Self-adaptive ranging methane concentration laser telemetering device and method

Abstract

The invention provides an adaptive ranging methane concentration laser telemetering device and method, and belongs to the technical field of methane concentration measurement, the device comprises a methane concentration laser telemetering module, a laser ranging module and an intrinsic safety master control communication module, the methane concentration laser telemetering module is used for measuring linear integral space methane concentration based on a methane concentration laser telemetering light beam; the laser ranging module is used for measuring the spatial distance from the device to the reflection module and the effective absorption optical path of methane absorption laser based on a laser ranging beam while the methane concentration laser telemetering module measures the linear integral space methane concentration. The intrinsic safety master control communication module is used for calculating a target methane concentration based on a linear integral space methane concentration and a space distance or an effective absorption optical path in a preset measurement mode; according to the scheme, self-adaptive distance measurement can be achieved, so that the accuracy of methane concentration measurement is improved, and high usability and practicability are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of methane concentration measurement, and in particular to a methane concentration laser telemetry device and method with adaptive ranging. Background Art

[0002] At present, the most widely used fixed methane sensors use catalytic combustion technology, thermal conductivity technology, and optical interference technology to measure methane concentration and the methane safety limit of mines. Catalytic combustion sensors are only suitable for detecting methane in a low volume fraction range, thermal conductivity sensors are suitable for detecting methane in a high concentration range, and optical interference methane sensors are easily interfered by other gas components. Fixed methane sensors have low accuracy in measuring methane concentration, and their sampling method is penetration or directional extraction. Methane needs to enter the measurement cavity to measure methane concentration. The response time is long and the response speed is slow, making it difficult to reflect the changing trend of methane concentration in real time.

[0003] Therefore, how to improve the accuracy and response speed of methane concentration measurement has become an issue to be resolved. Summary of the invention

[0004] The purpose of the present application is to provide an adaptive ranging methane concentration laser telemetry device, which can solve the problems of low accuracy and slow response speed of methane concentration measurement in the prior art.

[0005] In a first aspect, an embodiment of the present application provides a methane concentration laser telemetry device with adaptive ranging, the device comprising: a methane concentration laser telemetry module, a laser ranging module, and an intrinsically safe main control communication module;

[0006] The output end of the methane concentration laser telemetry module is connected to the input end of the intrinsically safe main control communication module. The methane concentration laser telemetry module is used to measure the line-integrated spatial methane concentration based on the methane concentration laser telemetry beam, and output the line-integrated spatial methane concentration to the intrinsically safe main control communication module.

[0007] The output end of the laser distance measurement module is connected to the input end of the intrinsically safe main control communication module. The laser distance measurement module is used to measure the spatial distance from the device to the reflection module and the effective absorption optical path of the methane absorption laser based on the laser distance measurement beam while the methane concentration laser telemetry module measures the line-integrated spatial methane concentration, and output the spatial distance and the effective absorption optical path to the intrinsically safe main control communication module;

[0008] The output end of the intrinsically safe main control communication module is connected to the host computer through a communication interface. The intrinsically safe main control communication module is used to calculate the target methane concentration based on the line-integrated spatial methane concentration and the spatial distance or the effective absorption optical path in a preset measurement mode, and output the target methane concentration to the host computer.

[0009] In a possible implementation of the first aspect, the methane concentration laser telemetry module includes: a first optical transmitting unit and a first optical receiving unit;

[0010] The first optical transmitting unit is used to transmit a methane concentration laser telemetry beam to the reflection module, and the reflection module reflects the methane concentration laser telemetry beam to the first optical receiving unit; the first optical receiving unit is used to receive the methane concentration laser telemetry beam and convert the optical signal of the methane concentration laser telemetry beam into an electrical signal.

[0011] In a possible implementation of the first aspect, the first optical transmitting unit includes: a first laser probe and a second laser probe, the first optical receiving unit includes a first detector, the methane concentration laser telemetry beam includes: a first telemetry beam and a second telemetry beam, and the first telemetry beam is a collimated visible light beam;

[0012] The first laser probe is used to emit a first telemetry beam to the reflection module, and the first telemetry beam is used to mark the measurement path and a first marking point of the first telemetry beam on the reflection module;

[0013] The second laser probe is used to emit a second telemetry beam to the reflection module, and the second telemetry beam is incident on the same position as the first marking point. The reflection module reflects the second telemetry beam into the first detector.

[0014] In a possible implementation of the first aspect, the laser ranging module includes: a second optical transmitting unit and a second optical receiving unit;

[0015] The second optical transmitting unit is used to transmit the laser ranging beam to the reflecting module, and the reflecting module reflects the laser ranging beam to the second optical receiving unit, and the second optical receiving unit is used to receive the laser ranging beam.

[0016] In a possible implementation of the first aspect, the second optical transmitting unit includes: a third laser probe and a fourth laser probe, the second optical receiving unit includes a second detector, the laser ranging beam includes: a first ranging beam and a second ranging beam, the first ranging beam is a visible light beam, and the first ranging beam is parallel to the first telemetry beam;

[0017] The third laser probe is used to emit a first ranging beam to the reflection module, and the first ranging beam is used to mark a second marking point of the first ranging beam on the reflection module; the fourth laser probe is used to emit a second ranging beam to the reflection module, and the second ranging beam is incident on the same position as the second marking point, and the reflection module reflects the second ranging beam into the second detector.

[0018] In a second aspect, an embodiment of the present application provides a methane concentration laser telemetry method with adaptive ranging, which is implemented based on the methane concentration laser telemetry device with adaptive ranging according to any one of the first aspects, and the method includes:

[0019] Based on the methane concentration laser telemetry module, the line-integrated spatial methane concentration is measured according to the methane concentration laser telemetry beam, and the line-integrated spatial methane concentration is output to the intrinsically safe main control communication module;

[0020] Based on the laser ranging module, while the methane concentration laser telemetry module measures the line-integrated spatial methane concentration, the spatial distance from the device to the reflection module and the effective absorption optical path of the methane absorption laser are measured according to the laser ranging beam, and the spatial distance and effective absorption optical path are output to the intrinsically safe main control communication module;

[0021] Based on the intrinsically safe main control communication module, the target methane concentration is calculated based on the line-integrated spatial methane concentration and the spatial distance or effective absorption optical path in the preset measurement mode, and the target methane concentration is output to the host computer.

