Point type laser flue gas composite detector

Abstract

The utility model discloses a point type laser flue gas composite detector, which comprises a shared flue gas chamber, a smoke sensing laser emission unit, a smoke sensing detection channel, a gas detection laser and a gas detection detector, the shared flue gas chamber comprises a gas measuring chamber unit; the gas measuring gas chamber unit comprises reflecting mirror groups which are oppositely arranged; the gas measuring laser and the gas measuring detector are arranged on one side of the gas measuring gas chamber unit; the smoke sensing laser emission unit comprises a smoke sensing laser and a light trap; the number of the smoke sensing detection channels is at least two; the gas measuring laser, the gas measuring detector, the smoke sensing laser and the smoke sensing detection channel are arranged on the edge of the shared smoke chamber and are lower than the gas measuring chamber unit; the light trap is higher than the gas measuring chamber unit; the connecting line of the smoke sensing laser and the light trap obliquely penetrates through the space where the gas measuring gas chamber unit is located. During measurement, composite detection of smoke and fire gas can be realized; smoke detection and gas detection share the same detection cavity, the overall structural layout is compact, and the integrity is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of laser detection, in particular to a point-type laser flue gas composite detector. Background Technique

[0002] The early detection and warning of fires and combustible gases have become the core and key of building fire prevention and control. Traditional optical and ion-type smoke detectors are severely interfered by complex objects such as water vapor, floating dust, and oil fumes, and the false alarm rate is as high as over 80%; the detection of gas (methane CH4) leakage based on catalytic reaction and thermal conductivity effect also has many problems such as slow response speed, difficult differentiation of volatile organic compounds, low accuracy, and short life under harsh environments such as high temperature and high humidity. In view of the multi-component composite detection requirements for building fires, smoke, and gas threats, the detection of the two major hazard sources of fire smoke and combustible gases has always developed independently, and a small number of current composite detectors are still mainly in the form of a combination of discrete sensors, and there are problems such as large volume and low technical integration. Therefore, it is necessary to study a new type of early fire and combustible gas composite detector that can integrate the detection of flue gas in one body.

[0003] The fire process is divided into stages such as early stage, smoldering stage, and flame heat release stage. In the early stage of incomplete combustion and pyrolysis, there is an objective law of fire in the early stage of "gas first, then smoke, smoke and gas coexist, and then there is flame". The early detection of fire gases is an effective means for early fire detection. Early fire gases mainly include CO, CO2, H2O, etc. Among them, CO has the characteristics of large differentiation from the atmospheric background, little influence from human activities, and rapid upward diffusion prior to smoke, and is most suitable as an early gas marker. By using the simultaneous detection of fire smoke and CO gas, and cross-verification of flue gas, it is beneficial to improve the reliability of early fire detection.

[0004] Traditional fire CO sensors, including semiconductor, electrochemical, and infrared types, generally have problems such as low reliability, susceptibility to interference, and slow response speed, which limit their wide application in the field of early fire detection. For example, traditional CO sensors are easily affected by water vapor, hydrogen, volatile organic compounds, etc., and have weak anti-interference ability. For example, the currently most widely used electrochemical sensors have a short service life, less than 2 years in harsh environments, and cannot meet the requirements of long-term application. In addition, early fire detection has high requirements for the sensitivity and rapid response of CO, which increases the development difficulty.

[0005] The existing simultaneous detection of flue gas is generally composed of a discrete fire smoke detector and a discrete fire carbon monoxide detector or combustible gas detector, rather than an integrated design of sensors, and has problems such as large volume, high power consumption, low sensitivity, and weak reliability. Content of the Utility Model

[0006] In view of the above deficiencies in current laser smoke detectors and distributed flue gas measurement methods, the present utility model provides a point-type laser flue gas composite detector, which can achieve composite flue gas detection and improve the integration, anti-interference ability and accuracy of flue gas detection equipment.

[0007] To achieve the above object, the embodiments of the present utility model adopt the following technical solutions:

[0008] A point-type laser flue gas composite detector includes a shared flue gas chamber, a smoke-sensing laser emission unit, a smoke-sensing detection channel, a gas-measuring laser and a gas-measuring detector; the shared flue gas chamber includes a gas-measuring gas chamber unit; the gas-measuring gas chamber unit includes a set of reflectors arranged oppositely; the gas-measuring laser and the gas-measuring detector are arranged on one side of the gas-measuring gas chamber unit; the smoke-sensing laser emission unit includes a smoke-sensing laser and a light trap; the number of the smoke-sensing detection channels is at least two; the gas-measuring laser, the gas-measuring detector, the smoke-sensing laser and the smoke-sensing detection channels are arranged on the edge of the shared flue gas chamber and are lower than the gas-measuring gas chamber unit; the light trap is located higher than the gas-measuring gas chamber unit; the connection line between the smoke-sensing laser and the light trap obliquely passes through the space where the gas-measuring gas chamber unit is located.

