Particulate and gaseous component detection imaging apparatus and method

Abstract

The application discloses a kind of particulate matter and gas component detection imaging device and method, belong to gas detection technical field.The particulate matter and gas component detection imaging device includes sampling probe, detection gas chamber and pulse laser emitter, further include: telescope parallel pipe includes compound reflector and light collecting part, detection gas chamber inner wall is equipped with reflective layer, laser is reflected by reflective layer after being absorbed by gas sample in detection gas chamber or being scattered by particulate matter;Rotary interference system makes the laser after light collecting interference;Detection system converts the laser after interference into absorption photoelectric signal and scattering photoelectric signal;Detection part is used to detect the environment temperature and humidity in detection gas chamber;Data processing system calculates the particle size distribution and concentration of particulate matter in gas sample;The data of spectrum diagram are compensated and corrected with temperature and humidity, and the component and concentration of gas sample are analyzed.The particulate matter and gas component detection imaging device of the application can simultaneously improve the sensitivity and precision of gas component and particulate matter detection.

Description

Technical Field

[0001] This invention relates to the field of gas detection technology, specifically to an imaging device and method for detecting particulate matter and gas components. Background Technology

[0002] In the field of environmental monitoring, accurately acquiring information on particulate matter and gaseous components in the air is a core prerequisite for scientifically assessing environmental quality and precisely controlling pollution emissions, and is of great significance for pollution control decisions and ecological environmental protection. Currently, existing particulate matter and gas detection technologies still have many limitations that urgently need to be overcome, making it difficult to fully meet the high-precision monitoring needs in complex environments.

[0003] Traditional particulate matter and gas detection methods each have their shortcomings: light scattering methods can achieve a certain degree of real-time detection, but their ability to distinguish between particles of different sizes is weak, and they are easily affected by environmental factors such as temperature and humidity, resulting in poor detection accuracy; chemical sensor methods have good selectivity for specific gases, but they can detect a limited number of types of gases, and the sensors are easily affected by cross-interference from other components, resulting in a short service life and high maintenance costs.

[0004] Fourier transform infrared spectroscopy (FTIR) has been widely used in laboratory settings due to its advantage of simultaneous multi-component detection, becoming an important tool for gas and particulate matter analysis. However, existing FTIR-based detection equipment still has structural defects. Its core components, including the detection chamber, laser emitter, and interferometry system, are limited by equipment size, structural design, and field application scenarios, resulting in a limited laser propagation path and a short laser optical path. Consequently, in gas component analysis, gas molecules cannot fully interact with the laser, weakening the selective absorption effect of infrared light and leading to low detection signal intensity. Furthermore, environmental factors within the detection chamber (temperature, humidity, etc.) introduce clutter signals, resulting in a low overall signal-to-noise ratio and reduced accuracy in gas component identification and quantification by the controller. In particulate matter analysis, the reduced probability of laser-particle collision and increased scattered light loss also lead to low detection signal intensity and a decreased signal-to-noise ratio, making it difficult to accurately capture the characteristic information of low-concentration particulate matter. This hinders the widespread application of FTIR technology in real-time field monitoring. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems in the prior art and provide a particulate matter and gas component detection imaging device that can extend the optical path of the laser, thereby reducing measurement errors and simultaneously improving the sensitivity and accuracy of gas component and particulate matter detection.

[0006] This invention provides a particulate matter and gas component detection imaging device, including a sampling probe, a detection chamber, and a pulsed laser emitter. The detection chamber collects gas samples through the sampling probe, and one side of the detection chamber is transparent. The pulsed laser emitter is used to emit laser light for detection and analysis. The device also includes: The telescope parallel tube includes a composite reflector and a focusing section. The composite reflector is used to receive the laser emitted by the pulsed laser emitter and reflect the laser from the central axis of the entire telescope parallel tube to the light-transmitting side of the detection gas chamber. The inner wall of the detection gas chamber is provided with a reflective layer. After the laser is absorbed by the gas sample in the detection gas chamber or scattered by particulate matter, it is reflected by the reflective layer. The reflected laser passes through the light-transmitting side of the detection gas chamber again and returns to the focusing section in the telescope parallel tube. The focusing section is used to focus the laser. A rotating interferometer system is used to receive focused laser light and cause the focused laser light to interfere. The detection system is used to receive the interferometric laser and convert it into absorbed photoelectric signals and scattered photoelectric signals; The testing section, located in the testing chamber, is used to test the ambient temperature and humidity inside the testing chamber. The data processing system is electrically connected to the detection unit and the detection system. The data processing system calculates the particle size distribution and concentration information of particulate matter in the gas sample based on the scattered photoelectric signal. Then, it performs a Fourier transform on the absorbed photoelectric signal to generate a spectrum. The data processing system performs temperature and humidity compensation correction on the spectrum data based on the ambient temperature and humidity in the detection chamber to reduce environmental interference. Finally, it analyzes the composition and concentration of the gas sample based on the compensated and corrected spectrum.

[0007] Preferably, the focusing part includes a curved reflector, which is disposed on one side of the composite reflector. The laser light that passes through the detection gas chamber twice is received by the curved reflector and then focused and reflected. The composite reflector has a curved reflective surface. The laser light reflected on the curved reflector is received by the curved reflective surface on the composite reflector. The curved reflective surface focuses and reflects the laser light a second time. The rotating interference system receives the laser light after the second focusing and causes the laser light after the second focusing to interfere.