[0022] In a possible implementation of the second aspect, the methane concentration laser telemetry module includes: a first optical transmitting unit and a first optical receiving unit, the first optical transmitting unit includes: a first laser probe and a second laser probe, the first optical receiving unit includes a first detector, and the methane concentration laser telemetry beam includes: a first telemetry beam and a second telemetry beam; based on the methane concentration laser telemetry module, measuring the line-integrated spatial methane concentration according to the methane concentration laser telemetry beam includes:

[0023] Based on the first laser probe, a first telemetry beam is emitted to the reflection module, and the first telemetry beam is used to mark the measurement path and the first marking point of the first telemetry beam on the reflection module; based on the second laser probe, a second telemetry beam is emitted, and the second telemetry beam is incident on the same position as the first marking point, and the reflection module reflects the second telemetry beam to the first detector; based on the first detector, an optical signal of the second telemetry beam is converted into an electrical signal;

[0024] Based on the methane concentration laser telemetry module, the absorption characteristic spectrum line of methane after absorbing laser is obtained according to the electrical signal converted from the optical signal of the second telemetry light beam; based on the methane concentration laser telemetry module, the electrical signal converted from the optical signal of the second telemetry light beam is fitted and normalized to obtain the peak height of the absorption characteristic spectrum line, and the line-integrated spatial methane concentration is inverted according to the peak height.

[0025] In a possible implementation manner of the second aspect, the laser ranging module includes: a second optical emitting unit and a second optical receiving unit, the second optical emitting unit includes: a third laser probe and a fourth laser probe, the second optical receiving unit includes a second detector, and the laser ranging beam includes: a first ranging beam and a second ranging beam; based on the laser ranging module, while the methane concentration laser telemetry module measures the line-integrated spatial methane concentration, the spatial distance from the device to the reflection module is measured according to the laser ranging beam, including:

[0026] Based on the third laser probe, a first ranging beam is emitted to the reflection module, and the first ranging beam is used to mark a second marking point of the first ranging beam on the reflection module; based on the fourth laser probe, a second ranging beam is emitted, and the second ranging beam is incident on the same position as the second marking point, and the reflection module reflects the second ranging beam to the second detector; based on the laser ranging module, the spatial distance is calculated according to the pulse laser ranging equation;

[0027] Among them, the formula of the pulse laser ranging equation is as follows:

[0028]

[0029] Wherein, Pr is the receiving power of the detector, Pt is the transmitting power of the laser ranging module, Kt is the transmittance of the second optical transmitting unit, Kr is the transmittance of the second optical receiving unit, A is the radius of the receiving objective lens of the second optical receiving unit, ρ is the target reflection coefficient, R is the spatial distance, K is the ratio of the target area to the spot area, α is the atmospheric attenuation coefficient, and e is a real number (≈2.71828).

[0030] In a possible implementation of the second aspect, the laser ranging module measures the spatial distance from the device to the reflection module according to the laser ranging beam while the methane concentration laser telemetry module measures the line-integrated spatial methane concentration, including:

[0031] Based on the third laser probe, a first ranging beam is emitted to the reflection module, based on the fourth laser probe, a second ranging beam is emitted, and the reflection module reflects the second ranging beam to the second detector;

[0032] Based on the laser ranging module, the phase difference between the optical signal when the second ranging beam is emitted and the optical signal received after the second ranging beam is reflected, as well as the time difference between emitting the second ranging beam and receiving the reflected second ranging beam are calculated; based on the laser ranging module, the product of the phase difference and the time difference is used as the spatial distance.

[0033] In a possible implementation of the second aspect, the preset measurement modes include: an open space measurement mode and a fixed closed space measurement mode; in the open space measurement mode, the effective absorption optical path is equal to the spatial distance, and in the fixed closed space measurement mode, the effective absorption optical path is equal to the methane thickness in the fixed closed space; based on the intrinsically safe main control communication module, in the preset measurement mode, the target methane concentration is calculated based on the line-integrated spatial methane concentration and the spatial distance or the effective absorption optical path, including:

[0034] Based on the intrinsically safe main control communication module, in the open space measurement mode, the target methane concentration is calculated based on the line-integrated spatial methane concentration and the spatial distance; or in the fixed closed space measurement mode, the target methane concentration is calculated based on the line-integrated spatial methane concentration and the effective absorption optical path.

[0035] The adaptive ranging methane concentration laser telemetry device of the present application has a laser ranging module that measures the spatial distance and effective absorption optical path from the device to the reflection module while the methane concentration laser telemetry module measures the line-integrated spatial methane concentration. Then, in different measurement modes, the intrinsically safe main control communication module calculates the final spatial methane concentration based on the line-integrated spatial methane concentration and the spatial distance, or based on the limited-integrated spatial methane concentration and the effective absorption optical path, thereby finally achieving high-precision measurement of low methane concentration in the return air shaft tunnel space of an underground coal mine.

[0036] The laser ranging module of the solution of the present application can perform adaptive ranging, and can timely calibrate the spatial distance when the telemetry device encounters vibration, angle change, etc., reducing the probability of distance error caused by spatial angle adjustment, thereby improving the accuracy of methane concentration measurement. Moreover, methane does not need to enter the telemetry device to measure the concentration, thereby accelerating the response speed of methane concentration measurement, and can reflect the trend of methane concentration changes in real time, with strong ease of use and practicality.

[0037] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] Figure 1 It is a schematic diagram of an application scenario of the methane concentration laser remote sensing device with adaptive ranging provided in an embodiment of the present application;

[0040] Figure 2is a schematic diagram of the structure of the reflection module provided in an embodiment of the present application;

[0041] Figure 3 It is a schematic block diagram of the overall modules of the adaptive ranging methane concentration laser remote sensing device provided in an embodiment of the present application;

[0042] Figure 4 It is a schematic block diagram of the overall units of the adaptive ranging methane concentration laser remote sensing device provided in an embodiment of the present application;

[0043] Figure 5 It is a schematic block diagram of the specific structure of the methane concentration laser remote sensing device with adaptive ranging provided in an embodiment of the present application;

[0044] Figure 6 It is a right view of the methane concentration laser remote sensing device with adaptive ranging provided in an embodiment of the present application;

[0045] Figure 7 It is a schematic diagram of the steps of the adaptive ranging methane concentration laser telemetry method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0047] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0048] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0049] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0050] As used in this specification and the appended claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0051] In addition, in the description of the present application, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0052] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0053] In the present application specification, unless otherwise specified, directional words such as "up, down, left, right" generally refer to the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the invented product is usually placed when in use.

