RU2791800C1 - Intratubal device start-up control system - Google Patents

Abstract

FIELD: gas industry.

SUBSTANCE: invention is related specifically to methods for cleaning and diagnosing the internal cavity of main gas pipelines, and can be used to improve the reliability and safe operation of the pipeline park in the automation of technological processes. The control system for the process of launching an intratubal device (ITD) includes a ITD launch chamber, piping, pressure sensors, ITD movement alarms, pipeline shut-off valves. According to the invention, the piping contains a ITD start-up line equipped with a regulator valve, pressure equalization and gas purge lines, spark plug and bypass lines. At the same time, the system additionally includes a controller configured to control processes of displacement of the gas-air mixture from the internal cavities of the pipeline piping and the ITD launch chamber and stage-by-stage equalization of gas pressure during the ITD launch into the pipeline. Moreover, the controller is connected to the valve-regulator of the ITD launch line, the control units for the shut-off valve drives of the indicated piping lines, the pressure sensors in the ITD launch chamber, as well as with the ITD movement signaling devices. The technical task is to ensure the safety of automated control of the process of launching the ITD in a natural gas environment directly in the process zone.

EFFECT: prevention of formation of an explosive gas-air mixture at the time of launching the ITD by automating the process of preliminary controlled purging of the piping cavities and the launch chamber of the ITD, as well as preventing the destruction of the elements of the launch unit due to the stage-by-stage filling of the internal cavities of the pipeline piping and the ITD launch chamber with gas.

1 cl, 2 dwg

Description

The invention relates to the field of the gas industry, in particular to methods for cleaning and diagnosing the internal cavity of main gas pipelines and can be used to improve the reliability and safe operation of the pipeline park in the automation of technological processes.

During the operation of the main pipeline, its inner surface is contaminated with turbine oil, scale exfoliated from pipes, condensate, etc., which leads to an increase in hydraulic resistance and, accordingly, to a decrease in the throughput of the pipeline. All main gas pipelines being designed and put into operation are provided with nodes (chambers) for launching and receiving inline devices, which are located at unequal crossings, or at compressor station connection nodes. To improve energy efficiency and safe operation of main gas pipelines, it is necessary to clean their internal surface and in-line flaw detection, which ultimately leads to a reduction in the material costs of the transporting enterprise and the prevention of man-made accidents with their consequences.

A device for launching and receiving in-line in-line cleaning and diagnostic tools into a pipeline is known, which contains chambers for launching and receiving an in-line device with fittings for supplying and discharging the product, equipped with a flexible connection unit with the linear part of the pipeline, ensuring their movement and rotation in horizontal and vertical planes, and along the axis of the chamber, and the chambers from one end are equipped with an end gate, consisting of a hinged cover and half-clamps, pivotally connected to each other on the same axis in the lower part of the hinged cover, and in the upper part connected to one screw (RU 2103597, publ. 27.01.1998 d.) However, the design complexity of the design of the device prevents the widespread use of the device, in addition, there is no possibility of remote automatic control of the process of launching and receiving the in-line device.

A device is known for starting and receiving cleaning devices at a given section of a pipeline of long length (RU 2449209, publ. 27.04.2012). However, such a device is designed for pipeline systems with a pressure of the pumped medium of not more than 2.5 MPa. In addition, automated control of the in-line device start-up process is not provided.

The closest to the claimed technical solution is an automated system for launching cleaning in-line devices, containing an expansion chamber, an end gate, shut-off valves equipped with an electric drive with the possibility of remote control, a pressure gauge with a pressure sensor, additionally contains a signaling device for the movement of the cleaning device, and the expansion chamber is made inclined to the pipeline and is equipped with rods for the sequential start of cleaning devices, which are equipped with an electric drive with the possibility of remote control (RU 2690111, publ. 05/30/2019).

The disadvantage of this system is that it is applicable when transporting liquid media through the pipeline, and not gas. Systems for transporting natural gas are characterized by increased pressure in the pipeline and the need for pre-purging the cavities of the pipeline to displace air and prevent the formation of an explosive concentration of gas, which the known prototype system cannot provide.

