Gas leakage detection and rapid traceability device

Abstract

The utility model discloses a gas leakage detection and rapid traceability device, relates to gas leakage detection and traceability, and aims to solve the technical problem of how to use visible light imaging for gas leakage traceability and realize rapid traceability of gas leakage in the prior art. Comprising a visible light imaging module and a gas tunable semiconductor laser absorption spectrum detection module, the visible light imaging module is used for imaging a gas leakage scene; the gas tunable semiconductor laser absorption spectrum detection module is used for collecting the gas leakage concentration of a leakage point in a scene; the gas leakage concentration detected by the gas tunable semiconductor laser absorption spectrum detection module is projected to an image obtained by the visible light imaging module and is used for detecting and positioning gas leakage. A concentration value measured by the gas tunable semiconductor laser absorption spectrum detection module is projected into an image obtained by the visible light imaging module, so that visible light imaging is used for gas leakage tracing, and rapid tracing of gas leakage is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas detection, relates to the detection and tracing of gas leakage, and in particular to a gas leakage detection and rapid tracing device. Background Art

[0002] Gas leak detection technology has broad and important applications in areas such as air pollution control, petrochemicals, and industrial process monitoring. For example, in industries like petrochemicals, there are numerous and complex methane gas storage or transportation equipment. Effectively monitoring leaks from these devices is a crucial prerequisite for ensuring safe production.

[0003] Contact leak detection equipment is currently widely used for gas leaks. The device's sensor needs to come into contact with the target gas to detect a leak. However, some leaks may be leaking, but most potential leaks have not yet occurred. Therefore, operators must personally inspect and detect each potential leak, which is inefficient and poses a health risk to inspectors. Furthermore, traditional gas leak detection technology can only measure concentration at a single point. While infrared imaging technology, developed specifically for methane gas leak detection, utilizes an infrared focal plane detector to image leaking gas, it offers the advantages of large-scale monitoring and rapid source tracing. However, it cannot quantitatively measure leak concentrations, and therefore cannot provide accurate situation analysis for subsequent accident assessment and remedial measures.

[0004] The invention patent application with application number 202010443190X discloses an infrared imaging and concentration detection device and method for methane gas leaks. The device includes an infrared thermal imager and a laser methane detection module. The infrared thermal imager is used to perform infrared imaging of the desired monitoring area to detect methane gas leaks. The laser methane detection module is aligned according to the leak points detected by infrared imaging and measures the methane concentration. The laser methane detection module is embedded in the infrared thermal imager, and the laser beam emission direction of the laser methane detection module is adjusted to be consistent with the optical axis direction of the infrared thermal imager. The two communicate with each other to achieve data exchange. The infrared thermal imager can detect a large area window to determine whether there is a natural gas leak in the window. The laser methane detection module can perform long-distance non-contact measurement of the methane leak point and obtain accurate methane gas concentration information. The combination of infrared thermal imaging technology for methane gas leak detection and laser methane detection technology simultaneously realizes non-contact, large-area rapid search for methane leak points and quantitative detection of methane gas concentration, achieving more efficient and accurate quantitative comprehensive detection than existing single detection devices.

[0005] In the above-mentioned invention patent application for infrared imaging and concentration detection device and method, although it achieves quantitative detection of methane leakage points and methane gas concentration. However, firstly, like traditional gas leak detection technology, it can only achieve single-point concentration measurement and cannot obtain the step-by-step concentration field; secondly, traditional gas leak tracing mostly uses infrared sensors for gas imaging, but infrared sensors are relatively expensive, which is not conducive to popularization and application; thirdly, existing visible light images only provide on-site evidence collection functions and do not have the ability to quickly trace the source. Therefore, in order to reduce costs and promote application, how to use visible light imaging for gas leak tracing and achieve rapid tracing of gas leaks is particularly important. It is necessary to provide a gas leak detection and rapid tracing device and method based on visible light imaging. Utility Model Content

[0006] The purpose of the utility model is to provide a gas leak detection and rapid tracing device in order to solve the technical problem of how to use visible light imaging for gas leak tracing and realize rapid tracing of gas leaks in the prior art.

[0007] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0008] A gas leak detection and rapid tracing device, comprising a visible light imaging module and a gas tunable semiconductor laser absorption spectrum detection module;

[0009] The visible light imaging module is used to image the leaking gas scene and provide the background and basic coordinate system for leak positioning;

[0010] The gas tunable semiconductor laser absorption spectroscopy detection module is used to collect the gas leakage concentration at the leakage point in the scene;

[0011] The gas leakage concentration measured by the gas tunable semiconductor laser absorption spectroscopy detection module is projected onto the image obtained by the visible light imaging module for gas leakage detection and positioning.

