RU23983U1 - DEVICE FOR DETERMINING PLACES AND SIZES OF PIPELINE LEAK - Google Patents

Abstract

A device for determining the parameters of a pipeline leak, containing n measuring channels, each of which consists of a series-connected block of acoustic transducers, a gain block, the output of which is connected to the first input of the filtering block, an analog-to-digital conversion block, and also containing a control unit, characterized in that the n-channel information compression unit, the multiplex information transmission channel, and the information decompression unit are additionally introduced into the device in series; At the same time, the n inputs of the n-channel information compression block are connected to the corresponding outputs of n analog-to-digital conversion blocks, the n-1 channel block for the accumulation and analysis of mutual spectra is introduced, which has n inputs and n-1 outputs, each of n physical channels the output of the decompression unit is connected to the corresponding input of the n-1 channel block for accumulation and analysis of mutual spectra, n-1 channel block for leak detection, n-1 channel block for determining the location of the leak, n-1 channel block for determining the dimensions The n-1 channel block for determining the filtering band, the inputs of which are connected in parallel with the corresponding outputs of the n-1 channel block for accumulating and analyzing mutual spectra, and the output n-1 of the channel block for determining the filtering band is connected to the second inputs of the filtering blocks; an alarm signal, the input of which is connected to the output n-1 of the channel block for detecting the leak, with the output n-1 of the channel block for determining the location of the leak and with the output n-1 of the channel block for determining the size of the leak, the location indicator is also introduced

Description

The utility model relates to the technique of monitoring pipeline systems and is intended to determine the location of damage and assess the size of damage in hard-to-reach or inaccessible to technical supervision pressure pipelines, in particular, in underwater pipelines and in dukes.

A device for detecting holes in a pipe is known from Japanese Patent No. 4-184133, comprising two acoustic sensors, two displays and a comparison unit in parallel to which the outputs of the displays are connected. If there is a small hole in the pipe, the compressed gas leaves it, the noise generated in this case reaches both ends of the pipe, where it is received by acoustic sensors, the signals from which are visualized for comparison. If the signal values are the same, then the hole is at the midpoint relative to the positions of the sensors, and if the signal value in one of the images is much larger than the other, then the hole is located near the corresponding sensor. The position of the hole is calculated from the ratio of the values of the sensor signals when propagating at different distances.

The disadvantages of the analog device are low accuracy and low noise immunity, as well as the inability to estimate the size of the hole.

A device is known according to the USSR author’s certificate No. 1610351. An analog device contains acoustic transducers, a switching unit, a control unit, a first block for amplifying, filtering and generating a high-frequency component of a signal, a block for determining the correlation function and the associated information parameter, a second block for amplifying, filtering and the formation of the low-frequency component of the signal, the integrator forming the reference signals, the comparator, the element "I. Acoustic signals from a leak are converted into electrical signals. By filtering, the high-frequency and low-frequency parts of the signal spectrum are separated. The correlation function of the high-frequency part of the signal spectrum is calculated. An information parameter for generating an alarm signal is extracted from the correlation function. The low-frequency component of the signal is filtered and integrated to form reference signals. When the amplitude of the signal exceeds the amplitude of the reference signal, an alarm is generated. The leak position is determined by the position of the converter from which the alarm was received.

The disadvantage of the tax device is the insufficiently efficient isolation of the signal from the leak, the inaccuracy of determining the coordinates of the leak and the lack of determining the extent of damage.

The closest in technical essence to the proposed is a device for determining the location of a leak as a source of acoustic radiation according to US patent No. 4858462. The prototype device contains two spaced acoustic sensors, two amplification and filtering units, two analog-digital converters, a floating threshold processor and a differential signal, a computer acting as a control unit, with display means.

The device allows you to monitor the acoustic radiation of the source using two spaced sensors. It is assumed that the acoustic radiation at the site of the leak is a noise background with emissions. Difference

the time of arrival of acoustic signals from the leak to each of the sensors is recorded as the offset of the signals in time. By measuring the offset between the spikes in the acoustic signals, the relative position of the source and the sensors is determined. To facilitate the separation of emissions from the background noise, floating threshold detection is used.

