RU188421U1 - LASER SCANNER OF METHANE LEAKAGES FOR UNCANDLESS AVIATION SYSTEMS - Google Patents

Abstract

The utility model relates to a device for detecting gas (methane) leaks from main pipelines and can be used for installation on unmanned aircraft with a maximum take-off weight of up to 30 kg. The methane leakage laser scanner includes a housing with electronic and opto-electronic components. The housing is a stator, inside which a rotor is mechanically connected to the drive. The opto-electronic component contains four independent lasers with four corresponding photodetectors, and each pair of laser-photodetector is connected by an optical fiber through an optocoupler with its corresponding collimator and lens to form an optoelectronic channel, with lasers, photodetectors, collimators and lenses mounted inside the rotor with uniform distribution in its internal cavity. The axes of the collimators are oriented at an angle to the longitudinal axis of the rotor. The electronic component is made in the form of printed circuit boards placed on the stator. The drive shaft is made of titanium alloy, and the stator and rotor walls are made of aluminum alloy. The dimensions of the scanner do not exceed 250 mm in height and 160 mm in diameter, and its weight does not exceed 5 kg. The technical result of the claimed utility model is to expand the functionality of the structure by reducing its mass and size while increasing the accuracy of identifying facts of leakage of natural gas. 5 hp f-ly, 3 ill.

Description

The utility model relates to a device for detecting gas (methane) leaks from main pipelines and can be used for installation on unmanned aircraft with a maximum take-off weight of up to 30 kg.

It is known the use of laser devices for detecting methane leaks on main pipelines. There are many devices of similar purpose, but these devices either cannot provide reliable results of leak detection and high performance due to the operating principle used, or have considerable dimensions and weight, and therefore cannot be used on the most common and accessible unmanned aircraft. .

For example, the Laser Methane mini laser device (developed by Tokio Gas Engineering Co., Ltd. (Japan, 2016)) is known for measuring methane content in the air, which is designed to work at a short distance from a source of possible leakage. With it, you can quickly determine the location and amount of methane leakage. To do this, it is enough to direct the laser beam of the device to the area in which there is supposedly a methane leak.

A disadvantage of the known construction is that it has a short detection range and is not intended for aviation use.

The remote laser detector of methane “DLS-Avia”, developed by JSC “PERGAM-ENGINEERING” and intended for on-line diagnostics of extended gas pipelines for leaks, is known. The device can be installed on a manned helicopter or light aircraft.

The disadvantages of the known device include significant dimensions and weight of the structure, which excludes the possibility of using it on unmanned aircraft weighing up to 30 kg. In addition, due to the design features, the well-known laser detector does not allow leak detection across the entire width of the surveyed corridor, which ultimately reduces the reliability of methane leak detection results.

The technical result of the claimed utility model is to expand the functionality of the structure by reducing its mass and size while increasing the accuracy of identifying facts of leakage of natural gas.

This technical result is achieved due to the fact that the laser scanner of methane leakage includes a housing, with electronic and opto-electronic components placed in it. The housing is a stator, inside which a rotor is mechanically connected to the drive. The optoelectronic component contains four independent lasers with four corresponding photodetectors, and each pair of laser-photodetector is connected by an optical fiber through an optocoupler with its corresponding collimator and lens to form an optoelectronic channel, with lasers, photodetectors, collimators and lenses mounted inside the rotor with uniform distribution in its internal cavity, with the axis of the collimators oriented at an angle to the longitudinal axis of the rotor. The electronic component is made in the form of printed circuit boards placed on the stator. The drive shaft is made of titanium alloy. The stator and rotor walls are made of aluminum alloy.

LSUM dimensions, as a rule, do not exceed 250 mm in height and 160 mm in diameter, and its weight in the collection does not exceed 5 kg, which makes it possible to use the proposed device on unmanned light-duty aircraft.

Reducing the mass and dimensions of the structure is achieved through a more rational implementation and compact arrangement of individual functional elements in the device case, as well as by the use of certain materials (titanium and aluminum alloys) for the manufacture of device elements. All this together allows you to expand the functionality of the device, with the result that it can be used not only on heavy aircraft, but also on unmanned aerial vehicles weighing no more than 30 kg.

In addition, the functionality of the claimed device is expanded due to the fact that it uses four optical-electronic channels, allowing you to scan a significant width of coverage of the surveyed area, as a result of which the reliability of detecting methane leaks is increased.

The claimed technical solution is illustrated with graphic materials, where in FIG. 1 shows a general view of the claimed device (laser scanner of methane leakage); FIG. 2 is a longitudinal section of the laser scanner; FIG. 3 is a schematic representation of the trajectories of scanning lasers of lasers.