[0009] According to one aspect of the present utility model, the light trap includes an incident section, a light guiding section and an extinction tube; the incident section is parallel to the laser beam emitted by the smoke-sensing laser; a reflection chamfer is arranged between the incident section and the light guiding section; a reflection chamfer is arranged between the light guiding section and the extinction tube.

[0010] According to one aspect of the present utility model, extinction rings are arranged inside the incident section and the light guiding section; a pyramid extinction structure is arranged inside the extinction tube.

[0011] According to one aspect of the present utility model, the set of reflectors is a set of plane mirrors or a set of curved mirrors.

[0012] According to one aspect of the present utility model, the gas-measuring gas chamber unit is detachably fixed in the shared flue gas chamber.

[0013] According to one aspect of the present utility model, the gas-measuring gas chamber unit is an integral structure, including a gas chamber substrate and a reflector installer.

[0014] According to one aspect of the present utility model, the smoke-sensing laser is used to emit laser beams of different wavelengths.

[0015] According to one aspect of the present utility model, a light-shielding cover is arranged on the shared flue gas chamber.

[0016] According to one aspect of the present utility model, the detector includes a housing; a dust-proof filter screen is arranged on the housing.

[0017] Advantages of the implementation of the present utility model:

[0018] The laser smoke detection part and the laser gas detection part adopt a shared flue gas chamber design. Each component is reasonably arranged around the shared flue gas chamber with a compact layout. Smoke detection and gas detection can be carried out simultaneously without interference. The smoke detection laser beam obliquely passes through the space of the shared flue gas chamber, which maximally ensures the flue gas intake space and is conducive to accurate detection results. The smoke detection part adopts multi-spectral and multi-channel laser detection, which can collect multiple groups of smoke aerosol scattering signal data, enabling more accurate judgment of smoke types and better anti-interference performance. Brief Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 Explosion schematic of an integrated laser flue gas composite detection device according to the present invention Figure 1 ;

[0021] Figure 2 Explosion schematic of an integrated laser flue gas composite detection device according to the present invention Figure 2 ;

[0022] Figure 3 Structural schematic of the shared flue gas chamber according to the present invention;

[0023] Figure 4 Structural and optical path schematic of the curved mirror reflector group chamber according to the embodiments of the present invention;

[0024] Figure 5 Structural schematic of the optical trap according to the present invention;

[0025] Figure 6 Optical path schematic of the optical trap according to the present invention.

[0026] Legend Explanation: 1. Shared flue gas chamber; 11. Gas detection chamber unit; 111. Reflector group; 112. Chamber substrate; 113. Reflector installer; 12. Light shield; 21. Smoke detection laser; 22. Optical trap; 221. Incident section; 222. Light guiding section; 223. Extinction tube; 224. Reflection chamfer; 225. Extinction ring; 226. Pyramidal extinction structure; 3. Smoke detection channel; 4. Gas detection laser; 5. Gas detection detector; 6. Shell; 61. Dust-proof filter screen. Detailed Embodiments

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0028] As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 shown, a point-type laser flue gas composite detector includes a shared flue gas chamber 1, a smoke-sensing laser emission unit, a smoke-sensing detection channel 3, a gas-measuring laser 4, and a gas-measuring detector 5; the shared flue gas chamber 1 includes a gas-measuring gas chamber unit 11; the gas-measuring gas chamber unit 11 includes a mirror group 111 arranged oppositely; the gas-measuring laser 4 and the gas-measuring detector 5 are arranged on one side of the gas-measuring gas chamber unit 11; the smoke-sensing laser emission unit includes a smoke-sensing laser 21 and an optical trap 22; the number of the smoke-sensing detection channels 3 is at least two; the gas-measuring laser 4, the gas-measuring detector 5, the smoke-sensing laser 21, and the smoke-sensing detection channels 3 are arranged on the edge of the shared flue gas chamber 1 and are lower than the gas-measuring gas chamber unit 11; the position of the optical trap 22 is higher than the gas-measuring gas chamber unit 11; the connection line of the smoke-sensing laser 21 and the optical trap 22 obliquely passes through the space where the gas-measuring gas chamber unit 11 is located;

