A transmissive in-situ laser gas analyzer

Abstract

The utility model relates to laser spectrum absorption technical detection technical field discloses a kind of against laser in-situ laser gas analyzer, including light emitting unit, it includes at least one light laser and at least one detection laser;Light receiving unit is used to receive the optical signal of at least one detection laser;Light receiving target is used to receive at least one light laser and form spot on target position;Connecting unit is used to carry out in-situ connection with the light emitting unit, light receiving unit or light receiving target and the space to be measured;Signal control processing device is electrically connected with light emitting unit and light receiving unit.The utility model carries out integrated packaging to light laser and detection laser, can directly in-situ detect the gas component concentration in large aperture industrial pipeline, and new light mode is adopted to avoid the problem that light emitting unit or light receiving unit is opened cover and other light mode error is big in need of light in field.

Description

Technical Field

[0001] This utility model relates to the field of laser spectral absorption technology detection technology, and in particular to a through-beam in-situ laser gas analyzer. Background Technology

[0002] Tunable semiconductor laser absorption spectroscopy (TDLAS) is a technique for detecting gas concentrations by utilizing the wavelength tuning characteristics of semiconductor lasers and the selective absorption of laser light by the analyte gas. It offers advantages such as high sensitivity, real-time measurement, dynamic measurement, and simultaneous measurement of multiple components. Due to the high monochromaticity of semiconductor lasers, measurements can be taken using an isolated absorption line of the analyte gas molecules, avoiding cross-interference from different molecular spectra. This allows for accurate identification of the analyte gas and can be applied to the detection of flammable, explosive, and greenhouse gases.

[0003] In-situ laser gas analyzers directly mount the laser emitter and receiver on the process pipeline, resulting in faster measurement response and no delay. Because no pretreatment system is required, the system structure is simple and maintenance costs are low. It can perform online measurement of parameters such as gas concentration in various environments (especially harsh environments such as high temperature, high pressure, and strong corrosion). It features high accuracy, fast response, high reliability, and low operating costs, greatly facilitating production optimization, energy recovery and utilization, safety control, environmental monitoring, and scientific research analysis.

[0004] Currently, when using in-situ laser gas analyzers for gas detection in industrial pipelines, the transmitter and receiver of the gas analyzer must be aligned and installed at both ends of the pipeline before detection. This process typically involves opening and disassembling the transmitter and / or receiver for adjustment, which is quite cumbersome. Existing technologies also employ additional auxiliary tooling to help align the transmitter and receiver of the gas analyzer, such as the alignment device similar to that in patent CN218350089U. This device uses mechanical adjustment to achieve concentric alignment of the two laser pointers, and after anchoring the two laser pointers, the analyzer is installed. However, this method is also very cumbersome. In addition, patent CN105372178B discloses determining whether the transmitter and receiver are aligned by measuring the light intensity received by the photodetector at the receiver. However, this method is only suitable for small-diameter industrial pipelines. In industrial pipelines several meters or even tens of meters long, the power will significantly attenuate during long-distance propagation, making it impossible to determine whether the alignment is correct.

[0005] Secondly, the high cost of the overall structural components and the troublesome installation and debugging of a single original analyzer due to industrial site explosion-proof and installation requirements have not been effectively resolved. Existing in-situ gas analyzers face significant challenges in completing both initial alignment and subsequent gas detection within a single device, especially when detecting multiple gas components. Current technologies typically couple light emitted from lasers at different locations using multiple independent optical coupling elements or optical fibers, followed by signal reception and processing by a detector. For example, patent CN114965358B proposes a miniaturized device for simultaneously measuring multiple gases using a single detector. This scheme employs a parabolic mirror for optical path collimation and coupling. While suitable for miniaturized sensors, the parabolic mirror arrangement is complex, and the collimation and coupling effects are unsuitable for large-diameter industrial pipeline inspection. Similarly, patent CN117629911A proposes a device for in-situ multi-component measurement of flue gas. This scheme uses a reflector, dichroic mirror, and lens to couple light into an optical fiber, which is then measured in a gas chamber. This scheme has a complex structure, faces challenges in fiber optic coupling, and uses a single-end design. The optical elements of the reflector are located inside a high-temperature pipeline, making it susceptible to high-temperature effects and posing significant operational difficulties. Utility Model Content

[0006] To address the aforementioned issues, this invention proposes a through-beam in-situ laser gas analyzer suitable for large-diameter industrial pipelines (several meters to over ten meters), enabling both convenient and effective light focusing and high-precision in-situ detection of gas within the pipeline.