[0054] In the present application specification, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] At present, the most widely used fixed methane sensors use catalytic combustion technology, thermal conductivity technology, and optical interference technology to measure methane concentration and the methane safety limit of mines. Catalytic combustion sensors are only suitable for detecting methane in a low volume fraction range, thermal conductivity sensors are suitable for detecting methane in a high concentration range, and optical interference methane sensors are easily interfered by other gas components. The three technical principles are all used for gas safety monitoring in mine tunnels, and timely alarms are issued when the dangerous concentration range is exceeded. The general range of fixed methane sensors is 0-100LEL and the accuracy is ±5LEL. The methane concentration range of the return air shaft tunnel of low-gas mines during coal mining and maintenance is 20ppm-2000ppm, which is far below the minimum explosion limit of 0.75% (7500ppm). Fixed methane sensors have low accuracy in measuring methane concentration, and their sampling method is penetration or directional extraction. Methane needs to enter the measurement chamber to measure the methane concentration. The response time is long and the response speed is slow, making it difficult to reflect the changing trend of methane concentration in real time.

[0056] Therefore, how to improve the accuracy and response speed of methane concentration measurement has become an issue to be resolved.

[0057] In response to the above-mentioned defects, the present application provides an adaptive ranging methane concentration laser telemetry device. While the methane concentration laser telemetry module measures the line-integrated spatial methane concentration, the laser ranging module measures the spatial distance and effective absorption optical path from the device to the reflection module. Then, in different measurement modes, the intrinsically safe main control communication module calculates the final spatial methane concentration based on the line-integrated spatial methane concentration and spatial distance, or based on the limited-integrated spatial methane concentration and effective absorption optical path, thereby finally achieving high-precision measurement of low methane concentration in the return air shaft tunnel space of an underground coal mine.

[0058] The laser ranging module of the solution of the present application can perform adaptive ranging. When the device encounters vibration, angle change, etc., it can timely calibrate the spatial distance, reduce the probability of distance error caused by spatial angle adjustment, and thus improve the accuracy of methane concentration measurement. The methane concentration can be measured by using the methane concentration laser telemetry beam without the need for methane to enter the interior of the adaptive ranging methane concentration laser telemetry device, thereby accelerating the response speed of the methane concentration measurement and being able to reflect the trend of methane concentration changes in real time. Laser telemetry technology is used to measure methane concentration, replacing the catalytic combustion, thermal conductivity, optical interference and other measurement technologies used by traditional fixed methane sensors for safety warning and alarm in mines. The device has high sensitivity and low detection limit detection performance, and can be used in low-concentration methane measurement and methane emission metering in low-gas mine environments, with strong ease of use and practicality.

[0059] See also Figure 1 , Figure 1It is a schematic diagram of an application scenario of the adaptive ranging methane concentration laser telemetry device 100 provided in an embodiment of the present application.

[0060] like Figure 1 As shown, the space of the return air shaft underground in the coal mine is full of methane, the adaptive ranging methane concentration laser telemetry device 100 is installed on the adjustable bracket 1, and the reflection module is installed on the adjustable bracket 2. The angles of the adaptive ranging methane concentration laser telemetry device 100 and the reflection module can be adjusted according to the specific situation in the actual application scenario. The adaptive ranging methane concentration laser telemetry device 100 emits a methane concentration laser telemetry beam to the reflection module, and the reflection module reflects the methane concentration laser telemetry beam into the adaptive ranging methane concentration laser telemetry device 100; the adaptive ranging methane concentration laser telemetry device 100 also emits a laser ranging beam to the reflection module, and the reflection module reflects the laser ranging reflected beam into the adaptive ranging methane concentration laser telemetry device 100.

[0061] In one embodiment, the adaptive ranging methane concentration laser telemetry device 100 measures the line-integrated spatial methane concentration CL (in ppm*m) based on the methane concentration laser telemetry beam. While measuring the line-integrated spatial methane concentration CL, the device measures the spatial distance from the device to the reflection module and the effective absorption optical path of the methane absorption laser in real time based on the laser ranging beam. In different preset measurement modes, the adaptive ranging methane concentration laser telemetry device 100 calculates the target methane concentration C (in ppm), i.e., the methane concentration in the return air shaft tunnel space of the coal mine, based on the line-integrated spatial methane concentration CL and the spatial distance, or based on the line-integrated spatial methane concentration CL and the effective absorption optical path, and finally achieves high-precision measurement of low methane concentration in the return air shaft tunnel space of the coal mine.

[0062] See also Figure 2 , Figure 2 It is a schematic diagram of the structure of the reflection module provided in the embodiment of the present application.

[0063] In one embodiment, the reflective module can be a reflective plate or a smooth wall surface, and the reflective plate includes a film layer with good weather resistance, a quartz microbead layer, a focusing layer, a reflective layer, an adhesive layer, and a peeling layer. Figure 2 As shown, the reflector includes a plurality of rhombus quartz micro-beads with a diameter of 2.5 to 5 mm, and the length of the reflector is 500 mm and the width is 400 mm.

[0064] Based on the above application scenarios, the present application embodiment provides a methane concentration laser remote sensing device and method with adaptive ranging. The structure of the device and the specific process of implementing the method are introduced below through specific embodiments.

[0065] The overall structure of the adaptive ranging methane concentration laser telemetry device provided in the embodiment of the present application is introduced below through a specific embodiment.

[0066] See also Figure 3 , Figure 3 FIG. 1 is a schematic block diagram of the overall modules of the adaptive ranging methane concentration laser remote sensing device 100 provided in the embodiment of the present application. Figure 3 As shown, the adaptive ranging methane concentration laser remote sensing device 100 includes: a methane concentration laser remote sensing module 110 , a laser ranging module 120 and an intrinsically safe main control communication module 130 .

[0067] In one embodiment, the output end of the methane concentration laser telemetry module 110 is connected to the input end of the intrinsically safe main control communication module 130. The methane concentration laser telemetry module 110 is used to measure the line-integrated spatial methane concentration CL based on the methane concentration laser telemetry beam using TDLAS (Tunable Diode Laser Absorption Spectroscopy) remote sensing measurement technology, and output the line-integrated spatial methane concentration CL to the intrinsically safe main control communication module 130.

[0068] In one embodiment, the output end of the laser ranging module 120 is connected to the input end of the intrinsically safe main control communication module 130. While the methane concentration laser telemetry module 110 measures the line-integrated spatial methane concentration CL, the laser ranging module 120 measures the spatial distance from the adaptive ranging methane concentration laser telemetry device 100 to the reflection module and the effective absorption optical path of the methane absorption laser in real time based on the laser ranging beam, and outputs the spatial distance and the effective absorption optical path to the intrinsically safe main control communication module 130.

