Double-light-path gas detection alarm device based on intermediate infrared SLD

Abstract

The invention discloses a dual-optical-path gas detection alarm device based on an intermediate infrared SLD, and relates to the technical field of gas safety monitoring and alarm, in particular to the dual-optical-path gas detection alarm device based on the intermediate infrared SLD. In order to solve the problems that an existing gas alarm device is high in false alarm rate and delayed in response, and cannot realize multi-component gas concentration threshold value judgment and sound-light alarm linkage at the same time, the invention provides a dual-light-path gas detection alarm device based on an intermediate infrared SLD. Comprising an SLD light source module, an optical beam splitting and transmission module, a multi-reflection gas absorption cell, a main tunable filter array, a main photoelectric detector array, a reference tunable filter array, a reference photoelectric detector array, a differential amplifier array, a signal processing module, a display module and an alarm module. The method is suitable for the application fields of petroleum, natural gas, mining, underground space operation and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of gas safety monitoring and alarm, and in particular to a dual-light-path gas detection and alarm device based on mid-infrared SLD. Background Art

[0002] With the rapid growth of industrial automation, urbanization, and environmental regulation, real-time detection and alarm technologies for gas leaks and excessive emissions are playing an increasingly important role in environmental monitoring, industrial safety, energy management, and other fields. Currently, mainstream gas detection and alarm devices include electrochemical sensors, catalytic combustion sensors, and infrared spectroscopy detection systems.

[0003] Although electrochemical and catalytic combustion sensors are low in cost, they are susceptible to cross-interference and temperature and humidity fluctuations in complex multi-component gas environments, resulting in a high false alarm rate. In addition, electrochemical and catalytic combustion sensors rely on chemical reactions or combustion thermal effects to detect gases, and their response speed is usually greater than 10 seconds. The slow response speed makes it difficult for electrochemical and catalytic combustion sensors to meet the needs of rapid alarm in high-risk scenarios.

[0004] Traditional infrared spectroscopy alarm devices, first of all, usually adopt a single optical path design, which cannot eliminate light source fluctuations or ambient light interference, resulting in concentration inversion errors, which directly affects the reliability of the alarm threshold; secondly, traditional infrared spectroscopy alarm devices rely on software algorithms to determine the alarm threshold, and their data processing delay is generally greater than 2 seconds, which cannot achieve hardware-level real-time response; thirdly, most existing infrared spectroscopy alarm devices lack multi-level alarm linkage functions, making it difficult to meet industrial safety standards.

[0005] In recent years, mid-infrared wide spectrum detection technology has gradually become a research hotspot. ) covers The absorption intensity of the fundamental frequency absorption region of various key industrial gases is about three orders of magnitude higher than that of traditional infrared spectroscopy, which can achieve lower detection limits and higher detection accuracy. Among them, the mid-infrared superradiant laser, with its wide spectral output, high brightness and low coherence characteristics, can detect the characteristic absorption peaks of multiple gases in parallel under a single light source, and effectively suppress the background noise caused by interference fringes, significantly improving the system signal-to-noise ratio. However, the mid-infrared superradiant laser itself has the problem of output power fluctuations and overlap with the absorption spectrum of different gases. Without synchronous calibration and high-resolution spectral separation, it will still cause a decrease in concentration inversion accuracy and cross-interference; in addition, factors such as ambient temperature changes or mechanical vibrations may also cause signal baseline drift, increasing the system's dependence on back-end algorithm correction, which is not conducive to long-term stable operation under dynamic or harsh working conditions.

[0006] Existing gas alarm devices mostly use electrochemical or catalytic combustion sensors, which have problems such as high false alarm rates and response delays. Especially in the gas characteristic absorption detection scenario in the mid-infrared band, there is a lack of solutions that can simultaneously realize multi-component gas concentration threshold determination and sound and light alarm linkage. Summary of the Invention