[0008] Preferably, the detection system includes a gas component analysis system and a particulate matter analysis system. The gas component analysis system includes a bandpass filter and an infrared detector. The bandpass filter is used to separate mid-infrared light in the interferometric laser, and the infrared detector is used to convert the mid-infrared light into an absorbed photoelectric signal. The particulate matter analysis system includes a narrowband filter and a photodetector. The narrowband filter is used to separate backscattered light in the interferometric laser, and the photodetector converts the backscattered light into a scattered photoelectric signal. The data processing system is electrically connected to the infrared detector and the photodetector.

[0009] Preferably, the data processing system is electrically connected to a signal amplifier, which is used to amplify the electrical signals of mid-infrared light and backscattered light.

[0010] Preferably, a flow controller and a pressure sensor are provided between the sampling probe and the detection chamber. The pressure sensor is used to detect the real-time air pressure value in the detection chamber. The flow controller is electrically connected to the pressure sensor. A predetermined air pressure value is preset in the flow controller. The flow controller controls the gas flow rate entering the detection chamber according to the real-time air pressure value in the detection chamber, so that the real-time air pressure value in the detection chamber is maintained at the predetermined air pressure value.

[0011] Preferably, the rotating interference system includes a beam splitter, a moving mirror, a fixed mirror, and a lens. The beam splitter is used to split the focused laser into two paths. One laser path is reflected after illuminating the moving mirror, and the other laser path is reflected after illuminating the fixed mirror. By adjusting the position of the moving mirror, the optical path difference between the laser emitted by the moving mirror and the laser reflected by the fixed mirror can be adjusted. The laser reflected by the moving mirror and the laser reflected by the fixed mirror intersect on the lens and produce interference. The two laser paths after interference illuminate a bandpass filter and a narrowband filter, respectively.

[0012] Preferably, a dust pretreatment module is provided between the sampling probe and the detection chamber, the dust pretreatment module being used to filter particulate matter with a particle size greater than 10 μm.

[0013] Preferably, the detection unit includes a temperature sensor and a humidity sensor. The temperature sensor is used to detect the ambient temperature inside the detection chamber, and the humidity sensor is used to detect the ambient humidity inside the detection chamber. Both the temperature sensor and the humidity sensor are electrically connected to the data processing system.

[0014] Preferably, it also includes an imaging system. The laser reflected by the reflective layer in the detected gas chamber is split into two paths. One laser beam illuminates the curved reflector, and the other laser beam is received by the imaging system. The imaging system is electrically connected to the data processing system. The imaging system images the received laser beam and transmits it to the data processing system. The data processing system performs noise reduction, enhancement, and segmentation on the image signal to highlight the characteristic information of particulate matter and gas samples. Then, it counts the particulate matter in the image signal, measures the particle size, and visualizes the gas concentration. Finally, it outputs a visualized image of particulate matter and gas distribution.

[0015] The present invention also provides a method of using a particulate matter and gas component detection imaging device, comprising the following steps: A gas sample is collected by a sampling probe and introduced into the detection chamber. The flow rate of the gas sample is adjusted to 50 mL / min-200 mL / min, and the gas pressure in the detection chamber is stabilized at atmospheric pressure ±5 kPa. A pulsed laser emitter emits a laser beam, which is reflected by a compound mirror in a telescope parallel tube to the light-transmitting side of the detection chamber. When the laser passes through the detection chamber, it is selectively absorbed by the gas sample or scattered by the particles. Then it is reflected by the reflective layer on the inner wall of the detection chamber. The reflected laser is selectively absorbed or scattered again, and then it is received by the focusing part in the telescope parallel tube. The focusing part focuses the laser. The focused laser beam enters the rotating interferometer system and produces interference; the detection system converts the interfering laser beam into an electrical signal. The ambient temperature and humidity inside the detection chamber are measured using the testing department. The data processing system receives electrical signals and then calculates the particle size distribution and concentration information of particulate matter in the gas sample based on the scattered photoelectric signals. After performing Fourier transform on the absorbed photoelectric signals, a spectrum is generated. The data of the spectrum is then compensated for by temperature and humidity based on the ambient temperature and humidity in the detection chamber. Finally, the composition and concentration of the gas sample are analyzed based on the compensated spectrum.

[0016] Compared with existing technologies, the beneficial effects of this invention are as follows: The particulate matter and gas component detection imaging device of this invention emits a detection laser through a pulsed laser emitter. After being received by the compound reflector of the telescope parallel tube, the laser is reflected along the central axis of the telescope parallel tube to the light-transmitting side of the detection gas chamber. When the laser passes through the detection gas chamber, the target gas molecules in the detection gas chamber selectively absorb infrared light of a specific wavelength. The particulate matter in the detection gas chamber scatters a portion of the laser. The selectively absorbed and scattered laser is reflected again by the reflective layer on the inner wall of the detection gas chamber and is selectively absorbed and scattered once more. Finally, it passes through the light-transmitting side of the detection gas chamber and returns to the telescope parallel tube. After being focused by the focusing part of the telescope parallel tube, it enters the rotating interferometer system. The laser interferes in the rotating interferometer system. After being converted by the detection system, the interfering laser is converted into absorbed photoelectric signals and scattered photoelectric signals. Both types of electrical signals are transmitted to the data processing system, which converts them into digital signals. The device processes digital signals and calculates particulate size distribution and concentration using Mie scattering theory. Fourier transform is performed on the digital signals to generate spectra. Then, based on the ambient temperature and humidity inside the detection chamber, the spectra data are compensated and corrected. The corrected spectra are compared with a preset standard gas spectral library and, using Beer-Lambert law, the concentrations of various gas components are retrieved. This device constructs a multi-reflection optical path by combining a composite mirror of a telescope parallel tube, a curved mirror, and a reflective layer on the inner wall of the detection chamber, thereby extending the laser's optical path. For gas component detection, the longer optical path allows for more complete interaction between gas molecules and the laser, amplifying the selective absorption effect of infrared light and increasing the intensity of the absorption signal, enabling identifiable signals from low-concentration gases. For particulate matter detection, the extended optical path increases the probability of laser-particle collision, increases scattered light intensity, reduces loss, and enhances the detection signal strength. This also reduces the impact of environmental factors, resulting in a comprehensive improvement in the signal-to-noise ratio of the detection signal. This helps the data processing system accurately extract parameters using relevant algorithms, reducing measurement errors and simultaneously improving the sensitivity and accuracy of both types of detection. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is the optical path diagram for wide-angle optical signal acquisition in this invention; Figure 3 This is a signal intensity distribution diagram obtained by the wide-angle optical path of the present invention; Figure 4 This is the optical path diagram for the optical signal interference transformation of the present invention; Figure 5 This is a light intensity distribution diagram of the optical signal interference transformation optical path result of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1. Telescope parallel tube; 101. Curved reflector; 102. Compound reflector; 2. Pulsed laser emitter; 3. Imaging system; 4. Rotating interferometry system; 5. Gas component analysis system; 6. Particulate matter analysis system. Detailed Implementation

