SU717687A1 - Device for determining the depth of underwater pipelines - Google Patents

Description

  .one , -. . The invention relates to the field of electrical measurements. Devices are known for determining the depth of metal subsea pipelines. Based on the excitation of an electromagnetic field around a pipeline, a generator is directly connected to it and contains a floating frame, the outputs of which are counter and Aceleum unbalance amplifier. phase-sensitive rectifier, load on the reversing motor, moving one of the frames, measuring device 1, Disadvantages of this The devices are poor in accuracy, limited by marks on the rod, and the inertia of the engine, poor performance due to the necessity of fixing the position of the measuring device over the pipeline for the duration of the measurement, the process for which is as good as possible, and low in reliability. items. All these shortcomings lead to a long and costly flash of the underwater crossing. It is also known a device for determining the depth of a metal semiconductor, containing measuring sensors, switching keys switched by a control logic circuit, a storage unit, a threshold element and an indicator at output 2. This device contains a controlled analog-type divider. pas, which has a relatively low speed and accuracy compared to, for example, with the integrator, inclusive in the two-step integration scheme. The presence of an analog indicator reduces the accuracy of measurements, increases the inspection time of the object, and the switch control unit, which is not synchronized with the frequency of the current flowing through the cable, when evaluating the depth measurement by the average amplitude current in the pipeline during the time between two cycles of work The frequency and amplitude of the current in the pipeline will add an additional dimension to the depth measurement value. This can be avoided by using a generator that is highly stable in amplitude and frequency. However, this is associated with certain

difficulties, especially if you need more power (at great depths). .

The closest technical solution to the invention is a device that implements a method for determining the depth of a hollow metal subsea pipelines and contains

f if Wec abi TejibHo of the United .inductive sensor located; vertically above the pipeline, a koMMyator, a unit for isolating the sum, difference, and ratio of voltages, a control unit, and an indicator, with the output of the first inductive Dane being. The switch's pins are connected to the input of the unit to isolate the sum, difference, and voltage ratio, output) M associated with the input of the TK indicator). This device has low accuracy in determining the depth of subsea metallic pipelines. ,, .

The goal of isbreteni is to increase: the accuracy of determining the depth of the bullet; neither;

The goal is achieved in that a device for determining the depth of metal subsea pipelines containing three series-connected inductive sensors located vertically above the pipe, a switch, a unit for isolating the sum, the difference and the voltage ratio, the control block and the indicator. of an inductive sensor through the contacts of the switch are connected to the input of the unit to isolate the sum, difference and voltage ratio, the output connected to the indicator input, itolnr two zero-body introduced porogbvy element, an integrator, and the point Connections Conclusions vtbrogo and the third is. inductive sensors connected to the common bus, free input of the third inductive sensor noftK iia "ie H to the inputs of the integrator, the first zero-body and the threshold element, and

the integrator’s output through the second nullgang and the inputs of the first null organ and

This fast-moving power cell is connected to the corresponding inputs of the control unit connected to the switch, and the indicator is made as a counter, the inputs of which are connected to the corresponding output unit 1 of the control unit and the output of the reference generator.

The schematic diagram of the proposed electrical device is presented in principle. ; .

The device contains inductive sensors 1,2,3, is a coil with identical parameters, atchiki 1 and 2 are rigidly fixed on.

.on they t each other, a; 6c and they are oriented parallel to the mirror of the w1 | s, th Görpöndi, CI-axis pipeline switch, made on the control of their keys 4,5,6,7,8; a unit for isolating the sum, difference, and ratio of voltages 9, containing a measuring amplifier 10 at the input, as well as a storage unit 11, input resistances 12, 13, and a capacitor 14, a generator 15, at the output of which the threshold element 16 is turned on.

The device also contains an integrator 17, made on an operational amplifier 18, two null organs 19, 20 extreme threshold element 21, a control unit 22, an indicator 23 made in the form of a counter with digital indication, a reference generator 24 and a metal conduit 25 to which electric current flows.

Measuring inductive sensors 1, 2 through controlled keys 4., 5 of the switch selective amplifier 10 and the storage unit 11 is connected to the input of the generator 15 of the measured signal, the output of which through the threshold element 16 and the control unit 22 is connected to an indicator 23 having a digital indication.

The inductive sensor 3 of the control signal in three parallel circuits, namely: through the integrator 17 and the null organ 19, directly through the second null organ 20 and through the extreme threshold element 21 is connected to the logic control unit 22, the output of which is connected to the control keys ..4,5,6,7,8 of the switch and the indicator 23 having feedback to the control unit 22.

The selective collider 10 provides for the isolation of inductive sensors 1, 2, 3c by the measuring channel due to the large input impedance, and also provides a narrow bandwidth of the operating frequency, suppressing interference of parasitic frequencies. The output of the selective amplifier 10 through a controlled key 6 is connected to the memory of unit 11, allowing the user to memorize the instantaneous value of the measured signal (EMF) when the key 6 is closed, and when the key is open

6, due to the large input impedance of the selective amplifier 10, without distortion, write off a constant voltage proportional to the maximum value of the measured signal OflOV-. ...: -. BUT... ,..:. /

The output of the storage unit 10 is connected to the input of the integrator 15, which is unknown according to the circuit of the integrated integrator, through the control of one of the keys

7.8 and input resistances 12, 13, which allow scaling of the measured signal.

