RU2190152C1 - Method for detecting leakage zone in main pipelines - Google Patents

Abstract

FIELD: measuring technique, possibly current monitoring of fluid tightness of main pipelines. SUBSTANCE: method comprises steps of registration time moment of arrival of two lowered-pressure waves formed at time moment of local rupture or damage of pipeline to ends of said monitored pipeline; detecting time difference of arrival of those waves and determining leakage position; generating high frequency oscillations at time moment of local rupture or damage of pipeline; manipulating said oscillation by phase by means of modulating code containing data related to number of damaged piece of pipeline and leakage position in order to form phase-manipulated alarm signal; amplifying received signal and irradiating it to atmosphere; receiving alarm phase- manipulated signal in control station by means of three antennas arranged along one line parallel to pipeline in the form of straight line piece; placing in center of said line receiving antenna of measuring channel common for receiving antennas of two direction finding channels arranged in azimuthal plane in order to create in that plane two measuring bases d and 2d satisfying to given inequality:

Description

 The proposed method relates to measuring equipment and can be used for routine monitoring of the tightness of trunk pipelines.

 To determine the magnitude and location of leaks of the transported product, it is advisable to use a combination of passive (according to the monitoring of the pumping process) and active (by skipping diagnostic devices) methods.

 Passive methods: according to the balance of pumping; comparing pressures along the route with pressure during normal operation of the pipeline; comparison of costs for sections of the pipeline; analysis of the passage of shock waves.

 Active methods: skipping diagnostic probes using acoustic, electromagnetic and other methods; launching into the stream and fixing various types of media - “tags”, control of acoustic noise, external signs of leakage when inspecting the track from the ground; the use of various types of radiation (infrared, ultrasonic, etc.) to control leaks from both air and the surface of the earth.

 For oil pipelines, the place of damage by the "according to the transfer balance" method is determined by calculation or graphically by the difference in hydraulic slopes at the beginning and end of the damaged pipeline.

 The method of comparing pressures along a pipeline route with pressures before damage allows only large damage to be determined. However, to determine the place of damage, it is necessary to have a pressure value along the pipeline route.

 The method of comparing costs for sections of the pipeline is used when using flowmeters of accuracy class 0.2 ... 0.5%. This method is most often used to determine the presence of leaks, since finding the damaged area requires a significant number of flow meters of high accuracy class.

 Complete ruptures of pipe joints, as well as ruptures of longitudinal and spiral joints, are determined by the pressure drop and the increase in flow rate (with centrifugal pumps).

 Of the known methods, the closest to the proposed one is a method for determining the location of leaks in main pipelines (Pipeline transport of oil and gas. - M., 1988, p. 334, Fig. 9.18), which is chosen as the closest analogue.

 The specified method is based on the analysis of shock waves of reduced pressure that occur at the time of local rupture or damage to the pipe. It provides a determination of the place of occurrence of leaks in the main pipelines, but does not allow timely inform staff about this.

 An object of the invention is to expand the functionality of the method by transmitting over the air the alarm signal about the place of occurrence of leaks in the main pipelines to the control point.

The problem is solved in that in a method for determining the location of leaks in main pipelines, based on recording the arrival time of two shock waves of reduced pressure generated at the time of local rupture or damage to the pipeline, at the ends of the controlled section of the pipeline, finding the difference in the arrival time of these waves and determining the location leaks, at the moment of local rupture or damage to the pipeline generate a high-frequency oscillation, manipulate it in phase modulating code Ohm, containing information about the number of the emergency section of the pipeline and the location of the leak, thereby generating an alarm signal with phase shift keying, amplify the generated signal by power, radiate it into the air, receive at the control point an alarm phase-shift signal on three antennas located on one line parallel to the pipeline in the form of a straight line segment, in the center of which is placed the receiving antenna of the measuring channel, common to the receiving antennas of two direction finding channels located in the azimuthal plane, thereby, in the given plane, two measuring bases d and 2d, between which the inequality
d / λ <1 / 2≤2d / λ,
where λ is the wavelength;
the smaller base d form a rough but unambiguous angle reference scale, and the larger base 2d form an accurate but ambiguous angle reference scale, convert the received signals by frequency, select the voltage of the first intermediate frequency, re-convert the voltage of the first intermediate frequency of the measuring channel, isolate the voltage of the second intermediate frequency, multiply it with the voltage of the first intermediate frequency of the direction finding channels, extract harmonic oscillations from the obtained voltages often those of the second local oscillator with the preservation of phase relations, measure the phase difference between harmonic oscillations and the voltage of the second local oscillator and estimate the azimuth of the damaged section of the pipeline from them.