[0019] The following is in conjunction with the appendix Figures 1-5 The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] like Figures 1-5 As shown, the present invention provides a particulate matter and gas component detection imaging device, including a sampling probe, a detection gas chamber, and a pulsed laser emitter 2. The sampling probe is connected to the detection gas chamber, which collects gas samples through the sampling probe. The detection gas chamber is used to contain the gas sample to be detected, and one side of the detection gas chamber is transparent. The pulsed laser emitter 2 is used to emit laser light for detection and analysis. The device also includes: a telescope parallel tube 1, a rotating interferometer system 4, a detection system, a detection unit, and a data processing system. The telescope parallel tube 1 includes a compound reflector 102 and a focusing unit. The compound reflector 102 is used to receive the laser light emitted by the pulsed laser emitter 2 and reflect the laser light from the central axis of the entire telescope parallel tube 1 to the transparent side of the detection gas chamber. The inner wall of the detection gas chamber is provided with a reflective layer. After the laser light is absorbed by the gas sample in the detection gas chamber or scattered by particulate matter, it is reflected by the reflective layer. The reflected laser light then passes through the detection unit again. The light-transmitting side of the gas chamber returns to the focusing section inside the telescope parallel tube 1, which is used to focus the laser light. The rotating interference system 4 is used to receive the focused laser light and cause it to interfere. The detection system is used to receive the interfered laser light and convert it into absorbed photoelectric signals and scattered photoelectric signals. The detection unit is located in the detection gas chamber and is used to detect the ambient temperature and humidity inside the detection gas chamber. The data processing system is electrically connected to the detection unit and the detection system. The data processing system calculates the particle size distribution and concentration information of the particulate matter in the gas sample based on the scattered photoelectric signals. Then, the absorbed photoelectric signals are subjected to Fourier transform to generate a spectrum. The data processing system performs temperature and humidity compensation correction on the data of the spectrum based on the ambient temperature and humidity inside the detection gas chamber to reduce environmental interference. Finally, the composition and concentration of the gas sample are analyzed based on the compensated and corrected spectrum.

[0021] The working principle of the above embodiments is briefly described below: The telescope parallel tube 1 is fixed with a vibration-resistant bracket to adapt to the bumpy environment of the detection site.

[0022] When this device is working, the sampling probe first collects a gas sample, which then enters the detection chamber through the connecting channel. The gas flow rate is controlled between 50 mL / min and 200 mL / min, and the real-time gas pressure value of the detection chamber is controlled within atmospheric pressure ±5 kPa.

[0023] The pulsed laser emitter 2 emits a detection laser, which is received by the composite reflector 102 of the telescope parallel tube 1 and reflected along the central axis of the telescope parallel tube 1 to the light-transmitting side of the detection gas chamber.

[0024] The laser beam passes through the light-transmitting side of the detection chamber and enters the chamber (the optical path length within the detection chamber can be adjusted by the chamber's design structure, ranging from 0.5m to 2m). Part of the laser interacts with target gas molecules within the detection chamber, where the target gas molecules selectively absorb infrared light of a specific wavelength. Another part of the laser is scattered by particles in the sample gas within the detection chamber. The selectively absorbed and scattered laser beam is then reflected by the reflective layer on the inner wall of the detection chamber (the reflective layer is an inert material coating), and then interacts again with the gas molecules and particles within the detection chamber. Finally, it passes through the light-transmitting side of the detection chamber and returns to the focusing section of the telescope parallel tube 1. During this process, the laser's optical path is extended, allowing for sufficient absorption by the gas molecules within the detection chamber and increasing the probability of collision between the laser and particles, thereby enhancing the intensity of the final absorbed and scattered photoelectric signals. The focusing section concentrates the received laser beam to the curved reflector 101, which then reflects it to the curved reflective surface of the composite reflector 102 for further focusing. The focused laser enters the rotating interference system 4 and produces interference. The interfered laser will produce interference laser. The focused laser can enhance the intensity of laser interference, thereby enhancing the intensity of the final absorbed photoelectric signal and scattered photoelectric signal.

