay A2: K1 is connected in series with the winding of the electromagnetic valve EO. In the initial state, when the control circuits are in good condition, the relay A2: K1 is in the activated state and its contacts A2: K1 form a signal about the integrity of the control circuits. The solenoid valve EO does not work, since the value of its response current is much higher than the response current of relay A2: K1, which has a high-resistance winding. In the event of an open circuit in the control circuit or open coil of the EO solenoid valve, relay A2: K1 is de-energized, its contacts A2: K1 open and this generates a fault signal.

When controlling a crane, the switching current of the EO electromagnetic valve passes through the current winding II of relay A2: K1. The electromagnetic valve EO is activated, and the relay A2: K1 remains in the activated state due to the current in the current winding II of relay A2: K1. The operation currents of the electromagnetic valve EO and current winding II of relay A2: K1 are equal. In this mode, the contacts A2: K1 also form a signal about the integrity of the control circuits since the relay A2: K1 is in the triggered state due to the current flowing through the current winding II of relay A2: K1. When adjusting, the alignment of the response currents of the electromagnetic valve EO and the current winding II of relay A2: K1 is done by soldering the jumpers ХВ1.

In blocks BK-23 ÷ BK-25, a similar principle of integrity control of electric circuits of remote control of a crane is used, as in the above-described block BK-22.

The closest to the claimed technical solution (prototype) is the automated control system for gas condensate and oil pipelines of the Pavlovsky corridor [4] Explanatory note of the working documentation of ACS TP "Repair of telemechanics, power supply for communications, drives and AACS of gas condensate and oil pipelines of the Pavlovsky corridor 57295386. 000.11. 10.046. P2, 2010 Orenburg, (sheet 56, appendix 25), which implements a method for checking telecontrol circuits, including a control mode or control mode, selection of control circuits, a signal about the integrity of the circuit is generated and the crane is controlled. Checking the remote control circuits of the crane is carried out by the telemetry controller STN-3000, by switching the crane control circuits from the remote control module to the telestate module. The formation of a signal about the integrity of the circuit is carried out when monitoring the flow of test current through the remote control circuit of the crane (see figure 2). The means of control is the discrete input of the telestate module (TS) of the STN-3000 controller. If the control circuits are operational, then the test current flowing through them forms a “single” value in the telestate module, and with faulty telecontrol circuits there is no test current and a “zero” value is generated. Accordingly, at the software level of the controller, the serviceability or malfunction of this control channel is recorded.

The operation of the circuit of Figure 2 for checking the crane telecontrol circuits will be considered using the Open control channel as an example:

- in the initial state, the voltage of the power source 110 V is supplied to the normally closed contact Kdop and then to the contacts of the control relay of the crane K1 and K2. When contacts K1 and K2 are open, the control circuits are de-energized, and the tap is in standby mode;

- in the “Open” control circuit integrity control mode, the controller generates a signal for testing, the TU3 telecontrol module relay activates and switches the Kdop contact. The voltage of 110 V is turned off, and the voltage of 24 V from the source of 24 V is supplied through the switched contact Kdop to the contacts of the relay control valve K1 and K2. The circuit is prepared for testing control circuits;

- the controller generates a signal to open the crane and the relay of the telecontrol module TU1 is activated, closing contact K1. Through the circuit from the source, the voltage is 24 V through the internal resistance of the telestate module TC1, the closed contact Kdop and K1, the winding of the solenoid valve "Open" flows test control current of about 5 mA. The test current is controlled by the TC1 telestate module, if its value is at the level of 5 mA, then a “single” value is generated in the TC1 telestate module. The controller, in turn, generates a signal about the integrity of the telecontrol circuit. If there is no test current, then in the telestate module TC1 a “zero” value is generated, and the controller generates a signal about a malfunction of the telecontrol circuit;

- at the end of the monitoring period of the control circuits, the controller removes the signal for testing, the relay of the TU3 telecontrol module releases the Kdop contact and the circuit returns to its original state.

At the software level in the controller, a clear blocking of simultaneous switching of the contacts Kdop and K1 should be implemented. Otherwise, when switching from the test mode (switching Kdop) and the closed contact K1, the electromagnetic valve and the crane as a whole will spontaneously operate.

When controlling the integrity of the control circuits “Close”, the controller generates a signal for testing, similar to the control circuit “Open”. The difference is that instead of the TU1 telecontrol module relay, the TU2 telecontrol module is turned on, which closes contact K2, and a test current flows through the “Close” electromagnetic valve circuit.

