RU104696U1 - MULTI-SECTION IN-TUBE APPARATUS FOR DIAGNOSTIC OF STRESSED-DEFORMED STATE OF PIPELINE - Google Patents

Abstract

 1. A multi-section in-tube projectile for diagnosing a stress-strain state of a pipeline, comprising successively articulated sections, one of which is a measuring section, each section contains a cylindrical body, at the ends of which are locomotor elements, the measuring section contains a magnetizing system that provides magnetization of the pipe walls a weak magnetic field and made in the form of two magnetizing belts of radial magnet mounted on the housing permanent magnets, at the poles of which are attached brushes of magnetically soft material, the direction of magnetization in the magnetizing belts being the opposite, and a measuring system installed between the magnetizing belts and made in the form of a moving measuring belt of magnetic field sensors spring-loaded to the pipe wall, which measure the tangential component НX magnetic field along the generatrix of the pipe, characterized in that a preparatory section is introduced containing a magnetizing system, cat The hot magnetizes the walls of the pipeline to saturation, and the direction of magnetization is the opposite of magnetization in the measuring section. ! 2. The device according to claim 1, characterized in that the magnetizing system of the preparatory section is made in the form of two magnetizing belts mounted on the housing of radially magnetized permanent magnets, at the poles of which are fixed brushes of magnetically soft material, and the direction of magnetization in the magnetizing belts is opposite.

Description

The utility model relates to devices for monitoring the state of long pipelines, by passing a diagnostic projectile inside the pipeline under test, recording data in the on-board computer, and then determining the state of the pipeline using mathematical methods for processing the accumulated data. The utility model is based on the magnetometric methods of non-destructive testing of ferromagnetic materials that experience static and dynamic mechanical stresses during operation and can be used for on-line diagnostics of mechanical stresses in underground trunk and field oil and gas pipelines.

The main sources of damage to pipelines, in particular those intended for the transportation and storage of oil, gas, and other environmentally hazardous products, are emerging defects and stress concentration zones in which processes unfavorable for the construction proceed most intensively (development of discontinuities, corrosion, plastic deformation and etc.).

Stresses in pipelines are the result of various reasons, including seasonal changes in temperature leading to soil displacement, changes in the pressure of the gas contained inside the pipeline.In addition, there may be residual stresses resulting from a violation of pipe manufacturing technology, pipe welding and any bending of the pipe during installation . These stresses are typically manifested in the contraction / expansion of local areas of the pipe wall and tend to further concentrate and increase stress, thereby accelerating fracture.

Traditional methods of non-destructive testing do not allow for early diagnosis and are aimed at searching for developed defects, which is not always sufficient to ensure the reliability of diagnosed objects. For the timely detection of areas of metal structures most susceptible to damage, it is necessary to know their actual stress-strain state. Early detection and elimination of nascent stresses can prevent further destruction of the pipeline.

Known multi-sectional in-line shells for determining the stress-strain state of the pipeline (US patent No. 5532587, op. 02.07.1996, US No. 68854336, op. 02.15.2005). Each of the articulated sections contains musculoskeletal devices for centering and moving the in-tube projectile. The projectile contains at least one measuring section.

The devices are based on the physical dependence of changes in the magnetic properties of materials under the action of mechanical forces. The devices use the principle of local magnetization of the pipeline section, measurement and registration of the magnetic field, followed by the assessment of mechanical stresses in the region of the magnetization section according to the experimental dependence.

The measuring section contains a measuring belt of probes (transducers) spring-loaded to the pipe walls. Each probe contains a U-shaped magnetic circuit with an excitation winding and a measuring winding. The poles of the magnetic circuit are directed towards the walls of the pipe, and the measuring winding is located between the poles, in the magnetization zone and in close proximity to the pipe wall. The shape of the magnetic cores can be various, including cruciform, in addition, they can be located at different angles to the guide tube.

The main disadvantage of the devices is the high energy consumption used to power the field windings of the magnetic circuits for magnetizing pipe sections and, as a result, the need to use an additional section containing rechargeable batteries.

Closest to the design of the claimed device is a multi-section apparatus for measuring magnetic fluxes of dispersion for the analysis of anomalies in the walls of the pipe (US patent No. 5864232, op. 26.01.1999).

The apparatus is structurally made in the form of successively articulated sections, each of which is an in-tube projectile. Each section has a cylindrical body, at the ends of which are located locomotor elements providing centering of the apparatus and its movement. The measuring section contains a magnetizing system and a measuring system. The magnetizing system contains two magnetizing belts, each of which contains a belt of permanent magnets, at the ends of which brushes are made of soft magnetic material. Between the belts of the magnetizing system are a measuring system containing magnetic field sensors, spring-loaded to the pipe walls.

The advantage of this apparatus is that the magnetizing system is made of permanent magnets, which do not require electricity to magnetize the walls of the pipeline.