[0025] After the interferometric laser is received by the detection system, it is converted into absorption and scattering photoelectric signals. The data processing system is electrically connected to the detection unit and the detection system. The data processing system first performs analog-to-digital conversion on the absorption and scattering photoelectric signals (analog electrical signals) detected by the detection system. The data processing system, equipped with dedicated algorithm software, analyzes and calculates the scattering photoelectric signal (digital signal), analyzing its intensity and the laser scattering angle it reflects. Combining Mie scattering theory and other algorithms, it accurately calculates the particle size distribution and concentration of particulate matter. This algorithm can perform Fourier transform on the absorption photoelectric signal to generate a spectrum. The data processing system performs temperature and humidity compensation correction on the spectrum data based on the ambient temperature and humidity in the detection chamber detected by the detection unit to reduce environmental interference and suppress clutter signals. Then, the data processing system compares it with a preset standard gas spectral library (such as the HITRAN database) and, using the Beer-Lambert law, inverts various gas components (such as CO, SO, NO). xThe data processing system performs temperature and humidity compensation as follows: the temperature sensor (accuracy ±0.1℃) and humidity sensor (accuracy ±1%RH) in the detection unit continuously monitor the environmental parameters in the detection chamber, transmitting the temperature and humidity data to the data processing system every 0.05 seconds. The system first filters and preprocesses the raw temperature and humidity data, removing transient fluctuations (such as humidity spikes caused by sampling airflow impact), retaining stable and valid environmental parameter values, and simultaneously recording the absorption photoelectric signal and spectral data at the corresponding time, establishing a one-to-one correspondence between "temperature and humidity" and "spectrum," providing a precise data benchmark for subsequent compensation. Secondly, the system performs precise adaptation and distortion correction of the compensation algorithm. The system has a built-in preset temperature and humidity compensation algorithm model, which is constructed based on the spectroscopic characteristics of gas molecules and has pre-recorded various target gases (CO, SO, NO) under different temperature and humidity conditions (such as temperature 5-40℃, humidity 10%-90%RH). x The system analyzes the absorption coefficient shift patterns, laser wavelength drift, and spectral baseline fluctuations of gases such as oxygen, carbon dioxide, and particulate matter (VOCs). For the original spectrum generated by Fourier transform, the system first extracts characteristic parameters (such as characteristic peak position, peak intensity, and baseline flatness). Then, combining real-time temperature and humidity data, it corrects three core distortions using algorithms: first, it corrects the decrease in gas molecule absorption coefficient and characteristic peak broadening caused by temperature increases, adjusting the peak intensity according to the absorption coefficient correction factor at the corresponding temperature; second, it corrects laser scattering loss and spectral baseline drift caused by humidity changes, offsetting the interference of water vapor on infrared light through a baseline calibration algorithm; and third, it corrects the characteristic peak position shift caused by the coupling effect of temperature and humidity, adjusting the characteristic peak coordinates based on the preset shift formula in the model to restore the true absorption spectrum of gas molecules. Finally, the system verifies and optimizes the compensated data. After correction, the system compares the compensated spectrum with a standard spectrum under standard temperature and humidity (e.g., 25℃, 50%RH) to verify whether the characteristic peak matching degree and baseline stability meet the standards. If the deviation exceeds a preset threshold (±2%), a second fine-tuning is performed based on historical data and the algorithm iteration model to ensure compensation accuracy. Meanwhile, the system will record and archive the temperature and humidity data, compensation parameters, and correction results to continuously optimize the adaptability of the algorithm model and improve the compensation stability under complex temperature and humidity fluctuation scenarios.

[0026] Taking industrial waste gas emission detection as an example, the device is placed 5m-10m downwind of the factory exhaust outlet, with the sampling probe aligned with the exhaust direction. After being powered by the lithium battery, the particulate matter detection channel outputs data in real time, and the gas detection channel outputs component concentration data once every second, achieving synchronous and accurate detection of particulate matter and gas components.

[0027] The particulate matter and gas component detection imaging device of the present invention integrates a dual system of particulate matter laser scattering detection and gas interferometric spectroscopy detection, which can simultaneously acquire particulate matter size distribution, concentration and multiple gas components (such as CO, SO, NO).x Concentration data for gases such as VOCs can be collected without splitting the detection process, significantly improving detection efficiency and adapting to the needs of simultaneous multi-parameter monitoring. A multi-reflection optical path is constructed using a composite reflector 102 with a telescope parallel tube 1, a focusing section, and a reflective layer on the inner wall of the detection chamber, thereby extending the laser's optical path. For gas component detection, the longer optical path allows for more complete interaction between gas molecules and the laser, amplifying the selective absorption effect of infrared light, increasing the absorption signal intensity, and enabling low-concentration gases to generate identifiable signals. For particulate matter detection, the extended optical path increases the probability of laser-particle collision, increasing the intensity of scattered light and reducing loss. The synergistic focusing of the composite reflector 102 and the curved reflector 101 further strengthens the signal. The data processing system, combined with relevant algorithms, accurately extracts parameters and reduces environmental interference and measurement errors by performing temperature and humidity compensation correction on the spectral data. By increasing the intensity of the detection signal and reducing environmental interference, the signal-to-noise ratio of the overall detection signal is improved, thereby simultaneously enhancing the sensitivity and accuracy of both types of detection.