The disadvantage is also the location of the launch chamber at an angle, which will complicate the process of reeving the inline device for gas pipeline diameters from DN700 to DN1400.

Thus, the use of the known system does not allow to safely control the process of launching the in-line device directly in the process zone in automatic mode.

The technical task is to ensure the safety of automated control of the process of launching the WTP in a natural gas environment directly in the process zone.

EFFECT: prevention of the formation of an explosive gas-air mixture at the time of launching the WTP by automating the process of preliminary controlled purging of the piping cavities and the launch chamber of the WTP, as well as preventing the destruction of the elements of the launch unit due to the phased filling of the internal cavities of the pipeline piping and the launch chamber of the WTP with gas.

The technical result is achieved by the fact that in the control system for the process of launching an in-line device (VTU), including an ITU launch chamber, piping, pressure sensors, VTU movement alarms, piping shutoff valves, according to the invention, the piping contains an ITU launch line equipped with a valve - a regulator, pressure equalization and gas purge lines, spark plug and bypass lines, the system additionally includes a controller configured to control the processes of gas-air mixture displacement from the internal cavities of the pipeline piping and the WTP launch chamber and stage-by-stage gas pressure equalization during the WTP launch into the pipeline. Moreover, the controller is connected to the valve-regulator of the WTU launch line, the control units for the shut-off valve drives of the indicated piping lines, with pressure sensors in the VTU launch chamber, as well as with the VTU movement signaling devices.

The essential features indicated in the formula are aimed at eliminating the risk of emergency depressurization of the WTU launch chamber and adjacent pipelines, which may occur as a result of an uneven pressure increase when the chamber is filled with natural gas, as well as in the event of ignition of the gas-air mixture located in the internal cavities of the pipeline lines and VTU launch chambers.

The inclusion in the system of a controller operating according to a given algorithm, as well as a regulator valve operating on the commands of the controller, makes it possible to automate the technological process, ensuring the safety of pipeline operation during the start-up of the WTU and carrying out in-line cleaning without human intervention.

Figure 1 shows the technological layout of the elements of the proposed system. The arrows indicate the direction of gas flow in the pipeline.

Figure 2 shows a block diagram of the WTU launch control system, where:

1- chamber for launching an in-line device (VTU);

2- signaling device for movement of the VTU;

3- gas pressure sensor in the launch chamber 1;

4- main piping line;

5-line crane of the main line 4;

6- pressure sensor in front of the linear valve 5;

7- pressure sensor downstream of the line valve 5;

8 - bypass piping line;

9 - signaling device for the movement of the WTU after the bypass line 8;

10 - bypass valve;

11 - pressure sensor in front of the bypass valve 10;

12 - pressure sensor after the bypass valve 10;

13,14 - bypass valves;

15- gas launch line;

16,17 - launching cranes of the launch line 15;

18,19 - bypass valves of launch line 15;

20-candle piping line;

21- valve of the candle line 20;

22 purge candle;

23-gas purge line;

24.25 - purge valves;

26-valve-regulator;

27 - gas pressure equalization line;

28-cock line 27 gas pressure equalization;

29-40 - control units for crane drives;

41- controller;

42-operator's workplace;

43-control room;

44 - technological zone.

As a controller 41, a program logic device is used, which is designed to receive and process incoming data from technological objects in real time in order to control the execution and regulate the implementation of technological operations, identify and prevent abnormal events.

Developed by the applicant and installed on the controller 41 special software allows you to control the process without the presence of service personnel directly in the process area 44 of the work.

The controller 41 is configured to connect directly to the linear telemechanics system (not shown) via a modem (not shown) using standard data transfer protocols (OPC, Modbus), it contains the required number of input-output boards for connecting control units for valve actuators , control valve, motion alarms and pressure sensors. It also incorporates an interface unit (not shown) with adjacent systems, which allows switching control and management of the technological process to the central control room 43.

The shut-off valves of the system include valves 5,10,13,14,16,17,18,19,21,24,25,28, the drives of which are equipped with control units 29-40, which allow adjusting the position of the valves (open / closed) using signals coming from the controller 41.

The proposed system works as follows.