[0069] In one embodiment, the output end of the intrinsically safe main control communication module 130 is connected to the host computer through a communication interface, and the communication interface can be an aerial plug-in communication interface or other forms of communication interface. In different preset measurement modes, the intrinsically safe main control communication module 130 calculates the target methane concentration C based on the line-integrated spatial methane concentration CL and the spatial distance, or based on the line-integrated spatial methane concentration CL and the effective absorption optical path, that is, the methane concentration in the return air shaft tunnel space of the coal mine, and finally achieves high-precision measurement of the low methane concentration in the return air shaft tunnel space of the coal mine. The intrinsically safe main control communication module 130 can output the target methane concentration signal to the host computer through the communication interface.

[0070] It should be noted that the laser distance measurement module 120 can measure the spatial distance in real time, and cooperate with the methane concentration laser telemetry module 110 to calculate the spatial methane concentration. The specific calculation is performed by the intrinsically safe main control communication module 130.

[0071] In one embodiment, the adaptive ranging methane concentration laser remote sensing device 100 further includes: a dual-wavelength filter window, a mechanical fixing structure, a sealing protective layer, and a stainless steel metal shell. The mechanical fixing structure is used to fix the methane concentration laser remote sensing module 110, the laser ranging module 120, and the intrinsically safe main control communication module 130.

[0072] In one embodiment, the methane concentration laser telemetry module 110 can also measure the laser intensity, and then output the laser intensity signal to the intrinsically safe main control communication module 130, and the intrinsically safe main control communication module 130 outputs the laser intensity signal to the upper computer through the communication interface. The upper computer implements the early warning and alarm functions of the methane emission measurement system (the adaptive ranging methane concentration laser telemetry device 100 is a part of the methane emission measurement system) through the laser intensity signal and the target methane concentration signal, which is convenient for maintaining the system and taking timely measures to reduce the spatial methane concentration when the spatial methane concentration is too high. Among them, the early warning and alarm functions are as follows:

[0073] (1) Early warning and alarm functions for the accuracy of spatial methane concentration measurement: The laser intensity signal output by the methane concentration laser telemetry module 110 is divided into 10 levels. When the laser intensity signal is at level 10, it meets the calculation requirements of the preset measurement mode and can ensure the accuracy of spatial methane concentration measurement. When the dual-wavelength filter window is contaminated, dust accumulates on the reflection module, or the measurement angle changes, the level of the laser intensity signal decreases and the measurement is disturbed. When the level of the laser intensity signal drops to level 6, the system will issue an early warning command to instruct the alarm device to issue an early warning; when the level of the laser intensity signal drops to level 3, the system will issue an alarm command to instruct the alarm device to issue an alarm.

[0074] (2) Early warning and alarm function of gas explosion: When the measured methane concentration in the space reaches 7500ppm, the minimum explosion limit is reached, and the system will issue an alarm command to instruct the alarm device to sound an alarm; when the measured methane concentration in the space reaches 80% of the minimum explosion limit, the system will issue an early warning command to instruct the alarm device to sound an early warning, and maintenance personnel can take timely measures to reduce the methane concentration in the space.

[0075] In one embodiment, the flowmeter in the methane emission measurement system can measure the flow of methane in the return air shaft tunnel space of the coal mine, and then the methane emission measurement system calculates the methane emissions based on the spatial methane flow and spatial methane concentration. The product of the spatial methane flow and the spatial methane concentration is the methane emissions.

[0076] This implementation can realize real-time monitoring of low-concentration spatial methane of the line-integrated spatial array, and the lowest concentration can be monitored to 30ppm*m. At the same time, an adaptive ranging function is added. Within the range of 5 to 10m in spatial distance, it can meet the technical needs of low-concentration methane measurement and methane emission metering in low-gas mine environments.

[0077] In this embodiment, the laser ranging module 120 can perform adaptive ranging. When the adaptive ranging methane concentration laser telemetry device 100 encounters vibration, angle change, etc., the spatial distance can be calibrated in time to reduce the probability of distance error caused by spatial angle adjustment, thereby improving the accuracy of methane concentration measurement, and the methane concentration can be measured by using the methane concentration laser telemetry beam without the need for methane to enter the interior of the adaptive ranging methane concentration laser telemetry device 100, thereby accelerating the response speed of methane concentration measurement and being able to reflect the trend of methane concentration changes in real time. The laser telemetry technology is used to measure methane concentration, replacing the catalytic combustion, thermal conductivity, optical interference and other measurement technologies used by the traditional fixed methane sensors for safety warning and alarm in mines. The adaptive ranging methane concentration laser telemetry device 100 has high sensitivity and low detection limit detection performance, and can be applied to low-concentration methane measurement and methane emission measurement in low-gas mine environments, and has strong ease of use and practicality.

[0078] See also Figure 4 , Figure 4 1 is a schematic block diagram of the overall unit of the adaptive ranging methane concentration laser remote sensing device 100 provided in the embodiment of the present application. Figure 4 As shown, the methane concentration laser telemetry module 110 includes: a first optical transmitting unit 112 and a first optical receiving unit 114 .

[0079] In one embodiment, the first optical transmitting unit 112 and the first optical receiving unit 114 can be independently provided in the methane concentration laser telemetry module 110. The first optical transmitting unit 112 is used to transmit a methane concentration laser telemetry beam to the reflection module, and the reflection module reflects the methane concentration laser telemetry beam to the first optical receiving unit 114. The first optical receiving unit 114 is used to receive the methane concentration laser telemetry beam and convert the optical signal of the methane concentration laser telemetry beam into an electrical signal.

[0080] In the prior art, fixed methane sensors are hung at different positions on the walls of mine tunnels. When the flow field distribution of the return air shaft tunnel in the coal mine is uneven, the gas concentration that penetrates into the fixed methane sensor is poorly representative and cannot be used as an important parameter for measuring methane emissions. In addition, the environmental adaptability of fixed methane sensors is poor. When the sulfide concentration in the return air shaft tunnel is too high, the CO2 concentration is too high, or the humidity is too high, the fixed methane sensor may have errors or even fail. Therefore, additional measures such as regular dehumidification, CO2 removal or sulfur removal are required, and the accuracy, reliability and stability of fixed methane sensors are difficult to guarantee.