[0028] As a preferred option, such as Figure 1 As shown, the focusing section includes a curved reflector 101, which is disposed on one side of the composite reflector 102. The laser light passing through the detection chamber is received by the curved reflector 101, focused, and then reflected. The composite reflector 102 has a curved reflective surface. The laser light reflected from the curved reflector 101 is received by the curved reflective surface on the composite reflector 102, which then focuses and reflects the laser light a second time. The rotating interference system 4 receives the laser light after this second focusing and causes interference. This second focusing mechanism using the curved reflector 101 and the curved reflective surface not only improves the laser intensity but also optimizes the parallelism and stability of the laser beam, reducing energy loss and stray light interference during laser transmission. Compared to single-focusing, double-focusing can improve the contrast of interference fringes by 40%, effectively reducing interference noise under weak signals, and enabling the detection system to more accurately separate absorbed light and scattered light signals. It is especially suitable for detection scenarios with low concentrations of gas and small particles, thereby improving detection accuracy.

[0029] As a preferred option, such as Figure 1As shown, the detection system includes a gas component analysis system 5 and a particulate matter analysis system 6. The gas component analysis system 5 includes a bandpass filter and an infrared detector. The bandpass filter separates the mid-infrared light in the interferometric laser, and the infrared detector converts the mid-infrared light into an absorption photoelectric signal. The particulate matter analysis system 6 includes a narrowband filter and a photodetector. The narrowband filter separates the backscattered light in the interferometric laser, and the photodetector converts the backscattered light into a scattered photoelectric signal. The data processing system is electrically connected to the infrared detector and the photodetector. After the interferometric laser passes through the bandpass filter of the gas component analysis system 5, the mid-infrared light in the interferometric laser is separated. The infrared detector (such as a mercury cadmium telluride detector, MCT) converts this mid-infrared light into an absorption photoelectric signal, which is then transmitted to the data processing system. When the laser passes through the detection chamber, if particulate matter is present in the chamber, the laser will backscatter. The backscattered light enters the particulate matter analysis system 6, is filtered by a narrow-band filter, and then received by a high-sensitivity photodetector (based on S and P polarization reception). The photodetector converts the backscattered light signal into an electrical signal and transmits it to the data processing system. A bandpass filter is precisely calibrated to the mid-infrared band (2.5μm-15μm) to ensure efficient separation of mid-infrared light from the interferometric laser, eliminating interference from scattered light and stray light. The infrared detector (preferably a mercury cadmium telluride (MCT) detector) is calibrated for signal conversion sensitivity to capture and convert weak mid-infrared signals. In the particulate matter analysis system, the narrow-band filter is calibrated to the corresponding band of the backscattered light to accurately filter it out. The photodetector's response speed and polarization reception capability are calibrated to ensure efficient conversion of the scattered light signal, thereby further improving the signal-to-noise ratio and the final detection accuracy.

[0030] As a preferred option, such as Figure 1 As shown, the data processing system is electrically connected to a signal amplifier, which amplifies the electrical signals of mid-infrared light and backscattered light. The mid-infrared photoelectric signal output from the infrared detector and the backscattered photoelectric signal output from the photodetector are synchronously transmitted to the signal amplifier. The amplifier performs targeted amplification of the two types of signals, effectively increasing the amplitude of weak signals and reducing signal distortion caused by noise interference, thereby improving detection accuracy.

[0031] As a preferred option, such as Figure 1As shown, a dust pretreatment module is installed between the sampling probe and the detection chamber. This module filters particulate matter with a diameter greater than 10 μm. By filtering particles larger than 10 μm while allowing smaller particles to enter the detection chamber, the dust pretreatment module prevents large particles from contaminating the gas sample and affecting the detection results. The dust pretreatment module and the detection chamber reduce the impact of particulate matter deposition and gas adsorption on the detection, thereby improving detection accuracy. The detection chamber is connected to a tail gas treatment device to environmentally treat the detected gas sample before discharge.

[0032] As a preferred option, such as Figure 1 As shown, a flow controller and a pressure sensor are installed between the sampling probe and the detection gas chamber. The pressure sensor detects the real-time gas pressure inside the detection gas chamber. The flow controller is electrically connected to the pressure sensor and has a preset pressure value. The flow controller controls the gas flow rate entering the detection gas chamber based on the real-time gas pressure to maintain the real-time gas pressure within the preset value. By using the flow controller and pressure sensor between the sampling probe and the detection gas chamber, the flow controller can precisely regulate the gas flow rate to the detection gas chamber, ensuring it remains between 50 mL / min and 200 mL / min. The pressure sensor detects the real-time gas pressure inside the detection gas chamber and controls the flow controller accordingly. This allows for precise adjustment of the real-time gas pressure inside the detection gas chamber, maintaining it at a preset pressure value (atmospheric pressure ± 5 kPa). This ensures a stable detection environment within the detection gas chamber, further reducing the impact of environmental factors on the detection results and improving detection accuracy.

[0033] As a preferred option, such as Figure 1 and Figure 4As shown, the rotating interference system 4 includes a beam splitter, a moving mirror, a fixed mirror, and a lens. The beam splitter splits the focused laser into two paths. One laser beam is reflected after illuminating the moving mirror, and the other is reflected after illuminating the fixed mirror. By adjusting the position of the moving mirror, the optical path difference between the laser emitted by the moving mirror and the laser reflected by the fixed mirror can be adjusted. The lasers reflected by the moving mirror and the lasers reflected by the fixed mirror intersect at the lens, producing interference. The two interfering laser beams then illuminate a bandpass filter and a narrowband filter, respectively. When the focused laser beam is incident on the beam splitter, it is split into two laser beams of the same origin. One beam is reflected by the moving mirror, and the other is reflected by the fixed mirror. The two laser beams intersect at the lens and interfere. By adjusting the position of the moving mirror, the optical path difference between the two laser beams is changed, resulting in stable interference fringes after intersection. This design allows for precise control of the optical path difference according to detection requirements (such as the absorption bands of different gas components and the scattering characteristics of particulate matter), optimizing the interference signal strength and clarity, and avoiding the weak signal problem caused by a fixed optical path difference. The two interferometric laser beams are precisely directed to the bandpass filter and the narrowband filter, respectively, ensuring a stable signal supply for the dual detection system, further improving the separation accuracy of gas and particulate matter signals, and enhancing the reliability of the detection results.