 The proposed method can be implemented by a device whose structural diagram is presented in figure 1.

 A diagram of the sensor element of the pressure sensor is shown in figure 2. Timing diagrams explaining the principle of operation of the method and device shown in Fig.3.

 The principle of direction finding of the damaged section of the main pipeline by the phase method is illustrated in Fig. 4. The structural diagram of the control point is presented in figure 5.

 The device contains a rupture or damage to the pipeline 1, two generated waves of reduced pressure 2, pressure sensors 3, amplifiers-converters 4, the control unit 5 of the valve, shut-off valve 6, power supply 7, winding 7.1 and relay contacts 7.2, key 8, counter time 9, computing unit 10, transmitter 11, code generator 12, modulating code generator 13, adder 14, high-frequency generator 15, phase manipulator 16, power amplifier 17 and transmitting antenna 18. Pressure sensors 3 are installed at the beginning and end of the monitoring forward portion of the conduit. An amplifier-converter 4, a valve control unit 5 and a shut-off valve 6 are connected in series to the output of the pressure sensor 3. Relay 7.1 windings and a key 8 are connected in series to the power supply 7, the control input of which is connected to the output of the amplifier-converter 4. To the sensor output 3 a pressure counter 9 is connected in series, a computing unit 10, a code generator 12, an adder 14, the second input of which is connected to the output of the modulating code generator 13, a phase manipulator 16, the second input of which is connected to the output ohm RF generator 15, power amplifier 17 and transmitting antenna 18.

 The control point 23 contains a measuring channel and two direction finding channels. The measuring channel consists of a series-connected receiving antenna 24, a mixer 27, the second input of which is connected to the output of the local oscillator 30, an amplifier 31 of the first intermediate frequency, mixer 35, the second input of which is connected to the output of the local oscillator 34, amplifier 36 of the second intermediate frequency, phase doubler 37, a narrow-band filter 38, a phase divider 39 into two, a frequency detector 40, a trigger, a balance switch 42, the second input of which is connected to the output of the phase divider 39 into two, a phase detector and a recording unit 50.

 Each direction finding channel consists of a series-connected receiving antenna 25 (26), a mixer 28 (29), the second input of which is connected to the output of the local oscillator 30, an amplifier 32 (33) of the first intermediate frequency, a multiplier 44 (45), the second input of which is connected to the output an amplifier 36 of a second intermediate frequency, a narrow-band filter 46 (47) and a phase detector 48 (49), the second input of which is connected to the output of the local oscillator 34 (narrow-band filter 46), the output of which is connected to the registration unit 50.

 A device that implements the proposed method works as follows.

 At the moment of local rupture or damage to the pipeline, a shock wave of reduced pressure is formed. Two waves 2 are moving from the point of discontinuity 1 in opposite directions at a speed C of sound propagation in the medium. A diagram of a sensitive element of a pressure sensor measuring very small high-frequency pressure disturbances (0.1 ... 0.001 MPa) against a background of significant, slowly varying pressures (3... 7.5 MPa) is shown in figure 2, where the following notation is introduced : 19 - housing, 20 - inlet pipes, 21 - damper, 22 - membrane.

 The signal from the pipeline at the measurement site is fed simultaneously to two input channels of the sensing element, i.e. the same pressure acts on the membrane from two sides. In one of the channels there is a multichannel or threaded damping insert that dampens high-frequency pressure fluctuations, i.e., it is a low-pass filter. With this scheme of switching on the device, the membrane will respond only to the measured value, since a slowly changing large background is compensated. In the converter amplifier, the readings of the device are converted into an electrical signal, which is integrated, and the result is compared with a known threshold value. As converters, capacitive or strain gauge sensors are used. When the sensor at one end of the section captures the moment of arrival of the pressure disturbance wave, a time counter 9 is turned on, which stops when the other wave arrives at the sensor at the other end of the section.

