Air-breathing laser scattering imaging extremely-early fire detection system

Abstract

The utility model discloses an inspiration type laser scattering imaging extremely early fire detection system, which comprises a laser imaging detection host and an independent inspiration pipeline, the laser imaging detection host is a twelve-airway laser scattering imaging detection module, and the twelve-airway laser scattering imaging detection module comprises a laser imaging detection cavity. An imaging airway module, a laser tube, a high-definition low-illumination camera, a sensor and a main processing board are arranged in the laser imaging detection cavity, and imaging, particle size calculation, concentration calculation and physical parameter perception of particles of multiple airways are carried out; the laser imaging detection host is arranged on the independent air suction pipeline; the laser imaging detection host is connected with a protected electrical cabinet or facility through an independent sampling pipeline. By adopting a multi-airway laser scattering imaging system, particle size distribution and concentration of dust particles passing through airflow are calculated more accurately, so that whole-process monitoring and alarming are carried out on extremely early pyrolysis particles, early smoke and early smoke of a fire.

Description

Technical Field

[0001] The utility model relates to the technical field of emergency fire fighting, in particular to an air-breathing laser scattering imaging very early fire detection system. Background Art

[0002] Aspiration smoke detection technology has been widely used, and two main technologies are used: light scattering method and cloud chamber method. The light scattering method is based on the fact that smoke or dust particles will scatter laser or other light beams, and the scattered light is received by a photoelectric tube to identify the concentration of smoke or dust. The cloud chamber method means that all particles are wrapped in a small water droplet through the cloud chamber. After the particles magnified by the cloud chamber pass through the photoelectric particle counter, the counter calculates the concentration of the particles based on their density. At present, there are the following main problems in the application of these technologies:

[0003] Because the detection chamber uses a single photoelectric tube method, when the detection is connected to multiple pipelines, the alarm pipeline cannot be distinguished. Utility Model Content

[0004] The purpose of the utility model is to provide an extremely early fire detection system with air-inhalation laser scattering imaging in response to the above-mentioned problems that currently exist, which completely abandons the previous methods of using a single photoelectric tube sensor or a PM detector that cannot identify the distribution of dust aerosol particles, and adopts a single-light or double-light scattering imaging method. It can simultaneously image multiple airways, and each airway corresponds to an external air intake pipe. Once an alarm is triggered, the alarm pipeline can be clearly indicated.

[0005] The technical solution of the utility model is as follows:

[0006] An air-intake laser scattering imaging very early fire detection system comprises a laser imaging detection host and an independent sampling pipeline. The laser imaging detection host is a twelve-airway laser scattering imaging detection module. The twelve-airway laser scattering imaging detection module comprises a laser imaging detection cavity. An imaging airway module, a laser tube, a high-definition low-light camera, a sensor and a main processing board are arranged in the laser imaging detection cavity to sense particles of multiple airways, particle size calculation, concentration calculation and other physical parameters. The laser imaging detection host is connected to the protected electrical cabinet or facility through an independent sampling pipeline.

[0007] Furthermore, the twelve-airway laser scattering imaging detection module also includes a laser imaging airway, which is arranged on the imaging airway module, and the laser imaging airway is arranged in a fan shape. A laser tube is arranged at the end of the laser imaging airway, and the opening and closing of the laser tube is controlled by the main processing board; the upper surface of the laser imaging airway and the laser emitting end are provided with transparent windows that transmit laser light, and the optical axis of the laser is the same as the airflow direction, and a high-definition low-light camera is arranged in the vertical direction of the optical axis, the field of view angle of the high-definition low-light camera is the arrangement direction of the laser imaging airway, and the transparent window is located in the vertical direction of the field of view of the high-definition low-light camera.

[0008] Furthermore, the laser imaging airway is also provided with an air intake interface, which is connected to an air circuit aviation plug through an internal connecting air circuit, and then connected to an independent sampling pipeline through the air circuit aviation plug.

[0009] Furthermore, a sensor is provided at the outlet side end of the laser imaging airway, and the sensor includes one or more of an airflow sensor, a CO sensor, a H2 sensor, a VOC sensor and a temperature sensor.