The disadvantage of the prototype device is the low noise immunity and the inability to assess the size of the damage.

The objective of the utility model is to provide noise immunity, high accuracy in determining the location of a leak and assessing the size of damage to the pipeline.

To solve the problem, a device for determining the location and size of a leak in a pipeline containing n measuring channels, each of which consists of a series-connected unit of acoustic transducers, an amplification unit, the output of which is connected to the first input of the filtration unit and the analog-to-digital conversion unit, is additionally determining the location of a leak on long-distance pipelines, the following are introduced: series-connected p-channel block of information compression, multiplex transmission channel info Rmation and information decompression unit, while the n inputs of the p-channel information compression block are connected to the corresponding outputs of the n analog-to-digital conversion blocks, the n-1 channel block for the accumulation and analysis of mutual spectra, which has n inputs and n-1 outputs, is also introduced each of the n physical channels of the output of the decompression block is connected to the corresponding input of the n-1 channel block for accumulation and analysis of mutual spectra, the n-1 channel block for detecting leaks, the p-1 channel block for determining the location are also introduced leak, p-1 channel block for determining the size of the leak, p-1 channel block for determining the filter band, the inputs of which are connected in parallel with the corresponding outputs of p-1 channel block for accumulation and analysis of mutual spectra, and the output of p-1 channel block for determining the filter band the second inputs of the filtration units, an alarm signal generation unit has also been introduced, the input of which is connected to the output of the p-1 channel block for detecting a leak, with the output of the p-1 channel block for determining the leak location and with the output of the p-1 channel block eniya leak sizes are also introduced place indicator and leak size, whose input is connected to the output formation unit alarm. The control unit for its control outputs and information inputs is connected to a p-channel block of information compression, a block of decompression of information, p-1 channel block for accumulation and analysis of mutual spectra, p-1 channel block for leak detection, p-1 channel block for determining the location of a leak, p -1 channel unit for determining the size of the leak, p-1 channel unit for determining the filtering band, the unit for generating an alarm signal and an indicator of the location and size of the leak.

The achievement of the technical result from the use of a utility model consisting in increasing the reliability of leak detection against the background of acoustic noise from the noise of the pipeline and environmental noise, determining the location of the leak with increased accuracy, obtaining an estimate of the size of the damage to the pipeline

It became possible as a result of the application of technologies for separating signals from noise over long time intervals by accumulation, filtering and cross-spectral analysis.

The utility model is illustrated by drawings. Figure 1 shows a block diagram of a device. Figure 2 presents a graph of the dimensionless power spectral density of a flooded subsonic jet as a function of the Strouhal number for the entire jet. (Adapted from the work of A.G. Lukin, M.A. Shchepochkin. Spectrum of the sound power of a subsonic jet - Acoustic Journal, T.XVIII, issue 2, 1972. - p. 282-299)

A device for determining the location and size of a leak in a pipeline contains parallel-series-connected acoustic sensors l..n (HELL), amplifiers 2..p (US), filters Z.K.Z.p (FI), analog-to-digital converters 4 .. p (ADC), connected in series: p-channel block 5 information compression, multiplex channel 6 information transfer, block 7

decompression of information, P - 1 - channel block 8 accumulation and analysis

mutual spectra, P - 1 - channel block 9 leak detection, block 10 of the formation of the alarm, the indicator 11 places and sizes of the leak, also contains

Parallel connected P - 1 - channel block 12 for determining leak points, P - 1 channel block 13 for determining leak sizes, P -1 - channel block 14

determining the filtering band, the inputs of which are connected to the output P - 1 of the channel unit 8 for accumulating and analyzing mutual spectra, and the outputs of the unit 12 for determining the location of the leak and the unit 13 for determining the size of the leak, respectively, with

the second and third inputs of the alarm generating unit 10, the output P - 1 of the channel block 14 determining the filtering band is connected to the second inputs of the filters 3.p, also contains a control unit 15, the control outputs and information inputs of which are connected to blocks 5, 7, 8 , 9, 10, 11, 12, 13, 14.

