RU2369783C1 - In-tube inspection shell-defectoscope with controlled movement speed - Google Patents

Abstract

FIELD: construction industry.

SUBSTANCE: invention refers to in-tube shells. Into in-tube inspection shell-defectoscope with controlled movement speed there introduced is tight container, hydraulic drive. In the back part of cylindrical housing there installed relative thereto is the module movable in axial direction, which contains poppet shutoff valves entering passage openings of cylindrical housing. At that, movable module consists of front and rear steel walls with holes, and those walls are connected to each other with hollow cylinder with thickenings, in which rods with poppet shutoff valves are installed in the front part of movable module; on external surface of hollow cylinder there installed is polyurethane hollow cylinder with four external longitudinal slides entering four steel slots of cylindrical housing; at that, tight container is coaxially connected to the end surface of cylindrical housing; inside it there installed is electric motor of hydraulic pump, electric drive of fluid distributor, a fluid tank and control system; in central part of the tight container there installed is hydraulic motor the stock of which is connected with an elastic connection joint to the back cover of the shell movable module; at that, on the stock there installed is displacement sensor the output whereof is connected to negative input of voltage adder of the control system, and its positive input is connected to the programming unit generating the value of the specified stock position owing to voltage so that the control system operating algorithm has the following ratio:

where F_y(S) - Laplace representation of control force produced with hydraulic motor; K_F - transfer ratio of in-series connected elements of control system; T - time constant of the forcing link; K_f - transfer ratio of negative feedback from position sensor on the hydraulic motor stock to negative input of the adder as to voltage; U₃(S) - representation of programme voltage specifying as to positive adder input the specified position of hydraulic motor stock; y(S) - Laplace representation of current position of hydraulic motor stock; S - Laplace transformation operator, at that, to hydraulic motor input there supplied from fluid distributor is pressure difference P_H, which is determined by the following formula:

owing to which there provided is the possibility for hydraulic motor piston to create pressure force for overcoming friction force and gas pressure force on movable module and for its being moved by value Δy, by which closing of four passage openings with shutoff valves is changed in relation to the specified value, owing to which there provided is control of gas pressure force F_c on the shell: F_c = 2pS_nW², w = υ-V, where V - shell speed relative to the tube; W - gas velocity relative to the shell; U - gas velocity relative to the tube, at that, surface area of opening one passage opening is determined by the following formula:

where R₀ - radius of each passage opening; L₀ - length of poppet shutoff valve; K_l - transfer ratio of hydraulic motor as to the pressure, and value of the specified voltage U₃ is determined and preset with the control system as per the established empirical relation V=V(S) of the shell movement speed V from total surface area S=4S, opening of holes with four passages.

EFFECT: investigating main pipelines with increased movement speed stability.

9 dwg

Description

The invention relates to in-pipe shells for inspection of trunk pipelines with increased stability of speed.

Known flaw detector for in-line inspection of pipelines (patent RU No. 2102738, IPC G01N 27/82, G01N 27/87). The projectile is equipped with a bypass pipe for bypassing the product transported through the pipeline being examined and an automatic speed control system containing a speed sensor, a control unit with a speed controller and a regulating body in the form of a brake device interacting with the pipe wall.

The disadvantage of this projectile is the adjustment of speed only due to friction forces, which lead to increased wear of the walls of the pipeline and the contact surface of the brake device. In addition, the introduction of an electromagnet for a braking device requires a lot of energy, and the battery power is limited.

Known scraper for cleaning the inner surface of the pipeline with variable speed (US patent No. 5208936 from 05/11/1993, MKI V08V 9/04), which consists of a cylindrical body with first and second open ends, an annular seal between the pipeline and the housing, a locking element located inside the housing to block the flow of fluid passing through the housing, but passing through numerous second holes, the first holes include devices that come into contact with the second holes and are bypass nye channels defining the fluid flow passing values, velocity sensors of the scraper, the drive control means and the closing means. The first and second holes are arranged around the circumference around the first and second plates, and the bypass channels include numerous tubes passing between the corresponding tubes of the first and second holes and forming a central cavity. This device does not allow to stabilize the velocity of the in-tube projectile at the maximum gas bypass due to the plates blocking the gas flow.