[0007] In order to solve the problems of high false alarm rate and response delay in existing gas alarm devices, as well as the lack of the ability to simultaneously determine the concentration threshold of multiple gas components and implement sound and light alarm linkage, the present invention proposes a dual-optical path gas detection and alarm device based on mid-infrared SLD. The specific scheme is as follows: A dual-light-path gas detection and alarm device based on mid-infrared SLD, the device comprising: SLD light source module, used to generate infrared wide spectrum light path and send it to the optical beam splitting and transmission module; An optical beam splitting and transmission module, configured to split the received infrared wide spectrum light path into a main light path and a reference light path, and transmit the main light path to a multi-reflection gas absorption cell, and transmit the reference light path to a reference tunable filter array; The multi-reflection gas absorption cell is connected to the detection area and is used to output the main light path to the main tunable filter array after multiple interactions with the gas to be measured; The main tunable filter array is used to perform dynamic narrowband filtering on the main light path output from the multi-reflection gas absorption cell according to the central wavelength of the characteristic absorption peak of the gas to be measured, decompose it into multiple independent narrowband light signals, and transmit them to the optical signal input end of the main photodetector array; a main photodetector array, configured to convert a received narrowband optical signal into a first electrical signal and transmit the first electrical signal to a differential amplifier array; A reference tunable filter array is used to dynamically narrowband filter the received reference light path, decompose it into multiple independent narrowband optical signals, and transmit them to the optical signal input end of the reference photodetector array; a reference photodetector array, configured to convert a received narrowband optical signal into a second electrical signal and transmit the second electrical signal to the differential amplifier array; A differential amplifier array, configured to perform real-time differential amplification on the first electrical signal and the second electrical signal, and output the differential signal to the signal processing module; The signal processing module is used to perform baseline correction, concentration inversion algorithm calculation and adaptive calibration decision on the received differential signal, obtain the concentration value of the gas component to be measured and send it to the display module; it is also used to generate alarm information based on the gas component to be measured and send the alarm information to the alarm module; The display module is used to display the concentration value of the gas component to be measured in real time on the screen in the form of numbers or curves; The alarm module is used to send out sound and light alarm signals according to the received alarm information.

[0008] Furthermore, the central wavelength range of the mid-infrared wide spectrum light path emitted by the SLD light source module is , spectral bandwidth .

[0009] Furthermore, the optical beam splitting and transmission module uses double-clad mid-infrared optical fiber, and the optical fiber attenuation , built-in optical isolator.

[0010] Furthermore, the multi-reflection gas absorption cell is composed of at least four surfaces with reflectivity The effective optical path in the cavity is , in order to increase the distance of the main light path in the gas to be measured.

[0011] Furthermore, the main tunable filter array and the reference tunable filter array are both implemented using MEMS tunable filter units, and the central wavelength of the tunable filter units is Adjustable within , and built-in temperature compensation mechanism, filtering characteristics in Drift within range .

[0012] Furthermore, the main photodetector array and the reference photodetector array are both implemented using high-sensitivity MCT detectors, and the detection responsivity of the detectors is , noise equivalent power .

[0013] Furthermore, each differential amplifier in the differential amplifier array has Adjustable gain and High common mode rejection ratio and built-in filter.

[0014] Furthermore, the signal processing module is embedded with an alarm judgment algorithm unit implemented by a computer program, which is used to generate alarm information based on the gas component to be measured; the alarm judgment algorithm unit is also used to compare the concentration value of the gas component to be measured with a preset threshold in real time, and is also used to generate alarm information when the comparison result is "greater than".

[0015] Furthermore, the display module is a touch-sensitive color LCD screen with a resolution of .

[0016] Furthermore, the device also includes a temperature stabilization module for performing constant temperature control on the SLD light source module, the main tunable filter array, the main photodetector array, the reference tunable filter array and the reference photodetector array.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention discloses a dual-optical path gas detection and alarm device based on a mid-infrared SLD. This device uses a wavelength-splitting dual-optical path physical isolation structure to simultaneously feed the SLD light source output into both the main and reference optical paths. A high-CMRR differential amplifier array directly outputs differential signals, enabling real-time differential processing of the absorption signals from the main and reference optical paths at the hardware level. This avoids the response lag associated with decision delays in traditional software algorithms, enabling the device to respond extremely quickly to exceeding gas concentration limits, shortening alarm delays and improving the timeliness of early warnings for gas leaks or excessive emissions in high-risk scenarios, effectively reducing accident risks.