[0010] Furthermore, the laser imaging detection host is arranged on the suction module; the suction module and the imaging airway module are connected and converged into the suction cabin, and the suction cabin is connected to the suction pump to complete the suction.

[0011] Furthermore, the high-definition low-light camera is a camera with no less than two million pixels; the high-definition low-light camera is connected to the main processing board via a data cable; the main processing board is connected to the interface and the power board via a network interface; and the main processing board is also connected to a display panel.

[0012] Furthermore, the air suction pump is a PWM variable speed controlled motor, and the air suction pump is controlled by a main processing board.

[0013] Furthermore, the high-definition low-light camera is connected to the main processing board via a data cable.

[0014] Furthermore, the main processing board is connected to the power board via a network interface.

[0015] Furthermore, the main processing board is also connected to a display panel.

[0016] Compared with the existing technology, the beneficial effects of the utility model are:

[0017] 1. An air-inhaled laser scattering imaging very early fire detection system, which uses a multi-airway laser scattering two-dimensional imaging system to more accurately calculate the particle size distribution and concentration of dust particles in the airflow, thereby implementing full-process monitoring and alarm for pyrolysis particles, early smoke and initial smog in the very early stages of a fire;

[0018] 2. An air-inhaled laser scattering imaging early-stage fire detection system. A laser imaging detection chamber of the detection system can simultaneously monitor no less than twelve airways in real time. The detection content includes the particle size distribution, concentration and a series of supporting gas sensor parameters of the particulate matter. Each airway independently obtains parameters, independently calculates and independently alarms, so that the system can accurately identify the cabinet or area location where the alarm occurs;

[0019] 3. An air-inhaling laser scattering imaging early-stage fire detection system will greatly improve the adaptability of the detection system. Each airway can be connected to a multi-inhalation air pipe or a single-inhalation air pipe, and can identify both pyrolysis particles and smoke of several hundred nanometers. The system automatically adjusts the speed of the air pump through the pressure and velocity detection of the airflow to obtain a stable airflow.

[0020] 4. An inhaled laser scattering imaging early fire detection system, the particles contained in the inhaled air can produce scattered light under the irradiation of laser, and form an image in the vertical direction through a high-definition camera, which is a typical two-dimensional data. Through the analysis of the image, the particle size distribution can be statistically calculated, and the concentration index of all particles can also be calculated. Detailed particle size analysis can ensure the detection and alarm of the entire process from pyrolysis particles to smoke particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the detection system architecture of the utility model.

[0022] Figure 2 This is a schematic diagram of the particle size distribution results of the two-dimensional image data analysis of the detection system of the utility model.

[0023] Figure 3 This is a schematic diagram of the principle of a twelve-airway laser scattering imaging detection module of the utility model.

[0024] Figure 4 It is a schematic cross-sectional view of a twelve-airway laser scattering imaging detection module of the utility model.

[0025] Figure 5 This is a schematic diagram of the hardware architecture of a twelve-airway laser scattering imaging detection module of the utility model.

[0026] Figure 6 The utility model is a flow chart of the detection method.

[0027] Figure numerals: 1-laser tube, 2-imaging airway module, 3-laser imaging detection cavity, 4-display panel, 5-high-definition low-light camera, 6-main processing board, 7-suction module, 8-suction pump, 9-inlet and outlet line interface, 10-sensor, 11-interface and power board, 12-internal connection air path, 13-air path aviation plug, 14-independent sampling pipeline, 15-detector chassis, 16-protected electrical cabinet or facility, 17-laser imaging airway, 18-suction interface, 19-transparent window. DETAILED DESCRIPTION

