RU2069288C1 - Flaw detector-tool for internal examination of pipe-lines - Google Patents

Abstract

FIELD: devices for internal examination of condition of walls, and/or geometric configuration, and/or attitude of pipe-lines mainly intended for distant conveying of natural gas (cross-country gas lines). SUBSTANCE: the flaw detector-tool uses a conveying unit, power unit, flaw detector unit, indicating unit and devices for determining the flaw coordinates placed in the pipe-line to be examined and moved in it by the flow of conveyed product, mechanically linked and positioned on the base (bases). The flaw detector is supplemented with a by-pass branch-pipe used to pass the conveyed product through the pipe-line under examination, and an automatic conveyance speed control system using a speed transducer, control unit and one or two control members, one of which is made as a shut-off-regulating device installed in the by-pass branch pipe, and the other - in the form of a retardation device engageable with the pipe-line. Depending on the number (one or two) and type of operation matching of the above control members, four variant of the automatic conveyance speed control system are probable. The flaw detector-tool is also provided with a detection signal generator ("beacon") and a circuit of special control of its operation in preemergency and emergency operating conditions at probable clogging of the pipe-line. EFFECT: enhanced reliability. 19 cl, 10 dwg

Description

 The invention relates to devices for in-pipe inspection of pipelines (referred to as flaw detectors, intelligent pistons, in-line diagnostic or flaw detection complexes, etc.), designed to move along the pipeline under inspection by the flow of the product transported through it, and can be used to monitor the technical condition and / or the geometric shape of the walls and / or the spatial position of pipelines intended primarily for long-distance transport of natural gas (the so-called main gas pipelines).

Analogues of the claimed device are:
the device according to the patent of the USSR N 745386, class. G 01 N 27/82, priority 05.05.78, publ. 06/30/80, BI N 24;
the device according to US patent N 3539915, class. G 01 R 33/12, priority 10.10.70 g.

 the device according to the patent of Germany N 2156434, class G 01 N 27/86, priority 5.06.75 g.

 the device according to the patent of Germany N 2423113, class G 01 N 27/87, priority 11/15/84

 as well as industrially manufactured defectoscopes-shells of foreign companies Piptropics (formerly Ipel Kopp, Canada, Germany), Vetko Tyuboskop (USA), British Hydroelectric Station (Great Britain), Hermann Rosen (Germany) and a domestic company "Saratovgazpriboravtomatika" JSC "Gazavtomatika".

 The prototype of the inventive flaw detector-projectile is the device according to the patent of Germany N 2423113.

 The disadvantage of all known flaw detectors of this type is the coincidence of their movement speed with the speed of the product transported through the pipeline being examined. This is caused by the complete overlap of the live sections of the pipelines with these flaw detectors, and the action of the well-known principle of continuity of flow in pressure pipelines. This circumstance to a certain extent is not very important when conducting an inspection of oil pipelines, in which the speed of the pumped oil is limited to 1.5-2 m / s, but acquires considerable sharpness when conducting a survey of main gas pipelines, in which the speed of the transported gas has values from 8 to 15 m / s depending on the operating mode, gas temperature and distance from the compressor station. At such moving speeds, magnetic flaw detectors, which are widely used in flaw detectors, significantly reduce their flaw detector efficiency due to the increasing influence of eddy currents induced by the magnetizing system in the piping walls, as well as the limited dynamic capabilities of the converters. The last limitation is inherent not only to magnetic flaw detectors, but also to other types of converters. In this regard, manufacturers of flaw detectors-shells indicate, as a rule, in the operating documents the desirability of their operation at optimal travel speeds that are relevant, for example, for Peiptronix flaw detectors from 7 to 10 km / h (i.e. 1 , 9-2.8 m / s), for flaw detectors of the company "Hermann Rosen" 1-2 m / s.

 The general range of operating speeds for the latter ranges from 0.3 to 5 m / s, and for line-detector flaw detectors of the Vetko Tyuboskop company from 0.5 to 3.25 m / s. The maximum permissible speed of movement at the level of 6 m / s, which is 1.5-2.5 times lower than the possible real speeds of its movement in gas pipelines, is regulated for a domestic flaw detector-type "Mole".

 In the light of the foregoing, it seems obvious that the use of well-known flaw detectors for examining main gas pipelines leads either to a sharp decrease in the speed of the pumped gas and a corresponding decrease in gas pipeline productivity for the period of the survey (which is organizationally, technically and economically unacceptable) or to a significant decrease in the reliability of the survey results. In addition, the use of flaw detectors with projectile velocities in the pipeline of 8-15 m / s causes increased dynamic loads on their nodes and pipeline elements protruding inward, and the pipeline cross-section is completely blocked by a flaw detector in the event of collision with possible obstacles in the pipeline (type incompletely open crane) leads to tremendous efforts of many hundreds and even more than a thousand tons, which can cause destruction as the flaw detector shell itself (which was repeatedly observed on in practice), and the damage of the subject pipeline.

 The aim of the present invention is to eliminate the noted drawbacks inherent in known flaw detectors designed for inspection of pipelines with their transportation by the flow of the pumped product, namely, increasing the reliability of the results of the inspection of pipelines, as well as the reliability of the flaw detector-projectile and the examined pipeline (during its inspection) for by reducing and stabilizing the speed of the flaw detector-projectile through the pipeline.

 This goal is achieved by the fact that a flaw detector for in-pipe inspection of pipelines, placed in the pipeline being inspected and moved by the product transported through it, contains a base resting on the pipeline’s support surface, a transporting unit in the form of an elastic cuffs, energy block, flaw detector block, fixed on the base and interacting with the walls pipelines are flaw detectors and / or measuring transducers, an information recording unit, and also devices for determining the coordinates of defects; it is additionally equipped with a bypass nozzle for passing the product transported through the pipeline and an automatic speed control system for its movement, containing a control unit with a speed adjuster connected to the input of the unit the control sensor for the speed of movement, as well as the regulatory body in the form of a shut-off valve installed in the bypass pipe a control device provided with an actuator control unit connected to the output, and / or fixed to the base and interacting with the brake system piping, equipped with an actuator connected to the output of the control unit.

 Mentioned supporting nodes supporting the base in the pipeline can be made in the form of running wheels or additional elastic cuffs, or a combination of wheels and cuffs.

 The energy block can be made, for example, in the form of a battery enclosed in a sealed compartment mounted on the base. The power unit may also contain electric generators driven by running wheels. It is also assumed that the energy block contains, if necessary, voltage converters that provide the necessary power parameters for all energy-consuming blocks and nodes of the flaw detector-projectile.

 The flaw detector unit can be made in the form of a system of magnets (electromagnets) that magnetize the walls of the pipeline under examination to the state of technical saturation, as well as magnetically sensitive elements located between the poles of the magnets, for example induction coils.

 The flaw detector unit may also contain measuring transducers for monitoring the diameter of the pipeline, made, for example, in the form of spring-loaded probes mounted on the base and in contact with the internal surface of the pipeline and connected to displacement transducers, for example, of a potentiometric type.

 The flaw detector unit may also contain measuring transducers for determining the spatial position of the axis of the examined pipeline, made, for example, in the form of gyroscopic direction sensors.

 The information recording unit may be performed, for example, in the form of a multi-channel magnetograph.

 The device for determining the coordinates can be performed, for example, in the form of an odometer equipped with a spring-loaded measuring wheel in contact with the inner surface of the pipeline.

 The coordinate determination device may also comprise a signal receiver of an external reference device, made, for example, in the form of a solenoid with a current located in certain places above the pipeline.

 As a bypass pipe in the inventive flaw detector can be used the base, made in the form of a hollow cylinder open from the ends or several similar cylinders mechanically interconnected by means of hinges or elastic spacers with the possibility of their angular displacement relative to each other.

 Mentioned cylindrical base can be supplemented by expanding conical sections joined to its ends, forming in the tail and nose parts of the bypass pipe, respectively, a confuser and a diffuser, providing a reduction in pressure loss on the bypass pipe.

 The locking and regulating device can be made in the form of a disk shutter (rotary damper) located in the bypass pipe, kinematically connected with an electric reversing motor.

 The brake device can be made in the form of electromagnets fixed on the base, containing brush pole lugs in contact with the inner surface of the pipeline, and windings connected directly or via an additionally introduced voltage converter to the power unit via a current regulator controlled by a reversible electric drive motor of a locking-regulating device or second independent electric motor.

 The mentioned current regulator can be made in the form of a transistor, the electromagnet windings are connected to the collector circuit, a current-stabilizing resistor is connected to the emitter circuit, and the base is connected to the output of a potentiometer connected to the voltage source, the motor of which is kinematically connected to the reversible electric motor.

 A flexible cuff on the transporting unit may be located in its bow, and the braking device in its tail. This solution provides a more favorable for the operation of the flaw detector, and especially the composite base of the bypass pipe, the application of forces that stretch the base.