The disadvantage of this apparatus is that the magnetizing system of the apparatus magnetizes the walls of the pipeline to saturation. The measuring system when working in such conditions is not able to distinguish between the stress-strain state of the walls of the pipeline.

The proposed utility model is based on the task of reducing projectile energy consumption.

The problem is solved in that the multi-section in-tube projectile for diagnosing the stress-strain state of the pipeline contains successively articulated sections, one of which is a measuring section, each section contains a cylindrical body, at the ends of which are supporting-motor elements, the measuring section contains a magnetizing system, providing magnetization of the walls of the pipeline with a weak magnetic field and made in the form of two magnets mounted on the housing belts of radially magnetized permanent magnets, on the poles of which are fixed brushes of magnetically soft material, the direction of magnetization in the magnetizing belts being the opposite and the measuring system installed between the magnetizing belts and made in the form of a moving measuring belt of magnetic field sensors, spring-loaded to the pipe wall, which measure the tangential component of the magnetic field H _X along the generatrix of the pipe. Additionally, a preparatory section is introduced into the device, containing a magnetizing system, which magnetizes the walls of the pipeline until saturated, the direction of magnetization being the opposite of magnetization in the measuring section.

The magnetizing system of the preparatory section is made in the form of two magnetizing belts mounted on the casing of radially magnetized permanent magnets, the poles of which are fixed with brushes of magnetically soft material, and the direction of magnetization in the magnetizing belts is opposite. Those. the design of the magnetizing system of the preparatory section is identical to the magnetizing system of the measuring section.

The utility model is based on the principle based on the property of ferromagnetic materials to change the magnetic state under the influence of mechanical stresses. The strongest dependence of the magnetic parameters of steel on the stress-strain state exists in weak magnetic fields, i.e. in fields in which magnetic domains exist and, accordingly, irreversible processes occur.

A detailed description of the design of the device and its operating principle is illustrated by drawings.

Figure 1 shows a General view of the device;

figure 2 shows the device side view;

figure 3 shows a cross-section of the device stockpiled in the pipeline;

figure 4 shows a cross section of the upper part of the device, stocked in the pipeline, indicating the direction of magnetic field fluxes in the walls of the pipe;

figure 5 is an electrical block diagram of the device.

A multi-section in-line device for diagnosing a stress-strain state of a pipeline contains a preparation section 1 and a measuring section 2, interconnected by a docking device 3, each of which is an in-line projectile. The preparatory section 1 contains a cylindrical body (yoke) 4 made of soft magnetic material (Fig.1, 2, 3). On the end faces of the housing 4 are installed supporting-motor elements 5, which provide centering of the device in the pipeline and bear the weight of the device. The pressure differential created by the snug fit of the musculoskeletal elements 5 to the walls 6 of the pipeline ensures the movement of the device in the examined pipeline by the flow of the product transported through it. Musculoskeletal elements 5 can be made in the form of cuffs made of wear-resistant polyurethane of high strength, or in the form of discs also made of polyurethane. In the bow of the preparatory section 1, a bracket 7 and a fairing are attached 8. The bracket 7 is used for transportation and loading operations, for installing the device in the pipeline, as well as for coupling it with an additional measuring device when creating a multi-section device. Inside the housing 4 there are means for controlling the velocity of the projectile in the form of an adjustable bypass pipe for bypassing the product transported through the pipeline (not shown in the drawings).

The magnetizing system of the preparation section 1 consists of a yoke 4 and two magnetizing belts, each of which contains a belt of permanent magnets, 9 and 10, respectively, and a belt of flexible magnetic brushes, respectively 11 and 12. The direction of magnetization in permanent magnets 9 and 10 is multidirectional.

The measuring section 2 contains a cylindrical body (yoke) 13 made of soft magnetic material (Fig.1, 2, 3). On the end faces of the housing 13, locomotor elements 14 are installed that provide centering of the device in the pipeline and bear the weight of the device. The pressure difference created by the snug fit of the musculoskeletal elements 14 to the walls 6 of the pipeline, provides movement of the device in the examined pipeline by the flow of the product transported through it. Musculoskeletal elements 14 can be made in the form of cuffs made of wear-resistant polyurethane of high strength, or in the form of discs also made of polyurethane. A fairing 15 is attached to the nose of the preparatory module. Inside the housing 13, means for controlling the velocity of the projectile are made in the form of an adjustable bypass pipe for bypassing the product transported through the pipeline (not shown in the drawings).

The magnetizing system of the measuring section 2 consists of a yoke 13 and two magnetizing belts, each of which contains a belt of permanent magnets, respectively 16 and 17 and a belt of flexible magnetic brushes, respectively 18 and 19. The direction of magnetization in the permanent magnets 16 and 17 is multidirectional, and the direction of the magnetic the flow in the pipe wall should coincide with the direction of the magnetic flux generated by the magnetizing system of the preparation section 1.