[0028] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0029] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0030] It is difficult for existing systems to distinguish the particle distribution of the actual inhaled dust aerosol. It is also impossible to distinguish the distribution ratio of particles in different particle size ranges; in recent years, pyrolytic particle detectors have become a new hot spot. The existing method of using air inhalation to analyze and alarm pyrolytic particles, such as patent CN113554843A pyrolytic particle fire detection method and detector. However, these patents all use sensors such as PM1.0, PM2.5, PM10 and / or VOC, and analyze and process the data after obtaining it. PM1.0, PM2.5, and PM10 detection is for the detection of dust particle concentrations below 1.0, 2.5, and 10 microns in diameter. These sensors are actually mainly for concentration calculation of particles below a specific particle size, and it is still difficult to truly identify the distribution of particle size, and cannot achieve accurate detection and alarm, and there will be many false alarms. The present application discloses an air-inhaled laser scattering imaging very early fire detection system, such as Figure 1As shown, it includes a laser imaging detection host and an independent sampling pipeline 14. The laser imaging detection host is a twelve-airway laser scattering imaging detection module. The twelve-airway laser scattering imaging detection module includes a laser imaging detection cavity 3. The laser imaging detection cavity 3 is provided with an imaging airway module 2, a laser tube 1, a high-definition low-light camera 5, a sensor 10 and a main processing board 6 for sensing particle imaging, particle size calculation, concentration calculation and other physical parameters of multiple airways. The laser imaging detection host is connected to the protected electrical cabinet or facility 16 through an independent sampling pipeline 14.

[0031] The twelve-airway laser scattering imaging detection module also includes a laser imaging airway 17, which is arranged on the imaging airway module 2, and is arranged in a fan shape. A laser tube 1 is arranged at the end of the laser imaging airway 17, and the laser tube 1 is controlled to open and close at a certain frequency by the main processing board 6. When the inhaled gas is pure, it will not scatter the incident laser, and the camera in the vertical direction will not have particle scattered light imaging. When there are particles in the air entering the air, it will scatter the laser beam, and the camera will capture the particle image video formed by the scattered light;

[0032] The upper surface of the laser imaging airway 17 and the laser emitting end are provided with a transparent window 19 that transmits laser light so that the laser can be emitted into the airway, and the optical axis of the laser is in the same direction as the airflow direction. A high-definition low-light camera 5 is provided in the vertical direction of the optical axis. Any light in the airway can be imaged. The field of view angle of the high-definition low-light camera 5 is the arrangement direction of the laser imaging airway 17, and the transparent window 19 is located in the vertical direction of the field of view of the high-definition low-light camera 5.

[0033] like Figure 3 Assume that a camera with a field of view of 85°×70° is used. In order to use one camera to achieve imaging detection of more airways, the 85° angle direction can be used as the arrangement direction of the airways. In addition, in order to keep the image size of scattered light from the same particles consistent, the airways are designed to be fan-shaped, and the optical axis of the laser tube is on the same radial plane, as shown in Figure 1. Figure 3 As shown. According to this arrangement method, twelve independent airways can be designed. A laser tube is designed at the end of the airway, which is turned on and off at a certain frequency under the control of the main processing board. For such a twelve-airway module design, in order to ensure sufficient imaging, the laser imaging detection cavity 3 fully utilizes the transparent window arranged in the vertical angle direction of the 70° field of view, that is, the airway is imaged as comprehensively as possible through the transparent window, which will be conducive to adapting to the airflow velocity and obtaining the scattered imaging of particles, such as Figure 4 shown.

[0034] The laser imaging airway 17 is also provided with an air intake interface 18, which is connected to the airway aviation plug 13 through the internal connecting airway 12, and then connected to the independent sampling pipeline 14 through the airway aviation plug 13. Through the suction of the suction pump 8, the air at the suction hole of the independent sampling pipeline 14 is continuously sucked and discharged to the outside of the box through the laser imaging airway 17 and the suction pump 8. The independent sampling pipeline 14 is connected to the internal connecting airway 12 and the air intake interface 18 one-to-one.

[0035] The outlet end of the laser imaging airway 17 is provided with a sensor 10, which includes one or more of an airflow sensor, a CO sensor, an H2 sensor, a VOC sensor and a temperature sensor. The calculation of the entire process from the very early pyrolysis particle stage of the fire to the fire smoke generation stage is to use imaging particle size distribution analysis, particle concentration and various sensor parameters for joint analysis to complete the early warning alarm.

[0036] The laser imaging detection host is arranged on the suction module 7; the suction module 7 is connected with the imaging airway module 2 and converges into the suction cabin, and the suction cabin is connected with the suction pump 8 to complete the suction.

