CN105300890A - Gas detection system - Google Patents

Abstract

The invention provides a gas detection system. The system includes a ground system and a flight system, the ground system includes a photoelectric detector and a data processing device; the flight system includes a flight device, a laser emitting device and an optical path conversion device; the laser emitting device is used to emit laser light to the detected area; the optical path conversion device is used It is used to receive the reflected laser light and turn it to the photodetector; the photodetector is used to receive the reflected laser light and convert it into the reflected laser parameter electrical signal; the data processing device is used to receive the reflected laser parameter electrical signal and the emitted laser parameter electrical signal emitted by the laser transmitter The signal is analyzed to determine the gas composition and/or content of the detected area. The invention more conveniently detects the gas leakage situation of the aerial pipeline, understands the leakage situation of the aerial pipeline in time, only needs to replace the optical conversion device and the laser emitting device when the flying device has a problem, and reduces the high-altitude detection cost.

Description

Gas detection system

technical field

The invention relates to the technical field of detection, in particular to a gas detection system.

Background technique

With the development of the economy, the application of gas in industry and civil use is becoming more and more extensive. As a kind of energy, the leakage of gas pipelines will not only cause economic losses, but also may cause personal injury. Therefore, gas detection is used as a preventive measure appears to be particularly important. At present, the commonly used detection method is through gas detectors, but due to the low detection efficiency and slow speed of gas detectors, it is difficult to meet the needs of practical applications, especially for some special applications, such as overhead pipelines in the chemical industry, Pipelines placed in the air, such as gas pipelines in high-rise buildings, are even more difficult to detect.

Contents of the invention

In view of this, the present invention proposes a gas detection system, aiming to solve the problem in the prior art that it is difficult to detect whether a pipeline placed in the air is leaking.

In one aspect, the present invention provides a gas detection system, which includes: a ground system and a flight system; wherein, the ground system includes a photoelectric detector and a data processing device; the flight system includes a flight device and is arranged on the The laser emitting device and the optical path conversion device of the flying device; the laser emitting device is used to emit laser light to the detected area; the optical path conversion device is used to receive the laser light reflected back from the detected area and turn it to the photodetector; the The photodetector is used to receive the reflected laser light and convert it into a reflected laser parameter electrical signal; the data processing device is connected to the photoelectric detector to receive the reflected laser parameter electrical signal, and according to the The gas component and/or content of the detected area is determined by the laser emission parameter electric signal and the pre-stored emission laser parameter electric signal of the laser emission device.

Further, in the above gas detection system, the laser emitting device is a single-wavelength laser emitting device.

Further, in the above gas detection system, the laser light emitted by the laser emitting device is transmitted to the optical path conversion device through air or optical fiber.

Further, in the above gas detection system, the laser light received by the optical path conversion device and reflected back by the detected area is transmitted to the photodetector through air or optical fiber.

Further, the above-mentioned gas detection system further includes: a ground vehicle, the photoelectric detector and data processing device are arranged on the ground vehicle.

Further, the above-mentioned gas detection system further includes: a first positioning system, configured to determine that the flying device is placed within a preset range above the ground system, so that the photodetector receives the steering position of the laser emitting device. Reflect the laser.

Further, in the above-mentioned gas detection system, the first positioning system includes: a laser, arranged on the ground system, for emitting laser light to the flying device; a photosensitive plate, arranged at the bottom of the flying device, for receiving the laser light emitted by the light-emitting device, and returning the photosensitive signal; the receiving device is arranged on the ground system, and is used to receive the returned photosensitive signal and determine whether the flying device is in the position according to the returned photosensitive signal. within a preset range above the ground system described above.

Further, in the above gas detection system, the first positioning system includes: a first GPS system, a second GPS system and a control device; wherein, the first GPS system is set on the ground system for locating the position of the ground system The second GPS system is set on the flight system for locating the position of the flight system; the control device is electrically connected with the first GPS system and the second GPS system, and is used to receive the ground system and the The location of the flight system, and controlling the flight system to place the flight system within a predetermined range above the ground system.

Further, the above gas detection system further includes: a second positioning system, arranged on the flying device, for ensuring that the distance between the flying device and the detected area is within a preset distance range.