[0081] See also Figure 5 , Figure 5 1 is a schematic block diagram of the specific structure of the methane concentration laser telemetry device 100 for adaptive ranging provided in an embodiment of the present application. The methane concentration laser telemetry beam includes: a first telemetry beam and a second telemetry beam. Figure 5 As shown, the first optical transmitting unit 112 includes: a first laser probe G1 and a second laser probe G2, and the first optical receiving unit 114 includes a first detector T1.

[0082] In one embodiment, the first laser probe G1, the second laser probe G2 and the first detector T1 can be independently arranged in the methane concentration laser telemetry module 110. The first laser probe G1 is used to emit a first telemetry beam to the reflection module. The first telemetry beam is a collimated beam of visible light, which can be red light or green light, and has a wavelength range of 500 to 700 nm. The first telemetry beam is used to mark the measurement path and the first marking point of the first telemetry beam on the reflection module. The first marking point is visible to the naked eye, which is convenient for determining the position where the second telemetry beam is incident on the reflection module.

[0083] Among them, the measurement path can be a midline path in the return air shaft mine tunnel space. The methane gas mass in the spatial midline path is used as the measurement sample of the line integral spatial methane concentration CL, replacing the penetration single-point measurement method of the fixed methane sensor. This can enhance the representativeness of the spatial methane concentration and can be used as an important parameter for methane emission measurement, thereby making the methane emission measurement more accurate.

[0084] In one embodiment, the second laser probe G2 is used to emit a second telemetry beam to the reflection module, and the second telemetry beam is incident on the same position as the first marking point. The reflection module reflects the second telemetry beam to the first detector T1 by mirror reflection or diffuse reflection.

[0085] The second telemetry beam is a characteristic beam for measuring the methane concentration in space. The central frequency of the characteristic beam is 6046.9636 cm -1 Nearby, methane has a central frequency of 6046.9636cm-1 There is a strong absorption characteristic of laser absorption nearby, with a line strength of 1.486E-21cm / mol, while CO2 and H2O have very weak absorption of laser near this frequency. The wavelength of the second telemetry beam can be 1653.7nm, which is an invisible laser. The absorption characteristic of the beam of this wavelength is that it will only be absorbed by methane and not by other gases. Therefore, the interference of other gas components on the measurement of spatial methane concentration can be reduced, and the accuracy, reliability and stability of the spatial methane concentration measurement of the present application scheme are good.

[0086] Please continue to see Figure 5 The laser ranging module 120 includes: a second optical transmitting unit 122 and a second optical receiving unit 124 .

[0087] In one embodiment, the second optical transmitting unit 122 and the second optical receiving unit 124 can be independently provided in the laser ranging module 120. The second optical transmitting unit 122 is used to transmit the laser ranging beam to the reflection module, and the reflection module reflects the laser ranging beam to the second optical receiving unit 124, and the second optical receiving unit 124 is used to receive the laser ranging beam.

[0088] The laser ranging beam includes: a first ranging beam and a second ranging beam, the first ranging beam is a visible light beam, and the first ranging beam is parallel to the first telemetry beam. Since the first telemetry beam is a collimated visible light beam and is perpendicular to the reflection module, the first ranging beam and the first telemetry beam are parallel and can also make the first ranging beam perpendicular to the reflection module, which is convenient for measuring spatial distance.

[0089] Please continue to see Figure 5 The second optical transmitting unit 122 includes: a third laser probe G3 and a fourth laser probe G4, and the second optical receiving unit 124 includes a second detector T2.

[0090] In one embodiment, the third laser probe G3, the fourth laser probe G4 and the second detector T2 can be independently arranged in the laser ranging module 120. The third laser probe G3 is used to emit a first ranging beam to the reflection module, and the first ranging beam is used to mark a second marking point of the first ranging beam on the reflection module, and the second marking point is visible to the naked eye, so as to facilitate the determination of the position where the second ranging beam is incident on the reflection module.

[0091] In one embodiment, the fourth laser probe G4 is used to emit a second ranging beam to the reflection module, the second ranging beam is incident on the same position as the second marking point, and the reflection module reflects the second ranging beam to the second detector T2.

[0092] Among them, the second ranging beam can be a beam with a wavelength of 1535nm, which is an invisible laser, different from the 960nm or 1064nm laser used in conventional laser ranging systems. The human eye safety threshold of the laser in the 1535nm band is two orders of magnitude higher than that of the laser in the band near 1000nm, which has the advantage of human eye safety. In addition to the advantage of human eye safety, the spatial transmission attenuation of the laser in the 1535nm band is low, and the anti-interference ability is stronger under harsh working conditions (such as high dust, high humidity and other environments), which is more suitable for spatial ranging in the return air shaft of coal mines.

[0093] See also Figure 6 , Figure 6 It is a right view of the adaptive ranging methane concentration laser remote sensing device 100 provided in the embodiment of the present application. With the side of the dual-wavelength filter window as the right side, it can be seen through the dual-wavelength filter window that the adaptive ranging methane concentration laser remote sensing device 100 includes: a methane concentration laser remote sensing module 110 and a laser ranging module 120. The methane concentration laser remote sensing module 110 includes: a first laser probe G1, a second laser probe G2 and a first detector T1. The laser ranging module 120 includes: a third laser probe G3, a fourth laser probe G4 and a second detector T2.

[0094] The laser ranging module 120 of the methane concentration laser telemetry device 100 with adaptive ranging provided by the embodiment of the present application can perform adaptive ranging. When the methane concentration laser telemetry device 100 with adaptive ranging encounters vibration, angle change, etc., the spatial distance can be calibrated in time to reduce the probability of distance error caused by spatial angle adjustment, thereby improving the accuracy of methane concentration measurement, and the methane concentration can be measured by using the methane concentration laser telemetry beam without the need for methane to enter the interior of the methane concentration laser telemetry device 100 with adaptive ranging, thereby accelerating the response speed of the methane concentration measurement and being able to reflect the trend of methane concentration changes in real time. The laser telemetry technology is used to measure the methane concentration, replacing the catalytic combustion, thermal conductivity, optical interference and other measurement technologies used by the fixed methane sensors for safety warning and alarm in traditional mines. The methane concentration laser telemetry device 100 with adaptive ranging has high sensitivity and low detection limit detection performance, and can be applied to low-concentration methane measurement and methane emission measurement in low-gas mine environments.