[0007] The above-mentioned technical objective of this utility model is achieved through the following technical solution: A through-beam in-situ laser gas analyzer is used to detect gases within the test space of a large-diameter industrial pipeline, including: The light emitting unit and the first connecting unit are provided. The light emitting unit is connected to a pre-embedded flange on one side of the space to be tested through the first connecting unit. The light emitting unit includes a first package, a laser mounting base inside the first package that can accommodate multiple lasers, and at least one matching laser and at least one detection laser disposed on the laser mounting base. One or more first through holes are provided at one end of the first package to allow light from the detection laser and the matching laser to be emitted. A light-transmitting explosion-proof window is provided at the front end of the first through hole corresponding to the matching laser. The light receiving target and the second connecting unit are provided. The light receiving target is connected to the pre-embedded flange on the other side of the space to be tested through the second connecting unit. The first connecting unit is provided with a movable part for adjusting the light emitting unit. When the light receiving target is used for light matching, the position of the light emitting unit is adjusted by adjusting the movable part, so that the light emitted by the light matching laser forms a light spot on the light receiving target, and the light matching is completed at a preset position before gas detection. A light receiving unit is used to replace the light receiving target and connect to the second connection unit after the light has been processed. The light receiving unit includes a second package, a detector mounting base disposed inside the second package, and a detector disposed on the detector mounting base for receiving the light signal emitted by the detection laser. A second through hole is opened at one end of the second package, and a receiving lens is fixedly disposed in the second through hole to focus the light emitted by at least one of the detection lasers onto the detector. The signal control and processing device is electrically connected to the optical emitting unit and the optical receiving unit. It is used to control the emission of laser light and the reception and processing of optical signals, which are ultimately converted into gas concentration.

[0008] As a further feature of this invention, the optical emitting unit includes two matching lasers and one detection laser. The detection laser is located at the center of the laser mounting base, and the two matching lasers are symmetrically distributed at the center of the laser mounting base.

[0009] As a further feature of this invention, the optical emitting unit includes a matching laser and multiple detection lasers. The matching laser is located at the center of the laser mounting base, and the multiple detection lasers are evenly distributed circumferentially around the matching laser.

[0010] As a further feature of this invention, a transmitting lens is provided at the front end of the first perforation corresponding to the detection laser, and the transmitting lens is used to collimate the laser of the detection laser.

[0011] As a further feature of this invention, the light emitting unit includes a focusing laser and multiple detection lasers. The multiple detection lasers are TO-packaged and each has a collimating lens. A prism is provided between the focusing laser and the explosion-proof window so that the light emitted by the focusing laser passes through the hole in the middle of the prism and the light-transmitting explosion-proof window in a horizontal direction. The multiple detection lasers are symmetrically arranged around the prism in a circumferential direction perpendicular to the horizontal light emitted by the focusing laser, so that the light emitted by the multiple detection lasers is reflected by the prism and has the same propagation path as the light emitted by the focusing laser.

[0012] As a further feature of this invention, the multiple detection lasers emit light of different wavelengths into the space to be tested in a time-division or simultaneous manner, and the light is focused onto the detector by the receiving lens to detect the multi-component gas.

[0013] As a further feature of this utility model, both the first connecting unit and the second connecting unit include a clamp, a purge pipe, an adjusting flange, and a control valve body connected in sequence; the clamp is detachably connected to the first or second encapsulation body, one end of the control valve body is detachably connected to the pre-embedded flange of the space to be measured, and the control valve body is used to control the connection and disconnection between the space to be measured and the first connecting unit / second connecting unit. In the first connecting unit, the movable part is located between the purge pipe and the adjusting flange.

[0014] As a further feature of this invention, the movable component is a corrugated pipe.