Further, in the above gas detection system, the second positioning system is also used to send an abnormal detection alarm signal when the reflection distance is less than a preset distance; the reflection distance is the distance between the optical path conversion device and the laser reflection in the detected area The distance in distance between points.

The gas detection system provided by the present invention detects the gas in the detected area through the laser emitted by the laser emitting device, and the gas detection system is divided into two parts: the ground system and the flight system, and the flight system carries the laser emitting device and the optical path conversion device to the air , can directly detect the pipeline in the air, compared with the prior art, the present invention can more conveniently detect the gas leakage of the pipeline in the sky, so as to know the leakage of the pipeline in the sky in time. In addition, when there is a problem with the flying device, only the optical conversion device and the laser emitting device need to be replaced, which effectively reduces the cost of high-altitude gas detection.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment. The drawings are only for the purpose of illustrating a preferred embodiment and are not to be considered as limiting the invention. Also throughout the drawings, the same reference numerals are used to designate the same parts. In the attached picture:

Fig. 1 is a structural block diagram of a gas detection system provided by an embodiment of the present invention;

Fig. 2 is a working state diagram of the gas detection system provided by the embodiment of the present invention.

detailed description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

Referring to FIG. 1 , FIG. 1 is a structural block diagram of a gas detection system provided by an embodiment of the present invention. As shown in the figure, the detection system includes: a ground system 1 and a flight system 2 . Wherein, the ground system 1 is set on the ground, and the flight system 2 can fly in the air. In this embodiment, the detection is completed through the cooperation of the ground system 1 and the flight system 2 .

The flying system 2 may include a flying device 21 , a laser emitting device 23 and an optical path conversion device 22 . The flying device 21 may be an aircraft, such as a helicopter, a drone, and the like. The laser emitting device 23 is used to directly emit laser light to the area to be detected. In specific implementation, the laser emitting device 11 may be a laser. The wavelength emitted by the laser emitting device 11 can be selected according to the detected gas. For example, when the detected gas is methane, the working wavelength of the laser is 1653.7nm, because methane gas can absorb laser light of this wavelength. The optical path conversion device 22 is used for receiving the laser light reflected back from the detected area, and changing the propagation direction of the laser light reflected back by the detected area, so that the reflected laser light propagates to the ground system 1 . During specific implementation, the laser light received by the optical path conversion device 22 and reflected back by the detected area may be transmitted to the photodetector 13 through air or optical fiber. It should be noted that, during specific implementation, the optical path conversion device 22 can be composed of optical devices such as concave mirrors, lenses, and prisms. As long as the optical conversion device 22 can achieve the purpose of turning, there are various specific implementation methods, and this embodiment does not address it. Make any restrictions.

The ground system 1 may comprise a photodetector 13 and a data processing device 12 . The photodetector 13 is used to receive the reflected laser light and convert it into a reflected laser parameter electric signal; the data processing device 12 is connected to the photoelectric detector 13 for receiving the reflected laser parameter electric signal; the data processing device 12 also pre-stores The laser emitting device 11 transmits the emitted laser parameter electric signal, and the data processing device 12 determines the gas composition and/or content of the detected area according to the pre-stored emitted laser parameter electric signal and the received reflected laser parameter electric signal. Wherein, the transmitted laser parameter electrical signal and the reflected laser parameter electrical signal may include information such as the wavelength and intensity of the laser, and the data processing device 12 may obtain the composition and content of each gas according to the wavelength and intensity loss of the received reflected laser loss . The data processing device 12 can determine the composition of the gas to be detected by analyzing the wavelength information of the laser spectrum, and obtain the content of each component in the gas to be detected by information such as the intensity loss of the reflected laser light. The analysis method can adopt three methods well known to those skilled in the art. Level identification method, overall analysis method and other analysis methods, etc. It should be noted that the types of parameters specifically included in the emission laser parameters and the reflection laser parameters may be determined according to actual conditions, which is not limited in this embodiment. During specific implementation, the data processing device 12 may be a single-chip microcomputer, a DSP, a computer, and the like.