 The time of arrival of waves is estimated by the maximum likelihood method, in other words, high-frequency pressure disturbances are filtered from high-intensity interference and their time of arrival is estimated.

где V_ср - средняя скорость движения транспортируемого продукта (вода, нефть, газ и т.п.).Having determined the difference in the time of arrival of waves (t ₁ , t ₂ ) at the end of the monitored section of length 1 (Fig. 1), the location of the leak is determined in the computing unit 10:

where V _cf - the average speed of the transported product (water, oil, gas, etc.).

 When the threshold value is increased, a constant voltage is generated in the amplifier-converter 4, which is supplied to the valve control unit 5 and to the control input of the key 8, opening it. In the initial state, key 8 is always closed. In this case, the control unit 5 includes a shut-off valve 6, and the relay coil 7.1 through the open key 8 closes to the ground, the relay operates and closes the contacts 7.2, through which the supply voltage is supplied to the transmitter 11.

After turning on the transmitter 11 high-frequency oscillation (Fig.3, a)
u _c (t) = U _c cos (ω _c t + φ _c ), 0≤t≤T _s ,
where U _c , ω _c , φ _c - amplitude, carrier frequency and the initial phase of high-frequency oscillations;
from the output of the master oscillator 15 is supplied to the first input of the phase manipulator 16.

0≤t≤T_с,
где φ_k(t) = {0,π} - манипулируемая составляющая фазы, отображающая закон фазовой манипуляции в соответствии с модулирующим кодом M(t), причем
φ_к(t) = const при kτ_э<t<(k+1)τ_э и может изменяться скачком при t = kτ_э, т.е. на границах между элементарными посылками (k=0, 1, 2, ..., N-1);
τ_э, N - длительность и количество элементарных посылок, из которых составлен сигнал длительностью T_с(T_с = Nτ_э).
Этот сигнал после усиления в усилителе 17 мощности излучается передающей антенной 18 в эфир.The place of the gap X _{about the} pipeline in the shaper 12 code is converted into the corresponding code, consisting of m chips. Generator 13 generates a code consisting of n chips, the number of which reflects the number of the monitored section of the pipeline. These chips are summed in the adder 14 (N = n + m) and a modulating code M (t) is generated (Fig. 3, b), which is fed to the second input of the phase manipulator 16. As a result of phase manipulation, a phase-manipulated phase-manipulator 16 is formed (PSK) signal (figure 3, c)

0≤t≤T _s ,
where φ _k (t) = {0, π} is the manipulated phase component that displays the phase manipulation law in accordance with the modulating code M (t), and
φ _к (t) = const for kτ _e <t <(k + 1) τ _e and can change stepwise at t = kτ _e , i.e. at the boundaries between elementary premises (k = 0, 1, 2, ..., N-1);
τ _e , N is the duration and number of chips that make up the signal with a duration of T _s (T _s = Nτ _e ).
This signal after amplification in the power amplifier 17 is radiated by the transmitting antenna 18 into the air.

φ_пр1 = φ₁-φ_г1;

φ_пр2 = φ₂-φ_г1;