 The movement speed sensor can be made in the form of a spring-loaded measuring wheel fixed on the base with the ability to move, in contact with the inner surface of the pipeline and kinematically connected with the induction tachogenerator.

 In a flaw detector equipped with an odometer, an odometer measuring wheel can be used as a measuring wheel of a displacement speed sensor.

 The displacement speed adjuster in the control unit can be made in the form of a voltage divider (potentiometer) connected to a voltage source, and the control unit can be equipped with a mismatch signal amplifier, the input of which is connected directly or through an additionally introduced signal comparison unit to the outputs of the sensor and displacement speed setter and the output of the amplifier is connected to a reversible electric motor of the drive of the locking-regulating and / or brake device with the possibility of increasing by the regulating device of the live section of the bypass pipe, and by means of the braking device, the braking force at a speed exceeding the value set by the master, and reducing the living section of the bypass pipe by means of a locking and regulating device, and by means of the braking device, the braking force at a speed of movement less than the set by the master values.

 It is understood that the comparison of the signals of the sensor and the setpoint of the speed of movement and the receipt of a signal of their mismatch can be carried out both by means of a special comparison unit, and without it.

 As a signal comparison unit, an analog signal addition unit on an operational amplifier or a differential amplifier with a balanced input can be used. In the latter case, the mentioned differential amplifier can be considered as the input stage of the amplifier of the error signals, to the input of which the outputs of the sensor and the speed setter are directly connected.

 It is also assumed that the system for automatically controlling the speed of movement in a flaw detector-projectile may contain one regulatory body (locking-regulating or braking device) or two of these regulatory bodies, the drives of which are equipped with one common reversible electric motor or separate electric motors.

 The choice of an embodiment of a system for automatically controlling the speed of movement depends on the ratio of the required speed of the flaw detector-projectile and the speed of the product transported through the pipeline, as well as on the design parameters of the flaw detector-projectile.

 So, for example, with small differences in the speeds of the flaw detector-projectile and the product transported through the pipeline, you can restrict yourself to the option of an automatic control system with one regulatory body in the form of a locking-regulating device. With large differences in travel speeds and difficulties in providing a relatively large cross-sectional area of the bypass pipe, it is advisable to use a system with a regulatory body in the form of a brake device. Finally, with its large differences in travel speeds, a variant of a system with two regulatory bodies of the indicated type is justified. Moreover, to eliminate the undesirable effect of the simultaneous operation of these regulatory bodies on the operation of the system and to prevent the possibility of losing its stability, the drives of both regulatory bodies are combined by a common electric motor.

 The capabilities of the automatic control system in the variant with two regulatory bodies can be significantly expanded if the locking-regulating and braking devices will have drives with separate electric motors and will be equipped with additionally introduced sensors of their initial positions corresponding to the maximum live section of the bypass pipe and the minimum braking force of the brake device , and the control unit will be equipped with an additionally introduced switching unit with an executive and control center with its control unit, and the switching unit will be connected between the output of the amplifier and the reversible electric motors of the shut-off and brake devices drives with the possibility in the first position of the switching unit to connect to the output of the amplifier of the reversing electric motor of the shut-off-control device, and in the second position of the switching unit of connecting to the output of the amplifier of the reversing electric motor of the drive of the brake device, while the outputs of the sensor and the speed adjuster, as well as the outputs sensors of the initial positions of the locking-regulating and braking devices are connected to the inputs of the control unit, and the control circuit of the switching unit is connected to the output of the control unit configured to set the switching unit to the first position at a movement speed less than the setpoint value and the initial position of the brake device, and in the second position at a speed of movement greater than the value set by the master, and the initial position of the locking-regulating device.

 Sensors of the initial position of the locking-regulating and braking devices can be made in the form of limit switches connected to a voltage source with the possibility of receiving voltage (high logic level signal) at the output of the sensors in the initial position of the mentioned devices and lack of voltage (low logic level signal) in all other provisions of these devices.

 The switching unit in the control unit can be made in the form of a polarized electromagnetic relay with a switching contact and two control windings, and the control unit can be made containing two voltage comparators, two logical elements AND, NOT, a logical element NOT and two output (matching) nodes, moreover, the first (reference) inputs of both voltage comparators are connected to the output of the movement speed sensor, the first input of the first logical element AND is NOT connected to the output of the first comparator, and the second input of the first logic AND gate is connected to the output of the sensor of the initial position of the locking and regulating device, the first input of the second logic gate AND is NOT connected to the output of the logic gate NOT, both inputs of which are connected to the output of the second comparator, and the second input of the second logic gate AND is NOT connected to the output of the sensor of the initial position of the brake device, the outputs of the first and second logic elements are NOT connected respectively to the inputs of the first and second output nodes, the outputs of which are connected respectively the first and second control winding of the polarized relay.

 The given version of the automatic control system for the velocity of the flaw detector with two separately operating (in time) regulating bodies expands the range of possible speeds of the product transported through the pipeline, which ensures stabilization of the velocity of the flaw detector and shell, and also allows for a special mode of its operation in pre-emergency and emergency situations when stuck in the pipeline. For this, a detection signal generator, hereinafter referred to as a beacon, can be additionally introduced into it, and the control unit can be equipped with an additionally introduced second switching unit with a control circuit and an executive circuit in the form of normally closed and normally open contacts, as well as a second control unit containing a master threshold level of the speed of movement (which may be absent), the third voltage comparator, the third logical element NAND, the second logical element NOT, the time delay node s drove, the third output (matching) node, and the first (reference) input of the third comparator is connected to a threshold speed threshold adjuster or to a common (ground) bus, the second input of the third comparator is connected to the output of the speed sensor, the output of the third comparator is connected via a logic element NOT (with parallel inputs) to the input of the time delay node of the signal, the output of which is connected to the first input of the third logical AND-NOT element, the second input of which is connected to the output of the initial sensor I have a locking and regulating device, and the output is connected to the input of the third output node, the output of which is connected to the control circuit of the second switching node, normally closed contacts of which are included in the power supply circuit of the beacon, and normally open contacts are included in the power supply circuit of all other energy-consuming nodes and units and shunted by an additionally entered start button with a make contact with self-resetting.

 At the same time, said threshold speed threshold level adjuster can be made in the form of a voltage divider (potentiometer) connected to a voltage source; said node of the time delay of the signal in the control unit can be made in the form of series-connected first differentiating chains, the first one-shot, logic element NOT the second differentiating chains and the second one-shot; said second switching unit may be in the form of an electromagnetic relay; said beacon can be made in the form of a low-frequency generator, the output of which through a matching transformer and brush current leads are connected to sections of the pipeline spaced along its axis.

 The above technical solutions provide in the case of a decrease in the speed of movement of the flaw detector-projectile below a threshold value specified by the master (which, in particular, can be zero in the case when the first input of the third comparator is connected to a common bus) when it gets stuck in the pipeline, the shut-off and control device cyclic mode ("open-closed") for a given time. This leads to the appearance of additional jerky axial forces applied to the flaw detector projectile, increasing the likelihood of overcoming obstacles in the path of the flaw detector projectile. In the case of the resumption of movement of the flaw detector-projectile within the aforementioned predetermined time, the system for automatically controlling the speed of movement continues to function in normal mode. If, after the specified time has elapsed, the flaw detector-projectile does not resume moving, the system will turn on the beacon and disconnect from the power unit all other power-consuming units and units of the flaw detector-projectile.

 It is important to note at the same time that the specified de-energization of the nodes and blocks occurs at the moment of the complete opening of the shut-off and regulating device in the bypass pipe, which ensures a near-normal operation of the pipeline under examination and extends the time frame for carrying out work on removing the flaw detector from the pipeline.

 It should also be borne in mind that the locking and regulating device must provide cyclic operation with one-sided rotation of the output shaft of the reversible electric motor in its drive. This condition is observed, for example, when executing a locking and regulating device in the form of a disk shutter with an unlimited angle of rotation of its disk. It is also possible to fulfill this condition by introducing additional nodes into the drive of the device to automatically reverse the movement of its working body in its extreme positions.

 To expand the time frame for conducting work on finding the location of a flaw detector-projectile jamming in the pipeline, it can be equipped with an additionally introduced emergency power source for the beacon, made in the form of a turbine installed in the bypass pipe and an electric generator connected to it.

 In FIG. 1 shows a structural diagram of a flaw detector with a bypass pipe and a system for automatically controlling the speed of movement with one regulatory body in the form of a disk shutter installed in the bypass pipe.

 In FIG. 2 is a functional diagram of a system for automatically controlling the speed of movement for a flaw detector-shell variant according to the structural diagram shown in FIG. 1.