[0015] As a further feature of this utility model, the first connecting unit and the second connecting unit each include a water-cooled pipe. In the first connecting unit, the water-cooled pipe is located between the movable part and the adjusting flange; in the second connecting unit, the water-cooled pipe is located between the purge pipe and the adjusting flange. The water-cooled pipe has a sandwich structure and an inlet and an outlet are provided on the pipe wall of the sandwich structure to allow external cold water to flow in and out.

[0016] As a further feature of this invention, the purge pipe is provided with an air inlet and an air outlet to allow inert gases at low or normal temperatures to flow in and out.

[0017] The beneficial effects of this utility model are: 1. The through-beam in-situ laser gas analyzer of this utility model integrates a beam-aligning laser and a detection laser within the package of the light-emitting unit, enabling high-precision detection of gas before and after beam alignment to be achieved on a single gas analyzer device. In beam alignment mode, by adjusting the movable part of the first connecting unit to bring the beam spot of the beam-aligning laser to a preset position on the light-receiving target, the light-receiving target can be directly replaced with the light-receiving unit. This not only avoids the previous need to remove the light-emitting unit's meter head and open the cover for alignment with the light-receiving unit, making it more efficient and labor-saving, but also makes it suitable for aligning the light-emitting and light-receiving units before gas detection in large-diameter (several meters to tens of meters) industrial pipelines.

[0018] 2. The through-beam in-situ laser gas analyzer of this invention is also suitable for detecting multi-component high-temperature gases in industrial pipelines. By integrating multiple detection lasers within the optical emitting unit, each detection laser emits light of different wavelengths simultaneously or at different times. After being absorbed by the gas components in the pipeline, the light is then focused onto the detector by a single receiving lens of the optical receiving unit. Finally, the signal control and processing device processes and outputs the optical signal received by the detector to obtain the concentrations of different gas components. The overall structure is compact, avoiding the need to use multiple optical couplers or optical fibers to couple and output the light emitted by lasers at different locations for detection. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1; Figure 2 This is a schematic diagram of the external structure of the optical receiving unit in Embodiment 1; Figure 3 This is a cross-sectional structural diagram of the optical receiving unit in Embodiment 1; Figure 4 This is a schematic diagram of the external structure of the optical emitting unit in Embodiment 1; Figure 5 This is a cross-sectional structural diagram of the light emitting unit in Embodiment 1; Figure 6 This is a schematic diagram of the external structure of the optical emitting unit in Embodiment 2; Figure 7 This is a cross-sectional structural diagram of the light emitting unit in Embodiment 2; Figure 8 This is the optical path schematic diagram of the detection chamber in Example 2; Figure 9 This is a schematic diagram of the external structure of the light emitting unit in Embodiment 3; Figure 10 This is a cross-sectional structural diagram of the light emitting unit in Embodiment 3; Figure 11 This is the optical path schematic diagram of the detection chamber in Example 3; In the figure, 1. Light emitting unit, 11. Optical laser, 12. Detection laser, 13. First package, 14. Laser mounting base, 15. Emitting lens, 16. Explosion-proof window, 2. Light receiving unit, 21. Second package, 22. Receiving lens, 23. Detector mounting base, 24. Detector, 3. Prism, 4. Clamp, 5. Purge tube, 6. Adjusting flange, 7. Control valve body, 8. Space to be measured, 9. Embedded flange. Detailed Implementation

[0021] The technical solution of this utility model will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0022] This utility model provides a through-beam in-situ laser gas analyzer, which is mainly used for in-situ detection of multi-component gases in large-diameter industrial pipelines. The space to be tested 8 is usually an industrial pipeline with a diameter ranging from a few meters to more than ten meters. In order to achieve in-situ detection, the industrial pipeline is pre-installed with two symmetrical embedded flanges 9 so as to be installed in situ with the laser gas analyzer.