[0012] Furthermore, there is an angle between the optical axis of the visible light imaging module and the optical axis of the gas tunable semiconductor laser absorption spectrum detection module. , and the angle Satisfaction relationship:

[0013] ;

[0014] ;

[0015] in, is the upper limit of the angle, is the distance between the optical center of the visible light imaging module and the optical center of the gas tunable semiconductor laser absorption spectrum detection module, is the nominal working distance.

[0016] Furthermore, the frame rate of the visible light imaging module and the sampling frequency of the gas tunable semiconductor laser absorption spectroscopy detection module The following conditions are met:

[0017] ;

[0018] ;

[0019] ;

[0020] ;

[0021] in, is the lower limit of the visible light image sampling frame rate, is the lower limit of TDLAS data sampling rate, The moving angular velocity of the gas leak detection and rapid tracing device; It is an experience value, take 1.

[0022] Furthermore, when the visible light imaging module and the gas tunable semiconductor laser absorption spectrum detection module are installed, the distance between the optical center of the visible light imaging module and the optical center of the gas tunable semiconductor laser absorption spectrum detection module is The following conditions are met:

[0023] ;

[0024] in, is the laser beam waist width, is the laser Rayleigh distance; It is the experience value, take 10.

[0025] The beneficial effects of the utility model are as follows:

[0026] In the present invention, the concentration values ​​of multiple spatial positions are collected by a tunable semiconductor laser absorption spectrum detection module, and the concentration values ​​are projected into the image obtained by the visible light imaging module, so that the concentration values ​​measured at different positions can be projected to the corresponding positions of the image obtained by visible light imaging and associated, which can be used to detect and locate the source of gas leakage, realize the use of visible light imaging for gas leakage tracing, and realize rapid tracing of gas leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural diagram of the utility model;

[0028] Among them, the dotted box is an optional functional module;

[0029] Figure 2 This is a schematic diagram of the positions of the visible light imaging module and the gas tunable semiconductor laser absorption spectrum detection module in the utility model;

[0030] Figure 3 Schematic diagram of the scanning trajectory in the present invention;

[0031] Among them, the figures are marked as: 1-visible light imaging module, 2-gas tunable semiconductor laser absorption spectrum detection module. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0033] Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0034] Example 1

[0035] This embodiment provides a gas leak detection and rapid source tracing device, which can be used to detect and locate the source of gas leaks by combining multi-point TDLAS concentration value measurement with visible light images. Figure 1 As shown, it includes a visible light imaging module 1 and a gas tunable semiconductor laser absorption spectrum detection module 2.

[0036] The visible light imaging module 1 is used to image the gas leakage scene and provide a background and basic coordinate system for leak location. The visible light imaging module 1 can be an existing module.

[0037] The gas tunable semiconductor laser absorption spectrum detection module 2 is used to collect the gas leakage concentration at the leakage point in the scene. The gas tunable semiconductor laser absorption spectrum detection module 2 can also be an existing module.

[0038] The gas leakage concentration measured by the gas tunable semiconductor laser absorption spectrum detection module 2 is projected onto the image obtained by the visible light imaging module 1 to detect and locate the gas leakage.

[0039] Example 2

[0040] On the basis of Example 1, there is an angle between the optical axis of the visible light imaging module 1 and the optical axis of the gas tunable semiconductor laser absorption spectrum detection module 2 , and the angle Satisfaction relationship:

[0041] ;

[0042] angle It can be solved by the following formula:

[0043] ;

[0044] in, is the upper limit of the angle, is the distance between the optical center of the visible light imaging module 1 and the optical center of the gas tunable semiconductor laser absorption spectrum detection module 2, is the nominal working distance.

[0045] The angle The calibration method can be used for calibration and fixation, and no secondary calibration is required during use. The calibration can be performed using an existing angle calibration method or an innovative calibration method (the innovative calibration method will be described and protected in another patent filed along with this application). In this embodiment, the existing calibration method can be used.

[0046] Frame rate of visible light imaging module 1 and the sampling frequency of the gas tunable semiconductor laser absorption spectrum detection module 2 The following conditions are met:

[0047] ;

[0048] ;

[0049] Should and All with nominal working distance And it is related to the angular velocity of the device, specifically:

[0050] ;

[0051] ;

[0052] in, is the lower limit of the visible light image sampling frame rate, is the lower limit of TDLAS data sampling rate, The moving angular velocity of the gas leak detection and rapid tracing device; It is an experience value, take 1.

[0053] When installing the visible light imaging module 1 and the gas tunable semiconductor laser absorption spectrum detection module 2, the distance between the optical centers of the two is required to be as small as possible. In this embodiment, the specific standards for the distance between the optical centers of the visible light imaging module 1 and the gas tunable semiconductor laser absorption spectrum detection module 2 are:

[0054] The distance between the optical center of the visible light imaging module 1 and the optical center of the gas tunable semiconductor laser absorption spectrum detection module 2 Should be less than the nominal working distance of the gas tunable semiconductor laser absorption spectrum detection module 2 The radius of the light spot generated, the distance The following conditions should be met:

[0055] ;

[0056] in, is the laser beam waist width, is the laser Rayleigh distance; It is the experience value, take 10.