[0018] 2. The dual-path gas detection and alarm device based on a mid-infrared SLD described in this invention effectively offsets the effects of the SLD's inherent power fluctuations and ambient light interference on measurement results, ensuring long-term stability of the signal baseline. This fundamentally addresses the large concentration inversion errors and inaccurate alarm thresholds associated with traditional single-path systems. Combined with the high absorption intensity of the mid-infrared band, the device achieves a lower detection limit and higher measurement accuracy, significantly reducing false alarm and missed alarm rates and improving the reliability of the alarm system.

[0019] 3. The dual-path gas detection and alarm device based on a mid-infrared SLD, described in this invention, leverages the wide spectral characteristics of the mid-infrared SLD, combined with a tunable filter array, to achieve parallel detection of multiple key gases, including carbon dioxide, carbon monoxide, methane, and nitrous oxide, while effectively separating overlapping interference between different gas absorption bands. Furthermore, an embedded alarm decision algorithm and independent alarm modules provide real-time audible and visual alarms based on preset thresholds for different gases, and a multi-level alarm linkage interface is reserved to meet the needs of simultaneous multi-gas monitoring and graded response in complex industrial scenarios.

[0020] 4. The dual-optical path gas detection and alarm device based on a mid-infrared SLD (SLD) described in this invention effectively mitigates the impact of temperature fluctuations on system performance by maintaining constant temperature for core optoelectronic components, including the SLD light source module, tunable filter array, and photodetector array. Combined with a double-clad mid-infrared fiber (with a built-in optical isolator) and the high common-mode rejection ratio of a differential amplifier, the device exhibits excellent resistance to electromagnetic interference and mechanical vibration, ensuring long-term stable operation and measurement repeatability in harsh industrial environments, while reducing ongoing maintenance costs.

[0021] 5. The dual-optical-path gas detection and alarm device based on a mid-infrared SLD, described in this invention, achieves a more compact structure and reduced system complexity while maintaining high accuracy through optimized optical paths and modular design. This allows the device to be more easily integrated into existing security monitoring systems or used as a standalone portable device, making it suitable for a wider range of applications, particularly those requiring large-scale, multi-point deployment in gas safety monitoring networks.

[0022] This invention can detect and alarm for leaks of flammable and toxic gases such as methane, hydrogen sulfide, and carbon monoxide in oil and gas fields, gas pipelines, refineries, liquefied natural gas (LNG) receiving stations, and drilling platforms, ensuring production safety. It can also provide real-time monitoring and alarm for excessive levels of gas, carbon monoxide, and carbon dioxide in coal mines and underground spaces, preventing accidents such as gas explosions and asphyxiation, and ensuring safe mine operations. It is suitable for applications in oil, gas, mining, and underground space operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural schematic diagram of a dual-optical-path gas detection and alarm device based on a mid-infrared SLD as described in embodiment 1, with the accompanying drawings marked with: SLD light source module 1, optical beam splitting and transmission module 2, multi-reflection gas absorption cell 3, main tunable filter array 4, main photodetector array 5, reference tunable filter array 6, reference photodetector array 7, differential amplifier array 8, signal processing module 9, display module 10, and alarm module 11. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] Implementation Method 1 like Figure 1 As shown, a dual-light-path gas detection and alarm device based on mid-infrared SLD includes: SLD light source module 1 is used to generate infrared wide spectrum light path and send it to optical beam splitting and transmission module 2; The optical beam splitting and transmission module 2 is used to split the received infrared wide spectrum light path into a main light path and a reference light path, and transmit the main light path to the multi-reflection gas absorption cell 3 and transmit the reference light path to the reference tunable filter array 6; The multi-reflection gas absorption cell 3 is connected to the detection area and is used to output the main light path to the main tunable filter array 4 after multiple interactions with the gas to be measured; The main tunable filter array 4 is used to perform dynamic narrowband filtering on the main light path output from the multi-reflection gas absorption cell 3 according to the central wavelength of the characteristic absorption peak of the gas to be measured, decompose it into multiple independent narrowband light signals, and transmit them to the optical signal input end of the main photodetector array 5; a main photodetector array 5, configured to convert the received narrowband optical signal into a first electrical signal and transmit the first electrical signal to the differential amplifier array 8; The reference tunable filter array 6 is used to perform dynamic narrowband filtering on the received reference light path, decompose it into multiple independent narrowband optical signals, and transmit them to the optical signal input end of the reference photodetector array 7; a reference photodetector array 7 for converting the received narrowband optical signal into a second electrical signal and transmitting the second electrical signal to a differential amplifier array 8; A differential amplifier array 8 is configured to perform real-time differential amplification on the first electrical signal and the second electrical signal, and output the differential signal to the signal processing module 9; The signal processing module 9 is used to perform baseline correction, concentration inversion algorithm calculation and adaptive calibration decision on the received differential signal, obtain the concentration value of the gas component to be measured and send it to the display module 10; it is also used to generate alarm information based on the gas component to be measured and send the alarm information to the alarm module 11; The display module 10 is used to display the concentration value of the gas component to be measured in real time on the screen in the form of numbers or curves; The alarm module 11 is used to send out an audible and visual alarm signal according to the received alarm information.