 In FIG. 3 shows a structural diagram of a flaw detector with a bypass pipe and a system for automatically controlling the speed of movement with one regulatory body in the form of an electromagnetic brake device.

 In FIG. 4 is a functional diagram of a system for automatically controlling the speed of movement for a flaw detector-shell variant according to the structural scheme shown in FIG. 3.

 In FIG. Figure 5 shows a structural diagram of a flaw detector with a bypass nozzle and a system for automatically controlling the speed of movement with two regulating bodies (in the form of a disk shutter in the bypass nozzle and an electromagnetic brake device) operating simultaneously from one reversing electric motor.

 In FIG. 6 is a functional diagram of a system for automatically controlling the speed of movement for a flaw detector-shell variant according to the structural diagram shown in FIG. 5.

 In FIG. Figure 7 shows a structural diagram of a flaw detector with a bypass nozzle, a system for automatically controlling the speed of movement with two regulating bodies (a disk shutter in the bypass nozzle and an electromagnetic braking device), operating alternately from two separate switched reversible electric motors, a beacon and an emergency power generator driven by a turbine in the bypass pipe.

 In FIG. 8 is a functional diagram of a system for automatically controlling the speed of movement for a flaw detector-shell variant according to the structural diagram shown in FIG. 7.

 In FIG. 9 is a schematic diagram of a current regulator in a winding of an electromagnet of a brake device.

 In FIG. 10 is a schematic diagram of a signal time delay unit in a control unit of an automatic speed control system of FIG. 8.

 In accordance with the above, the proposed flaw detector-projectile contains a base with a cylindrical middle part 2, a diffuser 3 in its nose and a confuser 4 in its tail, placed on the inner surface of the pipeline 1 by means of the support wheels 5. a flaw detector-projectile on the base diffuser 3 is fixed an elastic cuff 6 forming a transporting unit, and on the cylindrical part of the base 2 an energy unit 7, a flaw detector 8, a block are fixed registration 9, as well as odometer 10.

 The base with a cylindrical middle part 2, a diffuser 3 and a confuser 4 is hollow with open ends and thus forms a bypass pipe 11 through which the entire flow of the product transported through the pipeline 1 is passed.

 In addition to the above-mentioned known blocks and assemblies, the flaw detector is equipped with an additionally introduced automatic control and regulation system for the speed of movement, which contains a displacement sensor 12 (in the form of a tachogenerator kinematically connected to the measuring wheel of the odometer 10), a control unit 13 with a speed setter 14 and a control body (regulatory bodies) in the form of a disk shutter 15 located in the bypass pipe 11 or / and interacting with the pipeline of the brake device 16 in the form of electromagnets with precision pole lugs and windings 17. The disk shutter 15 is equipped with a drive with a reversible electric motor 18 and a sensor for the initial (fully open) position of the shutter 19.

 The windings 17 of the electromagnets 16 are connected to the energy block 7 through a current regulator 20, controlled either by a reversible electric motor 18, or by a separate second reversible electric motor 21. In the latter case, the current regulator 20 is equipped with a sensor 22 for the initial position (state) of the brake device, similar to the sensor 19 for the initial position of the disk shutter 15.

 The current regulator 20 is made in the form of a transistor 23, the collector circuit of which includes windings 17 of the electromagnets of the brake device 16, a current-stabilizing resistor 24 is included in the emitter circuit, and the base is connected to the output of a potentiometer 25 connected to a voltage source 26, the motor of which is kinematically connected to a reversible electric motor 18 (in the variant with one drive motor in both regulatory bodies) or with the reversible electric motor 21 (in the variant with separate drive motors in the regulatory bodies).

 The control unit 13 in embodiments of the flaw detector projectile shown in FIG. 1, 3, 5, contains, in addition to the displacement speed adjuster 14, a node 27 for comparing the sensor signals and the displacement speed adjuster, as well as an error signal amplifier 28.

 The control unit may also contain so-called corrective links introduced to ensure the stability of the system and the specified quality of regulation, however, for simplicity of presentation of the essence of the proposed technical solutions, these elements are omitted.

 The control unit 13 in the embodiment of the flaw detector projectile according to the structural scheme shown in FIG. 7, contains a number of additional nodes, namely: the first switching node in the form of a polarized relay 29 with two control windings and one changeover contact, the node (first) for controlling its operation 30, as well as the second switching node in the form of an electromagnetic relay 31 with one normally open and one normally closed contacts and a node (second) for controlling its operation 32. In this case, the control unit 30 contains two voltage comparators 33 and 34, two logical elements AND-NOT 35 and 36, a logical element NOT 37 and two output (matching) nodes 38 and 39.

 The control unit 32 contains a threshold level threshold for moving speed 40 (may be absent), a voltage comparator 41, a logic element HE 42, a time delay unit for a signal 43, an AND-44 logic element, and an output (matching) node 45.

 The first inputs of the voltage comparators 33 and 34 in the control unit 30 are connected to the displacement speed setter 31, and the second inputs of these comparators are connected to the output of the displacement speed sensor 12. The output of the voltage comparator 33 is connected to the first input of the AND-NOT 35 logic element, the second input of which is connected to the output of the sensor of the initial position of the disk shutter 19, and the output is connected to the input of the initial node 38, the output of which is connected to the first control winding of the polarized relay 29. The output of the voltage comparator 34 through the logic s NOT element 37 is connected to a first input of a logical AND-NO element 36, the second input of which is connected to the output of the sensor 22, the initial position of the brake device, and an output connected to an input of the output node 39, which is connected to the output of the second coil of the polarized relay 29.

 The first input of the voltage comparator 41 in the control unit 32 is connected to the output of the threshold speed threshold level adjuster 40 or to a common bus, and the second input of the mentioned voltage comparator is connected to the output of the movement speed sensor 12. The output of the voltage comparator 41 is connected via an NOT 42 logic element with parallel inputs to the input of the time delay node of the signal 43, the output of which is connected to the first input of the AND-44 logic element, the second input of which is connected to the output of the sensor for the initial position of the disk thief 19, and the output is connected to the input of the output node 45, the output of which is connected to the relay coil 31.

 In this case, the changeover contact of the polarized relay 29 connects to the output of the amplifier 28 in the first position a reversible electric motor 18, kinematically connected with a disk shutter 15, and in the second position, a reversible electric motor 21, which controls the operation of the current regulator 20, included in the power supply circuit of the coil of the brake solenoid 17 16.

 In addition to the listed 13 additional nodes included in the control unit, a variant of a flaw detector-projectile according to the structural scheme shown in FIG. 7, is additionally equipped with a detection signal generator (beacon), made in the form of a low-frequency generator 46, the output of which through a matching transformer and brush current conductors 47 are connected to sections of its inner surface spaced along the length of the pipeline.

 In addition, the indicated version of the flaw detector-projectile is additionally equipped with an emergency power generator 48 driven by a turbine 49 installed in the bypass pipe 11.

 The power supply circuit of the beacon 46 from the generator 48 includes normally closed contacts of the relay 31 in the control unit 13, and normally open contacts of the same relay are included in the power supply circuit of all other power-consuming units and units of the flaw detector-projectile and are shunted with the start button 50.

 The time delay unit of the signal 43 in the control unit 13 is made in the form of series-connected (see Fig. 10) the first differentiating circuit 51, the first one-shot 52, the logical element NOT 53, the second differentiating chain 54 and the second one-shot 55.

 The work of the proposed flaw detector projectile is as follows. First, it is introduced into the examined pipeline, which must be equipped for this so-called. a starting chamber with a lock passage and a device for creating a “starting” pressure in this chamber, which exceeds the pressure in the pipeline. Under the influence of the indicated pressure, the flaw detector-projectile is "pressed" into the pipeline under examination and begins to move along it at a certain speed (see below). After examining a given section of the pipeline, the flaw detector-projectile is sent to the so-called a receiving chamber (which should also be equipped with the examined pipeline), equipped with a lock passage and a device to reduce the pressure in it to atmospheric pressure and remove penetrating into the chamber together with the flaw detector projectile transported through the pipeline product.

 In the process of moving, the flaw block 8 monitors the technical condition and / or geometric characteristics and / or spatial position of the examined pipeline 1. In this case, the control results are recorded in the registration block 9, in which, in addition, data on the distance traveled by the flaw detector-projectile are recorded, Obtained by means of an odometer 10, as well as reference marks corresponding to the moments when a flaw detector-projectile passed previously installed reference points near the pipeline stroystv, and furthermore, moving velocity data of the projectile flaw obtained from the sensor 12, its movement speed.

 After passing through the examined section of the pipeline, the flaw detector-projectile is removed from the receiving chamber, and the data recorded in the registration unit 9 are processed, mainly using a computer. In this case, sections of the pipeline with defects in its walls such as corrosion ulcers and fistulas, cracks, etc., as well as (using appropriate transducers) sections of the pipeline with violations of its geometric shape (dents, corrugations, etc.) or with changes in spatial position are determined the axis of the pipeline and the associated additional mechanical stresses in its walls.