During testing, the solenoid valve does not turn on, since the test current of control flows no more than 5 mA, which is significantly lower than the operating current of the solenoid valve “150 mA for the solenoid valve 110 V and 730 mA for the solenoid valve 24 V” [4]. The magnitude of the test current is limited by the large internal resistance of the TC1 module and the low 24 V supply voltage used for testing.

Due to the fact that during the testing period the crane control circuits are switched from the TU1 telecontrol module to the TC1 telestate module, crane control is not possible, since the 110 V source for powering the electromagnetic valve is switched off by the Kdop contact. Accordingly, it is not possible to test the control circuits in the process of controlling the crane, since the TC1 telestate module is disconnected from the control circuits of the Kdop contact.

“Checking the control circuits of the solenoid valve is carried out periodically in automatic mode, once a day or at the command of the operator. The time and frequency of testing in automatic mode can be changed programmatically ”[4] (sheet 56, appendix 25).

In both well-known technical solutions described, a single principle is implemented to control the integrity of the crane control circuits, which is based on monitoring the passage of test current (current not sufficient for the electromagnetic valve to operate) through the control circuits. The control element in the telemechanics “Magistral-1” is the high-resistance winding I of relay A2: K1, and in the STN-3000 controller - the telestate module TC1.

The prototype has the following disadvantages:

- check the control circuits of the solenoid valve periodically;

- it is impossible to simultaneously monitor the integrity of the control circuits and control the crane. The prototype circuit allows you to either control the circuit or control the crane;

- there are elements that reduce the reliability of the control circuit, these include the relay of the TU3 module, with a movable mechanical contact Kdop;

- occasionally there is a false response of the electromagnetic valve when testing the control circuit, which in some cases led to spontaneous closing / opening of the valve.

There is a practical problem, the solution of which will allow for continuous monitoring of the integrity of the crane control circuits and at the same time control the crane, while increasing the reliability of the control circuit.

The problem is solved by the method of continuous monitoring of the integrity of the control circuits of pipeline valves, including the control mode, control mode, selecting a control circuit, generating a signal about the integrity of the circuit and an electrical control command and controlling the valve, in which according to the invention, the control is carried out by measuring the voltage at the ends of a normally open the contact of the solenoid valve control relay through the telemetry module of the telemechanics controller, and the integrity signal is pi is formed by comparing this voltage with a controller voltage threshold value stored in the controller memory. The inventive method is carried out by means of a continuous integrity control circuit for the control valves of pipelines, including a linear telemechanics controller with control elements and telecontrol modules, a power source, and a crane with solenoid valves connected by control circuits, in which according to the invention the linear telemechanics controller contains telemetry modules and converters, and the voltage of the threshold of its operation is recorded in the controller's memory.

Figure 1 presents the control circuit of the crane with the block BK-22, LTM "Highway 1" [3], figure 2 - scheme for checking the remote control circuits of the cranes of the prototype [4], figure 3 - the proposed scheme for continuous monitoring of circuit integrity control valves of pipelines. In Fig. 3, the following positions are indicated: (1) —control point of telemechanics; (2) - controller of linear telemechanics; (3), (4) - telemetry modules; (5), (6) - telecontrol modules; (7) - pipeline control valve; (8) - relay contact of the telecontrol module, controls the “open” solenoid valve; (10) - relay contact of the telecontrol module, controls the “close” electromagnetic valve; (9) - “open” solenoid valve; (11) “close” solenoid valve; (12), (13) - converters; (14) - power supply 110 V.

The method presented in this invention is proposed to be implemented in the automation of control of pneumatic and hydraulic actuators of safety or shut-off valves installed on pipelines. For its implementation, it is necessary to carry out the proposed scheme and, at the software level of the controller, implement processing of the method operations according to the corresponding algorithms. The operation of the method measures the voltage at the ends of a normally open contact of the solenoid valve control relay by means of the telemechanics module of the telemechanics controller, compares it with the voltage of the controller threshold, stored in the controller memory, and forms a signal about the integrity of the circuit. Depending on the mode - control, control or combined (control and management) the stages of the operation generate various signals about the integrity of the circuit according to the corresponding algorithms that process three types of faults and a good condition. The algorithms of the circuit are presented in detail below.