[0026] Furthermore, the preset threshold can be programmed through the touch screen interface of the display module, supporting three threshold storage levels: short-term exposure limit (STEL), time-weighted average (TWA) and immediately life-threatening health concentration (IDLH).

[0027] Furthermore, the alarm module 11 is a multi-level alarm module, comprising: Sound and light alarm submodule: directly linked to the signal processing module 9. When the concentration of the gas component to be measured exceeds the preset threshold, the signal processing module 9 sends an alarm signal to the alarm module 11. After receiving the alarm signal, the alarm module 11 triggers a 105dB buzzer and a flashing red LED. Grading alarm submodule: automatically activates Level I (early warning), Level II (high-risk) alarm, and Level III (evacuation) alarm according to the percentage of concentration exceeding the set threshold; Relay output submodule: provides two sets of passive contacts (normally open / normally closed) that can remotely link ventilation equipment or other safety systems.

[0028] This implementation utilizes a dual-optical path design, leveraging its innovative capability for differential measurement, effectively compensating for common-mode interference such as light source fluctuations, optical path loss, and detector response variations. This significantly improves measurement accuracy and stability, ensuring the reliability of the results. Furthermore, the multi-reflection gas absorption cell significantly enhances detection sensitivity by increasing the optical path. Dynamic narrowband filtering precisely targets characteristic gas absorption peaks, effectively avoiding interference. This implementation also enables real-time concentration display and provides multi-level audible and visual alarms and relay outputs, ensuring flexible and comprehensive safety warnings and external linkage control.

[0029] Implementation Method 2 This embodiment is a further limitation of the first embodiment. Further, the central wavelength range of the mid-infrared wide spectrum light path emitted by the SLD light source module 1 is , spectral bandwidth .

[0030] This embodiment uses the central wavelength , spectral bandwidth The beneficial effect of the mid-infrared SLD light source is that it covers the strong absorption bands of multiple key gases (such as hydrocarbons, carbon monoxide and carbon dioxide, etc.), giving the device the ability to detect multiple gases simultaneously or flexibly detect different gases by replacing filters, greatly improving the versatility and application range of the device.

[0031] Implementation Method 3 This embodiment is a further limitation of the embodiment 1. Furthermore, the optical beam splitting and transmission module 2 adopts double-clad mid-infrared optical fiber, and the optical fiber attenuation , built-in optical isolator.

[0032] This embodiment uses double-clad mid-infrared optical fiber (attenuation ) and built-in optical isolator. The optical fiber can significantly reduce the loss of optical signal transmission, ensuring sufficient light energy to reach the detector and improving signal quality. The built-in optical isolator effectively suppresses the interference caused by back reflection, ensuring the stable and efficient transmission of the infrared light path, thereby comprehensively improving the overall performance of the system.

[0033] Implementation Method 4 This embodiment is a further limitation of the first embodiment. Further, the multi-reflection gas absorption cell 3 is composed of at least four sides with reflectivity. The effective optical path in the cavity is , in order to increase the distance of the main light path in the gas to be measured.

[0034] This embodiment further defines a multi-reflection gas absorption cell, using at least four sides with reflectivity plane reflector and ensure the effective optical path in the cavity By maximizing the distance of the light path in the gas to be tested, the gas absorption signal is effectively amplified, thereby significantly improving the detection sensitivity of the device and enabling more accurate detection of trace or low-concentration gases.