 The data obtained as a result of the inspection of the pipeline are used to diagnose its technical condition and rational planning of repair and maintenance work, providing increased reliability and durability of the pipelines, as well as preventing their sudden destruction.

 As noted above, the main difference between the proposed flaw detector-projectile is its ability to move through the pipeline with a given speed less than the speed of the product transported through the pipeline. This nature of the movement of the flaw detector-projectile through the pipeline is ensured by the presence of a bypass pipe in it and the operation of the automatic speed control system introduced into it.

W_c фактическая скорость перемещения дефектоскопа-снаряда, м/с.The functioning of this system is as follows. The speed sensor 12 generates a signal containing information about the actual speed of movement of the flaw detector-projectile in the pipeline, for example, in the form of a constant voltage proportional to the speed of movement:
U _d K _d • W _c (1),
where U _{d the} magnitude of the output voltage of the speed sensor, V;
K _d the conversion coefficient of the sensor,

W _c actual velocity of the flaw detector-projectile, m / s.

The specified voltage of the sensor is compared with a constant voltage generated by the setpoint speed 14 in the control unit 13 in accordance with the ratio:
U _s C _s • W _s (2),
where U _{s the} magnitude of the output voltage of the setpoint, V;
K _s setpoint conversion factor, V / m / s;
W _{c the} set speed of the flaw detector projectile, m / s.

As noted above, the comparison of the signals of the sensor 12 and the setpoint 14 of the displacement speed can be carried out either in a special unit 27, for example, in the input stage of a differential amplifier (to one input of which a sensor 12 is connected, and to the other input of the setter 13), or due to an in-series enable the outputs of the sensor 12 and the setter 13. In both cases, the input voltage of the amplifier 28 receives the differential voltage (error signal):
ΔU = U _d -U _z = K _d • W _c -K _z • W _z ,
or under an easily fulfilled condition
K _d K _z K _w (3),
ΔU = K _w • (W _c -W _s ) (4)
The specified mismatch signal is amplified in the amplifier 28 to a power level sufficient for operation of the reversible electric motor 18 (21) of the drive of the locking-regulating (brake) device 15 (16).

Moreover, the connection of the specified motor 18 (21) to the amplifier 28 and the output stage circuit of the amplifier 28 are made so that when W _c > W _s (i.e., when ΔU> 0), the output shaft of the electric motor rotates toward the opening of the locking-regulating device 15 and in the direction of increasing the braking force of the braking device 16, and when W _c <W _s (that is, when ΔU <0), the output shaft of the electric motor rotates in the opposite direction. Therefore, the stationary state of the output shaft of the reversible electric motor meets the condition (accurate to the sensitivity threshold of the amplifier):
ΔU = 0 (5)
or
W _c W _s (6)
It is obvious that the stationary state of the output shaft of the reversible electric motor corresponds to the steady-state movement of the flaw detector-shell with a constant speed achieved when the known condition is fulfilled according to Newton's first law:
∑ F _oc = 0, (7)
or
F _dv F _torm 0 (8)
or
F _dv F _torm (9),
where F _OS applied to the flaw detector projectile forces acting along the axis of the pipeline, N;
F _dv and F _brakes, respectively, applied to the flaw detector-projectile resultant forces directed along the axis of the pipeline and acting in the direction of its movement (driving force) and against the direction of its movement (braking force), N.

(10)
где ΔP потеря полного давления на байпасном патрубке, Па;
S_эф S₁ S₀ эффективная площадь поперечного сечения дефектоскопа-снаряда, равная разности площади живых сечений трубопровода S₁ и байпасного патрубка S₀, м²;
l₁ коэффициент гидравлического сопротивления байпасного патрубка в целом (вместе с запорно-регулирующим устройством), безразмерная величина;
ρ плотность транспортируемого по трубопроводу продукта (в байпасном патрубке), кг/м³;
W₀ скорость потока в байпасном патрубке (относительно дефектоскопа-снаряда), м/с.The driving force can be expressed by the ratio:

(ten)
where ΔP is the loss of total pressure at the bypass pipe, Pa;
S _eff S ₁ S _{0 the} effective cross-sectional area of the flaw detector-projectile, equal to the difference between the living area of the pipeline S ₁ and the bypass pipe S ₀ , m ² ;
l ₁ coefficient of hydraulic resistance of the bypass pipe as a whole (together with a locking-regulating device), dimensionless quantity;
ρ density of the product transported through the pipeline (in the bypass pipe), kg / m ³ ;
W ₀ flow rate in the bypass pipe (relative to the flaw detector-projectile), m / s

(11)
где

конструктивный коэффициент;
D₁ и D₀ диаметры соответственно трубопровода и байпасного патрубка, м;
W₁ скорость потока в трубопроводе, м/с;
W_c скорость перемещения снаряда в трубопроводе, м/с.The flow rate in the bypass pipe can be determined by the ratio arising from the principle of continuity of flow in pressure pipelines:

(eleven)
Where

design coefficient;
D ₁ and D _{0 the} diameters of the pipeline and the bypass pipe, m;
W ₁ flow rate in the pipeline, m / s;
W _{c the} velocity of the projectile in the pipeline, m / s

или

откуда

или

откуда

(12)
Полученное соотношение (12) имеет ясный физический смысл: скорость перемещения дефектоскопа-снаряда в трубопроводе тем меньше, чем больше приложенная к нему тормозящая сила и чем меньше коэффициент гидравлического сопротивления байпасного патрубка и эффективная площадь поперечного сечения дефектоскопа-снаряда, а также чем больше отношение площади (диаметра) поперечного сечения байпасного патрубка к площади поперечного сечения (диаметру) трубопровода.From (9), (10) and (11) we can obtain:

or

where from

or

where from

(12)
The resulting relation (12) has a clear physical meaning: the speed of movement of a flaw detector-projectile in a pipeline is the lower, the greater the braking force applied to it and the lower the hydraulic resistance coefficient of the bypass pipe and the effective cross-sectional area of the flaw detector-projectile, as well as the larger the area ratio (diameter) of the cross section of the bypass pipe to the cross-sectional area (diameter) of the pipeline.

Relation (12) also confirms the fundamental possibility of automatic control of the speed of the flaw detector-projectile by changing the braking force F _brake and / or the hydraulic resistance of the bypass pipe l (by means of a shut-off and control device installed in it).

или

(13)
С другой стороны, тормозящая сила может быть определена по известному соотношению:
F_торм F_н•f (G + F_эм)•f (14),
где F_н равнодействующая сил, направленных нормально поверхности трубопровода, Н;
G вес дефектоскопа-снаряда, Н;
F_эм сила притяжения электромагнита тормозного устройства к трубопроводу, Н;
f коэффициент трения между контактирующими с трубопроводом поверхностями дефектоскопа-снаряда и стенкой трубопровода.Relation (12) can be converted to the form:

or

(thirteen)
On the other hand, the braking force can be determined by the known ratio:
F _brake F _n • f (G + F _em ) • f (14),
where F _{n the} resultant of forces directed normally to the surface of the pipeline, N;
G is the weight of the flaw detector, N;
F _{em the} force of attraction of the electromagnet of the brake device to the pipeline, N;
f the coefficient of friction between the surfaces of the flaw detector-projectile in contact with the pipeline and the wall of the pipeline.

(15)
где B_п величина магнитной индукции в полюсных наконечниках, Тл;
S_п площадь поперечного сечения полюсных наконечников, м²;
μ_o= 1,26•10^-6Гн/м магнитная постоянная.In turn, the magnitude of the attractive force of an electromagnet can be determined by the ratio:

(fifteen)
where B _{p the} magnitude of the magnetic induction in the pole pieces, T;
S _p the cross-sectional area of the pole pieces, m ² ;
μ _o = 1.26 • 10 ^-6 GN / m magnetic constant.

или

,
откуда

(16)
Полученное соотношение позволяет определить площадь поперечного сечения полюсных наконечников электромагнита, обеспечивающих требуемое тормозное усилие для стабилизации скорости перемещения снаряда на заданном уровне.From (13), (14) and (15) we get:

or

,
where from

(16)
The resulting ratio allows you to determine the cross-sectional area of the pole pieces of the electromagnet, providing the required braking force to stabilize the velocity of the projectile at a given level.

 However, additional restrictions must be imposed on this value, due to the need to take into account the increase in pressure on the walls of the pipeline due to the action of forces normal to its surface, as well as the nonlinear magnetic properties of the steel of the pipeline and the magnetic core of the electromagnet.

(17)
где

допустимая величина увеличения давления на стенки трубопровода, Па.The first of these restrictions can be expressed by the ratio:

(17)
Where

allowable value of increasing pressure on the walls of the pipeline, Pa.