φ_пр3 = φ₃-φ_г1;
K₁ - коэффициент передачи смесителей.At the control point 23 receive FMN signal with an unstable carrier frequency at three receiving antennas 24-26:
u ₁ (t) = U ₁ cos [(ω _c ± Δω) t + φ _k (t) + φ ₁ ];
u ₂ (t) = U ₂ cos [(ω _c ± Δω) t + φ _k (t) + φ ₂ ];
u ₃ (t) = U ₃ cos [(ω _c ± Δω) t + φ _k (t) + φ ₃ ], 0≤t≤T _c ,
where ± Δω is the instability of the carrier frequency caused by various destabilizing factors;
which enter the first inputs of the mixers 27-29, the second inputs of which the voltage of the local oscillator 30
u _g1 (t) = U _g1 cos (ω _g1 t + φ _g1 ).
At the output of the mixers 27-29, voltages of combination frequencies are generated. Amplifiers 31-33 distinguish the voltage of the first intermediate frequency:
u _CR1 (t) = U _CR1 cos [(ω _CR1 ± Δω) t + φ _k (t) + φ _CR1 ];
u _CR2 (t) = U _CR2 cos [(ω _CR1 ± Δω) t + φ _k (t) + φ _CR2 ];
u _CR3 (t) = U _CR3 cos [(ω _CR1 ± Δω) t + φ _k (t) + φ _CR3 ], 0≤t≤T _c ,
Where

φ _pr1 = φ ₁ -φ _g1 ;

φ _pr2 = φ ₂ -φ _g1 ;

φ _pr3 = φ ₃ -φ _g1 ;
K ₁ - gear ratio of the mixers.

ω_пр2 = ω_пр1-ω_г2 - вторая промежуточная частота;
φ_пр4 = φ_пр1-φ_г1.
Это напряжение поступает на первый вход фазового детектора 43 и на вход удвоителя 37 фазы. Так как 2φ_к(t) = {0,2π}, то в выходном напряжении удвоителя 37 фазы (фиг.3,д)
u₄(t) = U_пр4cos2[(ω_пр2±Δω)t+φ_пр4]
манипуляция фазы уже отсутствует. Это напряжение выделяется узкополосным фильтром 38, а затем делится по фазе на два в делителе фазы 39 (фиг.3,е)
u₅(t) = U_пр4cos2[(ω_пр2±Δω)t+φ_пр4].
Начальная фаза полученного напряжения может иметь два устойчивых значения φ_{пр4 =} и φ_пр4+π. Это легко показать аналитически. Если произвести деление, аналогичное предыдущему, но предварительно добавив к аргументу угол 2π, что не изменяет исходного напряжения, то после деления на два получится напряжение, сдвинутое по фазе на π:

Следовательно, двузначность фазы полученного напряжения вытекает из самого процесса деления. Физически указанная двузначность фазы объясняется неустойчивой работой делителя 39 фазы на два. Это явление "обратной работы" присуще всем устройствам (Пистолькорса А.А., Сифорова В.И., Костаса Д.Ф., Травина Г. А. ), которые выделяют опорное напряжение, необходимое для синхронного детектирования ФМн-сигналов, непосредственно из принимаемого ФМн-сигнала.In the measuring channel, the voltage u _pr1 (t) from the output of the amplifier 31 of the first intermediate frequency is supplied to the first input of the mixer 35, the second input of which supplies the voltage of the local oscillator 34
u _g2 (t) = U _g2 cos (ω _g2 t + φ _g2 ).
At the output of the mixer 35, voltages of combination frequencies are generated. The amplifier 36 is allocated the voltage of the second intermediate frequency (Fig.3, g)
u _CR4 (t) = U _CR4 cos [(ω _CR2 ± Δω) t + φ _k (t) + φ _CR4 ], 0≤t≤T _c ,
Where

_np2 ω = ω _z2 -ω _pr1 - second intermediate frequency;
φ _pr4 = φ _pr1 -φ _g1 .
This voltage is supplied to the first input of the phase detector 43 and to the input of the phase doubler 37. Since 2φ _to (t) = {0.2π}, then in the output voltage of the doubler 37 phase (Fig.3, d)
u ₄ (t) = U _CR4 cos2 [(ω _CR2 ± Δω) t + φ _CR4 ]
phase manipulation is already absent. This voltage is allocated by a narrow-band filter 38, and then divided by phase into two in the phase divider 39 (Fig.3, e)
u ₅ (t) = U _CR4 cos2 [(ω _CR2 ± Δω) t + φ _CR4 ].
The initial phase of the voltage obtained can have two stable values φ _{CR4 =} and φ _CR4 + π. This is easy to show analytically. If you make a division similar to the previous one, but after adding the angle 2π to the argument, which does not change the initial voltage, then after dividing by two, you get the voltage that is phase shifted by π:

Consequently, the ambiguity of the phase of the voltage obtained follows from the fission process itself. The physically indicated two-valued phase is due to the unstable operation of the phase divider 39 into two. This phenomenon of "reverse operation" is inherent in all devices (Pistolkors A.A., Siforov V.I., Kostas D.F., Travina G.A.), which emit the reference voltage necessary for the synchronous detection of PSK signals directly from received FMN signal.