[0029] During measurement, smoke aerosol and fire gas enter the shared flue gas chamber 1. The smoke-sensing detection channel 3 collects the aerosol scattering light signal of the laser beam emitted by the smoke-sensing laser emission unit. At the same time, the laser beam of the gas-measuring laser 4 is reflected multiple times in the gas-measuring gas chamber unit 11 and then received by the gas-measuring detector 5, so as to realize the composite detection of smoke and fire gas; the smoke detection and gas detection share the same detection cavity, and the overall structure layout is compact and the integrity is stronger.

[0030] The gas-measuring laser 4, the gas-measuring detector 5, the gas-measuring laser 4, and the smoke-sensing detection channels 3 are arranged on the circumference of the shared flue gas chamber 1 of the shared flue gas chamber 1, which is beneficial to making full use of the space and making the layout more compact; the position of the optical trap 22 is higher than the gas-measuring gas chamber unit 11, and the laser beam emitted by the smoke-sensing laser 21 obliquely passes upward through the gas-measuring gas chamber unit 11, so that it is convenient to place components such as the gas-measuring laser 4 and the gas-measuring laser 4 below the bottom surface of the gas-measuring gas chamber unit 11, maximizing the smoke intake space and ensuring that the measured flue gas can fully enter the interior of the shared flue gas chamber 1;

[0031] In practical applications, the emission directions of the smoke-sensing laser 21 and the gas-measuring laser 4 should be as perpendicular as possible, which is convenient for the scattered layout of each component, so that the smoke detection part and the gas detection part can be mutually non-interfering.

[0032] As Figure 5 shown, the optical trap 22 is used to absorb the laser beam of the smoke-sensing laser emission unit, and includes an incident section 221, a light guide section 222, and an extinction tube 223; wherein, the incident section 221 is parallel to the laser beam emitted by the smoke-sensing laser 21; reflection chamfers 224 are provided between the incident section 221 and the light guide section 222, and between the light guide section 222 and the extinction tube 223;

[0033] As Figure 6 shown, when the laser beam of the smoke-sensing laser emission unit passes through the common flue gas chamber 1 and enters the incident section 221, part of the beam will be directed towards the extinction tube 223 after two reflections at the reflection chamfer 224. A pyramid extinction structure 226 is provided inside the extinction tube 223, which can effectively weaken the scattered light of the laser beam; multi-layer extinction rings 225 are provided inside the incident section 221 and the light guide section 222, which can prevent the scattered laser from escaping from the optical trap 22 to the greatest extent and weaken the external scattered light to the lowest level.

[0034] The mirror group 111 is a plane mirror group or a curved mirror group. During measurement, the laser beam is received by the gas detector 5 after multiple reflections between the two mirrors. Multiple reflections can extend the effective optical path and improve the measurement accuracy; the number of reflections of the laser in the plane mirror group is relatively small, the effective optical path is relatively short, the debugging and packaging difficulty is small, and the accuracy requirement is low, which is suitable for occasions that are sensitive to cost and have low requirements for measurement accuracy; while the number of reflections of the laser beam between the curved mirror groups is relatively large (as Figure 4 shown), the effective optical path is long, the accuracy requirement is high and the debugging and packaging difficulty is large, which is suitable for usage scenarios with high requirements for measurement accuracy; the gas measurement chamber units 11 using different mirror groups 111 have the same size and are all fixed in the common flue gas chamber 1 in a detachable manner. Therefore, detectors using different mirror groups 111 can use the same specification of the common flue gas chamber 1, which can effectively reduce costs.

[0035] The gas measurement chamber unit 11 adopts an integrated structure and modular design, which is convenient for assembly and reduces the cost of later maintenance and upgrade. It includes a chamber substrate 112 and a mirror installer 113; the mirror installer 113 is fixedly connected to the chamber substrate 112 and is used to install the mirror group 111, the gas measurement laser, and the gas detector 5; the chamber substrate 112 can be connected to the body of the common flue gas chamber 1 by means of screw fixation.