A known method of in-line flaw detection and a flaw detector for its implementation (RF patent No. 2109206, F17D 51/00, B08B 9/04 of 04/20/1998 by G. Efremov, V. Usoshin and others), values electrical signals recorded by flaw detectors in the presence of defects during the movement of the flaw detector-projectile through the pipeline in the flow of the transported product, determine the coordinates of the detected defects, register and store them, generate the parameters of the specified movement, stop from the control system devices and return it to the coordinates of the detected deviation, perform a flaw detection at a given speed, process and record the measurement results, the flaw detectors are mounted between the poles of the permanent magnets and placed in groups in cassettes that cover the entire cross section of the pipeline, the flaw detector is a two-link mechanism with a hydraulic axial return drive - translational movement of one link relative to the other, each link has supporting organs.

The disadvantage of this invention is the complexity of the method of inspection and design of an in-line flaw detector-projectile.

Known in-line inspection projectile with a controlled speed of movement (RF patent No. 238158, F17D 5/00; F16L 55/26 from 02.27.2008, authors A. Sinev and others), containing an annular housing, wheels, cuffs, fitted circles to the body, four bore cylindrical holes through 90 ° along the body, an odometer, flaw detectors, a device for controlling changes in pressure drops in the form of cone elements with the possibility of relative movements from the drive along the axis on the guide of the parabolic body of revolution.

This technical solution is taken as a prototype.

The disadvantage of the device according to this patent is its complexity and unreliability of fixing the guide of the parabolic body of revolution with the help of a reversible electric motor and rack and pinion transmission at high axial loads arising from the pressure of the transported product, and the lack of design parameters and the speed regulation scheme of the inspection shell.

The objective of the invention is to simplify the design of an in-line inspection projectile-flaw detector with adjustable speed and increase the reliability of fixing the guide rail with valves by changing its design and control system.

The problem is solved due to the fact that in an in-tube inspection projectile-flaw detector with adjustable speed, containing a sealed cylindrical body, cuffs fitted around the circumference of the body, wheel bearings, flaw detectors, odometer, drive motor, control system, four through-hole cylindrical holes through 90 ° along the housing, the device for controlling changes in pressure drops in the form of cone elements with the possibility of movement from the drive relative to the housing, hermetic an axial container, a hydraulic actuator, an axially movable module is mounted in the rear part of the cylindrical body, comprising conical shut-off valves entering the passage openings of the cylindrical body, while the movable module contains front and rear steel walls with openings, the walls are interconnected by a hollow cylinder with bulges in which rods with conical shut-off valves are inserted in front of the movable module, a polyurethane floor is installed on the outer surface of the hollow cylinder a cylindrical cylinder with four outer longitudinal runners included in four steel grooves of the cylindrical body, the sealed container being connected coaxially to the end of the cylindrical body, a hydraulic pump electric motor, an electric fluid distributor, a fluid reservoir and a control system are installed in it in the central part of the second sealed container a hydraulic motor is installed, the rod of which is connected by an elastic connection node to the back cover of the movable projectile module, and a sensor of displacements, the output of which is connected to the negative input of the voltage adder of the control system, and its positive input is connected to a software device that generates the value of the specified position of the rod due to voltage, so the algorithm of the control system is the ratio:

,

,

where F _y (S) is the Laplace image of the control force developed by the hydraulic motor; K _F - transmission coefficient of series-connected elements of the control system; T is the time constant of the forcing link; K _OS - the negative transmission coefficient of the feedback from the position sensor on the stem of the hydraulic motor to the negative input of the adder voltage; U ₃ (S) - the image of the software voltage that sets the positive position of the hydraulic motor rod at the positive input of the adder; y (S) - Laplace image of the current position of the hydraulic motor rod; S is the Laplace transform operator, while the pressure difference P _H , determined by the formula, is supplied to the input of the hydraulic motor from the fluid distributor:

,

,

due to which it is possible to create a pressure force by the piston of the hydraulic motor to overcome the friction forces and gas pressure on the movable module and move it by Δy, by which the passage through the shut-off valves changes with respect to the set value, thereby controlling the pressure force F _C gas per projectile:

,

,

,

,

where V is the velocity of the projectile relative to the pipe; W is the gas velocity relative to the projectile; υ is the gas velocity relative to the pipe, while the opening area of one passage opening is determined by the formula:

;

;

where R ₀ is the radius of each bore hole; L ₀ is the length of the locking cone; K _W is the transmission coefficient of the hydraulic motor by pressure, and the value of the specified voltage U ₃ is determined and set by the control system according to the established experimental dependence V = V (S) of the velocity of the projectile V on the total area S = 4S _{n of the} opening of four through holes.

Figure 1 shows a structural diagram of an in-line projectile flaw detector (projectile), figure 2 shows the mounting of the rod with a locking cone valve; figure 3 shows a cross section of the projectile along aa; figure 4 shows a view of the shell along arrow B with the casing removed. Figure 5 presents the connection diagram of the hydraulic actuator with the control system. In Fig.6 shows a structural diagram of the unit of the shutoff valve, Fig.7 shows the site of the connection of the stem of the hydraulic motor with the rear wall. On Fig shows a structural diagram of a control system; figure 9 is a graph of V = V (S).

The projectile includes a cylindrical body 1 with cylindrical through holes 2. The rear movable part of the projectile 3 relative to the body 1, which makes up the movable module, consists of a steel frame containing the front 4 and rear 5 walls with openings 2 for passing gases. The front 4 and rear 5 walls are connected by a steel shell 6 (see Fig. 3) with four longitudinal cylindrical and rear holes in the bulges 7, inside which are inserted rods 8 (see Fig. 2), ending on the front with conical shut-off valves 9, and with the back - fastening devices 10 and 10 (see Fig. 4) of the rods 8 and the rod to the rear wall 5 in the form, for example, of nuts with stoppers (Fig. 7). (The fastening devices 10 and 10 are described below.) To ensure an elastic movable connection of the rear movable module 3 with the housing 1, a support, for example, a polyurethane hollow cylinder 11 with four outer longitudinal runners 12 included in four steel grooves 13 of the cylindrical, is mounted on the outer surface of the shell 6 casing 1. On the casing 1 a sealed container 14 is fixed, which is connected, for example, by bolts (not shown) to the end of the rear side of the cylindrical casing 1. A hydraulic actuator 15, a rod 16 (with m. Fig. 5) which is connected by the attachment unit (Fig. 7) with the back cover 5 in such a way as to enable the transmission of force from the hydraulic actuator to the movable module 3 in both positive and negative directions along the longitudinal axis of the projectile. The inlet and outlet pipelines to the hydraulic actuator and their switching device, the hydraulic pump and the hydraulic pump drive electric motor, an additional electric fluid distributor are installed in the inner sealed part 17 of the container 14. In the inner part 17 of the sealed container 14, the electronics and power supply units are also installed.

The inner cavity of the cylindrical body 1 is sealed with a lid 18, forming the main sealed container. It contains orientation and navigation devices 19, an electronics unit 20 for processing information, a power supply 21 in the form of, for example, lithium batteries. On the peripheral part of the cylindrical body 1 are either sensors for detecting corrosion and other defects of the pipe 22, or sensors for determining the profile of the pipe 22, etc. The projectile is also equipped with cuffs 23 with wheels, wheel odometers 24.

The node connecting the shutoff valves 9 (see figure 2) with the housing 1 includes a polyurethane sleeve 25 connected to the housing 1. The sleeve 25 has four conical holes 26, which include the corresponding shut-off valves 9. The hydraulic actuator 15, as the inner part 17, closed by a lid 27 with a tight seal.