(This refers to the possibility of neglecting the weight of the flaw detector-projectile distributed over an area significantly exceeding the area of the pole tips of the electromagnet.)
The second limitation can be expressed by obvious inequalities:
B _tr ≅ B _st.max (18),
B _m ≅ B _st.max (18a),
B _p ≅ B _st.max (18b),
where B _Tr , V _m , B _{p the} magnitude of the magnetic induction, respectively, in the walls of the pipeline, the magnetic circuit and the pole pieces of the electromagnet, T;
In _{st max the} magnitude of the induction of saturation of steel, T.

(19)
или

(20)
Используя предельное значение неравенств (20) и (16), получим:

(21)
Например, для дефектоскопа-снаряда, рассчитанного на обследование газопроводом диаметром 1420 мм (D₁ ≈ 1,4 м), принимая диаметр байпасного патрубка равным 700 мм (D₀ 0,7 м), скорость газа в трубопроводе W₁ 13 м/с (в конце участка), плотность газа ρ = 40 кг/м³ (при давлении 5 МПа), скорость дефектоскопа-снаряда W_c 2 м/с, значение коэффициента гидравлического сопротивления байпасного патрубка l₁ 4 (для малых углов закрытия затвора,) вес дефектоскопа-снаряда равным 6 тоннам (6•10⁴ H), величину коэффициента трения f 0,2 и величину допустимого увеличения давления на стенки трубопровода

(на уровне примерно 10% от максимального рабочего давления)

из (21) найдем:

Такая площадь поперечного сечения полюсных наконечников электромагнита тормозного устройства может быть получена при их ширине, определяемой из очевидного соотношения:
S_п= 2π•D₁•b_n, (22)
откуда

(23)
где b_п ширина полюсного наконечника электромагнита, м.In view of (15), constraint (17) can be represented as

(19)
or

(20)
Using the limit value of inequalities (20) and (16), we obtain:

(21)
For example, for a flaw detector designed to be inspected by a gas pipeline with a diameter of 1420 mm (D ₁ ≈ 1.4 m), assuming a bypass pipe diameter of 700 mm (D ₀ 0.7 m), the gas velocity in the pipeline is W ₁ 13 m / s (at the end of the section), gas density ρ = 40 kg / m ³ (at a pressure of 5 MPa), flaw detector velocity W _c 2 m / s, hydraulic resistance coefficient of the bypass nozzle l ₁ 4 (for small shutter closure angles,) the weight of the flaw detector-projectile equal to 6 tons (6 • 10 ⁴ H), the value of the coefficient of friction f 0.2 and the magnitude of the allowable increase in pressure at st Pipeline Enki

(at about 10% of maximum working pressure)

from (21) we find:

This cross-sectional area of the pole pieces of the electromagnet of the brake device can be obtained with their width, determined from the obvious ratio:
S _p = 2π • D ₁ • b _n , (22)
where from

(23)
where b _{p the} width of the pole tip of the electromagnet, m

что вполне реализуемо.Substituting the data, from (23) we obtain:

which is quite feasible.

что меньше индукции технического насыщения для малоуглеродистой и низколегированной стали, имеющей значение 1,6-1,8 Тл.In this case, the magnitude of the magnetic induction in the pole tips of the electromagnet according to (20) will have a value

which is less than the induction of technical saturation for mild and low alloy steel, having a value of 1.6-1.8 T.

Следует при этом иметь в виду, что для выполнения ограничительных условий (18а) и, особенно, (18б) конструкция электромагнита должна быть усложнена путем разделения его на секции, каждая из которых должна иметь площадь поперечного сечения полюсного наконечника, определяемую из соотношения:
B_п•S $\genfrac{}{}{0ex}{}{\text{(1)}}{\text{п}}$ = B_ст.max•S_тр, (24)
где S $\genfrac{}{}{0ex}{}{\text{(1)}}{\text{п}}$ площадь поперечного сечения полюсного наконечника секции электромагнита;
S_тр= πD_it_{тр =} площадь поперечного сечения стенки трубопровода, м²;
t_тр толщина стенки трубопровода, м².The magnitude of the force of attraction of the electromagnet to the pipeline according to (15):

It should be borne in mind that in order to fulfill the restrictive conditions (18a), and especially (18b), the design of the electromagnet must be complicated by dividing it into sections, each of which should have a cross-sectional area of the pole piece, determined from the relation:
B _p • S $\genfrac{}{}{0ex}{}{\text{(one)}}{\text{P}}$ = B _st.max • S _tr , (24)
where s $\genfrac{}{}{0ex}{}{\text{(one)}}{\text{P}}$ the cross-sectional area of the pole tip of the section of the electromagnet;
S _Tr = πD _i t _{Tr =} the cross-sectional area of the pipeline wall, m ² ;
t _mp the wall thickness of the pipeline, m ² .

(25)
Например, для рассмотренного выше примера, задаваясь значением B_ст.мах 1,8 Тл и толщиной стенки трубопровода t_тр 18 мм (18•10^-3 м), из (25) получим

При этом число секций электромагнита может быть определено из очевидного соотношения:

Для выполнения ограничительного условия (18а) достаточно обеспечить равновеликую площадь поперечного сечения магнитопровода по сравнению с площадью поперечного сечения полюса секции электромагнита:
S_м= S $\genfrac{}{}{0ex}{}{\text{(1)}}{\text{п}}$ (26)
Для магнитопровода в виде полого цилиндра, расположенного соосно трубопроводу, можно записать:
S_м= πD_м•t_м (27),
где D_м и t_м соответственно диаметр и толщина магнитопровода, м.From (24) we obtain

(25)
For example, for the example considered above, given a value of B _{stmax of} 1.8 T and a pipe wall thickness t _mp 18 mm (18 • 10 ^-3 m), from (25) we obtain

The number of sections of the electromagnet can be determined from the obvious ratio:

To fulfill the restrictive condition (18a), it is sufficient to ensure an equal cross-sectional area of the magnetic circuit compared to the cross-sectional area of the pole of the section of the electromagnet:
S _m = S $\genfrac{}{}{0ex}{}{\text{(one)}}{\text{P}}$ (26)
For a magnetic circuit in the form of a hollow cylinder located coaxially with the pipeline, one can write:
S _m = πD _m • t _m (27),
where D _m and t _m respectively the diameter and thickness of the magnetic circuit, m

В заключение определим возможные конструктивные и электрические параметры секции электромагнита тормозного устройства с определенными выше размерами магнитопровода и полюсных наконечников.Obviously, the diameter of the magnetic circuit can be chosen within the limits determined by the inequality
D ₀ <D _m <D ₁ (28)
Given, for example, for the above example, D _m 1 m, from (26) and (27) we find:

In conclusion, we determine the possible structural and electrical parameters of the section of the electromagnet of the brake device with the dimensions of the magnetic circuit and pole tips defined above.

(29)
откуда IW = B_п•S $\genfrac{}{}{0ex}{}{\text{(1)}}{\text{п}}$ •R_м (30),
где φ величина магнитного потока в замкнутой магнитной цепи магнитопровод полюсные наконечники стенка трубопровода, Вб;
I величина тока в обмотке секции электромагнита, А;
W число витков в обмотке секции электромагнита;
R_м общее магнитное сопротивление магнитной цепи, Гн^-1.Using the known relations, we write:

(29)
whence IW = B _p • S $\genfrac{}{}{0ex}{}{\text{(one)}}{\text{P}}$ • R _m (30),
where φ is the magnitude of the magnetic flux in a closed magnetic circuit magnetic circuit pole tips the wall of the pipeline, Wb;
I is the current value in the winding of the electromagnet section, A;
W is the number of turns in the winding of the electromagnet section;
R _{m the} total magnetic resistance of the magnetic circuit, GN ^-1 .

(31),
где R_м1,l₁,μ и S_м1 соответственно магнитное сопротивление, длина, относительная магнитная проницаемость и площадь поперечного сечения участка магнитной цепи.According to the known ratio for each section of the magnetic circuit

(31)
where R _m1 , l ₁ , μ and S _m1, respectively, are the magnetic resistance, length, relative magnetic permeability and cross-sectional area of the magnetic circuit section.

(32)
где L_м общая протяженность замкнутой магнитной цепи, м.In our case, it is possible to approximately take the indicated values equal in all sections of the magnetic circuit and write relation (31) in the form

(32)
where L _{m the} total length of the closed magnetic circuit, m

Подставляя это значение в (30) и используя ранее полученные значения В_п 1,42 и S $\genfrac{}{}{0ex}{}{\text{(1)}}{\text{п}}$ = 0,1м², найдем
IW 1,42•0,1•0,8•10⁴ ≈ 1140 А витков.Taking the approximate values of L _m 1 m, μ = 1000, S $\genfrac{}{}{0ex}{}{\text{(one)}}{\text{P}}$ = 0.1 m ² , from (32) we get:

Substituting this value in (30) and using the previously obtained values of In _p 1.42 and S $\genfrac{}{}{0ex}{}{\text{(one)}}{\text{P}}$ = 0.1m ² , we find
IW 1.42 • 0.1 • 0.8 • 10 ⁴ ≈ 1140 A turns.