The working principle of this embodiment is: for a specific gas, laser light with a specific wavelength can be absorbed, and the embodiment of the present invention uses this characteristic of the gas to detect the gas. For example, methane can absorb laser light with a wavelength of 1653.7nm. When methane is detected, the laser emitting device 11 is made to emit a laser light with a wavelength of 1653.7nm. , then the methane gas will absorb all or part of the laser light of this wavelength, and the laser light reflected back by the methane gas will no longer have the laser light of this wavelength or the laser light of this wavelength will be weakened; if there is no methane gas in the detected area, then the laser light of this wavelength The laser light will not be absorbed. It can be seen that according to this characteristic, the gas composition in the detected area can be determined by analyzing the emitted laser light and the reflected laser light from the detected area. In addition, when methane absorbs gas, it will also cause loss of laser intensity, and different gases have different abilities to cause loss of laser light, so the gas content can be determined by analyzing the loss of laser intensity.

The working process of this embodiment is: start the flying device 21, the flying device 21 carries the laser emitting device 23 and the optical path replacement device 22 and rises to the vicinity of the detected area, then the flying device 21 adjusts the position, and then adjusts the position of the optical path conversion device 22, So that the photodetector 13 can receive the reflected laser light after the optical path conversion device 22 turns, and after the position of the flying device 21 is adjusted, the detection starts. At this time, the laser emitted by the laser emitting device 11 directly shoots to the detected area. The laser is reflected by the gas to be detected, and the reflected laser is redirected through the optical path conversion device 22. The redirected laser propagates in the air or optical fiber medium and is transmitted to the photodetector 13. The photodetector 13 converts the reflected laser signal It is an electrical signal, which is sent to the data processing device 12, and the data processing device 12 analyzes the laser and the laser emitted by the laser emitting device 11 to obtain the composition and/or content of the gas to be detected.

The gas detection system provided in this embodiment detects the gas in the detected area through the laser emitted by the laser emitting device, and the gas detection system is divided into two parts: the ground system 1 and the flight system 2, and the flight system 2 carries the laser emitting device 23 And the optical path conversion device 22 to the air, can directly detect the pipeline in the air, compared with the prior art, this embodiment can more conveniently detect the gas leakage of the pipeline in the air, so as to know the status of the pipeline in the air in time Leakage. In addition, when there is a problem with the flying device 12, only the optical conversion device 22 and the laser emitting device 21 need to be replaced, which effectively reduces the cost of high-altitude gas detection.

In the above embodiments, the laser emitting device 23 may be a single-wavelength laser emitting device, that is, the laser emitting device can only emit laser light of one wavelength. Since the laser emitting device can only emit laser light of one wavelength, it can only detect one gas, but because the single-wavelength laser emitting device is light in weight, it is easier to carry into the air, and can directly irradiate the emitted laser light on the The detected area has a relatively high detection accuracy. It can be seen that in this embodiment, the heavy data processing device 12 is placed on the ground, and only the light path conversion device 22 and the laser emitting device 23 that can only emit a single wavelength are carried into the air through the flying device 21 Through this method, the core heavy equipment is transferred to the ground, thereby reducing the weight carried by the flying device 21, increasing the endurance of the flying device 21, and completing gas detection in a larger area at one time. In addition, for the data processing device 12 , the higher the detection accuracy, the heavier the weight. Since the data processing device 12 in this embodiment is placed on the ground, a data processing device 12 with higher accuracy can be selected, thereby improving the gas detection accuracy.

The above embodiments may also include: ground vehicles. Wherein, the photodetector 13 and the data processing device 12 are both arranged on the ground vehicle. Specifically, the ground vehicle may be a movable motor vehicle, etc., and the photodetector 13 and the data processing device 12 are arranged on the ground vehicle. It can be seen that the movement of the vehicle on the ground can drive the ground system 1 to move to any position on the ground, which facilitates the adjustment of the position of the ground system 1 and greatly improves the detection efficiency.

Referring to FIG. 1 and FIG. 2 , in order to make the laser emitting device 11 and the photodetector 13 better correspond to the optical path conversion device 22 , in each of the above embodiments, a first positioning system can also be added. Wherein, the first positioning system is used to determine that the flying device 21 is placed within a preset range above the ground system 1 , so that the photodetector 13 can receive the laser light reflected back from the detected area where the optical path conversion device 22 turns.