The hydraulic actuator 15 consists of a hydraulic motor 28 (see FIG. 5), a fluid reservoir 29, a hydraulic pump 30 driven by an electric motor 31. The hydraulic motor 28 is connected by pipelines 32 and 33 to the left and right outputs of the fluid distributor 34, which is connected to an additional electric drive 35.

In turn, the liquid distributor 34 is connected through the electric actuator 35 of the distributor to the discharge outlet 37 of the hydraulic pump 30, its suction inlet 38 is connected by a pipe 39 to the tank 29. The inlet 40 of the safety valve 41 is connected to the pipeline 36, and its outlet is connected via a pipe 42 to cistern 29.

All hydraulic connections and elements are sealed, there are tight couplings of the input-output pipelines from the container 14. A displacement sensor 43 is installed between the stem 16 and the hydraulic motor housing 28, its electrical output is connected to the corresponding input 44 of the computer control system 45 with actuators 47. With its other input 46 is connected to the output of the odometer 24.

The output 48 of the control system 45 is connected to the input of the electric actuator 35 of the distributor, and the output 49 of the control system 45 is connected to the input of the electric motor 31. The control system 45 includes a software device.

The elastic connection unit (Fig. 7) consists of washers 50, a rubber or polyurethane sleeve 51, a washer 53 and a cotter pin 54. Thanks to this fastening, an elastic connection of the hydraulic actuator rods 16 to the rear wall 5 is ensured, which ensures uniform distribution. It should be noted that the rear wall 5 also has elasticity, which contributes to the coordination of the connection of the hydraulic actuator rod with the rear wall 5, caused by the inaccuracy of their manufacture. In the manufacture of the projectile, the rigidity of the attachment points of the rear cover can be further reduced by cutting the jumpers between the fasteners of the nodes 10 on the rear wall 5. The rear of the projectile is protected by a casing with holes 56 ', with the front casing 56 "by an anchor bolt 58. The rod 16 is connected to the piston 57 of the hydraulic motor 28 .

On Fig shows a structural diagram of the rear movable module 3 with a control system, on which 59 is the adder forces, which is the movable module 3. Position 60 denotes the transfer function of the same movable module as a double integrating link, where m is its mass with attached elements; 61 is the transfer function of the piston of the hydraulic pump with the rod 16 and other moving parts, where n is the damping coefficient, and F _g (S) is the damping force. Position 62 denotes the gear ratio of the feedback of the hydraulic motor K _OS , including the product of the gear ratio of the displacement sensor 43 and the amplifier (not shown). Position 63 indicates the adder voltage U ₃ (S), which defines the movement of the rod 16, as well as negative feedback voltage U _OS . 64 (Fig. 8) designates the transfer function W _y (S) of a circuit from a corrector connected in series with a power amplifier (control system 44 (Fig. 5), an electric motor 31 with a hydraulic pump 30, and a hydraulic motor 28 developing a control force F _y ( S):

where K _F is the transmission coefficient of the series-connected elements of the node 64 of the control system; T is the time constant of the forcing link. In this case, the force F _y on the rod is provided due to the pressure difference P _H in the hydraulic motor generated by the hydraulic pump and the fluid pressure distributor, determined by the algorithm:

;

;

where K _W - transmission coefficient of the power part of the hydraulic control system; To _y is the transmission coefficient of the correction device with a power amplifier, while the increment of the displacement of the rod Δu and the transfer function of the correction device are determined by the formulas

;

;

where T is the time constant of the forcing link, balances the sum of external forces from gas pressure and friction forces in runners and other elements.