Acoustic signals from a leak are received using acoustic sensors 1.K1.P. (Here n is equal to or greater than two). Hydrophones are used as these sensors for pipelines running along the bottom of a river, lake, or sea, and geophones for a duker. Sensors 1..p are parallel to the pipeline at distances d from each other, according to formula (1). Coefficient

O recognition can be determined, for example, with the probability of false alarms of Rlt 10 and the probability of correct detection .98 approximately as O dB, i.e.

About A.P. Evtutov, V.B. Mitko. Engineering calculations in sonar. -L .: Shipbuilding, 1988. - p.139, fig.2.29, if used as acoustic

sensors omnidirectional hydrophones, that is, for example, for underwater

pipeline noise level was .- and the noise level

jetting jet with g. Therefore, for this example, was selected

The signals from each of the sensors are amplified in amplifiers 2.p. After that, the signals are filtered in band-pass filters Z.NZ.p and converted to digital form using analog-to-digital converters 4..p for further processing. Filters provide optimization of signal reception in the background and when a signal leaks from the stream. Experimental study of vibro-acoustic characteristics of the main pipeline Suleymanov, L.I. Verhayzer. Noise and vibration in the oil industry. Reference manual. -M .: Nauka, 1990. -160 s showed that the vibration spectra of the compressor and its elements, as well as the initial section of the pipeline, have pronounced discrete components. Displacement rates are maximum at low (17 and 65 Hz) and medium (1700, 2550, 3375 Hz) frequencies. However, at a distance of 1.5 km, only the low-frequency components of 17 and 65 Hz make a significant contribution to the vibration of the stand. These discrete components prevail in the underwater noise of the pipeline. Therefore, frequencies below 100 Hz are filtered.

Due to the fact that the distances over which the condition of the pipelines is monitored can be tens of kilometers, the sensors are connected to a control system that is resistant to electrical noise by a fiber-optic communication line. O.K. Sklyarov. Modern fiber optic transmission systems. Hardware and items. -M .: SOLOP-R, 2001.-237s. In block 5 of the seal of the information transmission channel, the data stream is converted from multiple sensors into one multiplicative channel in accordance with the transport protocol. The signals are transmitted on channel 6 for the transmission of information. Then in block 7 there is a decompression of the channel for transmitting information into parallel physical channels for subsequent processing.

The operation of the P - 1 channel block 8 of the accumulation and analysis of mutual spectra is carried out in accordance with the principles of multi-parameter spectral analysis of S.L. Marple ml. Digital spectral analysis and its applications. M.: Mir, 1990, ch. 15, p. 460-477. In block 8, mutually spectral analysis is performed.

between each pair of sensors, determining jk / by the formula:

GjkW -Go ((o) Coscotj, -iSina) tjJ + Gj, (Q))

where is the energy spectrum of the noise of the jet resulting from damage to the pipeline at a unit distance - Pa

j k - distance between damage in the pipeline and sensors j

and k, moreover,

Tj +

50000 ,,

n :::: + 1 101

In the absence of a leak, only the interference level Gj (10 j - Pa.

in case of volumetric noise NV / OV® / t, where K -

wave number, C is the speed of sound in the medium.

At frequencies, for example, above 100 Hz, about. , -: J ivJ

Therefore, in the cross-spectral analysis at d 500m the interference level is not large.

If there is a leak, in P - 1 channel detector 9, operating, for example, according to the Neumann-Pearson criterion, a leak is detected on

some 1st section of the pipeline. The mutual spectrum is divided into k bands. The signal level in each band is controlled by a threshold element. If, in accordance with the selected criterion in m of k elements, the threshold is exceeded, the detection unit transmits a damage signal to block 10 to generate data on the number of the section of the route that has damage. At the same time, the specified position in block VI is determined from the expression:

1Im

t ik - - arctg

coRe

 and J are the symbols of the imaginary and real component

The delay jk can be determined differently, for example,

by extracting only the imaginary component of the mutual spectrum V®;. To do this, find the frequencies of zero values

, (co) Go (a)) Sina), tj, 0

jk - 0 v; i "-jk - (3)

t-it., -100,. ,

and define JK as J O i, 11 1,2, .... This information

also enters block 10 to generate an alarm.