[0057] Example 3

[0058] On the basis of Example 1, the device in this embodiment further includes a signal synchronization acquisition module and a data processing unit, which are used to tightly integrate visible light imaging and gas tunable semiconductor laser absorption spectroscopy detection module 2 (i.e., TDLAS), design TDLAS leakage concentration acquisition trajectory, and combine the spatial perception of visible light images with the fluid mechanics constraints of gas leakage to achieve large-scale leakage concentration field estimation and rapid source tracing, such as Figure 1 shown.

[0059] The signal synchronization acquisition module is used to synchronize the data acquisition of the visible light imaging module 1 and the gas tunable semiconductor laser absorption spectrum detection module 2.

[0060] The data processing unit is used to realize gas leakage model building, concentration field fitting and projection.

[0061] In addition, a display screen, battery, and motion actuator can be optionally configured as needed. The display screen is used to display the detection and traceability process and results, the battery is used to provide power to the entire device, and the motion actuator is used to control imaging and the detection direction of TDLAS, including horizontal and vertical rotation. The display screen, battery, and motion actuator can directly adopt existing technologies without the need for creative work.

[0062] The signal synchronization acquisition module has software synchronization and hardware synchronization acquisition functions. When the signal synchronization acquisition module is used to synchronize data acquisition, the deviation between the time when the visible light imaging module 1 collects the image and the time when the gas tunable semiconductor laser absorption spectrum detection module 2 collects the concentration should be controlled within an acceptable range. Inside, and the With nominal working distance , the angular velocity of the device It can be expressed as:

[0063] ;

[0064] in, The moving angular velocity of the gas leak detection and rapid tracing device; It is an experience value, take 1.

[0065] The data processing unit is composed of an ARM or DSP. The function of the data processing unit is to complete scene modeling, concentration field fitting and projection, which is achieved by implanting the algorithms and programs described in this application.

[0066] Example 4

[0067] This embodiment provides a gas leak detection and rapid source tracing method, which uses the above-mentioned gas leak detection and rapid source tracing device to quickly locate and trace the gas leak, and specifically includes the following steps:

[0068] Step S1 : performing leakage detection using a gas leakage detection and rapid tracing device, wherein the leakage judgment criterion is the concentration of leaked gas detected by a tunable semiconductor laser absorption spectroscopy detection module.

[0069] Step S2: The visible light imaging module 1 captures the image of the scene to obtain a basic image. , and will take the base image The coordinate system of the visible light imaging module 1 is defined as the basic imaging coordinate system .

[0070] For the base image Perform spatial perception to identify candidate targets where leakage may occur and use them as spatial constraints for the gas leakage concentration field model.

[0071] When performing spatial perception, semantic segmentation is used to classify the base image Perform pixel-level classification and classify the basic image The model is divided into categories such as flanges, pipes, gas tanks, and background. In addition to the background, foreground objects such as flanges, pipes, and gas tanks are all potential leak targets. The spatial constraint of the leakage model is that the gas leakage concentration field must be connected to an instance of the foreground object, flange, pipe, gas tank, or background, and the concentration is highest near the connection.

[0072] When performing semantic segmentation, this example uses SAM, which is well known in the art, for semantic segmentation, that is, existing technology can be used. Those skilled in the art can choose and apply it as needed without having to make any creative efforts.

[0073] Step S3: establishing a gas leakage concentration field model using fluid mechanics constraints.

[0074] In this embodiment, when establishing the gas leakage concentration field model, a simplified model, namely the Gaussian feathering model, is adopted. The model is:

[0075] ;

[0076] and They are Direction and The center of the gas cloud in the direction of The correlation model between the two is:

[0077] ;

[0078] ;

[0079] in, The positive direction of the axis points to the downwind direction. The positive axis points in the direction of sight. The positive direction of the axis is vertical and the horizon is upward. is the gas leakage rate, for Wind speed in direction, and They are Direction and Variance of direction; represents the transfer factor of the gas cloud center along the y direction, represents the movement factor of the gas cloud center along the z direction, represents the offset factor of the gas cloud center along the y direction, represents the offset factor of the gas cloud center along the z direction.

[0080] Step S4: Use the signal synchronization acquisition module to control the tunable semiconductor laser absorption spectrum detection module and the visible light imaging module 1 to synchronously acquire the leakage concentration at time t. and the current image .