[0023] Example 1 refer to Figures 1 to 5 The through-beam in-situ laser gas analyzer includes: The light emitting unit 1 and the first connecting unit are connected to the pre-embedded flange 9 on one side of the space to be tested 8 through the first connecting unit. The light emitting unit 1 includes a first package 13, a laser mounting base 14 that can accommodate multiple lasers disposed inside the first package 13, and at least one beam-aligning laser 11 and at least one detection laser 12 disposed on the laser mounting base 14. One or more first through holes are provided on one end of the first package 13 to allow the light from the detection laser 12 and the beam-aligning laser 11 to be emitted. A light-transmitting explosion-proof window 16 is provided at the front end of the first through hole corresponding to the beam-aligning laser 11. The light receiving target (not shown in the figure) and the second connecting unit are connected to the pre-embedded flange 9 on the other side of the space to be tested 8 through the second connecting unit. The first connecting unit is provided with a movable part (not shown in the figure) for adjusting the light emitting unit 1. When the light receiving target is used for light matching, the position of the light emitting unit 1 is adjusted by adjusting the movable part so that the light emitted by the light matching laser 11 forms a light spot on the light receiving target and the light matching is completed in the preset position before gas detection. Optical receiving unit 2 is used to replace the optical receiving target and connect to the second connection unit after the light has been processed. (Refer to...) Figure 2 and Figure 3 The light receiving unit 2 includes a second package 21, a detector mounting base 23 disposed inside the second package 21, and a detector 24 disposed on the detector mounting base 23 for receiving the light signal emitted by the detection laser 12; a second through hole is opened at one end of the second package 21, and a receiving lens 22 is fixedly disposed in the second through hole to focus the light emitted by at least one detection laser 12 onto the detector 24. The signal control and processing device is electrically connected to the light emitting unit 1 and the light receiving unit 2. It is used to control the emission of laser and the reception and processing of light signals, which are ultimately converted into gas concentration.

[0024] This embodiment describes single-component gas detection in an industrial pipeline, referring to... Figure 4 and Figure 5The first package 13 of the light emitting unit 1 is formed by two package covers joined together by screws. The light emitting unit 1 includes two beam-aligning lasers 11 and one detection laser 12. The detection laser 12 is located at the center of the laser mounting base 14. The two beam-aligning lasers 11 are symmetrically distributed on both sides of the center of the laser mounting base 14. During the beam alignment process, the two beam-aligning lasers 11 emit two beams of light that hit the light receiving target. The light emitting unit 1 is adjusted by a movable component so that the two light spots on the light receiving target are aligned to two preset positions on the light receiving target. After the beam alignment is completed, the light receiving target is replaced by the light receiving unit 2 for gas detection. In this embodiment, the movable component can be a corrugated pipe.

[0025] Two beam-aligning lasers 11 are symmetrically distributed on both sides of the center position of the laser mounting base 14, which can form two light spots on the light receiving target. By aligning the two light spots at predetermined positions on the light receiving target, the beam alignment is accurate, ensuring the accuracy of the center point position, thereby ensuring the alignment of the detection laser 12 and the detector 24.

[0026] The explosion-proof window 16 must ensure that the laser emitted by the laser 11 can pass through while maintaining its own stability in harsh environments, not easily deformed or broken, so as to ensure the stable transmission of light from the laser 11 and guarantee the stability of the light transmission.

[0027] This through-beam in-situ laser gas analyzer integrates a focusing laser 11 and a detection laser 12 within the first package 13 of the light emitting unit 1, enabling high-precision detection of gas before and after light alignment to be achieved on a single gas analyzer device. In the focusing mode, by adjusting the movable part of the first connecting unit to bring the light spot of the focusing laser 11 to a preset position on the light receiving target, the light receiving target can be directly replaced with the light receiving unit 2. This not only avoids the previous need to remove the light emitting unit 1 and open the cover to align with the light receiving unit 2, making it more efficient and labor-saving, but also makes it suitable for aligning the light emitting unit 1 and the light receiving unit 2 before gas detection in large-diameter (several meters to tens of meters) industrial pipelines.

[0028] In this embodiment, the signal control and processing device includes multiple components, specifically a circuit unit, a signal processing unit, and a display unit. The circuit unit is used to electrically connect with the light emitting unit 1 and the light receiving unit 2 to drive the light emitting unit 1 and the light receiving unit 2 to emit light signals and receive light signals, respectively. Specifically, it drives the detection laser 12 and the matching laser 11 to emit lasers, and drives the detector 24 in the light receiving unit 2 to receive light signals. The signal processing unit processes the light signals received by the light receiving unit 2 and converts them into gas concentration signals. The display unit is used to display the concentration information of the multi-component gas to be measured.

