Airflow organization three-dimensional visualization measuring device and method

Abstract

The application discloses a kind of airflow organization three-dimensional visualization measuring device and method, it is related to airflow organization visualization detection, fluorescence spectrum analysis and electronics field, solve the problem that biological aerosol concentration distribution in indoor airflow organization cannot be measured in real time and visualized.Relative intensity distribution of fluorescence tracer concentration field in airflow organization is measured by laser radar scanning, laser radar telemetry data results are calibrated using fixed point fluorescence particle counting device, and interpolation is carried out on the laser radar scanning data after calibration, finally, the data results measured by laser radar are background-subtracted and displayed in the form of three-dimensional pseudo-color image on the measurement and control terminal computer.The application solves the limitation that existing detection methods cannot non-invasively measure airflow organization and biological aerosol distribution in three-dimensional space, and improves the accuracy and resolution of airflow organization and biological aerosol measurement.

Description

Technical Field

[0001] This invention relates to the fields of visual detection of airflow organization, fluorescence spectroscopy analysis, and electronics, specifically a visual detection device and method for the spatial distribution of airflow organization and bioaerosol concentration field in enclosed spaces such as hospitals or conference rooms. Background Technology

[0002] Visual measurement of airflow organization is a technique for studying indoor air flow and distribution, widely used in the design of fresh air conditioning systems and industrial environmental control. Traditional methods for evaluating the spatial distribution of airflow organization rely on complex mathematical models and calculations, which have certain limitations. They cannot accurately reflect the actual distribution of airflow organization within an indoor space.

[0003] In enclosed spaces such as hospitals and conference rooms, indoor airflow patterns often carry a large number of biologically-based particulate matter (aerosols), known as bioaerosols. Bioaerosols contain various pathogenic and non-pathogenic biological components, such as active or inactive fungi and bacteria, bacterial or fungal toxins, viruses, macromolecular allergens, and pollen. These complex and diverse bioaerosol components are directly influenced by human behavior and are closely related to human health, with pathogenic components constantly threatening human health. To mitigate the harm caused by harmful airflow patterns and protect key populations, the spatial distribution and monitoring of airflow patterns and bioaerosol concentration fields in specific scenarios are crucial. Considering the flow characteristics of airflow patterns, real-time techniques with a certain coverage area are preferable. Summary of the Invention

[0004] (I) Purpose of the Invention

[0005] The purpose of this invention is to provide a three-dimensional visualization measurement device and method for airflow organization, which solves the problem that the concentration distribution of bioaerosols in indoor airflow organization cannot be measured and visualized in real time.

[0006] (II) Technical Solution

[0007] To achieve the above objectives and solve the above technical problems, the technical solution of the present invention is as follows:

[0008] A three-dimensional visualization measurement method for airflow organization includes the following steps:

[0009] S1, use lidar to scan and measure the airflow containing fluorescent tracers to obtain the intensity distribution of scattered fluorescence signals in space;

[0010] S2, using a fluorescent particle counting device to perform air sampling at a specific location to obtain measured bioaerosol concentration data; combined with the lidar system in step S1, a rough distribution of the measured bioaerosol concentration field is obtained;

[0011] S3. Combine the measured bioaerosol concentration data obtained by the fluorescent particle counting device at a specific location, and use the rough distribution of the bioaerosol concentration field to calibrate the measurement results of the lidar system based on the measured data of the fluorescent particle counting device at the corresponding location, and establish a linear relationship between the fluorescence signal intensity and the measured bioaerosol concentration.

[0012] S4 repeats the S1-S3 process, and finally obtains the correspondence between the measurement results of the lidar system and the measured concentration of bioaerosols, outputting the fine distribution of the reconstructed aerosol concentration field.

[0013] S5 displays the fine distribution of bioaerosol concentration in the airflow organization as a three-dimensional pseudo-color image, realizing spatial three-dimensional visualization of airflow organization and bioaerosol concentration field distribution.

[0014] A three-dimensional visualization measurement device for airflow organization includes a lidar and a fluorescent particle counting device;

[0015] A lidar system consists of a laser emitting unit, a scanning unit, a signal detection unit, a signal acquisition unit, and a display and control terminal computer.