[0035] Implementation Method Five This embodiment is a further limitation of the embodiment 1. Further, the main tunable filter array 4 and the reference tunable filter array 6 are both implemented by MEMS tunable filter units, and the center wavelength of the tunable filter units is Adjustable within , and built-in temperature compensation mechanism, filtering characteristics in Drift within range .

[0036] This embodiment uses a MEMS tunable filter unit with a central wavelength of Adjustable within, bandwidth Features, and built-in temperature compensation mechanism (in Drift within range ), which can achieve accurate dynamic selection of the target absorption wavelength and effective suppression of background noise; at the same time, the temperature compensation mechanism ensures the stability of the filter characteristics in a wide temperature range, thereby ensuring the long-term accuracy and reliability of the measurement results.

[0037] Implementation Method 6 This embodiment is a further limitation of the embodiment 1. Furthermore, the main photodetector array 5 and the reference photodetector array 7 are both implemented using high-sensitivity MCT detectors, and the detection response of the detectors is , noise equivalent power .

[0038] This embodiment uses a high-sensitivity MCT detector (detection response , noise equivalent power ), these detectors have excellent photoelectric conversion efficiency and extremely low noise level, and can reliably capture the changes in weak light signals caused by gas absorption, thereby significantly improving the detection limit and signal-to-noise ratio of the device.

[0039] Implementation Method Seven This embodiment is a further limitation of the first embodiment. Further, each differential amplifier in the differential amplifier array 8 has Adjustable gain and High common mode rejection ratio and built-in filter.

[0040] The differential amplifier array of this embodiment has Adjustable gain and The high common-mode rejection ratio (CMRR) and built-in filter allow for flexible adaptation to varying signal intensities. The high CMRR effectively filters out noise and interference in both the main and reference optical paths, ensuring that only the true absorption signal is amplified, greatly improving measurement accuracy and system stability.

[0041] Implementation Method Eight This embodiment is a further limitation of embodiment one. Furthermore, the signal processing module 9 is embedded with an alarm judgment algorithm unit implemented by a computer program, and the alarm judgment algorithm unit is used to generate alarm information based on the gas component to be measured; the alarm judgment algorithm unit is also used to compare the concentration value of the gas component to be measured with a preset threshold in real time, and is also used to generate an alarm information when the comparison result is "greater than".

[0042] The signal processing module of this embodiment is embedded with an alarm judgment algorithm implemented by a computer program, which can perform real-time intelligent processing of the received differential signal, including baseline correction, concentration inversion and adaptive calibration, and compare the concentration of the gas to be measured with the preset threshold in real time, thereby achieving fast and accurate alarm judgment and decision-making, and improving the intelligence level of the device.

[0043] Implementation Method Nine This embodiment is a further limitation of the first embodiment. Furthermore, the display module 10 is a touch-sensitive color LCD screen with a resolution of .

[0044] The display module of this embodiment adopts a touch-sensitive color LCD screen (resolution ), provides users with a clear, intuitive and interactive graphical user interface, greatly improving the convenience of operation and user experience, allowing users to easily view real-time data and set parameters.

[0045] Implementation Method 10 This embodiment is a further limitation of embodiment one. Furthermore, the device also includes a temperature stabilization module for performing constant temperature control on the SLD light source module 1, the main tunable filter array 4, the main photodetector array 5, the reference tunable filter array 6 and the reference photodetector array 7.

[0046] This embodiment provides a temperature stabilization module to perform constant temperature control on key optoelectronic devices, effectively avoiding the impact of temperature fluctuations on the SLD light source output, filter center wavelength and detector response, thereby improving the long-term stability and measurement repeatability of the overall system.

[0047] The specific technical means further described in the above embodiments 2 to 10 can also be reasonably combined with each other to form new embodiments.

[0048] Implementation Method Eleven This embodiment integrates the technical solutions described in the aforementioned multiple embodiments, combines actual application scenarios and the use process of the computer program product that implements the method described in the present invention, and further verifies and explains the technical effects of the present invention through specific examples.