[0029] refer to Figure 1 The first connecting unit connected to the light emitting unit 1 and the second connecting unit connected to the light receiving unit 2 each include a clamp 4, a purge pipe 5, an adjusting flange 6, and a control valve body 7 connected in sequence. The front ends of the first encapsulation body 13 and the second encapsulation body 21 of the light emitting unit 1 and the light receiving unit 2 are provided with protrusions and grooves for easy engagement with the clamp 4. The control valve body 7 is connected to the pre-embedded flange 9 of the space to be measured 8. In the first connecting unit, a movable part is located between the purge pipe 5 and the adjusting flange 6. The control valve body 7 is used to control the connection and disconnection between the space to be measured 8 and the first or second connecting unit. In this embodiment, the control valve body 7 is specifically a ball valve for easy control. When gas detection is required, the ball valve can be opened; after detection is completed, the ball valve can be closed, and then the connecting pipe and detection components can be disassembled to avoid gas leakage in industrial pipelines. Other valve bodies can also be used to achieve the above technical effects without affecting the detection results.

[0030] Because the temperature of the gas to be tested in the industrial pipeline is high (usually above 200°C), in order to avoid the high temperature affecting the performance of the various components of the light emitting unit 1 and the light receiving unit 2, it is necessary to cool down the light emitting unit 1 and the light receiving unit 2. Therefore, as a further provision of this embodiment, the first connecting unit and the second connecting unit each include a water-cooling pipe (not shown in the figure). In the first connecting unit, the water-cooling pipe is located between the movable part and the adjusting flange 6, and in the second connecting unit, it is located between the purge pipe 5 and the adjusting flange 6. The water-cooling pipe has a jacket structure and an inlet and an outlet are provided on the outer wall of the jacket structure to allow external cold water to flow in and out. Through the action of cold water, the gas in the pipeline is cooled down, thereby reducing the impact of the high temperature gas in the pipeline on the light emitting unit 1 and the light receiving unit 2.

[0031] Furthermore, the purge tube 5 is equipped with an air inlet and an air outlet. By blowing gas into the tube body of the purge tube 5, an air curtain is formed within the tube body. Since the gas analyzer in this embodiment is installed in situ, dust particles may be present inside the pipe under test during detection. These dust particles will enter the purge tube 5 and adhere to the receiving lens or transmitting lens of the light receiving unit 2 or the light emitting unit 1, affecting the detection effect. The air curtain can prevent dust particles from entering the purge tube 5, thereby protecting the light receiving unit 2 and the light emitting unit 1 from being affected. In addition, the purge gas is set to a low-temperature or room-temperature inert gas with a temperature lower than that of the gas under test, which is introduced into the air inlet. After the gas enters the purge tube 5, it can reduce the temperature of the light emitting unit 1 and the light receiving unit 2, thereby maintaining the stability of the operation of the light emitting unit 1 and the light receiving unit 2. The gas is discharged from the outlet of the purge tube 5.

[0032] By combining water-cooled pipes and low-temperature or room-temperature inert gases, the impact of the high-temperature environment in the test space 8 on the light emitting unit 1 and the light receiving unit 2 can be reduced, creating a better testing environment for the light emitting unit 1 and the light receiving unit 2.

[0033] To ensure the accuracy of multi-component gas detection, the selected low-temperature or room-temperature gas should avoid gases with the same absorption wavelength as the gas to be tested, and should also not react chemically with the gas to be tested. Specifically, the gas selection should not affect the gas detection results, and any gas that can achieve the above technical objectives is acceptable.

[0034] Example 2 In practice, it is often necessary to detect multi-component gases in industrial pipelines. Existing technologies generally couple the light emitted by lasers at different locations using multiple independent optical coupling elements or optical fibers, and then the detector 24 receives and outputs the optical signals for processing. This process is costly and takes up a lot of space.