[0016] The laser emitting unit is used to emit laser light to induce fluorescence scattering in bioaerosol molecules;

[0017] The scanning unit is used to control the laser emission direction in order to measure the concentration distribution of bioaerosols in different directions;

[0018] The signal detection unit is used to receive the fluorescence scattering echo signal generated by bioaerosol molecules and convert it into an electrical pulse signal that the measuring device can process;

[0019] The signal acquisition unit is used to convert the electrical pulse signal output by the signal detection unit into a digital signal and upload it to the display and control terminal computer;

[0020] The display and control terminal computer is used to control the measurement process and process the measurement results, and to visualize the measurement results as a three-dimensional concentration field in real time.

[0021] The laser emitting unit emits two laser beams, one for identifying bioaerosol clouds and the other for identifying non-bioaerosol clouds. One beam, emitted from a 355nm high-repetition-rate (HRRF) semiconductor laser source, is expanded by a 355nm HRF semiconductor laser source beam expander. The other beam, emitted from a 470nm HRF semiconductor laser source, is expanded by the same 355nm HRF semiconductor laser source beam expander. The two beams, expanded separately, are then combined by a laser beam combiner before being emitted into the space containing the indoor airflow organization via a transmitting and receiving telescope and a scanning unit. The lasers are then targeted at areas containing fluorescent tracers. The airflow structure is scanned and measured; the backscattered fluorescence signal generated by the interaction between the laser and the fluorescent tracer in the airflow structure is received by the transmitting and receiving telescopes, and the background stray light is suppressed by the aperture. Then, it enters the color separation and filtering mechanism for signal reception wavelength selection. The filtered fluorescence scattering signal and the airflow structure Mie scattering signal enter the corresponding signal detection unit for photoelectric conversion. The laser backscattered echo signal is converted into an electrical pulse signal and enters the signal acquisition unit. The signal acquisition unit converts the electrical pulse signal into a digital signal and uploads it to the display and control terminal computer. The measurement and control software running on the display and control terminal computer performs signal analysis.

[0022] The detection unit contains two fluorescence signal detection channels: 470nm as the laser emission wavelength and 520nm as the fluorescence detection wavelength; 355nm is used as both the laser emission wavelength and the Mie scattering signal detection wavelength; the 355nm Mie scattering signal is used for the localization of airflow organization and background obstacle targets, and the 520nm fluorescence detection is used to correct the fluorescence signal and improve the inversion accuracy of the bioaerosol concentration field.

[0023] The fluorescent particle counting device collects measurement data and then uses it to calibrate the measurement results of the lidar.

[0024] (III) Effective Returns

[0025] This invention overcomes the limitations of existing detection methods that cannot non-invasively measure airflow organization and bioaerosol distribution in three-dimensional space, thereby improving the accuracy and resolution of airflow organization and bioaerosol measurements.

[0026] This invention establishes a bioaerosol concentration measurement device based on lidar, realizing real-time measurement of bioaerosol concentration in the air; this invention also proposes a spatial scanning measurement method, realizing the measurement of bioaerosol concentration at various locations in a three-dimensional indoor space.

[0027] This invention proposes a three-dimensional visualization inversion method for concentration field distribution, which realizes the reconstruction of three-dimensional concentration field data from discrete concentration data at various locations and visualizes it in real time.

[0028] This invention can provide guidance and decision-making basis for the diffusion assessment of airflow organization under typical indoor environmental conditions such as hospitals and conference rooms. Attached Figure Description

[0029] Figure 1 This is a structural diagram of the lidar of the present invention;

[0030] Figure 2 This is a structural diagram of the fluorescent particle counting device of the present invention;

[0031] Figure 3 This is a schematic diagram of the three-dimensional visualization inversion process of airflow organization and concentration field distribution in this invention. Detailed Implementation

[0032] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments.

[0033] Laser remote sensing is a technology that enables automatic, real-time, and continuous detection of airflow organization over a wide area. However, existing airflow organization detection methods have limitations, namely, they cannot non-invasively measure the airflow organization and bioaerosol distribution in three-dimensional space. Therefore, in order to meet the need for visual measurement of airflow organization and bioaerosol concentration field in small indoor spaces, this invention proposes a device based on the principle of laser-induced fluorescence, which combines lidar and fluorescent particle counting to achieve three-dimensional visual detection of indoor airflow organization concentration.

[0034] The design concept of this invention is described as follows: First, the relative intensity distribution of the fluorescent tracer concentration field in the airflow organization is measured by lidar scanning. Then, the lidar telemetry data results are calibrated using a fixed-point fluorescent particle counting device. The calibrated lidar scanning data is then interpolated. Finally, the lidar measurement data results are subjected to background subtraction and displayed as a three-dimensional pseudo-color image on the monitoring and control terminal computer. Ultimately, this achieves visualized monitoring of the spatial distribution characteristics of the bioaerosol concentration field in a small indoor space.