The essence of the proposal lies in the fact that in the normal state, the contact (8) of the telecontrol module relay (6) with the solenoid valve (9) is in the open state, and there is a voltage equal to the operating voltage of the electromagnetic solenoid on the contacts (8) of the telecontrol module relay (6) valve (9). The voltage at the contacts (8) of the telecontrol module (6) has a nominal value if the power supply unit of the electromagnetic valve (14) is good, the control circuits and the coil of the electromagnetic valve (9) do not have an open circuit, contact (8) is not stuck. In the event of a malfunction of the power supply unit (14), an open circuit of the control circuit or the winding of the electromagnetic valve (9), sticking of the contact (8), the voltage becomes zero. The presence or absence of voltage at the contacts (8) of the telecontrol module relay (6) is, accordingly, a sign of serviceability or serviceability of the control circuits.

It is proposed to control the voltage with the telemetry module (3), which is part of the telemechanics controller (2). Matching the magnitude of the measured voltage with the magnitude and type of input signal of the telemetry module (3) is carried out by the converter (13).

The essence of the functioning of the method is considered on the proposed circuit for checking the control circuits of the crane (Figure 3) and the circuit for testing the control circuits of the crane of the prototype (Figure 2) using the Open control channel as an example.

The proposed scheme (Figure 3) works according to the following algorithms:

1. The period of the control regime. The crane (7) is closed, the control circuit is operational. In this case, a voltage of 110 V is present at the ends of the contact (8) of the telecontrol module relay (6), since the contact (8) is in the open position. Voltage 110 V is generated by a power source (14) to power the solenoid valves (9) and (11);

2. Voltage 110 V from the contact (8) of the telecontrol module relay (6) is supplied to the input of the converter (13). Voltage 110 V is converted by the converter (13) into a signal - “unified signal 0-10 V” and fed to the input of the telemetry module (3);

3. If there is a signal “unified signal 0-10 V” within 7-10 V at the input of the telemetry module (3), the controller (2) generates a signal about the serviceability of the control circuits;

4. The control circuits are OK, the circuit is waiting for the crane control command (7) - “Open”;

5. During the period of the crane control mode (7) “Open”, the controller (2) generates a signal to open the crane (7). The telecontrol module (6) will close the contact (8) and the “Open” solenoid valve (9) will work, the valve (7) starts to open;

6. A closed contact (8) will reduce the voltage of 110 V to zero at its ends and at the input of the converter (13);

7. At the output of the converter (13) and the input of the telemetry module (3), the signal - “unified signal 0-10 V” will decrease to zero. The telemetry module (3) during this period transmits to the controller (2) a zero signal value. In the period of the crane control mode, unlike the control mode, the controller (2) does not generate a signal about the malfunction of the control circuits, since the contact closure (8) is a necessary condition during the period of the crane control mode (7);

8. A decrease in voltage of 110 V during the period of crane control mode (7) signals the normal operation of the telecontrol module (6) and its contact (8). This control was absent in the prototype;

9. After the valve (7) opens, the controller (2) removes the signal to open the valve (7) and the telecontrol module (6) opens the contact (8), at the ends of which voltage 110 V appears again;

10. According to the newly appeared voltage of 110 V at the ends of the contact (8), the controller (2) will again generate a signal about the serviceability of the control circuits in accordance with paragraphs 1-4 of this algorithm;

11. Type I malfunction detection. If the valve (7) opens, the controller (2) receives a signal to open the valve (7), but the contact (8) does not open (contact (8) burned or stuck), then the ends do not have a voltage of 110 V. At the input of the converter (13), the voltage will also be zero;

12. At the output of the converter (13) and the input of the telemetry module (3), the signal “unified signal 0-10 V” will be zero. The telemetry module (3) in this case transmits to the controller (2) the zero signal value and the controller (2) generates a signal about the failure of the crane control circuit;

13. Type II fault detection. If a malfunction occurs in the 110 V power supply unit (14), the control circuits or the solenoid valve coil (9) breaks, the voltage at terminal (8) will become zero. A signal is generated about a malfunction of the crane control circuit in accordance with paragraph 12 of this algorithm. The control of the 110 V power supply unit (14) was absent in the prototype;

14. Fault detection type III. During the period when the controller (2) sends the crane control command (7) “Open”, the voltage at the ends of the contact (8) did not change, due to a malfunction of the telecontrol module (6) or contact (8), the controller (2) generates a signal about malfunction of the crane control circuits. This control was absent in the prototype.

Control of the crane control circuits via the “Close” channel is carried out similarly to that described above. In this mode, the following circuit elements will be involved: contacts (10) of the telecontrol module relay (5), a converter (12), a telemetry module (4), an electromagnetic valve (11). The controller (2), 110 V power supply (14) and tap (7) remain the same.