[0035] Example 2 can be applied to the detection of multi-component gases in industrial pipelines, as shown in the following figure. Figures 6 to 8 Unlike Embodiment 1, in Embodiment 2, the light emitting unit 1 includes a focusing laser 11 and four detection lasers 12. The focusing laser 11 is located at the center of the laser mounting base 14, and the four detection lasers 12 are evenly distributed circumferentially around the focusing laser 11. The front end of the first perforation corresponding to the detection laser 12 is provided with an emitting lens 15, which is used to collimate the laser of the detection laser 12. As an alternative, the detection laser 12 can also be integrated with the emitting lens 15 using a TO package.

[0036] The detection principle of the multi-component in-situ laser gas detector in Example 2 is as follows: First, after aligning the light in the same way as in Example 1, the light alignment mode is turned off and the detection mode is turned on. The signal control and processing device controls the four detection lasers of the light emitting unit 1 to simultaneously emit light with preset absorption wavelengths to detect CO, CO2, CH4, and O2 in the industrial pipeline. After the four absorbed light beams are focused onto the detector 24 by the receiving lens 22 of the light receiving unit 2, the signal control and processing device demodulates the light signal received by the detector 24 using the frequency division multiplexing method to obtain the concentration of each component gas.

[0037] In addition, the signal control and processing device can also control the four detection lasers of the light emitting unit 1 to emit light with preset absorption wavelengths in a time-division manner to detect CO, CO2, CH4, and O2 in the industrial pipeline. After the four absorbed light beams pass through the receiving lens 22 of the light receiving unit 2 and are focused onto the detector 24, the signal control and processing device demodulates the light signal received by the detector 24 using a time-division multiplexing method to obtain the concentration of each component gas.

[0038] When detecting gas concentration, multiple detection lasers 12 emit light of different wavelengths into the space to be measured at different times or simultaneously through the signal control processing device. The light is then focused by the receiving lens 22 onto the detector 24 to detect the multi-component gas.

[0039] Example 3 Because the packaging volume of the light emitting unit 1 is limited, in order to make efficient use of space, an embodiment 3 is provided based on embodiment 2, such as... Figures 9 to 11 As shown, unlike Embodiment 2, the light emitting unit 1 in Embodiment 3 includes a focusing laser 11 and four detection lasers 12. The four detection lasers 12 are packaged in TO and each has a collimating lens. A prism 3 is provided between the focusing laser 11 and the explosion-proof window 16 so that the light emitted by the focusing laser 11 passes through the hole in the middle of the prism 3 and the light-transmitting explosion-proof window 16 in a horizontal direction. The four detection lasers 12 are arranged symmetrically around the prism 3 in a direction perpendicular to the horizontal light emitted by the focusing laser 11, so that the light emitted by the four detection lasers 12 is reflected by the prism 3 and has the same propagation path as the light emitted by the focusing laser 11.

[0040] By introducing the prism 3, the spatial range for arranging multiple detection lasers 12 is greatly expanded, and the detection of more component gases can be accommodated within the limited volume of the light emitting unit 1.

[0041] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A through-beam in-situ laser gas analyzer for detecting gas in the test space (8) of a large-diameter industrial pipeline, characterized in that: include, The light emitting unit (1) and the first connecting unit are connected to the pre-embedded flange (9) on one side of the space to be tested (8) through the first connecting unit. The light emitting unit (1) includes a first package (13), a laser mounting base (14) inside the first package (13) that can accommodate multiple lasers, and at least one beam-matching laser (11) and at least one detection laser (12) disposed on the laser mounting base (14). One or more first perforations are provided at one end of the first package (13) to allow the light from the detection laser (12) and the beam-matching laser (11) to be emitted. A light-transmitting explosion-proof window (16) is provided at the front end of the first perforation corresponding to the beam-matching laser (11). The light receiving target and the second connecting unit are connected to the pre-embedded flange (9) on the other side of the space to be tested (8) through the second connecting unit. The first connecting unit is provided with a movable part for adjusting the light emitting unit (1). When the light receiving target is used for light matching, the position of the light emitting unit (1) is adjusted by adjusting the movable part, so that the light emitted by the light matching laser (11) forms a light spot on the light receiving target, and the light matching is completed in the preset position before gas detection. The light receiving unit (2) is used to replace the light receiving target and connect to the second connection unit after the light is completed. The light receiving unit (2) includes a second package (21), a detector mounting base (23) disposed inside the second package (21), and a detector (24) disposed on the detector mounting base (23) for receiving the light signal emitted by the detection laser (12). A second through hole is opened at one end of the second package (21), and a receiving lens (22) is fixedly disposed in the second through hole to focus the light emitted by at least one of the detection lasers (12) onto the detector (24). The signal control and processing device is electrically connected to the light emitting unit (1) and the light receiving unit (2) to control the emission of laser and the reception and processing of light signals, which are ultimately converted into gas concentration.