Between the magnetizing belts there is a measuring system containing the measuring components of the magnetic field of the sensors 20, forming a measuring belt (figure 5). The sensors 20 of the magnetic field of the measuring belt are pressed against the inner surface of the pipeline 6 using elastic elements ("fins") 21.

At the ends of the musculoskeletal elements 14, rollers 22 and sensors of the distance traveled - odometers 23 can be installed.

A power supply 24 and an on-board computer 25 are located inside the housing 13 (Fig. 4). The power supply 24 contains a battery section 26, a module 27 for converting the battery voltage into voltage necessary to power the electronic modules, an intrinsically safe module 28, and a power distribution module 29. Electrical output the battery section 26 is connected to the input of the voltage conversion module 27, the outputs of which are connected through the spark protection module 28 to the power distribution module 29. The outputs of the power distribution module 29 are connected to all electronic modules and elements of the device. The on-board computer 25 includes a processor 30, a unit 31 for analog-to-digital conversion of the measurement data, and a storage device 32 based on a solid-state integrated circuit.

The device also contains additional sensors. An external pressure sensor 33, an angle rotation sensor 34, and a temperature sensor 35. The information outputs of the sensors 20, the odometer 23, the external pressure sensor 33, the angle rotation sensor 34 and the temperature sensor 35 are connected to the corresponding inputs of the analog-to-digital conversion unit 31.

Through a lock chamber, a device — a multi-sectional in-tube projectile — is introduced at the beginning of the monitored section of pipeline 6. Moreover, for the period of monitoring the pipeline 6, the flow of the transported product through it does not stop. The optimal design speed of the in-tube projectile through the pipe is 1-3 m / s at a speed of movement of the transported product, such as gas, up to 17 m / s. The speed of movement is ensured by the so-called "bypass" interaction scheme of the transported product and the in-tube projectile, in which the transported product flowing around the projectile structure creates an aerodynamic force, causing the projectile to continuously move in the direction of flow of the transported product.

When the device moves along the pipeline, each of the wall sections in the pipe cross-section is first exposed to the magnetizing system of the preparation section 1, and then to the magnetizing system of the measuring section 2, and there is no magnetizing effect in the intersection interval.

The preparatory section 1 magnetizes a portion of the pipe wall to saturation (zone A, Fig. 4). Then this section is demagnetized in the opposite direction (zone B) and after removal of the preparation section 1, the section is demagnetized to residual magnetization (zone C). Then this section of the pipe wall is magnetized by the weak field of the magnetizing system of the measuring section 2 (zone D).

Thus, in zone D, the magnetic characteristics are determined both by the parameters of the magnetic system of the measuring section 2 and by the residual magnetization. This creates optimal conditions between the magnetizing belts of the measuring section for measuring the characteristics of the magnetic field, which contain information about the stress-strain state of the pipeline.

The magnetic field sensors 20 measure the tangential component of the magnetic field H _x along the guide tube. The amplitude of the measured field is not more than four, five coercive forces of the studied pipe steels, i.e. these are weak magnetic fields of not more than 70 A / cm.

The signals from the sensors 20 of the magnetic field are fed to the on-board computer 25. Then, the measurement data are processed and recorded in the storage 32 of the on-board computer 25.

Upon completion of the control of a given section of the pipeline 6, the device is removed from the pipeline 6 and the data accumulated during the diagnostic process are transferred to a stationary computer.

Subsequent analysis of the recorded data allows you to build a topographic map of the stresses of the pipeline and conclude that there are sections in a critical stress-strain state.

Claims (2)

1. A multi-section in-tube projectile for diagnosing a stress-strain state of a pipeline, comprising successively articulated sections, one of which is a measuring section, each section contains a cylindrical body, at the ends of which are locomotor elements, the measuring section contains a magnetizing system that provides magnetization of the pipe walls a weak magnetic field and made in the form of two magnetizing belts of radial magnet mounted on the housing permanent magnets, at the poles of which are attached brushes of magnetically soft material, the direction of magnetization in the magnetizing belts being the opposite, and a measuring system installed between the magnetizing belts and made in the form of a moving measuring belt of magnetic field sensors spring-loaded to the pipe wall, which measure the tangential component magnetic field H along the _X forming pipe, characterized in that the preparatory section is introduced, comprising magnetizing system to oraya magnetizes to saturation the pipeline wall, the direction of magnetization opposite to the magnetization of the measuring section. 2. The device according to claim 1, characterized in that the magnetizing system of the preparatory section is made in the form of two magnetizing belts mounted on the housing of radially magnetized permanent magnets, at the poles of which are fixed brushes of magnetically soft material, and the direction of magnetization in the magnetizing belts is opposite.