[0034] As a preferred option, such as Figure 1 and Figure 3As shown, the system also includes an imaging system 3. The laser reflected from the reflective layer within the detected gas chamber is split into two paths: one path illuminates the curved reflector 101, and the other path is received by the imaging system 3. The imaging system 3 is electrically connected to the data processing system. The imaging system 3 images the received laser and transmits the image to the data processing system. The data processing system performs noise reduction, enhancement, and segmentation on the image signal to highlight the characteristic information of the particulate matter and gas samples. Then, it counts the particulate matter in the image signal, measures the particle size, and visualizes the gas concentration, ultimately outputting a visualized image of the particulate matter and gas distribution. The imaging system 3 uses a charge-coupled device (CCD) camera or a complementary metal-oxide-semiconductor (CMOS) camera as the imaging element. An imaging lens is placed at a specific location within the detected gas chamber to image the scattered or absorbed light from the particulate matter and gas within the chamber onto the photosensitive surface of the imaging system 3. The image signal acquired by the imaging system 3 is transmitted to the data processing system for processing and analysis, providing a visual representation of the spatial distribution of particulate matter and gas. The data processing system includes an image acquisition card, image processing software, and a display. The image acquisition card transmits the image signals acquired by the imaging system 3 to the image processing software. The software performs noise reduction, enhancement, and segmentation on the images to highlight the characteristic information of particulate matter and gases. Using existing algorithms, it can count particles, measure particle size, and visualize gas concentrations (e.g., using different color gradients to label gas distribution areas in the image based on gas concentration detected by interferometric laser). Finally, a clear image of particulate matter and gas distribution is displayed on the monitor. The image processing software of the data processing system simultaneously generates a real-time distribution map containing particulate matter counts and gas concentration color annotations, which is then displayed on the monitor. During the detection process, staff can view the data on the monitor. If a gas concentration exceeds the standard, the sampling location can be adjusted, and the specific emission point of the pollution source can be located by combining the imaging map. After the detection is completed, the data is automatically saved in Excel format, and the imaging map is saved in JPG format for easy report compilation.

[0035] As a preferred option, such as Figure 1 As shown, the bandpass filter is a mid-infrared bandpass filter, and the infrared detector is a cooled mercury cadmium telluride infrared detector. The fundamental vibrational absorption peaks of most gas molecules (such as CH4, CO2, CO, NH3, etc.) are located in the mid-infrared band (2.5μm-25μm). This means that in the mid-infrared band, gas absorption of light is very significant; even a slight change in gas concentration can cause a significant change in light intensity, thus achieving high-sensitivity detection. The mid-infrared bandpass filter can accurately filter out the characteristic wavelengths of corresponding gases. The cooled mercury cadmium telluride infrared detector is currently one of the best-performing photodetectors in the mid-infrared (MWIR) and long-wave infrared (LWIR) bands, and is widely used in high-end infrared imaging, spectral analysis, and laser detection systems.

[0036] As a preferred option, such as Figure 1 As shown, the reflective layer in the detection chamber is an inert material coating. The reflective layer uses an inert material coating (such as a gold-plated coating), which possesses excellent chemical stability and can resist corrosive gases (such as SO2 and NO) within the detection chamber. x This process avoids erosion and oxidation of the reflective layer, preventing a decrease in reflectivity and ensuring stable optical path reflection efficiency during long-term detection, thus reducing signal loss. Simultaneously, the gold-plated coating possesses extremely high infrared reflectivity, maximizing the reflection of mid-infrared and scattered light. Combined with a multi-reflection optical path design, this further extends the optical path, enhances the interaction between the laser and the sample, amplifies low-concentration signals, and improves detection sensitivity.

[0037] The present invention also provides a method of using a particulate matter and gas component detection imaging device, comprising the following steps: A gas sample is collected by a sampling probe and introduced into the detection chamber. The flow rate of the gas sample is adjusted to 50 L / min-200 mL / min, and the gas pressure in the detection chamber is stabilized at atmospheric pressure ±5 kPa. The pulsed laser emitter 2 emits a laser, which is reflected by the composite mirror 102 of the telescope parallel tube 1 to the light-transmitting side of the detection gas chamber; When the laser passes through the detection chamber, it is selectively absorbed by the gas sample or scattered by the particulate matter. Then it is reflected by the reflective layer on the inner wall of the detection chamber. The reflected laser is selectively absorbed or scattered again, and then it is received by the focusing part in the telescope parallel tube 1. The focusing part focuses the laser. The focused laser beam enters the rotating interferometer system 4 and produces interference. The detection system converts the interfering laser beam into an electrical signal. The ambient temperature and humidity inside the detection chamber are measured using the testing department. The data processing system receives electrical signals and then calculates the particle size distribution and concentration information of particulate matter in the gas sample based on the scattered photoelectric signals. After performing Fourier transform on the absorbed photoelectric signals, a spectrum is generated. The data of the spectrum is then compensated for by temperature and humidity based on the ambient temperature and humidity in the detection chamber. Finally, the composition and concentration of the gas sample are analyzed based on the compensated spectrum.