Next, in block 13, the size of the leak is determined. For this, it is taken into account that the spectral density of the nthum radiation by the subsonic jet as a whole has a maximum

with the Strouhal number Shj 0.275, find the frequency (OQ at which

 L jk V® / has a maximum, and determine the diameter D of the hole-damage as

/ h / h SinKd

Kd (

Sinkd3

Pjk (").

G j, (co) J

- -1 where and is the jet velocity at the cut

eg.

 2P, Zh.u VP, R.

where FJ, p2 - pressure in the pipeline and in the environment, respectively,

P | and P2 are the densities of the fluid in the pipe and in the environment, respectively;

V | - the velocity of the fluid in the pipe,

moreover, carry out filtering in the frequency band LHBJ,

- ShmaxU ShmaxU, where fn-oc, b- | 3-fT, (6),

DQ is selected based on the minimum diameter of damage that

it is necessary to detect that the OS and p coefficients are selected at the level of - 8 dB of the spectral plane curve. If the size of the leak exceeds some predetermined value, for example, a justifying message is sent to block 10

the need for an alarm.

If there is an alarm signal generation unit 10 at the same time

from P - 1 channel block of damage detection, P - 1 channel block

determining the places of damage and P - 1 of the channel unit for determining the size of damage the coincidence scheme includes on the indicator 11 means for displaying the number of the damaged section, its position on the pipeline route, information about the location and size of the leak. At the same time, in block 14, the most acceptable filtering band is specified using the graph of the dimensionless spectral radiation density of the flooded subsonic jet (Fig. 2) according to algorithm (6). The data on the velocity of the jet expiration are calculated according to the information on the pressures in the pipeline and in the environment and on the density of liquids in the pipe and in the environment, as well as on the speed of the liquid in the pipe. This information is known for each pipeline in operation by I.L. Povh. Technical hydromechanics. -L.: Mechanical Engineering, 1969. - 524s; I.P. Spitsin, V.A. Sokolova. General and river hydraulics. -L .: Gidrometeoizdat, 1990.-p.90; under the editorship of A.G. Munin. Aviation acoustics.-M.: Mechanical Engineering, 1973. -448с.

Thus, a device for determining the location and size of a leak in a pipeline provides the required technical result.

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pipe wall equal to

Claims (1)

A device for determining the parameters of a pipeline leak, containing n measuring channels, each of which consists of a series-connected unit of acoustic transducers, a gain unit, the output of which is connected to the first input of the filtering unit, an analog-to-digital conversion unit, and also containing a control unit, characterized in that the n-channel information compression unit, the multiplex information transmission channel, and the information decompression unit are additionally introduced into the device in series; At the same time, n inputs of the n-channel block of information compression are connected to the corresponding outputs of n blocks of analog-to-digital conversion, an n-1 channel block for the accumulation and analysis of mutual spectra is introduced, having n inputs and n-1 outputs, each of n physical channels the output of the decompression unit is connected to the corresponding input of the n-1 channel block for the accumulation and analysis of mutual spectra, n-1 channel block for detecting leaks, n-1 channel block for determining the location of the leak, n-1 channel block for determining the dimensions t ni-1 channel block for determining the filtering band, the inputs of which are connected in parallel with the corresponding outputs of the n-1 channel block for accumulating and analyzing mutual spectra, and the output n-1 of the channel block for determining the filtering band is connected to the second inputs of the filtering blocks; an alarm signal, the input of which is connected to the output n-1 of the channel block for detecting the leak, with the output n-1 of the channel block for determining the location of the leak and with the output n-1 of the channel block for determining the size of the leak, the location indicator is also introduced the size of the leak, the input of which is connected to the output of the alarm generating unit, while the control unit with its control outputs and information inputs is connected to the corresponding control and information inputs and outputs of the n-channel information compression unit, information decompression unit, n-1 channel storage unit and analysis of mutual spectra, n-1 channel block for detecting leaks, n-1 channel block for determining the location of a leak, n-1 channel block for determining the size of a leak, n-1 channel block for determining the floor sy filtering unit generating an alarm and location indicator and leak size.