In the proposed scheme, the type of converters (12); (13) is not fundamental and completely depends on the practical crane control schemes. In the particular case, when a telemetry module (3), (4) is used as the described module, a module with a unified input signal of 0-10 V, a simple resistive divider can be used.

The threshold value at which the controller (2) determines whether the circuits are working or not working is selected during the adjustment of the telemechanics system at the program level. The response threshold is stored in the controller's memory in the form of a certain constant (setpoint). If the voltage at the input of the telemetry module (3) is higher than a constant, then the controller (2) generates a signal about the serviceability of the control circuits. If the voltage at the input of the telemetry module (3) is lower than a constant, then the controller (2) generates a signal about the malfunction of the control circuits. The selection of the threshold value is determined by the necessary sensitivity of the control elements of the crane control circuits and the minimum response voltage of the electromagnetic valve.

The proposed scheme in comparison with the prototype has several advantages that provide:

- continuous automatic control of the integrity of the electrical circuits for controlling the crane due to the fact that the elements of control and control of the crane are constantly connected to the controller, power source and operate independently;

- the ability to simultaneously monitor the integrity of the control circuits and control the crane, due to the absence of switching circuit elements when switching from the control circuit control mode to the crane control mode, through the telecontrol module TU3 with contact Kdop (Figure 2);

- reducing the number of elements with mechanically movable contacts, by eliminating the telecontrol module TU3 with a movable mechanical contact Kdop (Figure 2);

- elimination of spontaneous closing or opening of the crane, by eliminating the telecontrol module TU3 with the contact Kdop, and eliminating the need to use the blocking of simultaneous switching of contacts Kdop and K1 or Kdop and K2 (Figure 2). In addition, the exclusion of mechanically movable contacts Kdop increases the reliability of the crane control circuit (7).

The technical and economic effect when applying the proposed method and scheme is to increase the reliability of crane control, and accordingly the reliability of operation of pipelines is increased. Improving reliability is ensured by constant, automatic control of the integrity of the electrical circuits of crane control, due to the ability to simultaneously control the integrity of control circuits and control the crane. The control mode of the crane does not depend on the test mode of the control circuits, the modes are executed in parallel. An additional option appears to control the integrity of the control circuits and the operability of the equipment directly during the crane control period. During commissioning, it is possible to adjust the sensitivity of the control elements of the crane control circuits. False responses of the crane are eliminated, which eliminates the unauthorized stoppage of transport of the product through the pipeline.

List of sources of information:

[1] D.F. Gurevich, O.N. Zarinsky, Yu.K. Kuzmin. Handbook of fittings for gas and oil pipelines. Leningrad: "Nedra", Leningrad Branch, 1988. Chapter 9, pp. 388-412

[2] TECHNICAL DOCUMENTATION. EMERGENCY AUTOMATIC DETECTION SYSTEM WITH SEPARATION OF A CLOSING ENVIRONMENT WITH DIGITAL ADJUSTMENT FOR LIQUIDS AND HIGH PRESSURE GAS PIPES OPERATING AT LOW TEMPERATURES. Via Gandini 4, 27058 Voghera (Pavia) Italy Tel. + 39-0383.343311 Telefax + 39-0383.62289-366105. 2012 year

[3] Technical description and instruction manual 3IO.239.006 TO Blocks BK. Telemechanics "Highway-1". VNPO "Soyuzgazavtomatika", SKB "Gazpriborav-tomatika" 1988

[4] Explanatory note of the ACS TP working documentation “Repair of telemechanics, communication power supply, drives and AACC of gas condensate and oil pipelines of the Pavlovsky corridor” 57295386.000.11. 10.046. P2, 2010 Orenburg, (sheet 56, appendix 25).

Claims (2)

1. A method for continuously monitoring the integrity of the control circuits of pipeline valves, including the monitoring mode, control mode, selecting a control circuit, generating a signal about the integrity of the circuit and the electrical control command and controlling the valve, characterized in that the control is carried out by measuring the voltage at the ends of the normally open relay contact control the electromagnetic valve through the telemetry module of the telemechanics controller, and a signal about the integrity of the circuit is formed when comparing this voltage Nia controller with the threshold voltage value stored in the controller memory. 2. The scheme of continuous monitoring of the integrity of the control circuits of the valves of pipelines, including a linear telemechanics controller with control elements and telecontrol modules, a power source, as well as a crane with solenoid valves connected by control circuits, characterized in that the linear telemechanics controller contains telemetry modules as control elements with converters, and the voltage of the threshold of its operation is recorded in the controller's memory.

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