SU1756733A1 - Device for detection of damage to pipe-line - Google Patents

Abstract

SUMMARY OF THE INVENTION: A damage sensor in the form of an optical fiber cable 1 is laid in the forward direction along the monitored section of pipeline 2. The cable 1 is connected at one end to a radiation source 3 and a photodetector 4; A mirror reflector 10 is installed at the other end. The output of the master oscillator b is connected to the control input of source 3 and the input of delay device 7, the output of which is connected to the primary input of element 8. And the output of photodetector 4 is connected to the second input of element 8, the output which through the integrating device 9 is connected to the input of the recorder 5.1 Il.

Description

VI

GJ SB

The invention relates to pipeline transport, in particular, to devices for remote continuous monitoring of the state of high pressure trunk pipelines.

A device for detecting a leak in a pipeline is known. It consists of an insulated conductor located along the outer surface of the pipeline (damage sensor), one end of which is connected to one of the recorder's clips, the conductive wall of the pipeline is connected to the other clip of the recorder.

The disadvantages of the known device include its fire and explosion hazards due to the constant presence of a potential difference between the pipe wall and an insulated conductor, which in the case of a spark in an accident in a pipeline with a combustible medium, can lead to loss of function at a large distance due to the increase in the resistance of the circuit.

The closest in technical terms to the proposed technical solution is a device for detecting pipeline damage, consisting of a damage sensor in the form of a fiber optic cable located along the monitored pipeline section in the forward and reverse directions, a radiation source, a photodetector and a recorder.

The disadvantages of this device include the high consumption of fiber-optic cable caused by the need to lay it in the forward and reverse directions.

The aim of the invention is to reduce the consumption of fiber-optic cable laid along the monitored section of the pipeline in one direction only.

The goal is achieved by the fact that a pipeline damage detection device containing a damage sensor in the form of a fiber optic cable running in the forward direction along the monitored pipeline section, a radiation source optically coupled to it, a photodetector and a recorder, is additionally equipped with a master oscillator, device delays, an And element, an integrating device and a mirror reflector, whereby the fiber optic cable is connected at one end to both the radiation source and the photo photo A mirror reflector is installed at the other end of the fiber-optic cable, the output of the master oscillator is connected to the control input of the radiation source and the input of the delay device, the output of which is connected to the first input of the element And, the output of the photodetector is connected to the second input of the element And, the output of which an integrating device is connected to the recorder input.

0 The proposed device uses the property of reflecting an optical pulse from the surface of a specular reflector, which makes it possible to reduce the consumption of fiber optic cable.

5 The drawing is a schematic diagram of the device.

The pipeline damage detection device comprises a damage sensor in the form of a fiber optic cable 1,

0 laid in the forward direction along the monitored section of the pipeline 2, a radiation source 3, optically coupled to it, a photodetector 4 and a recorder 5. The device is equipped with a master oscillator

5 6, a delay device 7, an AND element 8, an integrating device 9 and a mirror reflector 10.

The output of the radiation source 3, which can be used, for example, quantum-electronic modules of the types MPD-A-1A, CEM 8-4 PD-A and the like, is optically coupled to the first end of the optical fiber cable 1, which is also optically connected to the input of the photodetector 4, made, for example, on quantum-electronic modules of the types KEM-2-4PR, KEM-8-4PRA, etc. At the second end of the fiber-optic cable 1 there is a mirror reflector 10 , Which can

0 be made, for example, in the form of a polished end of an optical fiber coated with a mirror coating. The output of the master oscillator 6, made, for example, in the form of a rectangular generator

5 pulses connected to the control input of the radiation source 3 and the input of the delay device 7, made, for example, in the form of a delay line. The output of the delay device 7 is connected to the first input of the element And 8, the output of the photoreceiver 4 is connected to the second input of the element And 8, the output of which is connected via an integrating device 9, for example an integrating circuit, to the input of the recorder 5,

5 for example, in the form of a signal amplifier with an output to a visual alarm indicator or an actuating element of an automatic pipeline control system 2.