The threshold element 16 forms the end of the working interval supplied via the control unit 22 to the indicator 23 with a digital indication. The integrator 17 shifts the phase:; oidal EMF per l,. Zero-bodies 19 20 fix the moments of equality of zero sinusoidal EMF. The extreme threshold element generates a gating pulse at the moment when inductive sensors 1, 2, 3 intersect the zone of maximum magnitude of the magnetic field. The logical control unit is designed in such a way that, synchronously with the sinusonal EMF, control the control keys 4, 5 b, 7, 8 of the switch. Two control circuits are connected from the output of the control unit 22 to the counter-indicator 23: one T switches the counter on when the reference interval T is read; another one connects the working interval T. In addition, the reference oscillator 24 is connected to the input of the indicator 23 pulse frequency f, the device operates as follows. Alternating current is passed through the metal conduit 25, varying sinusoidally and. creating an electric magnet around the pipeline. Magnetic flux induces in inductive sensors 2, a sinusoidal emf. The control signal E from the inductive sensor 3 is supplied simultaneously to the integrator 17, the null organ 20 and the extreme threshold element 21. At the output of the null organ 20, rectilinear pulses are generated that coincide in phase with the control signal. The output of the null organ 19 produces similar pulses that are phase-shifted by nr. A strobing pulse from the output of the extreme threshold element 21 allows the logic control unit 22 to operate at the moment the sensor passes over the axis of the pipeline, while the effective value of the induced EMF reaches its maximum value i The measurement process and the output of the result occur in one sinusoid period. The key 4, which is in the closed state from 0 to ms, will connect the inductive sensor 2, and the key 5, which is in the closed state, from SL TO; 2 L, connects the inverse inductive sensors 1 and 2 to the input of the bi-directional amplifier 10. As a result, at the last of the latter, EMF Exi is formed {at the moment before О to:) and Е (from -JC to 2 Tt) oE.ANo (.- ) -A. where А К, о fsw is a constant coefficient depending on the gain factor K of the selective amplifier 10, the current frequency in the pipeline f, the number of turns w of sensors 1, 2 and their area S. . Key 6 closes at time from O. Dokh / 2 and from ts to. At that moment, at instant t / 2, the instantaneous and, at the instant of 3/27, the value of E, the instantaneous value of E, is constant. The emf constant at the output of the | 1transmitting unit 11 from. С- / 2 To takes the value E o, - г from 3/2 L- 2YAG-, 3Qn. .2 - N ,, (2-) н. Minus before the coefficient takes into account the inversion of the recording gain of the K-block 11. EMF EZ, ", and EZD", the blackout switch and 7 are output from the memory of the block 11. , 8 to the input of the integrator 15., with, IT happens two times, sha, integrator. vv A: -, .-, in the first step, with .jcH tSf & fii fif- - cha 7, 6, the moment the triangulation nocTOjfHii 3ff is the reference flow, K.G; S, -. This is formed with no i | i® HHA ftKa, Tbr pa 23 controlling the block, 22 and is defined by the expression:. .. N is the specified number of pulses, determining T, and is the frequency of the reference oscillator. After the time T „key 7 closes. In the second step when closing the key-. cha 8 at time 3/2 tf. The oppositely occurring constant emf Eep occurs simultaneously, the indicator counter 23 is switched on, the fixing time deintegration T, which is determined by the formula where the number of pulses entered into the indicator counter 23 from the time the key was turned on 8 until the output 4 of the integrator is fixed -uil threshold element 16. Time Tjj is determined from the equality of zero sum of the emf of integration Ej and disintegrating E. ..C J / aan.

Claims (1)

The claims h ^ mcn: ^ When огда, and Sr ^W hgpoh b guide R ~ “t. .. - ..... Hi. N. and f _nn from condition 1 ¹ g-: - 10ό, 1000 and t, d The limiting condition for the operation of the device, caused by the need to synchronize the logic circuit to control the frequency f of the current passed through the pipeline, 'is the following' Τ _ο έ l / 4f. .. (Π) · Based on the calculations and experimental data, one can draw a “conclusion” that this device, in comparison with the known ones, makes it possible to measure depth / occurrence of a metal pipeline with high accuracy. / the proposed device 'also allows you to take measurements in many barrels above the pipeline directly during the movement of the vehicle with anyone. speed fight. In addition, it can be used ..... 1st, A device for determining the depth of metal underwater pipelines, comprising: three serially connected 'inductive sensors, a switch,' a unit for isolating the sum, difference and voltage ratio, a control unit and an indicator, the outputs of the first inductive sensor through the contacts of the switch connected to the input of the unit for allocation sums, differences and ratios of stresses, 'in the course of the indicator connected with the input, is related to the fact that, in order to increase the accuracy of determining the depth of flight of the pipe water, it is further introduced Dwan / ul body integrator and a threshold element, and the connection point of the second terminals and the third inductive sensor podklyuche25 on a common bus, free output. • the third inductive sensor is connected to the inputs of the integrator, the first 'zero-organ .. and the threshold element,' and the integrator output through the second 30 ° ^C UL-organ 'outputs of the first zero-organ and the extreme threshold element are connected to the corresponding '. the corresponding inputs of the control unit associated with the switch, and the indicator is made in the form of a counter, the inputs of which are connected to the corresponding outputs of the control unit and the output of the reference generator. ''