[0036] The smoke detection channel 3 consists of an optical amplifier, a focusing lens, and a smoke photodetector; each smoke laser 21 should preferably be equipped with at least two smoke detection channels 3, one channel for collecting forward scattering signals and the other for collecting backward scattering signals; preferably, the smoke laser emission unit should be able to provide at least two wavelengths (and cover as many different bands as possible) of laser beams; the specific method can be to set a plurality of single-wavelength lasers, optically combine multiple single-wavelength lasers, or use a single multi-wavelength laser; the combination of multi-spectral and multi-channel can measure more sets of smoke aerosol scattering signal data, which is more conducive to accurately judging the type of smoke, avoiding false alarms, and improving anti-interference performance;

[0037] Furthermore, the gas detection laser 4 can be an adjustable laser, which emits tunable lasers with multiple gases and multiple characteristic points in a time-division manner during measurement, enabling multi-gas composite measurement of CH4, CO, etc., and also supporting single-gas laser measurement.

[0038] A light-shielding cover 12 is provided on the shared flue gas chamber 1. The light-shielding cover 12 adopts an optical maze design, which can greatly weaken the influence of external environmental background light on the inside of the shared flue gas chamber 1, while not affecting the entry of smoke, and can ensure that the smoke stays inside the flue gas chamber for a sufficient long time.

[0039] An outer shell 6 is provided on the light-shielding cover 12; a dust-proof filter screen 61 is provided on the outer shell 6 to prevent the entry of dust and mosquitoes.

[0040] Advantages of the implementation of the present utility model:

[0041] The laser smoke detection part and the laser gas detection part adopt a shared flue gas chamber design, and each component is reasonably arranged around the shared flue gas chamber with a compact layout. Smoke detection and gas detection can be carried out simultaneously without interference; the smoke laser beam obliquely passes through the space of the shared flue gas chamber, which maximally ensures the smoke intake space and is conducive to accurate detection results; the smoke detection part adopts multi-spectral and multi-channel laser detection, which can collect multiple sets of smoke aerosol scattering signal data, enabling more accurate judgment of the smoke type and better anti-interference performance.

[0042] As described above, it is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claimed rights.

Claims

1. A point-type laser smoke composite detector, characterized in that: The invention comprises a common smoke chamber (1), a smoke sensing laser emitting unit, a smoke sensing detection channel (3), a gas measuring laser (4) and a gas measuring detector (5); the common smoke chamber (1) comprises a gas measuring chamber unit (11); the gas measuring chamber unit (11) comprises a reflecting mirror group (111) arranged opposite to each other; the gas measuring laser (4) and the gas measuring detector (5) are arranged on one side of the gas measuring chamber unit (11); the smoke sensing laser emitting unit comprises a smoke sensing laser (21) and a light trap (22); the number of the smoke sensing detection channel (3) is at least two; the gas sensing laser (4), the gas sensing detector (5), the smoke sensing laser (21) and the smoke sensing detection channel (3) are arranged on the edge of the common smoke chamber (1) and are lower than the gas measuring chamber unit (11); the light trap (22) is located higher than the gas measuring chamber unit (11); and the line connecting the smoke sensing laser (21) and the light trap (22) obliquely passes through the space where the gas measuring chamber unit (11) is located.

2. The point-type laser smoke compound detector according to claim 1, characterized in that: The light trap (22) comprises an incident section (221), a light guide section (222) and a light extinction tube (223); the incident section (221) is parallel to a laser beam emitted by a smoke sensing laser (21); a reflection chamfer (224) is provided between the incident section (221) and the light guide section (222); and a reflection chamfer (224) is provided between the light guide section (222) and the light extinction tube (223).

3. The point-type laser smoke compound detector according to claim 2, characterized in that: The incident section (221) and the light-guiding section (222) are provided with extinction rings (225) inside; and the extinction tube (223) is provided with a pyramid extinction structure (226) inside.

4. The point-type laser smoke compound detector according to claim 1, characterized in that: The reflector group (111) is a plane mirror group or a curved mirror group.

5. The point-type laser smoke compound detector according to claim 1, characterized in that: The gas measuring chamber unit (11) is detachably fixed in the common smoke chamber (1).

6. The point-type laser smoke compound detector according to claim 5, characterized in that: The gas measuring chamber unit (11) is an integrated structure, comprising a chamber substrate (112) and a reflector mounter (113).

7. The point-type laser smoke compound detector according to claim 1, characterized in that: The smoke sensing laser (21) is used to emit laser beams with different wavelengths.

8. The point-type laser smoke compound detector according to claim 1, characterized in that: The common smoke chamber (1) is provided with a light shield (12).

9. The point-type laser smoke compound detector according to claim 1, characterized in that: The detector comprises a housing (6); a dustproof filter (61) is arranged on the housing (6).

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