The shell works as follows. When it is stocked in the pipeline, the control system 44 (see FIG. 5), in the absence of projectile movement (V = 0), installs the hydraulic pump 28 using the rods 16 of the movable rear module 3 in the left extreme position, which is shown in FIG. 1. When the gas pressure P is applied (Fig. 1), the projectile begins to move, since the shutoff valves 9 overlap the four through-holes 2. At a high velocity V of the projectile’s movement (for example, more than 4-5 m / s), the control system 44 outputs 49 includes an electric motor 31, and through a clutch 55, it drives a hydraulic pump 30. In addition, according to the signals of the control system 44 from the output 48, the electric actuator 35 installs a fluid distributor 34 so that the fluid transferred from the left through the pipe 32 (or to the right through the pipe 33) moves w approx 16 to a position in which the rear movable unit 3 is displaced in a fixed position, in which the gas rushes into the gaps between the shut-off valves 9 and the openings 2. The pressure difference between the front and rear walls is reduced, and the speed of the projectile decreases. To ensure stability and quality of speed regulation V, a displacement sensor 43 of the rod 16 is introduced into the hydraulic motor 44.

The driving force of the projectile F _dv is determined by the approximate formula:

; S=4S_n

; S = 4S _n

where ΔF _p is the pressure force, determined by the difference ΔР _{from the} static gas pressures to the front and rear sides of the projectile, varying depending on the opening area of the cylindrical passages 2; ρ is the gas density; S ₀ is the total cross-sectional area of the projectile; R _C is the radius of the projectile (pipe); S is the total opening area of the through holes, and S _n is the opening area of one through hole 2. Since the velocity of the projectile relative to gas is determined by the formula:

where υ is the gas velocity relative to the pipe, the velocity of the projectile relative to the pipe V is equal to:

V = υ-W.

It is easy to see that increasing the opening area of the passage openings S with valves 9 reduces the driving force of the projectile F _s . The calculations showed that if the through-holes in the shell of the projectile are fully open, then the force of the gas pressure on the projectile is less than the friction force of the projectile on the inner wall of the pipeline. In this case, the projectile does not move. When the movable module 3 approaches the shell body 1, the passage openings 2 in the shell partially overlap, the driving force increases, and the shell begins to move along the pipeline.

As the calculations show, ΔР _с varies little with a change in the area of the open part of the cross-section of passages and the velocity of the projectile in the pipeline at constant working pressure and working speed of gas in the pipeline. Figure 6 shows the position of the valve 9, closing the cylindrical passage 2 of circular cross section of radius R ₀ (dashed line), as well as its position when shifted to the right by the value of y. In Fig.6, the radius R corresponds to the area of overlap by the valve 9 through passage, therefore, the opening area of one passage is equal to:

For four passes, we have

An increase in S leads to a decrease in F _dv (formulas (1) and (2)) and, consequently, the velocity V of the projectile relative to the pipeline.

If we approximate the experimentally measured dependence of the projectile

where K is the proportionality coefficient, it is thereby possible to analytically describe the law of pressure force control F _D developed by a hydraulic motor:

Calculations show that the force with open passage openings 2 acting from the side of the moving gas on the movable module 3 is 15-20% of the total gas-dynamic force acting on the entire projectile.

The formation of a signal proportional to the given velocity V _{3 of the} projectile is carried out at the stage of debugging and adjusting its parameters on the bench or in the pipeline. Experimentally, the dependence of the velocity V of the projectile motion, determined by the odometer, on the value of the specified displacement of the rod y and, therefore, on the area S of the opening of four through-holes S.

;

;

where L ₀ is the length of the shutoff valve, this determines the validity of taking characteristics V = V (y). It is not possible to establish the exact analytical dependence for this characteristic because of the complex aerodynamics of the projectile with its specific design. Obviously, the characteristic is falling (Fig.9). It is stored in the memory of the computer control system and, according to the program laid down, depending on the distance of the pipeline or the projectile travel time, sets the value of U ₃ (t) to the control system input. This value, taking into account (6) and (7), is compared at the input of this system with the current signal K _oc y (t) from the position sensor 43, and the control system, moving the rear movable module 3, eliminates the voltage difference U ₃ (t) -K _os y (t). In the steady state, the movement of the movable module 3 will be proportional to the specified value of U ₃ :

, а, значит, и скорость снаряда будет равна V=V₃. Алгоритм работы системы управления имеет вид:Therefore, the velocity of the projectile according to Fig.9 will be equal to the specified V = V ₃ . In practice, the steady-state value of U ₃ is constant, so that the position of the movable module 3 will be unchanged, i.e.