The design of a methane leak laser scanner (LSUM) includes a stator 1, on which are mounted electronic boards 2, designed to control the device and process measurements. The stator 1 is mechanically coupled to the rotor 3 by means of a drive 4 (electric motor). The electronic coupling of the stator and the rotor is carried out by means of a high-frequency rotating transformer (not indicated in the drawings) and an optical communication line.

The rotor 3 is designed to accommodate optical and electronic elements of a scanning device, namely, an opto-electronic component comprising four lasers 5 uniformly distributed inside the rotor 3, four corresponding photodetector 6 and electronic signal processing boards (not indicated in the drawings). Each pair of laser 5 - photodetector 6 is connected by an optical fiber (not shown in the drawings), by means of an optical connector 7, with its corresponding collimator 8 and lens 9 forms an optical-electronic channel. The presence of four such measuring laser opto-electronic channels provides the required scanning density. A further increase in the number of lasers is possible, but found to be ineffective due to the increase in mass and cost of the device.

The output of the laser radiation to the outside and reception of the reflected radiation is performed using elements forming the optical channel, which includes lenses 9 and collimators 8, connected to the other optical elements using appropriate optical connectors and optical fiber. The separation of the light fluxes passing through the fiber to the input and output is performed using a fiber-optic circulator. Thus, the axes of receiving and radiating optical systems are strictly collinear. The axes 10 of the collimators 8 are oriented at an angle of about 15 degrees to the longitudinal axis 11 of the rotor 3, which allows scanning the surveyed area of considerable width.

Thus, the layout of all elements of the claimed device in a single package and the implementation of a significant number of lightweight alloys provides a noticeable reduction in its mass and size reduction, which makes it possible to install it on unmanned aircraft with a take-off weight of up to 30 kg.

The operation of the claimed device (LSUM) is based on the method of differential diode-laser spectrometry and consists of the following.

In order to carry out a remote survey of the territory to detect suspected methane leaks, the claimed device is installed on an unmanned aircraft that flies along the main pipeline.

The controller (not shown), which connects the LSUM to the onboard automatic control system of the unmanned aircraft, starts the scanning process, the rotor starts to rotate, the lasers emit rays to the surface of the surveyed area. In this case, the rays of four lasers mounted on a rotating rotor, form in space the surface of a cone. Longitudinal sweep is performed by moving an unmanned aircraft on which LSUM is located. The rotor speed is synchronized with the flight speed of an unmanned aircraft, which allows for uniform coverage of the surveyed surface with measurement points. A schematic representation of the trajectories of scanning beams on the surface of the earth is shown in FIG. 3

The photodetector receives the returned (reflected) signals, which are transmitted to electronic signal processing boards located in the rotor, and then to electronic boards of the electronic component for further processing of measurements.

To measure the gas concentration, a differential method is used, consisting in that the measurement is performed at two frequencies. One corresponds to the maximum absorption of this radiation in the gas (1650.95 nm), the second corresponds to the minimum (1649.95 nm). At the same time, a part of the measuring radiation is passed through a gas cell filled with the measured gas. The relationship of the energies of the signals that have passed through the measured volume and through the gas cell gives the concentration of the desired gas.

The scanner continuously reads and transmits methane concentration data (measurements from each of the four lasers), which are processed in the LSUM electronic unit.

The collected data is processed on board an unmanned aircraft and can be transmitted in real time via satellite or radio to the ground control station (if the threshold concentration of methane exceeds the allowable) or stored on the drive for subsequent post-flight processing.

Claims (6)

1. Laser scanner of methane leakage, including a housing, with electronic and opto-electronic components placed in it, characterized in that the housing is a stator, inside which a rotor is mechanically connected to the drive, and the optoelectronic component contains four independent lasers with four corresponding photodetectors, and each pair of laser-photodetector is connected by an optical fiber through an optoelectric connector with its corresponding collimator and lens to form an optical-electronic channel, and lasers, photodetectors, lenses and collimators mounted inside the rotor with a uniform distribution in its internal cavity, wherein the collimator axis oriented at an angle to the longitudinal axis of the rotor. 2. The scanner under item 1, characterized in that the electronic component is made in the form of printed circuit boards placed on the stator. 3. The scanner under item 1, characterized in that the drive shaft is made of titanium alloy. 4. The scanner according to claim 1, characterized in that the stator and rotor walls are made of aluminum alloy. 5. The scanner under item 1, characterized in that its dimensions do not exceed 250 mm in height and 160 mm in diameter. 6. Scanner according to any one of paragraphs. 1-5, characterized in that its weight does not exceed 5 kg.

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