[0038] Specific examples: Calibration of particulate matter detection channel: Select standard polystyrene latex ball (PSL) samples with particle sizes of 0.3μm, 1μm, and 5μm, and introduce them into the detection gas chamber through the sampling probe; adjust the laser source power of pulsed laser emitter 2 to 5mW-10mW, and adjust the gain of photodetector accordingly until the particle size distribution data output by the system deviates from the standard sample by ≤5%, thus completing the calibration.

[0039] Gas detection channel calibration: Introduce a standard mixed gas of known concentration (e.g., CO2: 500 ppm, SO2: 100 ppm, NO2: 100 ppm) into the detection chamber. x (50ppm) The rotating interferometer system 4 is activated to interfere with the reflected laser, and the infrared absorption spectrum is collected by the gas component analysis system 5. The data processing system compares it with the standard spectral library. The moving mirror speed of the rotating interferometer system 4 (0.1cm / s-0.5cm / s) and the integration time of the infrared detector (10ms-50ms) are adjusted so that the deviation between the gas concentration detection value and the standard concentration is ≤3%. At the same time, environmental data in the temperature range of 5℃-40℃ and humidity range of 20%-80% are collected by temperature and humidity sensors to establish a temperature and humidity compensation model and complete the calibration.

[0040] Imaging System 3 Debugging: Using the 1951 USAF resolution board as the shooting object, the focal length and exposure parameters of Imaging System 3 were adjusted to ensure that the image resolution reached 1024×768 pixels or higher, and that the edges were clear and without distortion; the gas concentration-color mapping rules (low concentration: blue, medium concentration: yellow, high concentration: red) were set through the software of the data processing system to verify the matching degree between the imaging labels and the actual detection data, and the debugging was completed.

[0041] Furthermore, this device can also be used independently of the detection chamber. It can be combined with a pulsed laser emitter 2, a telescope parallel tube 1, a rotating interferometer system 4, a detection system, a detection unit, and a data processing system. The combined device serves as a telemetry unit. The composite reflector 102 of the telescope parallel tube 1 directs the detection laser emitted by the pulsed laser emitter 2, ensuring the laser is directly directed along a preset central axis towards the target area of ​​the environment being measured. During atmospheric propagation, the laser selectively absorbs gas molecules within the target area and scatters with particulate matter. The laser carrying gas composition and particulate matter characteristics is reflected back to the telescope parallel tube 1 and received by the focusing unit. The focusing unit then concentrates the returned laser before transmitting it to the rotating interferometer system 4. The rotating interferometer system 4 uses a beam splitter, a moving mirror, a fixed mirror, and a lens to create stable interference. The interfered laser is then transmitted to the detection system. The mid-infrared light is separated by the bandpass filter of the gas composition analysis system 5, converted into an absorbed photoelectric signal by the infrared detector, and then separated by the narrowband filter of the particulate matter analysis system 6 before being scattered. The light and photodetector convert the scattered photoelectric signals into scattered photoelectric signals. Simultaneously, the detection unit collects the ambient temperature and humidity parameters of the area to be measured in real time and transmits them to the data processing system. The data processing system first amplifies and performs analog-to-digital conversion on the two types of photoelectric signals. Based on the Mie scattering theory, it calculates the particle size distribution and concentration information of the particulate matter in the area to be measured according to the scattered photoelectric signals. It performs Fourier transform on the absorbed photoelectric signals to generate a spectrum. Based on the real-time temperature and humidity data, it performs temperature and humidity compensation correction on the spectrum to eliminate noise interference caused by factors such as ambient temperature, humidity, and air pressure. Then, it compares the corrected spectrum with the standard gas spectrum library and uses the Beer-Lambert law to invert the gas composition and concentration of the target area. At the same time, it can be used with the imaging system 3 to receive the returned laser signals to complete the imaging processing. After noise reduction, enhancement, and segmentation, it realizes the visualization and labeling of particulate matter and gas distribution. Finally, it completes the long-distance real-time telemetry of gas and particulate matter in open environments without the need to collect gas samples. It is suitable for the non-contact rapid detection needs of open scenarios such as industrial parks, atmospheric monitoring stations, and the vicinity of pollution sources, greatly expanding the application scenarios and usage flexibility of the device.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A particulate matter and gas component detection imaging device, comprising a sampling probe, a detection chamber, and a pulsed laser emitter (2), wherein the detection chamber collects gas samples through the sampling probe, one side of the detection chamber is transparent, and the pulsed laser emitter (2) is used to emit laser light for detection and analysis, characterized in that, Also includes: The telescope parallel tube (1) includes a composite reflector (102) and a focusing part. The composite reflector (102) is used to receive the laser emitted by the pulse laser emitter (2) and reflect the laser from the central axis of the entire telescope parallel tube (1) to the light-transmitting side of the detection gas chamber. The inner wall of the detection gas chamber is provided with a reflective layer. After the laser is absorbed by the gas sample in the detection gas chamber or scattered by particulate matter, it is reflected by the reflective layer. The reflected laser passes through the light-transmitting side of the detection gas chamber again and returns to the focusing part in the telescope parallel tube (1). The focusing part is used to focus the laser. A rotating interference system (4) is used to receive the focused laser and cause the focused laser to interfere. The detection system is used to receive the interferometric laser and convert it into absorbed photoelectric signals and scattered photoelectric signals; The testing section, located in the testing chamber, is used to test the ambient temperature and humidity inside the testing chamber. The data processing system is electrically connected to the detection unit and the detection system. The data processing system calculates the particle size distribution and concentration information of particulate matter in the gas sample based on the scattered photoelectric signal. Then, it performs a Fourier transform on the absorbed photoelectric signal to generate a spectrum. The data processing system performs temperature and humidity compensation correction on the spectrum data based on the ambient temperature and humidity in the detection chamber to reduce environmental interference. Finally, it analyzes the composition and concentration of the gas sample based on the compensated and corrected spectrum.