[0095] In addition, by using the methane gas mass in the linear path in space as the measurement sample of the line-integrated spatial methane concentration CL, instead of the penetration-type single-point measurement method of the fixed methane sensor, the representativeness of the spatial methane concentration can be enhanced, and it can be used as an important parameter for the measurement of methane emissions, thereby making the measurement of methane emissions more accurate. The wavelength of the second telemetry beam can be 1653.7nm, which is an invisible laser. The absorption characteristic of the beam of this wavelength is that it will only be absorbed by methane, but not by other gases. Therefore, the interference of other gas components on the measurement of spatial methane concentration can be reduced. The accuracy, reliability and stability of the spatial methane concentration measurement of the present application scheme are good, and it has strong ease of use and practicality.

[0096] See also Figure 7 , Figure 7 Schematic diagram of the steps of the methane concentration laser remote sensing method with adaptive ranging provided by the embodiment of the present application. The method is implemented based on the methane concentration laser remote sensing device 100 with adaptive ranging, such as Figure 7 As shown, the method may include the following steps:

[0097] S701 , based on the methane concentration laser telemetry module 110 , the line-integrated spatial methane concentration CL is measured according to the methane concentration laser telemetry beam, and the line-integrated spatial methane concentration CL is output to the intrinsically safe main control communication module 130 .

[0098] In one embodiment, when measuring the line-integrated spatial methane concentration CL, TDLAS remote sensing measurement technology may be used for measurement.

[0099] Combination Figure 4 and Figure 5 In one embodiment, the methane concentration laser telemetry module 110 includes: a first optical transmitting unit 112 and a first optical receiving unit 114. The first optical transmitting unit 112 includes: a first laser probe G1 and a second laser probe G2, and the first optical receiving unit 114 includes a first detector T1. The methane concentration laser telemetry beam includes: a first telemetry beam and a second telemetry beam.

[0100] According to an embodiment of the present application, based on the methane concentration laser telemetry module 110, measuring the line-integrated spatial methane concentration CL according to the methane concentration laser telemetry beam, the following steps may be included:

[0101] Based on the first laser probe G1, a first telemetry beam is emitted to the reflection module, and the first telemetry beam is used to mark the measurement path and the first marking point of the first telemetry beam on the reflection module; based on the second laser probe G2, a second telemetry beam is emitted, and the second telemetry beam is incident on the same position as the first marking point, and the reflection module reflects the second telemetry beam into the first detector T1; based on the first detector T1, the optical signal of the second telemetry beam is converted into an electrical signal.

[0102] Based on the methane concentration laser telemetry module 110, the absorption characteristic spectrum line of methane after absorbing laser is obtained according to the electrical signal converted from the optical signal of the second telemetry light beam; based on the methane concentration laser telemetry module 110, the electrical signal converted from the optical signal of the second telemetry light beam is fitted and normalized to obtain the peak height of the absorption characteristic spectrum line, and the line-integrated spatial methane concentration CL is inverted according to the peak height.

[0103] In one embodiment, the optical signal of the second telemetry beam is a scanning signal, which is a signal obtained by scanning a laser with a wavelength of 1653-1655 nm, and the scanning signal can be converted into an electrical signal. The characteristic absorption laser wavelength of methane is 1653.7 nm, and by quickly tuning the laser wavelength, a single vibration or rotation energy level absorption characteristic spectrum of a methane molecule can be directly obtained.

[0104] It should be noted that the inversion of the line-integrated spatial methane concentration CL according to the peak height is performed by a main control board (not shown in the figure) in the methane concentration laser telemetry module 110. The main control board is integrated with a controller, which can be a control chip, such as a single-chip microcomputer or an MCU (Micro Controller Unit).

[0105] The laser intensity before and after being absorbed by methane is related to parameters such as methane pressure, temperature and concentration. The specific relationship is as follows:

[0106]

[0107] Among them, τ(v) represents the transmittance, I t represents the reflected laser intensity, I0 represents the incident laser intensity, exp represents the natural exponential function, P represents the total pressure of methane, X represents the concentration of methane, L represents the effective absorption path, S(T) represents the intensity of the absorbed laser of methane at temperature T; Φ(v) is a function of the characteristic absorption spectrum of methane and satisfies α(v) represents the spectral absorbance.

[0108] In one embodiment, the main control board of the methane concentration laser telemetry module 110 performs fitting normalization on the electrical signal converted from the optical signal of the second telemetry beam to obtain the peak height of the absorption characteristic spectrum line. During the fitting normalization, the normalization calculation can be uniformly performed based on the methane thickness of 1m.

[0109] In one embodiment, according to the Beer-Lamber law, the relationship between the incident laser intensity and the reflected laser intensity and the line-integrated spatial methane concentration CL is as follows:

[0110]

[0111] Where CL is the line-integrated spatial methane concentration, α(v) represents the spectral absorptivity, I0(v) represents the incident laser intensity, and I t (v) represents the reflected laser intensity.

[0112] According to the above two formulas, the line-integrated spatial methane concentration CL is proportional to the peak height of the absorption characteristic spectrum line, and the specific ratio is determined by the line intensity of the methane absorption laser. Therefore, the main control board of the methane concentration laser telemetry module 110 can reversely infer the line-integrated spatial methane concentration CL based on the peak height of the absorption characteristic spectrum line.

[0113] S702, based on the laser ranging module 120, while the methane concentration laser telemetry module 110 measures the line-integrated spatial methane concentration CL, the spatial distance from the adaptively ranging methane concentration laser telemetry device 100 to the reflection module and the effective absorption optical path of the methane absorption laser are measured according to the laser ranging beam, and the spatial distance and the effective absorption optical path are output to the intrinsically safe main control communication module 130.

[0114] Combination Figure 4 and Figure 5 The laser ranging module 120 includes: a second optical emitting unit 122 and a second optical receiving unit 124, the second optical emitting unit 122 includes: a third laser probe G3 and a fourth laser probe G4, the second optical receiving unit 124 includes a second detector T2, and the laser ranging beam includes: a first ranging beam and a second ranging beam.