2. The through-beam in-situ laser gas analyzer according to claim 1, characterized in that: The light emitting unit (1) includes two matching lasers (11) and a detection laser (12). The detection laser (12) is located at the center of the laser mounting base (14), and the two matching lasers (11) are symmetrically distributed at the center of the laser mounting base (14).

3. The through-beam in-situ laser gas analyzer according to claim 1, characterized in that: The light emitting unit (1) includes a matching laser (11) and multiple detection lasers (12). The matching laser (11) is located at the center of the laser mounting base (14), and the multiple detection lasers (12) are evenly distributed circumferentially around the matching laser (11).

4. A through-beam in-situ laser gas analyzer according to any one of claims 2-3, characterized in that: The detection laser (12) is provided with a transmitting lens (15) at the front end of the first perforation, and the transmitting lens (15) is used to collimate the laser of the detection laser (12).

5. A through-beam in-situ laser gas analyzer according to claim 1, characterized in that: The light emitting unit (1) includes a beam laser (11) and multiple detection lasers (12). The multiple detection lasers (12) are packaged in TO and each is provided with a collimating lens. A prism (3) is provided between the beam laser (11) and the explosion-proof window (16) so that the light emitted by the beam laser (11) passes through the hole in the middle of the prism (3) and the light-transmitting explosion-proof window (16) in the horizontal direction. The multiple detection lasers (12) are arranged symmetrically around the prism (3) in a direction perpendicular to the horizontal light emitted by the beam laser (11) so that the light emitted by the multiple detection lasers (12) is reflected by the prism (3) and has the same propagation path as the light emitted by the beam laser (11).

6. The through-beam in-situ laser gas analyzer according to any one of claims 3 or 5, characterized in that: The multiple detection lasers (12) emit light of different wavelengths into the space to be tested (8) at different times or simultaneously, and the light is focused onto the detector (24) by the receiving lens (22) to detect the multi-component gas.

7. A through-beam in-situ laser gas analyzer according to claim 1, characterized in that: The first and second connecting units each include a clamp (4), a purge pipe (5), an adjusting flange (6), and a control valve body (7) connected in sequence; the clamp (4) is detachably connected to the first encapsulation body (13) or the second encapsulation body (21), and one end of the control valve body (7) is detachably connected to the pre-embedded flange (9) of the space to be measured (8). The control valve body (7) is used to control the connection and disconnection between the space to be measured (8) and the first or second connecting unit. In the first connecting unit, the movable part is located between the purge pipe (5) and the adjusting flange (6).

8. A through-beam in-situ laser gas analyzer according to claim 7, characterized in that: The movable component is a corrugated pipe.

9. A through-beam in-situ laser gas analyzer according to claim 7, characterized in that: The first connecting unit and the second connecting unit each include a water-cooled pipe. In the first connecting unit, the water-cooled pipe is located between the movable part and the adjusting flange (6). In the second connecting unit, the water-cooled pipe is located between the purge pipe (5) and the adjusting flange (6). The water-cooled pipe has a sandwich structure and an inlet and an outlet are provided on the pipe wall of the sandwich structure to allow external cold water to flow in and out.

10. A through-beam in-situ laser gas analyzer according to claim 7, characterized in that: The purge pipe (5) is provided with an air inlet and an air outlet to allow inert gases of low temperature or normal temperature to flow in and out.

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