The phenomenon of "reverse work" is due to spasmodic transitions of the phase of the reference voltage from one state φ _CR4 to another φ _CR4 + π under the influence of interference, short-term termination of reception and other factors. These transitions during the reception of the QPSK signal occur at random times (for example, t ₁ , t ₂ ) (Fig. 3, g), which significantly reduces the reliability of receiving information contained in the modulating code M (t) (Fig. 3, b)

 To stabilize the phase of the reference voltage and eliminate the phenomenon of "reverse operation", a frequency detector 40, a trigger 41, and a balance switch 42 are used.

When the phase of the reference voltage jumps by +180 ^o at the time t ₁ (Fig. 3, f), a positive short pulse appears at the output of the frequency detector 40, and when the phase jumps by -180 ^o at the time t ₂ (return of the phase of the voltage in the initial state) is a negative impulse (figure 3, h). Alternating pulses from the output of the frequency detector 40 control the operation of the trigger 41, the output voltage of which (Fig. 3, and), in turn, controls the operation of the balance switch 42.

 In a stable state, when the phase of the reference voltage coincides, for example, with the zero phase of the received PSK signal, a negative voltage is generated at the output of the trigger 41 and the balance switch is in its initial position, at which the reference voltage is supplied from the output of the phase divider 39 to the phase input detector 43 without change.

When the phase of the reference voltage jumps by +180 ^o , due, for example, to the unstable operation of the phase divider 39 under the influence of interference, the trigger 41 is transferred by a positive pulse from the output of the frequency detector 40 to another stable state. In this case, the output voltage of the trigger 41 at time t ₁ becomes and remains positive until the next phase jump at time t ₂ , which returns the phase of the reference voltage to its original state. The positive output voltage of the trigger 41 transfers the balance switch 42 to another stable state, in which the reference voltage from the output of the phase divider 39 is supplied to the reference input of the phase detector 43 with a phase change of -180 ^o . This eliminates the instability of the phase of the reference voltage and the associated "reverse work".

 Therefore, the frequency detector 40 provides detection of the moment of occurrence of "reverse operation", and the trigger 41 and the balance switch 42 eliminate it.

К₂ - коэффициент передачи фазового детектора;
пропорциональное модулирующему коду M₂(t).In this case, a reference voltage with a stable phase is supplied to the reference input of the phase detector 43 (Fig. 3, k)
u ₆ (t) = U _CR4 cos [(ω _CR2 -Δω) t + φ _CR4 ].
The output of the phase detector 43 is formed of a low-frequency voltage (Fig.3, l)
u _n (t) = U _n cosφ _k (t),
Where

K ₂ is the transfer coefficient of the phase detector;
proportional to the modulating code M ₂ (t).

К₃ - коэффициент передачи перемножителей;

α - азимут поврежденного участка магистрального трубопровода (фиг.4);
которые выделяются узкополосными фильтрами 46, 47 и поступают на первые входы фазовых детекторов 48, 49 соответственно. На второй вход фазового детектора 48 подается напряжение u_г2(t) гетеродина 34, на второй вход фазового детектора 49 подается гармоническое колебание u₈(t) с выхода узкополосного фильтра 46.At the same time, the voltage of the second intermediate frequency u _p4 (t) from the output of the amplifier 36 of the second intermediate frequency is supplied to the second inputs of the multipliers 44 and 45, the first inputs of which are supplied with the voltage u _p2 (t) and u _p3 (t) from the outputs of the amplifiers 32 and 33 of the first intermediate frequency respectively. At the outputs of the multipliers 44 and 45, harmonic oscillations are formed:
u ₇ (t) = U ₇ cos (ω _g2 t + φ _g2 + Δφ ₁ ),
u ₈ (t) = U ₈ cos (ω _g2 t + φ _g2 + Δφ ₂ ),
Where