[0115] According to an embodiment of the present application, based on the laser ranging module 120, while the methane concentration laser telemetry module 110 measures the line-integrated spatial methane concentration CL, the spatial distance from the methane concentration laser telemetry device 100 to the reflection module is measured according to the laser ranging beam. The following steps may be included:

[0116] Based on the third laser probe G3, a first ranging beam is emitted to the reflection module, and the first ranging beam is used to mark a second marking point of the first ranging beam on the reflection module; based on the fourth laser probe G4, a second ranging beam is emitted, and the second ranging beam is incident on the same position as the second marking point, and the reflection module reflects the second ranging beam to the second detector T2; based on the laser ranging module 120, the spatial distance is calculated according to the pulse laser ranging equation;

[0117] Among them, the formula of the pulse laser ranging equation is as follows:

[0118]

[0119] Among them, Pr is the receiving power of the second detector T2, Pt is the transmitting power of the second optical transmitting unit 122, Kt is the transmittance of the second optical transmitting unit 122, Kr is the transmittance of the second optical receiving unit 124, A is the radius of the receiving objective lens (not shown in the figure) of the second optical receiving unit 124, ρ is the target reflection coefficient, R is the spatial distance, K is the ratio of the target area to the spot area, α is the atmospheric attenuation coefficient, and e is a real number (≈2.71828).

[0120] It should be noted that the calculation of the spatial distance is performed by a main control board (not shown in the figure) in the laser ranging module 120 .

[0121] According to another embodiment of the present application, based on the laser ranging module 120, while the methane concentration laser telemetry module 110 measures the line-integrated spatial methane concentration CL, the spatial distance from the methane concentration laser telemetry device 100 to the reflection module is measured according to the laser ranging beam. The following steps may be included:

[0122] Based on the third laser probe G3, a first ranging beam is emitted to the reflection module, and based on the fourth laser probe G4, a second ranging beam is emitted, and the reflection module reflects the second ranging beam to the second detector T2; based on the laser ranging module 120, the phase difference between the optical signal when the second ranging beam is emitted and the optical signal after the second ranging beam is received and reflected is calculated, as well as the time difference between emitting the second ranging beam and receiving the reflected second ranging beam; based on the laser ranging module 120, the product of the phase difference and the time difference is used as the spatial distance.

[0123] In one embodiment, the optical signal of the emitted second ranging light beam may be modulated, and then the spatial distance may be calculated according to the time phase relationship based on the theory of the invariance of the speed of light.

[0124] S703, based on the intrinsically safe main control communication module 130, in a preset measurement mode, a target methane concentration C is calculated based on the line-integrated spatial methane concentration CL and the spatial distance or the effective absorption optical path, and the target methane concentration C is output to a host computer.

[0125] In some embodiments, under different preset measurement modes, the intrinsically safe main control communication module 130 can calculate the target methane concentration C based on the line-integrated spatial methane concentration CL and the spatial distance; the intrinsically safe main control communication module 130 can also calculate the target methane concentration C based on the line-integrated spatial methane concentration CL and the effective absorption optical path, and finally achieve high-precision measurement of low methane concentration in the return air shaft tunnel space of the coal mine.

[0126] Among them, the preset measurement modes include: open space measurement mode and fixed closed space measurement mode. Open spaces include the return air shaft tunnel in coal mines, and fixed closed spaces include calibration chambers (such as closed optical calibration pools) or closed standard transparent air bags. In the open space measurement mode, methane is distributed in the entire space, and the methane thickness is equal to the effective absorption optical path and equal to the spatial distance, that is, the laser transmission length; in the fixed closed space measurement mode, the methane thickness is equal to the length of the fixed closed space, and the effective absorption optical path is equal to the methane thickness in the fixed closed space, but not equal to the spatial distance. The methane thickness can be obtained by measurement.

[0127] According to an embodiment of the present application, based on the intrinsically safe main control communication module 130, in a preset measurement mode, the target methane concentration C is calculated based on the line-integrated spatial methane concentration CL and the spatial distance or the effective absorption optical path, which may include the following steps:

[0128] Based on the intrinsically safe main control communication module 130, in the open space measurement mode, the target methane concentration C is calculated based on the line-integrated spatial methane concentration CL and the spatial distance; or in the fixed closed space measurement mode, the target methane concentration C is calculated based on the line-integrated spatial methane concentration CL and the effective absorption optical path.

[0129] In one embodiment, in the open space measurement mode, the target methane concentration C is obtained by dividing the line-integrated spatial methane concentration CL by the spatial distance based on the intrinsically safe main control communication module 130 .

[0130] In another embodiment, in the fixed closed space measurement mode, the target methane concentration C is obtained by dividing the line-integrated spatial methane concentration CL by the effective absorption optical path based on the intrinsically safe main control communication module 130 .

[0131] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0132] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0133] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An adaptive ranging methane concentration laser remote sensing device, characterized in that: The device comprises: a methane concentration laser telemetry module, a laser distance measurement module and an intrinsically safe main control communication module; The output end of the methane concentration laser telemetry module is connected to the input end of the intrinsically safe main control communication module, and the methane concentration laser telemetry module is used to measure the line-integrated spatial methane concentration based on the methane concentration laser telemetry beam, and output the line-integrated spatial methane concentration to the intrinsically safe main control communication module; The output end of the laser distance measuring module is connected to the input end of the intrinsically safe main control communication module. The laser distance measuring module is used to measure the spatial distance from the device to the reflection module and the effective absorption optical path of the methane absorption laser based on the laser distance measuring beam while the methane concentration laser telemetry module measures the line-integrated spatial methane concentration, and output the spatial distance and the effective absorption optical path to the intrinsically safe main control communication module; The output end of the intrinsically safe main control communication module is connected to the host computer through a communication interface. The intrinsically safe main control communication module is used to calculate the target methane concentration based on the line-integrated spatial methane concentration and the spatial distance or the effective absorption optical path in a preset measurement mode, and output the target methane concentration to the host computer.

2. The methane concentration laser remote sensing device with adaptive ranging according to claim 1 is characterized in that: The methane concentration laser telemetry module comprises: a first optical transmitting unit and a first optical receiving unit; The first optical transmitting unit is used to transmit a methane concentration laser telemetry beam to the reflection module, and the reflection module reflects the methane concentration laser telemetry beam to the first optical receiving unit; the first optical receiving unit is used to receive the methane concentration laser telemetry beam and convert the optical signal of the methane concentration laser telemetry beam into an electrical signal.

3. The adaptive ranging methane concentration laser remote sensing device according to claim 2 is characterized in that: The first optical transmitting unit includes: a first laser probe and a second laser probe, the first optical receiving unit includes a first detector, the methane concentration laser telemetry beam includes: a first telemetry beam and a second telemetry beam, and the first telemetry beam is a collimated visible light beam; The first laser probe is used to emit a first telemetry beam to the reflection module, and the first telemetry beam is used to mark the measurement path and the first marking point of the first telemetry beam on the reflection module; the second laser probe is used to emit a second telemetry beam to the reflection module, and the second telemetry beam is incident on the same position as the first marking point, and the reflection module reflects the second telemetry beam into the first detector.