[0035] A three-dimensional visualization measurement method for airflow organization, the test procedure is as follows: Figure 3 As shown, it includes the following steps:

[0036] S1, use lidar to scan and measure the airflow containing fluorescent tracers to obtain the intensity distribution of scattered fluorescence signals in space;

[0037] S2, using a fluorescent particle counting device to perform air sampling at a specific location to obtain measured bioaerosol concentration data; combined with the lidar system in step S1, a rough distribution of the measured bioaerosol concentration field is obtained.

[0038] S3. Combine the measured bioaerosol concentration data obtained by the fluorescent particle counting device at a specific location, and use the rough distribution of the bioaerosol concentration field to calibrate the measurement results of the lidar system based on the measured data of the fluorescent particle counting device at the corresponding location, and establish a linear relationship between the fluorescence signal intensity and the measured bioaerosol concentration.

[0039] S4 repeats the S1-S3 process, and finally obtains the correspondence between the measurement results of the lidar system and the measured concentration of bioaerosols, outputting the fine distribution of the reconstructed aerosol concentration field.

[0040] S5 displays the fine distribution of bioaerosol concentration in the airflow organization as a three-dimensional pseudo-color image, realizing spatial three-dimensional visualization of airflow organization and bioaerosol concentration field distribution.

[0041] The distribution of bioaerosols is displayed using pseudo-color maps, the size of which corresponds to the spatial resolution of the lidar. The specific implementation process is as follows: different concentrations within the airflow are displayed on the software interface using different color blocks, the size of which corresponds to the spatial resolution of the lidar. These pseudo-color maps are then superimposed onto the real-world image according to their spatial dimensions. This creates a three-dimensional visualization pseudo-color map that reflects the spatial distribution of the bioaerosol concentration field and includes spatial distance parameters, thus achieving a spatial three-dimensional visualization reproduction of the airflow organization and the bioaerosol concentration field distribution.

[0042] Meanwhile, the present invention also provides a three-dimensional visualization measurement device for airflow organization, such as... Figure 1 As shown, the measuring device includes a lidar and a fluorescent particle counting device;

[0043] A lidar system consists of a laser emitting unit, a scanning unit, a signal detection unit, a signal acquisition unit, and a display and control terminal computer.

[0044] The laser emitting unit is used to emit laser light to induce fluorescence scattering in bioaerosol molecules;

[0045] The scanning unit is used to control the laser emission direction in order to measure the concentration distribution of bioaerosols in different directions;

[0046] The signal detection unit is used to receive the fluorescence scattering echo signal generated by bioaerosol molecules and convert it into an electrical pulse signal that the device can process;

[0047] The signal acquisition unit is used to convert the electrical pulse signal output by the signal detection unit into a digital signal and upload it to the display and control terminal computer;

[0048] The display and control terminal computer is used to control the measurement process and process the measurement results, and visualizes the measurement results as a three-dimensional concentration field in real time.

[0049] The laser emitting unit emits two laser beams, one for identifying bioaerosol clouds and the other for identifying non-bioaerosol clouds, thus distinguishing between the scattering signals generated by bioaerosols and the background air signals. The 355nm ultraviolet laser is used to effectively excite bioaerosol molecules and is less affected by atmospheric absorption, making it suitable for identifying bioaerosol clouds. The 470nm laser is used to distinguish between the scattering signals generated by bioaerosols and the background air signals. One beam, emitted by a 355nm semiconductor high-repetition-rate pulsed laser source 1, is expanded by a 355nm semiconductor high-repetition-rate pulsed laser source beam expander 2; the other beam, emitted by a 470nm semiconductor high-repetition-rate pulsed laser source 3, is expanded by a 355nm semiconductor high-repetition-rate pulsed laser source beam expander 4. The two beams, expanded separately, are then combined by a laser beam combiner 5 and emitted through a transmitting and receiving telescope 6 and a scanning unit 7 into the space containing the indoor airflow organization, where the airflow organization containing fluorescent tracers is scanned and measured. The backscattered fluorescence signal generated by the interaction between the laser and the fluorescent tracer in the airflow structure is received by the transmitting and receiving telescope 6, and the background stray light is suppressed by the aperture 8. Then, it enters the color separation and filtering mechanism 9 for signal reception wavelength selection. The selected fluorescence scattering signal and the airflow structure Mie scattering signal enter the corresponding signal detection unit 10 for photoelectric conversion. The laser backscattered echo signal is converted into an electrical pulse signal and enters the signal acquisition unit 11. The signal acquisition unit converts the electrical pulse signal into a digital signal and uploads it to the display and control terminal computer 12. The measurement and control software running on the display and control terminal computer performs signal analysis.