[0049] A dual-optical gas detection and alarm device based on a mid-infrared SLD addresses issues of light source power stability, multi-component cross-interference, and signal drift in wide-spectrum gas detection through innovative hardware architecture. The system utilizes a wavelength-splitting reference optical path and a multi-channel differential amplifier array for high-precision, real-time detection without algorithmic dependency.

[0050] A dual-optical path gas detection and alarm device based on mid-infrared SLD includes an SLD light source module, an optical beam splitting and transmission module, a multi-reflection gas absorption cell, a main tunable filter array, a main photodetector array, a reference tunable filter array, a reference photodetector array, a differential amplifier array, a signal processing module, a display module, and an alarm module.

[0051] The SLD light source module is responsible for outputting a mid-infrared broad spectrum light beam, the spectral range of which covers the characteristic absorption band of the target gas.

[0052] The optical beam splitting and transmission module divides the SLD output into a main light path and a reference light path through a beam splitter. The main light path passes through a multi-reflection gas absorption cell, utilizing multiple reflections or a long optical path structure to enhance the interaction between the gas and the light wave, while the reference light path is directly guided to a reference tunable filter array through an independent optical fiber transmission channel.

[0053] The main tunable filter array and the reference tunable filter array, the main detector array and the reference detector array are completely matched in terms of the number of spectral channels, central wavelength and detector model, thus ensuring consistency in temperature drift.

[0054] The main tunable filter array and reference tunable filter array, as well as the main detector array and reference photodetector array, can dynamically narrowband filter the broad spectrum of the main optical path according to the preset gas absorption peak center wavelength, decompose the mixed absorption spectrum into multiple independent narrowband channels, and convert the optical signal into an electrical signal through a high-sensitivity photodetector group, effectively solving the problem of broad spectrum overlap interference.

[0055] The differential amplifier array suppresses cross-interference, eliminates common-mode interference, and extracts pure gas absorption signals by independently configuring amplifiers for each gas channel.

[0056] The signal processing module is used to perform baseline correction, concentration inversion algorithm calculation and adaptive calibration decision on the received differential signal, obtain the concentration value of the gas component to be measured and send it to the display module; it is also used to generate alarm information based on the gas component to be measured and send the alarm information to the alarm module; The display module is used to display the concentration value of the gas component to be measured in real time on the screen in the form of numbers or curves; The alarm module is used to issue an audible and visual alarm when the concentration of the gas to be measured exceeds a preset threshold.

[0057] Furthermore, the preset threshold can be programmed through the touch screen interface of the display module, supporting three threshold storage levels: short-term exposure limit (STEL), time-weighted average (TWA) and immediately life-threatening health concentration (IDLH).

[0058] Furthermore, the alarm module is a multi-level alarm module, comprising: Sound and light alarm submodule: directly linked to the signal processing module. When the concentration of the gas component to be measured exceeds the preset threshold, the signal processing module sends an alarm signal to the alarm module. After receiving the alarm signal, the alarm module triggers a 105dB buzzer and a flashing red LED. Grading alarm submodule: automatically activates Level I (early warning), Level II (high-risk) alarm, and Level III (evacuation) alarm according to the percentage of concentration exceeding the set threshold; Relay output submodule: provides two sets of passive contacts (normally open / normally closed) that can remotely link ventilation equipment or other safety systems.

[0059] The alarm control submodule is integrated into the signal processing module, and its workflow includes: receiving a real-time concentration signal output by a differential amplifier array; The concentration value is compared with the stored preset threshold value through FPGA; When the concentration of any gas component exceeds the exposure limit (STEL), the LED indicator light changes from green to yellow and an intermittent alarm (0.5Hz) is sounded through the buzzer; When the concentration of any gas component exceeds the time-weighted average (TWA), the switching LED lights up continuously in red, the buzzer turns to a continuous alarm, and the relay output submodule links the ventilation equipment or other safety systems. When the concentration exceeds the immediately life-threatening health concentration (IDLH), the LED switches to flashing red intermittently (0.5s), the buzzer turns to a long alarm, and the ventilation equipment or other safety systems are linked through the relay output submodule.