[0081] Step S5: In the same scene and at a similar time, the position of the mobile gas leak detection and rapid tracing device is adjusted so that the point detected by the tunable semiconductor laser absorption spectrum detection module moves along a certain trajectory. The trajectory is related to the wind direction at the current moment. The trajectory along the wind direction is longer, and the trajectory perpendicular to the wind direction is shorter, such as Figure 3 During use, the trajectory can be automatically determined by the device after collecting the wind speed and direction on site, and then drawn on the display screen, making it convenient for the operator to scan the trajectory. and the current image , get n data pairs on this trajectory ( )、( )、( ),…,( In this embodiment, 100 data pairs located on the trajectory are captured ( )、( )、( ),…,( ).

[0082] Step S6: perform image registration based on n data pairs and project all images into the basic imaging coordinate system. In the corresponding basic imaging coordinate system Multi-point concentration value ( )、( )、( ),…,( ), where x is the two-dimensional coordinate of the image.

[0083] According to the 100 data pairs collected in step S5, image registration is performed. The registration process is as follows: the current image and the base image The feature point pairs that match between the two images are then calculated. and the base image The affine matrix projects all images into the basic imaging coordinate system In the image, the image corresponding to the basic imaging coordinate system is the basic image Finally, the multi-point concentration values ​​in the basic imaging coordinate system are obtained ( )、( )、( ),…,( ), where x is the two-dimensional coordinate of the image.

[0084] Step S7: Fit the gas leakage concentration field model obtained in steps S2 and S3, combined with the multi-point concentration values ​​obtained in step S6. .

[0085] Fitting the concentration field of gas leakage When , the fitting steps are:

[0086] Step S7-1, based on the multi-point concentration values ​​in the basic imaging coordinate system The distribution in , calculates the possible foreground intersection points of the leakage area.

[0087] In step S7-2, the gas leakage concentration field model established in step S3 is fitted with the multi-point data using the foreground intersection as the origin, and the fitting error is calculated. When fitting, the existing fitting method can be used without creative work.

[0088] Step S7-3: If the error is too large, update the origin until the origin with smaller fitting error is found, and then fit to establish the final concentration field. .

[0089] Step S8: Based on the gas leakage concentration field model obtained in steps S2 and S3, combined with the basic image , calculate the current image and the base image The registration relationship between ; Using the registration relationship , the concentration field Align to current image and locate the leakage source based on the aligned images.

[0090] In the concentration field Align to current image When , the alignment method is:

[0091] Step S8-1, calculate the basic image To the current image Feature point matching: This embodiment can use the SIFT method commonly used in the art to perform feature matching.

[0092] Step S8-2, calculate the basic image based on the matched feature points To the current image The transformation matrix .

[0093] Step S8-3, using the transformation matrix , the concentration field Align to current image middle.

[0094] By converting the concentration field Perform pseudo color processing and superimpose it on the current image It is convenient for operators to quickly locate the source of the leak.

Claims

1. A gas leak detection and rapid tracing device, characterized by: It includes a visible light imaging module (1) and a gas tunable semiconductor laser absorption spectrum detection module (2); The visible light imaging module (1) is used to image the leaking gas scene and provide a background and basic coordinate system for leak positioning; The gas tunable semiconductor laser absorption spectrum detection module (2) is used to collect the gas leakage concentration at the leakage point in the scene; The gas leakage concentration measured by the gas tunable semiconductor laser absorption spectrum detection module (2) is projected onto the image acquired by the visible light imaging module (1) for detecting and locating the gas leakage.

2. A gas leak detection and rapid source tracing device according to claim 1, characterized in that: There is an angle between the optical axis of the visible light imaging module (1) and the optical axis of the gas tunable semiconductor laser absorption spectrum detection module (2) , and the angle Satisfaction relationship: ； ； in, is the upper limit of the angle, is the distance between the optical center of the visible light imaging module (1) and the optical center of the gas tunable semiconductor laser absorption spectrum detection module (2), is the nominal working distance.

3. A gas leak detection and rapid source tracing device according to claim 1, characterized in that: Frame rate of visible light imaging module (1) and the sampling frequency of the gas tunable semiconductor laser absorption spectrum detection module (2) The following conditions are met: ； ； ； ； in, is the lower limit of the visible light image sampling frame rate, is the lower limit of TDLAS data sampling rate, The moving angular velocity of the gas leak detection and rapid tracing device; It is an experience value, take 1.

4. A gas leak detection and rapid source tracing device according to claim 1, characterized in that: When the visible light imaging module (1) and the gas tunable semiconductor laser absorption spectrum detection module (2) are installed, the distance between the optical center of the visible light imaging module (1) and the optical center of the gas tunable semiconductor laser absorption spectrum detection module (2) is The following conditions are met: ； in, is the laser beam waist width, is the laser Rayleigh distance; It is the experience value, take 10.

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