, and, therefore, the velocity of the projectile will be equal to V = V ₃ . The control system operation algorithm has the form:

,

,

where K _F is the transmission coefficient of the control system; T is the time constant of the forcing link.

Here K _F = K _F K _U , where K _y is the transmission coefficient of the correction device and the power amplifier of the control system.

The equation of motion of the movable module 3 will be:

(ms ³ + ns ² + K _OS K _F Ts + K _OS K _F ) y = (Ts + 1) K _F U ₃ (S) + sF _C (s),

where m is the mass of the module; F _C - resistance force of the movable module due to friction, gas pressure, etc .; n is the damping coefficient created by the hydraulic motor and gas flows. Subject to conditions

;

; T=τ

;

; T = τ

The management system will ensure high quality management. The time constant τ is assigned from the condition of ensuring a short transient process taking into account the parameters of the projectile and is a fraction of a second.

The application of the present invention will significantly simplify the method of flaw detection and the design of the in-tube shell-flaw detector. This is determined by the fact that due to the proposed solutions, the accuracy of controlling the velocity of the projectile and the reliability of locking the valves increases significantly.

Claims (1)

Variable speed in-line inspection projectile-defectoscope comprising a sealed cylindrical body, cuffs fitted around the body to the wheel, wheel bearings, flaw detectors, odometer, drive motor, control system, four bore cylindrical openings through 90 ° along the body, change control device pressure drops in the form of cone elements with the possibility of movement from the drive relative to the housing, characterized in that the sealed container, hydraulic drive, are introduced into an axially movable module is mounted on the rear part of the cylindrical body relative to it, comprising a conical shut-off valve included in the passage openings of the cylindrical body, the movable module comprising front and rear steel walls with openings, the walls are interconnected by a hollow cylinder with thickenings into which are inserted rods with conical shut-off valves in front of the movable module, a polyurethane hollow cylinder with four external valves is installed on the outer surface of the hollow cylinder with longitudinal runners included in four steel grooves of the cylindrical body, the sealed container being connected coaxially to the end of the cylindrical body, a hydraulic pump electric motor, a fluid distributor electric drive, a fluid reservoir and a control system are installed in the central part of the sealed container, the hydraulic motor of which connected by an elastic connection node to the back cover of the movable projectile module, while a displacement sensor is installed on the rod, the output of which is connected the negative input of the adder control system voltage and its positive input connected to the programming device, is generated by a voltage value U ₃ predetermined stroke position, so that the algorithm of the control system is the relation:

where F _y (S) is the Laplace image of the control force developed by the hydraulic motor; To _F is the transmission coefficient of series-connected elements of the control system; T is the time constant of the forcing link; To _OS - the transmission coefficient of negative feedback from the position sensor on the stem of the hydraulic motor to the negative input of the adder voltage; U ₃ (S) - the image of the software voltage that sets the positive position of the hydraulic motor rod at the positive input of the adder; y (S) - Laplace image of the current position of the stem of the hydraulic motor; S is the Laplace transform operator, while the pressure difference P _H , determined by the formula, is supplied from the fluid distributor to the inlet of the hydraulic motor:

due to which it is possible to create a pressure force by the piston of the hydraulic motor to overcome the friction forces and gas pressure on the movable module and move it by an amount Δу, which changes with respect to the set value, the shutoff valves overlap the four passage openings, thereby controlling the pressure force F _C gas per projectile:

,

,
where V is the velocity of the projectile relative to the pipe; W is the gas velocity relative to the projectile; υ is the gas velocity relative to the pipe, while the opening area of one passage opening is determined by the formula:

;

where R ₀ is the radius of each bore; L ₀ - the length of the locking cone valve; К _ж - hydraulic motor transmission coefficient by pressure, and the value of the specified voltage U ₃ is determined and set by the control system according to the established experimental dependence V = V (S) of the velocity of the projectile V on the total area S = 4S _{n of the} opening of four through holes.

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