The device works as follows

Square pulses produced by master oscillator b are fed to the control input of the radiation source 3, which contains an injection laser and matching devices for inputting radiation into the optical fiber, as well as a driver, a blocking circuit and a system for stabilizing the output optical power,

An electrical impulse is converted in the source 3 of the radiation 5 by an optical pulse that arrives at the first end of the fiber optic cable 1 and also at the photodetector 4. The optical pulse passes through the fiber optic cable 1 and hits the reflector 10, is reflected from it, passes the opposite direction of the fiber-optic cable 1 and enters the photodetector 4, which contains a preamplifier and an amplifier with an AGC system.

Consequently, two pulses appear successively on the photodetector 4 — direct from the radiation source 3 and reflected from the mirror reflector 10. But since the information on the state of the pipeline 2 is carried only by the reflected pulse, the direct pulse from the source 3 is parasitic, and it needs to be neutralized. An electric pulse from the master oscillator 6 also arrives at the input of the delay device 7, which delays the signal from the master oscillator 6 for a time equal to the time of the light pulse passing through the fiber optic cable 1 along the monitored pipeline 2 in the forward and reverse directions x. In this case, the delayed pulse from the output of the delay device 7 is fed to the first input of the element I 8 simultaneously with the arrival at the second input of an electric pulse that has formed as a result of In the photodetector 4 of the reflected light pulse, and at the output of element 1L 8, an electric pulse is formed corresponding to the normal state of the pipeline 2. The direct optical pulse from the source 3 of the radiation, transformed in the photodetector 4, also goes to the second input of element 8, however this time, there is no pulse at the first input from the delay device 7 and at the output of the element 8. Next, the driving oscillator 6 generates the next pulse, and the described process repeats.

From the output of the element AND 8, the pulses arrive at the input of the integrating device 9 and at its output a signal appears that is amplified by an amplifier included in

recorder 5. At the same time, the output of the amplifier shows the signal level corresponding to the normal state of pipeline 2, and there is no alarm indication on the indicator of the recorder 5 of 5.

If pipeline 2 is damaged, fiber optic cable 1 is destroyed. The reflected optical pulse ceases to arrive at the input of the photodetector 4, and the signal disappears at its output. The signal at the second input of the And 8 element also disappears. And despite the arrival of a pulse from the device 7 of the delay at the output of the And 8 element, there is no signal. The possible occurrence of impulses from a broken fiber-optic cable 1 is neutralized in the same way as a direct impulse from the source 3 of the radiation, since these impulses arrive at the input of the And 8 element earlier than the delayed impulse from the device 7 delays. Consequently, the signal at the output of the integrating device 9 disappears, and at the output of the amplifier of the recorder 5 a signal level appears corresponding to the damage to the pipeline 2, when an alarm indicator is turned on.

In the manufacture of the device, it is necessary to consider that the pulse duration of the master oscillator b should be

0 is much shorter than the duration of the light pulse passing along the test section of the pipe line 2 in the forward and reverse direction in order to avoid the appearance of spurious pulses at the output of the And 8 element when the pipeline 2 is in emergency.

The proposed device, in comparison with the base object, provides a 2-fold reduction in the consumption of fiber-optic cable by using

The quality of the sensor is a fiber optic cable, laid along the monitored section of the pipeline in one direction, p | 5РГс security and all the advantages of the prototype (fire safety, reliability of control).

Claims (1)

The proposed technical solution can have the greatest effect when using pipelines with combustible media in the control areas, of a large extent, and significantly, taking into account the high cost of fiber-optic cable, reduce the cost of manufacturing. Invention Formula Damage Detection Device 5 of the pipeline, containing a sensor of damage in the form of a fiber-optic cable, laid in the forward direction along the monitored pipeline section of the radiation source, optically coupled to it and the fiber-optic cable a photodetector and a recorder, distinguished by an optical cable installed mirrored by the fact that, in order to reduce the consumable reflector, the output of the master oscillator cable is connected to the control input Equipped with master oscillator, device-source of radiation and device input In the delay, an AND element integrating 5 delays, the output of which is connected to a power supply and a mirror reflector, the input of the element I, the output of the photo-receiving fiber-optic cable of one terminal, is connected to the second input of the element AND, It is connected with the radiation source and its output through an integrating device with a photo-receiver, and at the other end of the fiber is connected to the recorder's input.