[0037] The high-definition low-light camera 5 is a camera with no less than 2 million pixels, and the sampling value of each pixel is in the range of 0 to 4096. A higher value range is also advantageous. During specific calculations, the main processing board 6 can stretch the value range in different stages to obtain the best particle scattering imaging image. For example, in the stage where there are few particles and the particle size is small, the value range of 0 to 255 can be stretched separately for analysis. The main purpose of the analysis is to calculate the concentration of dust particles and to count the distribution of particles in the corresponding particle size range, such as Figure 2 As shown, it is a typical particle size distribution diagram for smoke identification and analysis. From this distribution, it can be seen that it fully conforms to the characteristics of early fire smoke. Most of the particle sizes of smoldering fire smoke are distributed below 1000nm. The initial particle size morphology is mainly reflected in the range of 10nm or tens of nm. Once the numerical range statistically calculated for this range meets the extremely early characteristics of the fire, the system can trigger an early warning. In the implementation of this embodiment, CO, H2 or VOC gas detection is usually performed for each airway, and more accurate alarm results can be obtained through multi-parameter composite calculations. For example, for the detection of battery cabinets, H2 detection plays an important role, including the detection of VOC gas is also auxiliary. VOC gas usually includes CH4 functional group gas, etc.

[0038] The high-definition low-light camera 5 is connected to the main processing board 6 through a data cable. After the main processing board controls the laser tube to start emitting laser, it continuously collects the video images output by the camera. The sampling frequency can match the airflow speed. For a particle to move through the airway, there is at least one chance to form a scattered image. Assuming the effective window length is L and the image sampling frame rate is F, the airflow speed cannot be greater than .like Figure 3 , Figure 4 Design, L = 110mm, F sampling frequency is 50, Of course, too slow a flow rate is not good either, because it takes time for the airflow to enter the analyzer from the air inlet. Assuming the air inlet pipe is 100m long, it means that it takes at least 100 / 5.5=18.2s for the particles to enter the airway. When the flow rate is slower, the inhalation time is obviously longer. Therefore, a suitable flow rate control is generally required.

[0039] like Figure 5 As shown, the main processing board 6 is connected to the power board 11 through a network interface, mainly completing the acquisition of sensor signals, and controlling the output of alarm signals after decision-making alarms; and the main processing board 6 is also connected to the display panel 4. Various parameter indicators and alarm signals are transmitted to the display panel 4 for display. The display panel 4 can realize the setting of system alarm sensitivity, alarm logic relationship, etc., and complete the display of concentration, particle size distribution, alarm level, system status, and can realize a series of functions such as resetting and silencing of the detection system.

[0040] The air pump 8 is a PWM variable speed control motor to ensure that the system can adjust the air pressure according to the number of connected pipelines to form a stable airflow and flow rate. The moderate flow rate is conducive to particle scattering imaging and obtaining images for detailed calculations. The main processing board 6 directly controls the air pump 8 and the laser module. The control of the air pump is achieved through PWM pulse width modulation control to control the speed and flow of the air pump; for the control of the laser module, the switch control is mainly carried out according to a specific frequency.

[0041] The interface and power board 11 mainly completes the collection, arrangement and signal transmission of sensor signals, completes the control instructions for outputting alarm signals, realizes the arrangement of system working power supply and the processing of EMC electromagnetic compatibility performance. The interface and power board 11 can communicate with various sensors through I2C, CAN or other serial ports.

[0042] The utility model also includes an air-inhaling laser scattering imaging very early fire detection method, such as Figure 6 As shown, the following steps are included:

[0043] After powering on an air-breathing laser scatter imaging very early fire detection system, an initialization action is performed to complete the status detection of the internal circuit, sensor, camera, input and output components, and after the detection, the system is started to operate;

[0044] Control the action of the suction pump and adjust it to achieve the appropriate flow rate and flow rate, and control the laser tube to open and close according to the frequency;

[0045] During the laser tube on time period, the system controls the camera to obtain laser scattering imaging images, and the number of image frames collected in each laser on cycle is not less than three frames;

[0046] Perform image analysis to obtain particle size and distribution data of particles in airway airflow;

[0047] At the same time, data sampling is performed on various sensors installed in the system, and data from various sensors are preprocessed;

[0048] Calculate the concentration index based on the comprehensive particle size data, and make a comprehensive judgment and analysis based on various sensor data;

[0049] Determine whether the extremely early fire warning characteristic threshold is reached. If so, the control interface and the corresponding alarm device of the power board are activated, an alarm signal is output or detailed alarm information is output through the network, and various information is displayed or operation control and setting are performed through the display screen.