или округленно 600 витков.Taking the value of I 2 A, which is convenient from the point of view of the current regulator, we find the corresponding value of the turns in the winding of the electromagnet section

or rounded 600 turns.

The average length of one coil of the winding will be approximately _lp1 ≈ πD _m = 3.14 • 1 ≈ 3.2 m.
The total length of the wire in the winding of the electromagnet section will be
l _pr 600 • 3.2 ≈ 2000 m.

которой соответствует диаметр провода обмотки d_пр 1,6 мм.Given the current density in the coil of an electromagnet
j 1 A / mm ² ,
we find the cross-sectional area of the winding wire from the known ratio:

which corresponds to the diameter of the winding wire d _PR 1.6 mm

где

удельное электрическое сопротивление меди.The resistance of the winding of the electromagnet section is determined by the known ratio:

Where

electrical resistivity of copper.

The power supply voltage of the electromagnet is determined by the known ratio:
U $\genfrac{}{}{0ex}{}{\text{(one)}}{\text{uh}}$ = I • R _e = 2 • 18 = 36 B.
The electric power consumed by one section of the electromagnet will be
N $\genfrac{}{}{0ex}{}{\text{(one)}}{\text{uh}}$ = U $\genfrac{}{}{0ex}{}{\text{(one)}}{\text{uh}}$ • I = 36 • 2 = 72 W.
Thus, 5 sections of the electromagnet of the braking device at maximum braking force will consume power of 5 • 72 360 W, which is quite acceptable when supplying power from electric generators driven by the running wheels of a flaw detector-projectile.

где К_пр 0,8 коэффициент заполнения окна обмотки,
то есть обмотка секции электромагнита может иметь размеры поперечного сечения, например, 100 х 15 мм, вполне приемлемые по конструктивным соображениям.The winding of the electromagnet section with the obtained data (W _p 600 turns, d _pr 1.6 mm) will occupy a window with an area determined by the known ratio:

where K _ol 0.8 the fill factor of the winding window,
that is, the winding of the electromagnet section can have cross-sectional dimensions, for example, 100 x 15 mm, which are quite acceptable for structural reasons.

 It should be borne in mind that, if necessary, the power consumption of the electromagnets of the braking device can be repeatedly reduced by increasing the dimensions and mass of the winding.

 In fact, by increasing, for example, the cross-section of the wire by two times and simultaneously the length of the wire of the winding by two, we get a winding with the same resistance, but with the number of turns of 1200 (instead of 600), in which it is enough to skip to obtain the same magnetizing force the current through it is two times smaller, i.e. 1 A instead of 2 A. At the same time, the power supply voltage of the electromagnet will also decrease by half and will be equal to 18 V, and the power consumption will decrease by four times and will be 18 W per section or 90 W for the entire electromagnet, which makes realizing the power supply of the electromagnetic brake with the parameters defined above, not only from electric generators, but also from rechargeable batteries.

 Thus, the above calculations testify to the real possibility of creating a flaw detector-projectile with the previously mentioned features, providing the possibility of its movement in the pipeline with significantly lower values compared to the speed of the product transported through it and stabilization of the speed of movement at a given level.

 The process of stabilization (regulation) of the speed of movement is as follows.

 If the conditions that ensure a constant speed of movement of the flaw detector-projectile in the pipeline, for example, the speed of the product transported through the pipeline or the braking force, are violated, the equality between the output signals of the sensor 12 and the setter 14 of the movement speed is violated. As a result, at the input of amplifier 28, a mismatch signal appears in the form of a constant voltage, the polarity of which depends on the ratio between the actual and the set speed of the displacement speed. For definiteness, we assume that when the actual speed exceeds a predetermined value, the voltage of the error signal will be positive, and in the opposite situation negative. This mismatch signal after amplification of the amplifier 28 is supplied to the reversible electric motor 18 or the reversible electric motor 21.

 Moreover, in the first case (when the actual speed of movement exceeds a predetermined), the direction of rotation of the output shaft of the electric motors is such that the disk shutter 15 opens (reducing the hydraulic resistance of the bypass pipe, pressure loss on it and the driving force), and the current regulator 20 increases the current in the winding 17 of the electromagnet of the braking device 16 (increasing the braking force) until the equality of the actual and predetermined velocities of the flaw detector-projectile is achieved.

 In the second case (when the actual speed of movement is less than the specified), the direction of rotation of the output shaft of the electric motors is reversed, so that the disk shutter 15 closes (increasing the hydraulic resistance of the bypass pipe, pressure loss on it and the driving force), and the current regulator 20 reduces the current winding 17 of the electromagnet of the braking device 16 (reducing braking force) until then, until the equality of the actual and predetermined speeds of movement of the flaw detector-projectile.

 As noted above, variants of a system for automatically controlling the speed of a flaw detector-projectile with only one regulatory body are possible, i.e. with a butterfly valve 15 (Fig. 1, 2) or with a brake device 16 (Fig. 3, 4), or with two regulating bodies 15 and 16 working simultaneously in concert from one reversing electric motor 18 (Fig. 5, 6), or operating from two separate reversible electric motors 18 and 21 in a coordinated fashion alternately (Fig. 7, 8).

 In the latter case, the rotation of the regulatory bodies is controlled by the signals received by the control unit 13 from the speed sensor 12 and the sensors of the initial position of the disk shutter and the brake device 19 and 22, as well as by the signals generated by the setpoint speed 14 and the setpoint threshold level 40 (which may be absent). This control is carried out as follows.

 First, we consider the case when the actual velocity of the flaw detector-projectile is less than the specified one, i.e., the output voltage of the displacement velocity sensor 12 is less than the voltage of the setter 14.

 In this case, the output of voltage comparators 33 and 34 has output signals of a low logic level (logical "0"), which are respectively supplied to the first input of the AND-NOT 35 logic circuit and through the logic circuit NOT 37 to the first input of the AND-NOT 36 logic circuit.

 At the same time, the second inputs of the AND-NOT 35 and 36 logic circuits receive output signals from the outputs of the sensors of the initial position of the disk shutter and the brake device 19 and 22, respectively. Since there is a logical “0” signal at the first input of the AND-NOT 35 logic circuit, and a logical “0” signal can be present at the second input of this circuit (for any position of the disk shutter 15, except for the initial one), and the logical signal “1 "(at the initial position of the shutter 15), then at the output of the NAND circuit, in all these cases, a high level signal will be present, i.e. logical "1". In this case, the output node 38 will be in a conductive state, and the control winding of the polarized relay 29 connected to it will establish its changeover contact in the first position, connecting the reversible electric motor 18 of the drive of the disk shutter 15 to the output of the amplifier 28. At the same time, at the first input of the logic circuit AND-NOT 36 there is a logic signal “1” (the result of inverting the output signal of the logic “0” of the comparator 34 is NOT). Therefore, at the initial position of the brake device, when the logical 1 signal is received from the output of the initial position sensor of the brake device 22 to the second input of the AND-36 logic circuit, the output of the specified logic circuit (36) has a low logic level signal (logical "0" ), leading to a closed state of the output node 39 and a de-energized state of the control winding of the polarized relay 29 connected to it. Thus, under the indicated conditions, the system of automatic control of the speed of movement will work Similarly to the above-described operation of the system with one regulatory body in the form of a disk shutter 15, i.e. the reversible electric motor 18 will close the indicated shutter until, due to an increase in the hydraulic resistance of the bypass pipe 11, pressure losses on it and a corresponding increase in the moving force, the speed of the flaw detector-projectile will not increase to a predetermined value.

 Let us now consider the case when the actual velocity of the flaw detector-projectile exceeds its predetermined value, i.e. the output voltage of the displacement speed sensor 12 is greater than the setpoint voltage 14. At the same time, the output of voltage comparators 33 and 34 has output signals of a high logical level (logical 1).

 Therefore, at the first inputs of the AND-NOT 35 and 36 logic circuits there are signals of logical "1" and logical "0", respectively.