[0050] The detection unit contains two fluorescence signal detection channels: a 470nm laser emission wavelength, which excites the target to produce scattered fluorescence at a wavelength of 520nm, is therefore selected as the fluorescence detection wavelength; and a 355nm light source excites aerosol particles to emit Mie scattering signals of the same wavelength, so 355nm serves as both the laser emission wavelength and the Mie scattering signal detection wavelength. The 355nm Mie scattering signal is used for locating airflow organization and background obstacles, while the 520nm fluorescence detection is used to correct the fluorescence signal, improving the accuracy of the bioaerosol concentration field inversion.

[0051] Lidar devices can achieve real-time measurement of the intensity of fluorescence scattering signals of bioaerosols over long distances. However, the intensity of fluorescence scattering signals can only qualitatively reflect the concentration of bioaerosols. To achieve quantitative analysis of the concentration of bioaerosols along the laser target direction, it is necessary to calibrate the lidar measurement results using measurement data from a fluorescence particle counting device.

[0052] The fluorescent particle counting device can measure the precise number of bioaerosol particles at a fixed point, and the particle number is the most direct reflection of the bioaerosol concentration. By using a lidar and the fluorescent particle counting device to perform joint measurement on the same target area, and repeating the experiment by changing the concentration of the target area, the fluorescent scattering signal intensity can be calibrated with the number of bioaerosol particles, so as to realize long-distance and accurate measurement of bioaerosol concentration using the lidar. For example Figure 2 As shown, the fluorescent particle counting device is mainly composed of components such as an airflow control and sampling system, a laser light source, a photomultiplier tube module PMT, a high-voltage and amplification circuit matched with the PMT, and a display and control terminal computer. The airflow control and sampling system uses a micro pump to extract gas for sampling. To achieve accurate counting of aerosol particles as much as possible, the diameter of the airflow input pipe entering the measurement chamber is not greater than 1mm, and the flow rate of the micro pump controlled to enter the measurement chamber does not exceed 2L / min, so that the fluorescent tracers in the airflow structure brought into the measurement chamber can realize single-particle measurement to the maximum extent. The laser light source uses a continuous light laser diode with a wavelength of 470nm as the fluorescence excitation wavelength. After the laser hits the fluorescent tracer entering the measurement chamber, the fluorescence scattering signal is converged to the photosensitive surface of the photomultiplier tube module (PMT) through the filter and lens group. The signal after photoelectric conversion is collected, analog-to-digital converted, and then enters the display and control terminal computer for analysis.

[0053] The fixed points measured by the fluorescent particle counting device are relatively discrete, and only a rough distribution of the bioaerosol concentration field can be obtained. The calibrated lidar device can measure a more precise concentration distribution in the target direction. After a complete spatial scan, a precise bioaerosol concentration distribution in the space can finally be obtained.

[0054] The present invention uses the constructed lidar, combined with the fluorescent particle counting device for joint measurement, and finally integrates the results of telemetry and point measurement data to perform three-dimensional visualized measurement inversion of indoor airflow structure and bioaerosol concentration field distribution.

[0055] The above content is a further detailed description of the present invention in combination with specific embodiments, which shall not be construed as limiting the specific implementation of the present invention to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, several simple deductions or substitutions can be made without departing from the concept of the present invention, all of which shall be regarded as falling within the protection scope of the present invention.