[0050] The specific steps of the image analysis are as follows:

[0051] Take out a frame of image and perform hierarchical stretching of the image first;

[0052] For the stretched image, image filtering, binarization, binary morphological filtering, and edge detection are used to perform particle size statistical analysis and calculate particle concentration indicators.

[0053] Calculations are performed for three or more frames of images, and weighted average processing is performed on the obtained data to obtain a parameter of the current cycle.

[0054] The judgment of whether the very early fire warning characteristic threshold is reached is that the data fusion parameter is greater than or equal to the threshold, the particle concentration and particle size are within the specified range, and the values ​​of some important sensors are greater than or equal to the threshold range.

[0055] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. An air-breathing laser scattering imaging very early fire detection system, characterized in that: The invention comprises a laser imaging detection host and an independent sampling pipeline (14), wherein the laser imaging detection host is a twelve-airway laser scattering imaging detection module, and the twelve-airway laser scattering imaging detection module comprises a laser imaging detection chamber (3), wherein an imaging airway module (2), a laser tube (1), a high-definition low-light camera (5), a sensor (10) and a main processing board (6) are arranged in the laser imaging detection chamber (3), and the imaging of particles, particle size calculation, concentration calculation and physical parameter perception of multiple airways are performed; the laser imaging detection host is connected to the protected electrical cabinet or facility via the independent sampling pipeline (14). (16); the twelve-airway laser scattering imaging detection module also includes a laser imaging airway (17), which is arranged on the imaging airway module (2), the laser imaging airway (17) is arranged in a fan shape, and a laser tube (1) is arranged at the end of the laser imaging airway (17); the laser imaging airway (17) is also provided with an air intake interface (18), the air intake interface (18) is connected to an airway aviation plug (13) through an internal connecting airway (12), and is further connected to an independent sampling pipeline (14) through the airway aviation plug (13); each airway corresponds to an external air intake pipe.

2. The air-breathing laser scattering imaging very early fire detection system according to claim 1, characterized in that: The laser tube (1) is controlled to be turned on and off by a main processing board (6); a transparent window (19) that transmits laser light is provided on the upper surface of the laser imaging airway (17) and the laser emission end, and the optical axis of the laser light is in the same direction as the airflow direction; a high-definition low-light camera (5) is provided in a direction perpendicular to the optical axis; the field of view of the high-definition low-light camera (5) is the arrangement direction of the laser imaging airway (17), and the transparent window (19) is located in a direction perpendicular to the field of view of the high-definition low-light camera (5).

3. The air-inhaling laser scattering imaging very early fire detection system according to claim 1 or 2, characterized in that: A sensor (10) is provided at the outlet-side end of the laser imaging airway (17), and the sensor (10) comprises one or more of an airflow sensor, a CO sensor, a H2 sensor, a VOC sensor and a temperature sensor.

4. The air-inhaling laser scattering imaging very early fire detection system according to claim 1 or 2, characterized in that: The laser imaging detection host is arranged on the air suction module (7); the air suction module (7) is connected to the imaging airway module (2) and converges into an air suction cabin, and the air suction cabin is connected to an air suction pump (8) to complete suction.

5. The air-inhaling laser scattering imaging very early fire detection system according to claim 1 or 2, characterized in that: The high-definition low-light camera (5) is a camera with no less than 2 million pixels.

6. The air-breathing laser scattering imaging very early fire detection system according to claim 4, characterized in that: The air suction pump (8) is a PWM variable speed controlled motor, and the air suction pump (8) is controlled by the main processing board (6).

7. The air-inhaling laser scattering imaging very early fire detection system according to claim 1 or 2, characterized in that: The high-definition low-light camera (5) is connected to the main processing board (6) via a data cable.

8. The air-inhaling laser scattering imaging very early fire detection system according to claim 1 or 2, characterized in that: The main processing board (6) is connected to the power board (11) via a network interface.

9. The air-inhaling laser scattering imaging very early fire detection system according to claim 1 or 2, characterized in that: The main processing board (6) is also connected to the display panel (4).

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