 At the second input of the I-NOT 35 logic circuit, there is either a logical "0" signal (for an arbitrary position of the disk shutter 15 other than the initial one) or a logical "1" signal (for an initial position of the disk shutter 15). In the first case, the logical "1" signal will remain at the output of the I-NOT 35 logic circuit, leaving the position of the polarized relay 29 and the operation scheme of the automatic speed control system of the flaw detector-projectile with a disk shutter 15. In the second case, the I- The logical "0" signal will NOT appear, as a result of which the output node 38 will go into a non-conductive state, and the control winding of the polarized relay 29 connected to it will be de-energized. Since at this time there is a logical “0” signal at the first input of the AND-NOT 36 logic circuit, and a logical “1” signal (the brake device was in the initial position) at the second input of this circuit, there will be a signal at the output of the specified logic circuit logical "1", which will open the output node 39, will pass current through the second control winding of the polarized relay 29 connected to it and transfer the switching contact of this relay to the second position, in which the reverse motor will be connected to the output of the amplifier 28 spruce 21, which controls the position of the slider of the potentiometer 25 in the base circuit of the transistor 23 of the current regulator 29 in the winding 17 of the electromagnet of the brake device 16.

 In this case, at the first moment of time, the potentiometer engine 25 is in its lowest position (see Fig. 9), in which there is no current in the base circuit of the transistor 23, as a result of which the transistor is locked, the electromagnet coil 17 is de-energized and the brake device 16 does not create additional braking force. But due to the mismatch of the signals of the sensor 12 and the setter 14 of the movement speed at the input and output of the amplifier 28, there is a signal that rotates the output shaft of the electric motor 21 and moves the slider of the potentiometer 25 up. In this case, the voltage from the source 26 appears at the output of the potentiometer, and a current begins to flow in the base circuit of the transistor 23, which opens the transistor and determines the current value in the winding 17 of the electromagnet of the braking device 16 included in the collector circuit of the transistor 23. The magnitude of the indicated current and the corresponding value of the braking the efforts of the braking device 16 increase until the speed of movement of the flaw detector-projectile does not decrease to a value set by the setter 14.

 In the case of a subsequent decrease in the speed of movement of the flaw detector / projectile below the value set by the setter 14, the sign of the mismatch voltage at the input of the amplifier 28 will change, which will lead to a change in the rotation voltage of the output shaft of the electric motor 21 and the direction of movement of the slider of the potentiometer 25 towards its initial position, corresponding to a decrease in the current value in the winding 17 of the electromagnet of the braking device and a decrease in its braking force. This process can continue until the current is completely interrupted in the electromagnet winding 17 in the position of the potentiometer 25 engine, which is taken as the initial one. If, in such a situation, the velocity of the flaw detector-projectile will still be less than its predetermined value, the polarized relay 29 will switch back and the regulating body will act in the form of a disk shutter 15, as described above.

 Cases of stuck flaw detector-projectile in the pipeline due to various obstacles or breakdowns. Obviously, in this case, the velocity of the flaw detector-projectile will be close to zero and not substantially correspond to the set one. In such a situation, the automatic control system will initially react in the same way as any other disturbance associated with a decrease in speed, i.e. to the output of the amplifier 28 will be connected a reversible electric motor 18 of the drive of the disk shutter 15 (while the brake device 16 will be in the initial position), which will begin to close the bypass pipe 11 to increase the driving force to its maximum value. Due to the fact that when the bypass pipe 11 is completely blocked, unacceptably large forces can be applied to the flaw detector-projectile, measures can be taken to limit this effort. One of such measures may be the use of a disk shutter with a disk area substantially smaller than the live section of the bypass pipe 11.

 It should be borne in mind that when performing a disk shutter without limiters of its angular position, it will go into the closed-open cyclic mode of operation if the flaw detector-jam is stuck with the disk rotating in one direction, which can lead to the resumption of movement of the flaw detector-projectile.

 To expand the possibilities of releasing a flaw detector-projectile stuck in the pipeline, additional nodes were introduced into the automatic control system for the speed of movement, the functioning of which is as follows.

 The first (reference) input of the voltage comparator 41 is connected to the master 40 of the threshold level of the speed of movement or to a common bus. In this case, at this input of the indicated voltage comparator there is a zero or sufficiently low (threshold) level of the reference voltage, with which the output voltage from the output of the displacement speed sensor 12 is compared to the output voltage of the displacement sensor 12. As long as the output voltage of the specified sensor is greater than the threshold voltage level at the reference input of the voltage comparator 41, the output of this comparator has a high logic level signal (logical "1"), and the output is connected in series logical circuit NOT 42, respectively, the logic signal "0". Therefore, the time delay unit of signal 43 connected to the output of the indicated circuit and the functional units connected in series with it do not work as long as the flaw detector-projectile moves through the pipeline. But if it gets stuck, the output voltage of the speed sensor becomes less than the threshold level, and a low logic level signal (logical "0") appears at the output of the voltage comparator 41, and a high logic level signal (logical "1") appears at the output of the logic circuit NOT 42.

 This signal is fed to the input of the time delay unit 43 (Fig. 10), where, having passed the first differentiating chain 51, it starts a single-shot 52 with the first specified duration of the output rectangular pulse having a high logic level ("1"). After passing through the logic circuit NOT 53, the indicated signal is inverted and converted into a pulse of the same duration of a low logic level ("0"). After passing through the second differentiating circuit 54, the last pulse with its trailing edge starts the second one-shot 55, generating a pulse with a second predetermined duration, having a high logic level ("1"), fed to the first input of the AND-44 logic circuit, to the second input of which the output signal from the initial position sensor 19 of the disk shutter 15, which during cyclic operation of the specified shutter (see above) will periodically change the logic level from "0" to "1" and vice versa. Therefore, while there is a low logic level signal at the first input of the AND-NOT 44 logic circuit, there will be a high logic level signal at the output of this circuit, and the relay coil 31 connected to the output node 45 will be energized, closing the normally open contact of this relay, through which power supply to all energy-consuming units and units of the flaw detector-projectile, with the exception of the beacon, the power of which is provided from the emergency generator 48 through normally closed contacts of the relay 31 located I am in the open state when the relay coil is energized.

 When a high logic level signal ("1") is supplied to the first input of the AND-44 logic circuit from the output of the time delay node 43, and a high logic level signal ("1") is also output to the second input of this circuit from the output of the initial position sensor 19 of the disk shutter 15 (and this happens in the fully open position of the bypass pipe 11), the output of the logic circuit 44 appears a signal of a low logic level ("0"), which closes the output node 45 and provides a winding of the relay 31.

 In this case, the lighthouse 46 is connected to the emergency power generator 48 and at the same time all other power-consuming units and units of the flaw detector-projectile are disconnected from the power unit 7.

 It should be noted that the time delay unit of signal 43 contains two single-vibrators (52 and 55) with a given duration of the pulses generated by them. The pulse duration of the first one-shot (52) should be set so that during this period of time the shutter disk 15 has managed to make several (for example, 5-10) full revolutions around its axis in the bypass pipe, which will be accompanied by a cyclic (jerky) rise and fall of the a flaw detector-projectile of axial force of significant magnitude, capable in some cases of releasing a stuck flaw detector-projectile and enable it to continue moving through the pipeline.

 The pulse duration of the second one-shot (55) should be no less than the duration of the open-close cycle of the disk shutter in order to ensure the relay 31 is activated (in case of unsuccessful attempts to release the stuck flaw detector-projectile during the duration of the first one-shot pulse) and the associated fixation of the disk the shutter 15 in the position of maximum opening of the bypass pipe 11. The latter allows you to operate the pipeline with a flaw detector stuck in it for a long time with a minimum nymi costs, consisting in additional expenditure of energy due to pressure loss in the flow resistance of the bypass pipe.

 It should be noted that in the case of the resumption of the flaw detector projectile through the pipeline during the period of the pulse of the first single vibrator (52) in the time delay node of the signal 43, the relay 31 will not switch to emergency mode. This is due to the fact that the resumption of the flaw detector projectile is possible only when the position of the disk shutter 15 is different from the initial one, in connection with which, at this time, a signal of a low logic level ("0") will be received at the second input of the AND-44 logic circuit the output of this circuit will be a signal of a high logical level ("1") regardless of the signal level at the first input of the specified circuit.

 In the event of unsuccessful attempts to release a flaw detector-projectile stuck in the pipeline, as noted above, the beacon 46 is turned on, which facilitates the search and detection of the location of the flaw detector-projectile in the pipeline.

 At the same time, the power supply of the beacon from the generator 48 driven by the turbine 49 installed in the bypass pipe 11 greatly facilitates this operation, because virtually eliminates time limits on the timing of these works associated with the limited capacity and operating time of the batteries in the energy block 7.

 The principle of operation of the beacon 46 is to generate low-frequency electrical signals supplied through a matching device and brush current leads 47 to sections of its inner surface spaced along the length of the pipeline. In this case, an electric current begins to flow in the wall of the pipeline, partially leaving the soil in the surrounding pipeline through the "pipeline - soil" tank. The specified current creates a magnetic field that is easily detected by search equipment equipped with a receiving frame and signal amplifier.