K ₃ - transmission coefficient of the multipliers;

α is the azimuth of the damaged section of the main pipeline (figure 4);
which are allocated by narrow-band filters 46, 47 and are supplied to the first inputs of phase detectors 48, 49, respectively. The voltage u _g2 (t) of the local oscillator 34 is supplied to the second input of the phase detector 48, and harmonic oscillation u ₈ (t) is supplied to the second input of the phase detector 49 from the output of the narrow-band filter 46.

где

которые фиксируются блоком 50 регистрации.The signs "+" and "-" before the phase shifts Δφ ₁ and Δφ ₂ correspond to diametrically opposite positions of the receiving antennas 25 and 26 relative to the antenna 24. At the outputs of the phase detectors 48 and 49, constant voltages are generated:
u _n1 (α) = U _n1 cosΔφ ₁ ,
u _n2 (α) = U _n2 cosΔφ ₃ ,

Where

which are fixed by the registration unit 50.

Так предполагается использовать фазовый метод пеленгации поврежденного участка магистрального трубопровода с помощью трех приемных антенн, расположенных на пункте приема, в виде отрезка прямой, параллельной магистральному трубопроводу на некотором расстоянии R₁ от него.Receiving antennas 24 ... 26 are placed so that the measuring base form a straight line segment, in the center of which is placed the receiving antenna 24 of the measuring channel (figure 4). In this case, the smaller base d form a rough but unambiguous direction finding scale, and the larger base 2d forms an accurate but ambiguous direction finding scale:

So it is supposed to use the phase method of direction finding of the damaged section of the main pipeline using three receiving antennas located at the reception point, in the form of a straight line segment parallel to the main pipeline at a certain distance R ₁ from it.

Knowing the distance R ₁ and measuring the angular coordinate α, it is possible to accurately and unambiguously determine the coordinates of the damaged section of the main pipeline. This information is refined by the modulating code M (t), which is extracted from the received PSK signal by its synchronous detection. The modulating code M (t) contains information about the number of the damaged section of the main pipeline and the location of the damaged section.

The proposed method is invariant to the instability of the carrier frequency and the type of modulation (manipulation) of the received signals, since direction finding of the damaged section of the main pipeline is carried out at a stable frequency ω _{g2 of the} second local oscillator 34. The proposed method allows to register emergency sections of the transported product of a very small size (less than 1%) along sections of trunk pipelines with a length of several hundred meters to several kilometers with an accuracy of at least 0.1% (uncertainty Δx <30 m).

 The above work of the proposed method and device for its implementation corresponds to the case of placing the receiving point on the ground at some distance from the main pipeline.

где λ - длина волны,
при этом меньшие базы d образуют грубые, но однозначные шкалы отсчета углов α и β, а большие базы 2d образуют точные, но неоднозначные шкалы отсчета углов α и β, где α - азимут места повреждения магистрального трубопровода, β - угол места повреждения магистрального трубопровода (фиг.6).To control the long trunk pipelines, the control point is placed on board the spacecraft, the projection of the flight path of which is located near the main pipeline parallel to it. Moreover, the receiving antennas are located at the ends of special panels in the form of a geometric cross, at the intersection of which the receiving antenna 24 of the measuring channel is placed, common to the receiving antennas 25 and 26, 51 and 52 of direction finding channels located in the azimuthal (horizontal) and elevation (vertical) planes, two on each plane, thereby forming in each plane two measuring bases d and 2d, between which establish the inequality

where λ is the wavelength
the smaller bases d form rough but unambiguous reference frames for the angles α and β, and the larger bases 2d form accurate but ambiguous reference frames for the angles α and β, where α is the azimuth of the damage point of the main pipeline, β is the angle of the place of damage of the main pipeline ( 6).