Initially, the launch chamber 1 is in a closed state, in the internal cavity of which there is a gas-air mixture (GWS) under pressure. Therefore, before opening chamber 1 for “reserving” WTU, it is necessary to bleed hot water from chamber 1 and from the internal cavities of the piping to which it is connected.

Before “reserving” the VTU into the launch chamber 1, the internal cavities of the piping lines and the chamber 1 are emptied from the hot water supply. To do this, before starting work, the valves 5,17,19,28,16,13,14,21 are closed, the valves 10,24,25 are opened, and the regulator valve 26 is kept in the closed position.

After that, the end gate (not shown) of chamber 1 is opened and, using a crane-beam and storage sleds (not shown), the VTU is placed inside chamber 1. Then the end gate of chamber 1 is tightly closed by tightening its latches and clamping mechanisms (not shown). VTU is placed in chamber 1 between branch pipes of valves 24.25 of line 20 of piping. In chamber 1, a pressure sensor 3 is located at the inlet, and a signaling device 2 for the movement of the WTU is located at the outlet.

Then the valves 19 and 28 are opened. The cavity of the chamber 1 is purged after opening the regulator valve 26 with a gas with a pressure of not more than 1 kgf/cm ² , and the purging is carried out until the oxygen content in the hot water supply does not exceed 2%. The oxygen content is controlled using a gas analyzer (not shown).

After purging and closing the taps 24,25, the cavity of the chamber 1 is filled with gas by opening the regulator valve 26 at the signal of the controller 41, while the pressure growth rate should be no more than 10 kgf/cm ² per minute. The rate of pressure growth is controlled and regulated by the controller 41 according to the readings of pressure sensors 3 and 6.

The chamber 1 is filled with gas in stages.

At stage 1, chamber 1 is filled to 1/3 of the working pressure in the gas pipeline. At the 2nd stage - filling up to 2/3 of the operating pressure. At stage 3, chamber 1 is filled with gas up to the operating pressure.

The occupancy of chamber 1 is controlled by controller 41, which receives a signal from pressure sensors 3 and 6. This is necessary to prevent the destruction of the elements of the launch unit due to the phased filling of the internal cavities of the pipeline piping and the launch chamber of the WTU with gas.

After each stage, the chamber 1 is kept under pressure for 20 minutes, the equipment is inspected and possible leaks are determined by listening, a gas analyzer, or the controller 41 signals leaks by recording the pressure drop.

When leaks are detected, the filling of chamber 1 is stopped, the cause of the leak is determined, the gas pressure is released through the spark plug line 20.

After the cause of the leak has been eliminated, chamber 1 is refilled with gas.

After equalizing the pressure in chamber 1 and in the piping, according to the readings of sensors 3 and 6, the controller 41 sends a signal to open valves 5,16,17 and close valves 19,18,28. After that, a signal is received to close the valve 10. By closing the valve 10, the system creates a pressure drop across the WTP in chamber 1.

Due to the pressure drop in the range from 0.5 to 1.5 kgf/cm ² (calculated data), the gas, passing through the gas launch line 15, pushes the WTU from the launch chamber 1 into the main line 4 and further into the gas pipeline. The output of the VTU from the chamber 1 controls the signaling device 2 of the movement of the VTU.

After the passage of the VTU through the signaling device 9, the controller 41 gives a command to open the bypass valve 10, close the linear valve 5 and the trigger valve 16. The chamber 1 is released from gas through the gas purge line 23 by opening the purge valves 24,25 on commands from the controller 41.

Claims (1)

The system for controlling the process of launching an inline device (VTU), including an ITU launch chamber, piping, pressure sensors, VTU movement signaling devices, pipeline piping shut-off valves, characterized in that the piping contains an ITU launch line equipped with a regulator valve, pressure equalization lines and gas purging, candle and bypass lines, while the system additionally includes a controller configured to control the processes of expelling the gas-air mixture from the internal cavities of the pipeline piping and the WTU launch chamber and the phased equalization of gas pressure during the WTU launch into the pipeline, the controller being connected to the valve - VTU launch line regulator, control units for shut-off valve actuators of the indicated piping lines, with pressure sensors in the VTU launch chamber, as well as with VTU movement signaling devices.

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