In one embodiment of the present invention, the first positioning system may include: a laser, a photosensitive plate, and a receiving device. Wherein, the laser device is arranged on the vehicle in the ground system 1, and is used to emit laser light to the bottom of the flying device 21; the photosensitive plate can be arranged on the bottom of the flying device 21, and is used to receive the laser light emitted by the laser device and return the sensing photoelectric signal; the receiving device It is also arranged on the ground system 1 to receive the returned photosensitive signal and determine whether the flying device 21 is within the preset range according to the returned photosensitive signal. When the flying device 21 is not within the preset range, the receiving device receives There is no photosensitive signal. The ground system 1 emits a vertical positioning laser at a certain frequency to correct the vertical position of the ground system 1 and the flying device 21. During specific implementation, a laser rapid positioning system can be used, for example, more than 100 positioning signals per second.

In another embodiment of the present invention, the first positioning system may include a first GPS system, a second GPS system and a control device. Wherein, the first GPS system is arranged on the ground system 1, and is used for positioning the position of the ground system 1; the second GPS system is arranged on the flight system 2, and is used for positioning the position of the flight system; the control device is connected with the first GPS system and the second GPS The system is electrically connected for receiving the positions of the ground system 1 and the flight system 2 , and controlling the flight system 1 so that the flight system 2 is placed within a preset range above the ground system 1 . During specific implementation, the control device can be connected with the control system in the flight device 21. When the flight device 21 exceeds the preset range, the control device sends a position adjustment signal to the flight device 21, and the flight device 21 adjusts the position according to the position adjustment signal. within the preset range.

It should be noted that during specific implementation, the preset range may be determined according to actual conditions, which is not limited in this embodiment.

It can be seen that in this embodiment, the flying device 21 is positioned by the first positioning system, which can ensure that the photodetector can receive the laser light reflected back from the detected area.

In order to achieve a better detection effect, the above embodiment can be further improved by adding a second positioning system. Wherein, the second positioning system is arranged on the flying device 21 to ensure that the distance between the flying device 21 and the detected area is within a preset distance. Specifically, the second positioning system may include a laser and a receiving device. The laser emits laser light to the detected device, and the detected area reflects the laser light emitted by the laser device, and the receiving device receives the reflected laser light from the detected area, and determines the distance between the flying device 21 and the detected area according to the received reflected laser light .

In this embodiment, the second positioning system can ensure that the distance between the flying device 21 and the detected area is within a preset distance, thereby better ensuring the detection effect.

In the above embodiment, the second positioning system is also used to send out an abnormal detection alarm signal when the reflection distance is less than the preset distance; the reflection distance is the distance between the optical path conversion device 22 and the laser reflection point in the detected area. For example, for the detection of gas pipelines in a residential building, assuming that the distance between the flying device 21 and the residential building is 10 meters, and the depth of the residential building is 4 meters, the reflection distance should be between 10 meters and 14 meters. . If the reflection distance is 10 meters, it is considered that the laser light may be blocked by the curtain at the window of the residential building, it is judged that the detection is wrong, and an abnormal alarm signal is sent.

Take the detection of whether there is methane gas in a residential building as an example below to describe the embodiment of the present invention in more detail:

A diode laser is used for the laser emitting device, a drone is used for the flying device, and a prism can be used for the optical path conversion device. The prism in the optical path conversion device is installed at the lower end of the UAV. When installing, a certain angle must be ensured. This angle is mainly to ensure that the laser beam passes through the optical path conversion device to undergo total reflection, so that the laser light is irradiated to the photoelectric sensor along the vertical direction. Detector 13, the total reflection angle can be determined according to the formula, wherein, c is the critical angle, and n is the refractive index, so that the laser light is incident on the prism at the critical angle, and the prism can be a prism made of glass, and the critical angle of the glass is: 32- 42°. When installing, make the light-transmitting side of the prism vertical to the ground at an angle of 45°, and install and fix the prism to ensure that the angle remains unchanged during the drone’s battery life. Detection area. In addition, the photodetector 13 and the data processing device 12 must be assembled in the ground system.