2. The particulate matter and gas component detection imaging device as described in claim 1, characterized in that, The focusing part includes a curved reflector (101), which is located on one side of the composite reflector (102). The laser light that passes through the detection chamber twice is received by the curved reflector (101) and then focused and reflected. The composite reflector (102) is provided with a curved reflective surface. The laser light reflected on the curved reflector (101) is received by the curved reflective surface on the composite reflector (102). The curved reflective surface focuses and reflects the laser light twice. The rotating interference system (4) receives the laser light after the second focusing and causes the laser light after the second focusing to interfere.

3. The particulate matter and gas component detection imaging device as described in claim 2, characterized in that, The detection system includes a gas component analysis system (5) and a particulate matter analysis system (6). The gas component analysis system (5) includes a bandpass filter and an infrared detector. The bandpass filter is used to separate mid-infrared light in the interferometric laser, and the infrared detector is used to convert mid-infrared light into an absorbed photoelectric signal. The particulate matter analysis system (6) includes a narrowband filter and a photodetector. The narrowband filter is used to separate backscattered light in the interferometric laser, and the photodetector converts backscattered light into a scattered photoelectric signal. The data processing system is electrically connected to the infrared detector and the photodetector.

4. The particulate matter and gas component detection imaging device as described in claim 3, characterized in that, The data processing system is electrically connected to a signal amplifier, which is used to amplify the electrical signals of mid-infrared light and backscattered light.

5. The particulate matter and gas component detection imaging device as described in claim 1, characterized in that, A flow controller and a pressure sensor are provided between the sampling probe and the detection chamber. The pressure sensor is used to detect the real-time air pressure value in the detection chamber. The flow controller is electrically connected to the pressure sensor. A predetermined air pressure value is preset in the flow controller. The flow controller controls the flow rate of gas entering the detection chamber according to the real-time air pressure value in the detection chamber, so that the real-time air pressure value in the detection chamber is maintained at the predetermined air pressure value.

6. The particulate matter and gas component detection imaging device as described in claim 3, characterized in that, The rotating interference system (4) includes a beam splitter, a moving mirror, a fixed mirror, and a lens. The beam splitter is used to split the focused laser into two paths. One laser path is reflected after irradiating the moving mirror, and the other laser path is reflected after irradiating the fixed mirror. By adjusting the position of the moving mirror, the optical path difference between the laser emitted by the moving mirror and the laser reflected by the fixed mirror can be adjusted. The laser reflected by the moving mirror and the laser reflected by the fixed mirror intersect on the lens and then interfere. The two laser paths after interference are respectively irradiated onto the bandpass filter and the narrowband filter.

7. The particulate matter and gas component detection imaging device as described in claim 1, characterized in that, A dust pretreatment module is provided between the sampling probe and the detection chamber. The dust pretreatment module is used to filter particulate matter with a particle size greater than 10 μm.

8. The particulate matter and gas component detection imaging device as described in claim 1, characterized in that, The detection unit includes a temperature sensor and a humidity sensor. The temperature sensor is used to detect the ambient temperature inside the detection chamber, and the humidity sensor is used to detect the ambient humidity inside the detection chamber. Both the temperature sensor and the humidity sensor are electrically connected to the data processing system.

9. The particulate matter and gas component detection imaging device as described in claim 2, characterized in that, It also includes an imaging system (3). The laser reflected by the reflective layer in the detected air chamber is divided into two paths. One laser irradiates the curved reflector (101), and the other laser is received by the imaging system (3). The imaging system (3) is electrically connected to the data processing system. The imaging system (3) transmits the received laser image to the data processing system. The data processing system performs noise reduction, enhancement and segmentation processing on the image signal to highlight the characteristic information of particulate matter and gas samples. Then, it counts the particulate matter in the image signal, measures the particle size and visualizes the gas concentration. Finally, it outputs a visualized image of particulate matter and gas distribution.

10. The method of using the particulate matter and gas component detection imaging device as described in claim 1, characterized in that, Includes the following steps: A gas sample is collected by a sampling probe and introduced into the detection chamber. The flow rate of the gas sample is adjusted to 50 mL / min-200 mL / min, and the gas pressure in the detection chamber is stabilized at atmospheric pressure ±5 kPa. The pulsed laser emitter (2) emits a laser, which is reflected by the composite mirror (102) of the telescope parallel tube (1) to the light-transmitting side of the detection gas chamber; When the laser passes through the detection chamber, it is selectively absorbed by the gas sample or scattered by the particles. Then it is reflected by the reflective layer on the inner wall of the detection chamber. The reflected laser is selectively absorbed or scattered again, and then received by the focusing part in the telescope parallel tube (1). The focusing part focuses the laser. The focused laser enters the rotating interference system (4) and produces interference. The detection system converts the interfered laser into an electrical signal. The ambient temperature and humidity inside the detection chamber are measured using the testing department. The data processing system receives electrical signals and then calculates the particle size distribution and concentration information of particulate matter in the gas sample based on the scattered photoelectric signals. After performing Fourier transform on the absorbed photoelectric signals, a spectrum is generated. The data of the spectrum is then compensated for by temperature and humidity based on the ambient temperature and humidity in the detection chamber. Finally, the composition and concentration of the gas sample are analyzed based on the compensated spectrum.

Images