[0060] The technical solution provided by the present invention is further described in detail through the above specific embodiments in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the above specific embodiments are not intended to limit the present invention. Any reasonable modification and improvement of the present invention, combination of embodiments and equivalent replacement, etc. based on the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0061] Those skilled in the art will understand that the above description is only a preferred embodiment of the present invention, and the various embodiments disclosed in the present invention and / or the features described in the claims can be combined or coupled in various ways, even if such combinations or couplings are not explicitly described in the disclosure of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0062] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A dual-path gas detection and alarm device based on mid-infrared SLD, characterized in that: The device comprises: An SLD light source module (1) is used to generate an infrared wide-spectrum light path and send it to an optical beam splitting and transmission module (2); An optical beam splitting and transmission module (2) is used to split the received infrared wide spectrum light path into a main light path and a reference light path, and transmit the main light path to a multi-reflection gas absorption cell (3), and transmit the reference light path to a reference tunable filter array (6); The multi-reflection gas absorption cell (3) is connected to the detection area and is used to output the main light path to the main tunable filter array (4) after multiple interactions with the gas to be measured; A main tunable filter array (4) is used to perform dynamic narrowband filtering on the main light path output from the multi-reflection gas absorption cell (3) according to the central wavelength of the characteristic absorption peak of the gas to be measured, decompose it into multiple independent narrowband light signals, and transmit them to the light signal input end of the main photodetector array (5); A main photodetector array (5) is used to convert a received narrowband optical signal into a first electrical signal and transmit the first electrical signal to a differential amplifier array (8); A reference tunable filter array (6) is used to dynamically narrowband filter the received reference light path, decompose it into multiple independent narrowband optical signals, and transmit them to the optical signal input end of the reference photodetector array (7); A reference photodetector array (7) is used to convert the received narrowband optical signal into a second electrical signal and transmit it to a differential amplifier array (8); A differential amplifier array (8) is used to perform real-time differential amplification on the first electrical signal and the second electrical signal, and output the differential signal to a signal processing module (9); A signal processing module (9) is used to perform baseline correction, concentration inversion algorithm calculation and adaptive calibration decision on the received differential signal, obtain the concentration value of the gas component to be measured and send it to the display module (10); and is also used to generate alarm information based on the gas component to be measured and send the alarm information to the alarm module (11); A display module (10) is used to display the received concentration value of the gas component to be measured in real time on the screen in the form of numbers or curves; The alarm module (11) is used to send out an audible and visual alarm signal according to the received alarm information.

2. The device according to claim 1, characterized in that The central wavelength range of the mid-infrared wide spectrum light path emitted by the SLD light source module (1) is , spectral bandwidth .

3. The device according to claim 1, characterized in that The optical beam splitting and transmission module (2) adopts double-clad mid-infrared optical fiber, and the optical fiber attenuation , built-in optical isolator.

4. The device according to claim 1, characterized in that The multi-reflection gas absorption cell (3) is composed of at least four sides with reflectivity The effective optical path in the cavity is , in order to increase the distance of the main light path in the gas to be measured.

5. The device according to claim 1, characterized in that The main tunable filter array (4) and the reference tunable filter array (6) are both implemented using MEMS tunable filter units, the central wavelength of the tunable filter units being Adjustable within , and built-in temperature compensation mechanism, filtering characteristics in Drift within range .

6. The device according to claim 1, characterized in that The main photodetector array (5) and the reference photodetector array (7) are both implemented using high-sensitivity MCT detectors, the detection response of which is , noise equivalent power .

7. The device according to claim 1, characterized in that Each differential amplifier in the differential amplifier array (8) has Adjustable gain and Common mode rejection ratio and built-in filter.

8. The device according to claim 1, characterized in that The signal processing module (9) is embedded with an alarm decision algorithm unit implemented by a computer program, and the alarm decision algorithm unit is used to generate alarm information according to the gas component to be measured; the alarm decision algorithm unit is also used to compare the concentration value of the gas component to be measured with a preset threshold in real time, and is also used to generate alarm information when the comparison result is "greater than".

9. The device according to claim 1, characterized in that The display module (10) is a touch-sensitive color liquid crystal screen with a resolution of .

10. The device according to claim 1, characterized in that The device further comprises a temperature stabilization module for performing constant temperature control on the SLD light source module (1), the main tunable filter array (4), the main photodetector array (5), the reference tunable filter array (6) and the reference photodetector array (7).

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