4. The methane concentration laser remote sensing device with adaptive ranging according to claim 1 is characterized in that: The laser ranging module comprises: a second optical transmitting unit and a second optical receiving unit; The second optical transmitting unit is used to transmit a laser ranging beam to the reflecting module, and the reflecting module reflects the laser ranging beam to the second optical receiving unit, and the second optical receiving unit is used to receive the laser ranging beam.

5. The adaptive ranging methane concentration laser remote sensing device according to claim 4 is characterized in that: The second optical transmitting unit includes: a third laser probe and a fourth laser probe, the second optical receiving unit includes a second detector, the laser ranging beam includes: a first ranging beam and a second ranging beam, the first ranging beam is a visible light beam, and the first ranging beam is parallel to the first telemetry beam; The third laser probe is used to emit a first ranging beam to the reflection module, and the first ranging beam is used to mark a second marking point of the first ranging beam on the reflection module; the fourth laser probe is used to emit a second ranging beam to the reflection module, and the second ranging beam is incident on the same position as the second marking point, and the reflection module reflects the second ranging beam into the second detector.

6. A methane concentration laser remote sensing method with adaptive ranging, characterized in that: The methane concentration laser telemetry device based on the adaptive ranging described in any one of claims 1 to 5 is implemented, and the method comprises: Based on the methane concentration laser telemetry module, the line-integrated spatial methane concentration is measured according to the methane concentration laser telemetry beam, and the line-integrated spatial methane concentration is output to the intrinsically safe main control communication module; Based on the laser ranging module, while the methane concentration laser telemetry module measures the line-integrated spatial methane concentration, the spatial distance from the device to the reflection module and the effective absorption optical path of the methane absorption laser are measured according to the laser ranging beam, and the spatial distance and the effective absorption optical path are output to the intrinsically safe main control communication module; Based on the intrinsically safe main control communication module, a target methane concentration is calculated based on the line-integrated spatial methane concentration and based on the spatial distance or the effective absorption optical path in a preset measurement mode, and the target methane concentration is output to a host computer.

7. The adaptive ranging methane concentration laser remote sensing method according to claim 6 is characterized in that: The methane concentration laser telemetry module comprises: a first optical transmitting unit and a first optical receiving unit, the first optical transmitting unit comprises: a first laser probe and a second laser probe, the first optical receiving unit comprises a first detector, and the methane concentration laser telemetry beam comprises: a first telemetry beam and a second telemetry beam; based on the methane concentration laser telemetry module, the methane concentration of the line-integrated space is measured according to the methane concentration laser telemetry beam, including: Based on the first laser probe, a first telemetry beam is emitted to the reflection module, where the first telemetry beam is used to mark a measurement path and a first marking point of the first telemetry beam on the reflection module; Based on the second laser probe emitting a second telemetry beam, the second telemetry beam is incident on the same position as the first marking point, and the reflection module reflects the second telemetry beam into the first detector; converting an optical signal of a second telemetry light beam into an electrical signal based on the first detector; Based on the methane concentration laser telemetry module, an absorption characteristic spectrum line of methane after absorbing laser light is obtained according to an electrical signal converted from an optical signal of the second telemetry light beam; Based on the methane concentration laser telemetry module, the electrical signal converted from the optical signal of the second telemetry light beam is fitted and normalized to obtain the peak height of the absorption characteristic spectrum line, and the line-integrated spatial methane concentration is inverted according to the peak height.

8. The adaptive ranging methane concentration laser remote sensing method according to claim 6, characterized in that: The laser ranging module comprises: a second optical transmitting unit and a second optical receiving unit, the second optical transmitting unit comprises: a third laser probe and a fourth laser probe, the second optical receiving unit comprises a second detector, and the laser ranging beam comprises: a first ranging beam and a second ranging beam; based on the laser ranging module, the methane concentration laser telemetry module measures the line-integrated spatial methane concentration while measuring the spatial distance from the device to the reflection module according to the laser ranging beam, including: Based on the third laser probe, a first ranging beam is emitted to the reflection module, where the first ranging beam is used to mark a second marking point of the first ranging beam on the reflection module; Based on the fourth laser probe emitting a second ranging beam, the second ranging beam is incident on the same position as the second marking point, and the reflection module reflects the second ranging beam into the second detector; Based on the laser ranging module, the spatial distance is calculated according to the pulse laser ranging equation; Among them, the formula of the pulse laser ranging equation is as follows: Wherein, Pr is the receiving power of the second detector, Pt is the transmitting power of the laser ranging module, Kt is the transmittance of the second optical transmitting unit, Kr is the transmittance of the second optical receiving unit, A is the radius of the receiving objective lens of the second optical receiving unit, ρ is the target reflection coefficient, R is the spatial distance, K is the ratio of the target area to the spot area, α is the atmospheric attenuation coefficient, and e is a real number (≈2.71828).

9. The adaptive ranging methane concentration laser remote sensing method according to claim 8, characterized in that: Based on the laser ranging module, the methane concentration laser telemetry module measures the line-integrated spatial methane concentration while measuring the spatial distance from the device to the reflection module according to the laser ranging beam, including: Based on the third laser probe, a first ranging beam is emitted to the reflection module, based on the fourth laser probe, a second ranging beam is emitted, and the reflection module reflects the second ranging beam to the second detector; Based on the laser ranging module, the phase difference between the optical signal when the second ranging beam is emitted and the optical signal after the second ranging beam is reflected, as well as the time difference between emitting the second ranging beam and receiving the reflected second ranging beam are calculated; Based on the laser ranging module, the product of the phase difference and the time difference is used as the spatial distance.

10. The adaptive ranging methane concentration laser remote sensing method according to claim 9, characterized in that: The preset measurement modes include: an open space measurement mode and a fixed closed space measurement mode; in the open space measurement mode, the effective absorption optical path is equal to the spatial distance, and in the fixed closed space measurement mode, the effective absorption optical path is equal to the methane thickness in the fixed closed space; based on the intrinsically safe main control communication module, the target methane concentration is calculated based on the line integral spatial methane concentration and the spatial distance or the effective absorption optical path in the preset measurement mode, including: Based on the intrinsically safe main control communication module, in an open space measurement mode, the target methane concentration is calculated according to the line-integrated spatial methane concentration and the spatial distance; or In a fixed closed space measurement mode, the target methane concentration is calculated based on the line-integrated spatial methane concentration and the effective absorption optical path.

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