 In this case, two additional direction finding channels, each of which consists of a series-connected receiving antenna 51 (52), a mixer 53 (54), the second input of which is connected to the output of the local oscillator 30, amplifier 55 (56) of the first intermediate frequency, and multiplier 57 (58) the second input of which is connected to the output of the amplifier 36 of the second intermediate frequency, the narrow-band filter 59 (60) and the phase detector 61 (62), the second input of which is connected to the output of the local oscillator 34 (narrow-band filter 59), and the output is connected to the registration unit 50, provide accurate and about unambiguous determination of the elevation angle β of the damaged section of the main pipeline and work in the same way as two direction finding channels in the azimuthal plane (Fig. 7). In this case, the registration code 50 fixes the manipulation code M (t), azimuth α and elevation angle β of the damaged section of the main pipeline.

 To control the long trunk pipelines, a control point is placed on board an airplane flying over the trunk pipeline. Moreover, four receiving antennas 25 and 26, 51 and 52 are located at the ends of the fuselage and wings in the form of a geometric cross, at the intersection of which the receiving antenna 24 of the measuring channel is placed (Fig. 8). The composition and operation of the measuring and four direction finding channels are the same as for the spacecraft (Fig. 7).

 To control long trunk pipelines, a control point is located on board a helicopter flying over the trunk pipeline. The solution to this problem requires high-precision coordinate measurement, which in relation to a helicopter has its own characteristics. The presence of rotating screws can be used as a positive factor to determine the direction of the PSK signal (damaged section of the main pipeline) to the radiation source using a direction finding device, four receiving antennas 25 and 26, 51 and 52 of which are located at the ends of the four rotor blades, and the receiving the antenna 24 of the measuring channel is placed above the sleeve of the screw (Fig.9).

 The direction finding channels in this case have the following differences: a multiplier 48 (63) is connected in series to the output of the narrow-band filter 46 (59), the second input of which is connected to the output of the narrow-band filter 47 (60), the narrow-band filter 47 (60), the narrow-band filter 49 (64) ) and a phase meter 70 (72), the second input of which is connected to the output of the reference generator 68, and the output is connected to the registration unit 50. A delay line 61 (65), a phase detector 62 (66) and a phase meter 69 (71) are connected in series to the output of the narrow-band filter 47 (60), the second input of which is connected to the output of the reference oscillator 68, and the output is connected to the registration unit 50. The engine 67 is kinetically connected with the helicopter propeller and the reference generator 68 (Fig. 10).

 Direction finding of the radiation source of the QPSK signal (damaged section of the main pipeline) in two planes is carried out by the differential-phase method using phase modulation due to the Doppler effect that occurs when the receiving antennas 25 and 26, 51 and 52 are rotated around the receiving antenna 24.

где R - радиус окружности, на которой расположены приемные антенны 25, 26, 51 и 52 (длина лопастей винта вертолета);
Ω - скорость вращения винта вертолета;
преобразуются по частоте, перемножаются и узкополосными фильтрами 46, 47, 59 и 60 выделяются следующие напряжения:

Эти напряжения обрабатываются двумя автокорреляторами, каждый из которых состоит из фазового детектора 62 (66) и линии задержки 61 (65), что способствует уменьшению индекса фазовой модуляции Δφ_m = 2πR/λ и устранению неоднозначности отсчета углов α и β.
На выходе автокорреляторов образуются напряжения:
u₁₈(t) = U₁₈cos(Ωt-α);
u₁₉(t) = U₁₉cos(Ωt-β),
которые поступают на первые входы фазометров 69 и 70, на вторые входы которых подается напряжение опорного гетеродина 68
u_o(t) = U_ocosΩt.
Измеренные фазометрами 69 и 70 угловые координаты фиксируются блоком 50 регистрации.In this case, the received FMN signals 24, 25, 26, 51 and 52:
υ ₉ (τ) = ϒ ₉ χοσ [(ω _c ± Δω) t + φ _k (t) + φ ₁ ];

where R is the radius of the circle on which the receiving antennas 25, 26, 51 and 52 are located (the length of the rotor blades of the helicopter);
Ω is the rotational speed of the helicopter rotor;
are converted in frequency, multiplied and the following voltages are allocated by narrow-band filters 46, 47, 59 and 60:

These voltages are processed by two autocorrelators, each of which consists of a phase detector 62 (66) and a delay line 61 (65), which helps to reduce the phase modulation index Δφ _m = 2πR / λ and eliminate the ambiguity of the reading of the angles α and β.
At the output of autocorrelators, voltages are formed:
u ₁₈ (t) = U ₁₈ cos (Ωt-α);
u ₁₉ (t) = U ₁₉ cos (Ωt-β),
which are supplied to the first inputs of the phase meters 69 and 70, to the second inputs of which the voltage of the reference local oscillator 68 is supplied
u _o (t) = U _o cosΩt.
The angular coordinates measured by phase meters 69 and 70 are recorded by the recording unit 50.

 Thus, the proposed method in comparison with the prototype provides enhanced functionality by transmitting over the air the alarm signal about the place of occurrence of leaks in the main pipelines to the control point. In this case, the alarm signal is manipulated in phase, which allows the use of a new type of selection - structural selection. This means that there is a new opportunity to separate signals operating in the same frequency band and at the same time intervals.

 To isolate the modulating code M (t) from the received QPSK signal, its synchronous detection at the control point is used.

 Moreover, the reference voltage necessary for the synchronous detection of the PSK signal is extracted directly from the received PSK signal, and the phenomenon of "reverse operation" that arises from this is eliminated by frequency detection, a trigger, and a balance switch.

 To control long trunk pipelines, the control point is placed on an aircraft (spacecraft, airplane or helicopter).

Claims (4)

 1. A method for determining the location of leaks in main pipelines, based on recording the time of arrival of two shock waves of reduced pressure generated at the time of local rupture or damage to the pipeline, at the ends of the controlled section of the pipeline, finding the difference in the time of arrival of these waves and determining the location of the leak, characterized in that at the moment of local rupture or damage to the pipeline generate a high-frequency oscillation, they manipulate it in phase with a modulating code containing The information about the number of the emergency section of the pipeline and the location of the leak, thereby generating an alarm signal with phase shift keying, amplifies the generated signal by power, emits it on the air, receives an alarm phase signal from a control signal on three antennas located on one line parallel to the pipeline, in in the form of a straight line segment in the center of which is placed the receiving antenna of the measuring channel, common to the receiving antennas of two direction-finding channels located in the azimuthal plane, thereby forming this plane, two measuring bases d and 2d, between which establish the inequality d / λ <1 / 2≤2d / λ, where λ is the wavelength, while the smaller base d form a rough but unambiguous angle reference scale, and the larger base 2d form an accurate but ambiguous angle reference scale, the received signals are converted in frequency, the voltage of the first intermediate frequency is isolated, the voltage of the first intermediate frequency of the measuring channel is converted in frequency, the voltage of the second intermediate frequency is isolated, it is multiplied with the voltage of the first th intermediate frequency direction finding channel, isolated from the obtained stress harmonic oscillations at the frequency of the second local oscillator preserving phase relationships, measured phase difference between the harmonic oscillations and the voltage of the second local oscillator and evaluate them azimuth damaged section of pipeline.  2. The method according to p. 1, characterized in that the control point is placed on board the spacecraft, the projection of the flight path of which is laid near the main pipeline parallel to it, and the receiving antennas are placed at the ends of special panels in the form of a geometric cross, at the intersection of which a receiving antenna is placed measuring channel, common for receiving antennas of four direction finding channels located in the azimuthal and elevation planes, two on each plane, thereby forming in each plane awn two measuring base d and 2d.  3. The method according to p. 1, characterized in that the control point is placed on board an airplane flying over the main pipeline, the receiving antennas being placed at the ends of the fuselage and wings in the form of a geometric cross.  4. The method according to p. 1, characterized in that the control point is placed on board a helicopter flying over the main pipeline, and four receiving antennas of direction finding channels are located at the ends of the rotor blades, and the receiving antenna of the measuring channel is located above the rotor hub.

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