 It should be noted that the adopted in the system of automatic control of the speed of movement according to the variant of FIG. 8, the logic of disconnecting all energy-consuming nodes and blocks of the flaw detector-projectile from the energy block in emergency situations when it gets stuck in the pipeline when the state is de-energized, relay 31 requires these nodes and blocks to work for short-term connection to the energy block if there is an output signal from the speed sensor 12, i.e. when the flaw detector-projectile moves through the pipeline. For this, a start button 50 is provided in the control unit circuit 13, which can be performed, for example, in the form of an end switch that is activated when a flaw detector passes through a lock device in the start chamber.

 It should also be noted that the presence in the automatic control system of the displacement velocity sensor 12 allows the registration of this parameter in an additional channel of the recording unit 9, which will provide additional information about the features of the flaw detector-projectile in the pipeline and facilitate the interpretation of defectoscopic data.

 The use of the proposed flaw detector-projectile for inspection of gas pipelines will significantly increase the reliability of the data obtained, as well as increase the reliability of its operation and the pipeline under examination due to operation at optimal values of the speed of movement, many times lower than the speed of natural gas transported through the pipeline.

Claims (19)

 1. A flaw detector for in-pipe inspection of pipelines, placed in the pipeline being inspected and moved by the product transported through it, containing a base resting on the pipeline surface with support nodes, a transporting unit in the form of an elastic sleeve fixed to the base and in contact with the pipe inner surface, an energy block , a flaw detector unit comprising flaw detectors fixed on the base and interacting with the walls of the pipeline and whether / and measuring transducers, an information recording unit, as well as defect coordinate determination devices, characterized in that it is additionally equipped with a bypass pipe for passing the product transported through the pipeline and an automatic speed control system for its movement, comprising a control unit with a speed adjuster connected to the input the control unit, the speed sensor, as well as the regulatory body in the form of shut-off and control devices installed in the bypass pipe Equipped with a drive connected to the output of the control unit, and / or fastened to the base and cooperating with the conduit braking device provided connected to the output of the drive control unit.  2. The flaw detector shell according to claim 1, characterized in that the base is used as a bypass pipe, made in the form of a hollow cylinder open from the ends or several similar cylinders mechanically interconnected by means of hinges or elastic spacers with the possibility of their angular displacement relative to each other friend.  3. The flaw detector according to claim 2, characterized in that the cylindrical base is supplemented by expanding conical sections docked to its ends, forming respectively a confuser and a diffuser in the tail and nose parts of the bypass pipe.  4. The flaw detector according to claim 1, characterized in that the locking and regulating device is made in the form of a disk shutter located in the bypass pipe kinematically connected to an electric reversing motor.  5. The flaw detector according to claim 1, characterized in that the brake device is made in the form of electromagnets fixed on the basis of electromagnets, containing brush pole pieces in contact with the inner surface of the pipeline, and windings connected directly or via an additional voltage converter to the power unit via a current regulator controlled by a reversible electric motor of a drive of a locking-regulating device or a second independent reversible electric motor.  6. The flaw detector according to claim 5, characterized in that the current regulator is made in the form of a transistor, the electromagnet windings are connected to the collector circuit, a current-stabilizing resistor is included in the emitter circuit, and the base is connected to the output of a potentiometer connected to a voltage source, the motor of which is kinematically connected to a reversible electric motor.  7. The flaw detector according to claim 1, characterized in that the flexible cuff on the transporting unit is located in its bow and the brake device in its tail.  8. The flaw detector according to claim 1, characterized in that the displacement speed sensor is made in the form of a spring-loaded measuring wheel fixed on the base with the ability to move, which is in contact with the inner surface of the pipeline and kinematically connected with the induction tachogenerator.  9. The flaw detector according to claim 8, equipped with an odometer as a coordinate determining device, characterized in that the odometer measuring wheel is used as a measuring wheel of the displacement speed sensor.  10. Flaw detector shell according to claims. 1, 4, 5, 6, characterized in that the speed adjuster in the control unit is made in the form of a voltage divider (potentiometer) connected to a voltage source, and the control unit is equipped with an error signal amplifier, the input of which is connected directly or through an additionally introduced comparison unit voltages to the outputs of the sensor and the setpoint of the speed of movement, and the output of the amplifier is connected to the reversible electric motor of the drive of the locking and / or brake device with the possibility of increasing the by means of a locking and regulating device of the live section of the bypass pipe, and by means of a brake device of brake reinforcement at a speed exceeding the value set by the setpoint, and reducing the living section of the bypass pipe by means of a locking and regulating device, and by means of the braking device of the braking force when the speed of movement is less than the value set by the setpoint .  11. The flaw detector according to claim 7, characterized in that the locking-regulating and braking devices have actuators with separate reversible electric motors and are equipped with additionally introduced sensors of their initial positions (states) corresponding to the maximum live section of the bypass channel and the minimum braking force, and the control unit is equipped with an additionally introduced switching unit with an executive and control circuit and its control unit, and the switching unit is connected between the output of the amplifier and reversible electric electric motors of the drives of the locking-regulating and brake devices with the possibility in the first position of the switching unit to connect to the output of the amplifier of the reversible electric motor of the drive of the locking-regulating device, and in the second position of the switching unit of connecting to the output of the amplifier of the reversing electric motor of the drive of the brake device, while the outputs of the sensor and speed adjuster movements, as well as the outputs of the sensors of the initial positions of the locking-regulating and brake devices are connected to the inputs of the control the control circuit of the switching unit is connected to the output of the control unit configured to set the switching unit to the first position at a speed of movement less than the value set by the master, and the initial position of the brake device, and at a speed of movement greater than the value set by the master, and the initial position locking-regulating device - in the second position.  12. The flaw detector according to claim 11, characterized in that the sensors of the initial position of the shut-off and brake devices are made in the form of limit switches connected to a voltage source with the possibility of receiving voltage at the output of the sensors in the initial position of the said devices and its absence in all other provisions.  13. A flaw detector according to claims 11 and 12, characterized in that the switching unit in the control unit is made in the form of a polarized electromagnetic relay with two control windings, and the control unit is made up of two voltage comparators, two logical elements AND - NOT, a logical element NOT and two output (matching) nodes, with the first (reference) inputs of both voltage comparators connected to the speed controller, and the second (information) inputs of both comparators connected to the output of the speed sensor the first input of the first logical element AND is NOT connected to the output of the first comparator, and the second input of the first logical element AND is NOT connected to the output of the sensor of the initial position of the locking and regulating device, the first input of the second logical element AND is NOT connected to the output of the logical element NOT, both inputs which are connected to the output of the second comparator, and the second input of the second logical element AND is NOT connected to the output of the sensor of the initial position of the brake device, the outputs of the first and second logic elements are NOT connected cheny respectively to the inputs of the first and second output nodes, the outputs of which are connected respectively to the first and second control winding of the polarized relay.  14. The flaw detector according to claim 13, characterized in that the detection signal generator, a “beacon”, is additionally introduced into it, and the control unit is equipped with an additionally introduced second switching unit with a control circuit and an executive circuit in the form of a normally-closed and normally-open contacts, as well as a second control unit containing a threshold speed threshold level adjuster, a third voltage comparator, a third logical element AND NOT, a second logical element NOT, a time delay node for the signal, a third output a node), and the first (reference) input of the third comparator is connected to a threshold speed threshold adjuster or to a common (ground) bus, the second input of the third comparator is connected to the output of the speed sensor, the output of the third comparator is connected via a logic element NOT parallel the included inputs to the input of the time delay node of the signal, the output of which is connected to the first input of the third logical element AND NOT, the second input of which is connected to the output of the initial position sensor a device, and the output is connected to the input of the third output node, the output of which is connected to the control circuit of the second switching node, normally closed contacts of which are included in the power supply circuit of the “beacon”, and normally open contacts are included in the power supply circuit of all other energy-consuming nodes and blocks are shunted by an additionally introduced start button with a make contact with self-resetting.  15. The flaw detector according to claim 14, characterized in that the threshold speed level adjuster is made in the form of a voltage divider (potentiometer) connected to a voltage source.  16. The flaw detector according to claim 14, characterized in that the second switching unit is made in the form of an electromagnetic relay.  17. The flaw detector according to claim 14, characterized in that the time delay unit of the signal in the control unit is made in the form of a first differentiating chain, a first one-shot, a logical element NOT, a second differentiating chain and a second one-shot connected in series.  18. A flaw detector according to claim 14, characterized in that the “beacon” is made in the form of a low-frequency generator, the output of which through a matching transformer and brush current leads is connected to sections of the pipeline spaced along its axis.  19. The flaw detector according to claim 14, characterized in that it is equipped with an additionally introduced emergency power source for the “beacon”, made in the form of a turbine installed in the bypass pipe and an electric generator connected to it.

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