Claims

1. A three-dimensional visualization measurement method for airflow organization, characterized in that, This is achieved using a three-dimensional visualization measurement device for airflow organization, specifically including the following steps: S1, use lidar to scan and measure the airflow containing fluorescent tracers to obtain the intensity distribution of scattered fluorescence signals in space; S2, using a fluorescent particle counting device to perform air sampling at a specific location to obtain measured bioaerosol concentration data; combined with the lidar system in step S1, a rough distribution of the measured bioaerosol concentration field is obtained; S3. Combine the measured bioaerosol concentration data obtained by the fluorescent particle counting device at a specific location, and use the rough distribution of the bioaerosol concentration field to calibrate the measurement results of the lidar system based on the measured data of the fluorescent particle counting device at the corresponding location, and establish a linear relationship between the fluorescence signal intensity and the measured bioaerosol concentration. S4 repeats the S1-S3 process, and finally obtains the correspondence between the measurement results of the lidar system and the measured concentration of bioaerosols, outputting the fine distribution of the reconstructed aerosol concentration field. S5 displays the fine distribution of bioaerosol concentration in the airflow organization as a three-dimensional pseudo-color image, realizing spatial three-dimensional visualization of airflow organization and bioaerosol concentration field distribution; The three-dimensional visualization measurement device for airflow organization includes a lidar and a fluorescent particle counting device; The lidar consists of a laser emitting unit, a scanning unit, a signal detection unit, a signal acquisition unit, and a display and control terminal computer; The laser emitting unit is used to emit laser light to induce fluorescence scattering in bioaerosol molecules; The scanning unit is used to control the laser emission direction in order to measure the concentration distribution of bioaerosols in different directions; The signal detection unit is used to receive the fluorescence scattering echo signal generated by bioaerosol molecules and convert it into an electrical pulse signal that the measuring device can process; The signal acquisition unit is used to convert the electrical pulse signal output by the signal detection unit into a digital signal and upload it to the display and control terminal computer; The display and control terminal computer is used to control the measurement process and process the measurement results, and to visualize the measurement results as a three-dimensional concentration field in real time. The laser emitting unit emits two laser beams, one for identifying bioaerosol clouds and the other for identifying non-bioaerosol clouds. One beam, emitted from a 355nm high-repetition-rate (HRRF) semiconductor laser source, is expanded by a 355nm HRF semiconductor laser source beam expander. The other beam, emitted from a 470nm HRF semiconductor laser source, is expanded by the same 355nm HRF semiconductor laser source beam expander. The two beams, expanded separately, are then combined by a laser beam combiner before being emitted into the space containing the indoor airflow organization via a transmitting and receiving telescope and a scanning unit. The lasers are then targeted at areas containing fluorescent tracers. The airflow structure is scanned and measured; the backscattered fluorescence signal generated by the interaction between the laser and the fluorescent tracer in the airflow structure is received by the transmitting and receiving telescopes, and the background stray light is suppressed by the aperture. Then, it enters the color separation and filtering mechanism for signal reception wavelength selection. The filtered fluorescence scattering signal and the airflow structure Mie scattering signal enter the corresponding signal detection unit for photoelectric conversion. The laser backscattered echo signal is converted into an electrical pulse signal and enters the signal acquisition unit. The signal acquisition unit converts the electrical pulse signal into a digital signal and uploads it to the display and control terminal computer. The measurement and control software running on the display and control terminal computer performs signal analysis. The detection unit contains two fluorescence signal detection channels: 470nm as the laser emission wavelength and 520nm as the fluorescence detection wavelength; 355nm is used as both the laser emission wavelength and the Mie scattering signal detection wavelength; the 355nm Mie scattering signal is used for the localization of airflow organization and background obstacle targets, and the 520nm fluorescence detection is used to correct the fluorescence signal and improve the inversion accuracy of the bioaerosol concentration field. The fluorescent particle counting device collects measurement data and then uses it to calibrate the measurement results of the lidar.

2. The three-dimensional visualization measurement method for airflow organization according to claim 1, characterized in that, The specific implementation process of step 5 is as follows: different concentrations in the airflow organization are displayed on the software display interface using different color block images. The size of the color block image corresponds to the spatial resolution of the lidar, and the pseudo-color image is superimposed onto the real scene image according to the spatial size ratio.

3. The three-dimensional visualization measurement method for airflow organization according to claim 1, characterized in that, The fluorescent particle counting device includes an airflow control and sample introduction system, a laser light source, a photomultiplier tube module (PMT), a high-voltage and amplification circuit for the PMT, and a display and control terminal computer; the airflow control and sample introduction system uses a micro pump to sample the gas.

4. The three-dimensional visualization measurement method for airflow organization according to claim 1, characterized in that, To ensure accurate aerosol particle counting, the diameter of the airflow input pipe entering the measurement chamber should not exceed 1 mm, and the flow rate of the micro pump entering the measurement chamber should be controlled to not exceed 2 L / min.

5. The three-dimensional visualization measurement method for airflow organization according to claim 1, characterized in that, The laser source uses a continuous-wave laser diode with a wavelength of 470nm as the fluorescence excitation wavelength.

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