Since the absorption wavelength of methane gas is 1653.7nm, during detection, the laser emission wavelength of the laser emitting device 11 is first adjusted around 1653.7nm, and then the flight position of the drone is adjusted so that the laser emitted by the laser in the first positioning system can When the laser is shot on the photosensitive plate at the lower end of the UAV, the laser light diverted by the optical path conversion device can be received by the photoelectric detector, and the UAV stops at this position, and then the laser emitting device emits laser light to the detected area, and the laser emitted by the laser The laser beam is irradiated horizontally to the area to be detected, and the laser light is reflected by the gas to be measured, and the reflected and absorbed laser light is condensed by the prism in the optical path conversion device, and the condensed laser light is transmitted to the photodetector 13 in the air, and the photoelectric detection The device 13 converts the received optical signal into an electrical signal and transmits it to the data processing device 12. The data processing device 12 analyzes the laser signal emitted back and the laser signal emitted by the laser emitting device to obtain the composition and content of the gas to be measured.

In summary, because the embodiment of the invention arranges the heavier laser emitting device and the spectral data processing device on the ground, but only carries the lighter optical path conversion device into the air through the flying device, this will greatly reduce the weight of the flying device. burden, increase the mileage of the flight device, and can complete the gas detection of a large area at one time.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (10)

1. A gas detection system, characterized in that it comprises: a ground system (1) and a flight system (2); wherein, The ground system (1) includes a photoelectric detector (13) and a data processing device (12); the flight system (2) includes a flight device (21) and a laser emitting device ( 23) and optical path conversion device (22); The laser emitting device (11) is used to emit laser light to the detected area; the optical path conversion device (22) is used to receive the laser light reflected back from the detected area and turn it to the photodetector (13); The photodetector (13) is used to receive the reflected laser light and convert it into an electrical signal of reflected laser light parameters; The data processing device (12) is connected with the photodetector (13), and is used for receiving the reflected laser parameter electric signal, and according to the reflected laser parameter electric signal and the pre-stored laser emitting device ( 1) The emitted laser parameter electric signal determines the gas composition and/or content of the detected area. 2. The gas detection system according to claim 1, characterized in that the laser emitting device (11) is a single-wavelength laser emitting device. 3. The gas detection system according to claim 1, characterized in that, The laser light emitted by the laser emitting device (11) propagates to the optical path conversion device (22) through air or optical fiber. 4. The gas detection system according to claim 1, characterized in that, The laser light received by the optical path conversion device (22) and reflected back by the detected area is transmitted to the photodetector (13) through air or optical fiber. 5. The gas detection system according to claim 1, further comprising: The ground vehicle, the photoelectric detector (13) and the data processing device (12) are both arranged on the ground vehicle. 6. The gas detection system according to any one of claims 1 to 5, further comprising: The first positioning system is used to determine that the flying device (21) is placed within a preset range above the ground system (1), so that the photodetector (13) receives the steering direction of the laser emitting device (11) Reflect the laser. 7. The gas detection system according to claim 6, wherein the first positioning system comprises: a laser device, arranged on the ground system (1), for emitting laser light to the flying device (11); A photosensitive plate, arranged at the bottom of the flying device (21), is used to receive the laser light emitted by the laser and return a photosensitive signal; The receiving device is arranged on the ground system (1), and is used for receiving the returned photosensitive signal and determining whether the flying device (21) is above the ground system (1) according to the returned photosensitive signal. within the set range. 8. The gas detection system according to claim 6, wherein the first positioning system comprises: a first GPS system, a second GPS system and a control device; wherein, The first GPS system is set on the ground system (1), and is used for locating the position of the ground system (1); The second GPS system is set in the flight system (2), and is used for locating the position of the flight system (2); A control device, electrically connected to the first GPS system and the second GPS system, for receiving the positions of the ground system (1) and the flight system (2), and controlling the flight system (2) so that the flight system (2) is placed within a preset range above the ground system (1). 9. The gas detection system according to any one of claims 1 to 5, further comprising: The second positioning system is arranged on the flying device (21), and is used to ensure that the distance between the flying device (21) and the detected area is within a preset distance range. 10. The gas detection system according to claim 9, characterized in that, The second positioning system is also used to send out a detection abnormality alarm signal when the reflection distance is less than a preset distance; the reflection distance is the distance between the optical path conversion device (22) and the laser reflection point in the detected area.