Airflow organization three-dimensional visual measurement device and method

Abstract

The invention discloses a three-dimensional visual measurement device and method for airflow organization, relates to the fields of airflow organization visual detection, fluorescence spectrum analysis and electronics, and solves the problem that the concentration distribution of biological aerosol in indoor airflow organization cannot be measured and visualized in real time. The relative intensity distribution of a fluorescent tracer concentration field in the airflow structure is scanned and measured through a laser radar, a fixed point position fluorescent particle counting device is used for calibrating a laser radar telemetry data result, and interpolation is carried out on calibrated laser radar scanning data; and finally, background deduction is carried out on a data result measured by the laser radar, and the data result is displayed on a measurement and control terminal computer in a three-dimensional pseudo-color image mode. According to the invention, the limitation that an existing detection method cannot measure the distribution condition of the airflow organization and the biological aerosol in the three-dimensional space in a non-invasive manner is solved, and the accuracy and the resolution ratio of the measurement of the airflow organization and the biological aerosol are improved.

Description

Technical Field

[0001] The present invention relates to the fields of airflow organization visualization detection, fluorescence spectrum analysis and electronics, and specifically to a visualization detection device and method for airflow organization and spatial distribution of bioaerosol concentration fields in confined spaces such as hospitals or conference rooms. Background Art

[0002] Visual measurement of airflow organization is a technique for studying indoor air flow and distribution, widely used in fields such as fresh air conditioning system design and industrial production environmental control. Traditional methods for evaluating the spatial distribution of airflow organization rely on complex mathematical models and calculations, which have limitations and cannot truly reflect the actual distribution of airflow organization in indoor spaces.

[0003] In confined spaces such as hospitals and conference rooms, indoor airflow often carries large quantities of biologically specific particles (aerosols), known as bioaerosols. Bioaerosols contain a variety of pathogenic and non-pathogenic biological components, such as active or inactive fungi and bacteria, bacterial or fungal toxins, viruses, macromolecular allergens, and pollens. These complex and diverse bioaerosol components are directly influenced by human behavior and are closely related to human health. Pathogenic components pose a constant threat to human health. To mitigate the harm caused by harmful airflow and protect key populations, monitoring airflow and the spatial distribution of bioaerosol concentrations in specific scenarios is crucial. Considering the flow characteristics of airflow, it is best to employ real-time, range-covering technologies. Summary of the Invention

[0004] (1) Purpose of the invention

[0005] The purpose of the present 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] (2) Technical solution

[0007] In order to achieve the above objectives and solve the above technical problems, the technical solutions of the present invention are as follows:

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

[0009] S1, using laser radar to scan and measure the airflow organization containing fluorescent tracers to obtain the intensity distribution of scattered fluorescent signals in space;

[0010] S2, using a fluorescent particle counting device to extract air samples at a specific location to obtain measured bioaerosol concentration data; combining the laser radar system in step S1 to obtain a rough distribution of the measured bioaerosol concentration field;

[0011] S3, combining the measured bioaerosol concentration data obtained by the fluorescent particle counting device at a specific location and using the rough distribution of the bioaerosol concentration field, calibrate the measurement results of the lidar system according to 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 corresponding relationship between the measurement results of the lidar system and the measured concentration of bioaerosols, and outputs the reconstructed fine distribution of the aerosol concentration field;

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

[0014] A three-dimensional visualization measurement device for airflow organization, comprising a laser radar and a fluorescent particle counting device;

[0015] The laser radar 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 of bioaerosol molecules;

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

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

[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 visualize the measurement results as a three-dimensional concentration field in real time;

[0021] The laser emitting unit emits two lasers, which are respectively used for the identification of bioaerosol clouds and non-biological aerosol clouds; the laser emitted by one of the 355nm semiconductor high repetition rate pulsed laser light source is expanded by the 355nm semiconductor high repetition rate pulsed laser light source beam expansion mechanism; the laser emitted by the other 470nm semiconductor high repetition rate pulsed laser light source is expanded by the 355nm semiconductor high repetition rate pulsed laser light source beam expansion mechanism. The lasers of two different wavelengths are respectively expanded and then combined by the laser beam combining mechanism, and then emitted into the space where the indoor airflow organization is located through the transmitting and receiving telescope and the scanning unit, and the fluorescent tracer is detected. The airflow organization is scanned and measured; the backscattered fluorescence signal generated by the interaction between the laser and the fluorescent tracer in the airflow organization is received by the transmitting and receiving telescopes, and the background stray light is suppressed by the aperture, and then enters the color separation and filtering mechanism for signal reception wavelength screening. The screened fluorescence scattering signal and the airflow organization Mie scattering signal respectively enter the corresponding signal detection unit for photoelectric conversion, and the laser backscattered echo signal is converted into an electric pulse signal and enters the signal acquisition unit. The signal acquisition unit converts the electric pulse signal into a digital signal and uploads it to the display and control terminal computer, and 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 to locate airflow organization and background obstacles, 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 uses it to calibrate the measurement results of the lidar.

[0024] (3) Effective income

[0025] The present invention solves the limitation of existing detection methods that they cannot non-invasively measure the airflow organization and bioaerosol distribution in three-dimensional space, and improves the accuracy and resolution of airflow organization and bioaerosol measurements.

[0026] The present invention builds a bioaerosol concentration measurement device based on laser radar, which realizes the real-time measurement of bioaerosol concentration in the air; the present invention proposes a spatial scanning measurement method, which realizes the measurement of bioaerosol concentration at various positions in a three-dimensional indoor space.

[0027] The present invention proposes a three-dimensional visualization inversion method for concentration field distribution, which realizes the reconstruction of discrete concentration data at each measured position into three-dimensional concentration field data and real-time visualization.

[0028] The present invention can provide guidance and decision-making basis for the diffusion evaluation of airflow organization in typical indoor environmental conditions such as hospitals and conference rooms. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural diagram of the laser radar 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 It is a schematic diagram of the three-dimensional visualization inversion process of airflow organization and concentration field distribution of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further explained and illustrated 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 airflow organization and bioaerosol distribution in three-dimensional space. Therefore, to address the need for visual measurement of airflow organization and bioaerosol concentration fields in small indoor spaces, the present invention proposes a device that combines laser radar and fluorescent particle counting based on the principle of laser-induced fluorescence to achieve three-dimensional visual detection of indoor airflow organization concentration.

[0034] The design concept of this invention is as follows: First, the relative intensity distribution of the fluorescent tracer concentration field in the airflow is measured using laser radar scanning. Then, a fixed-point fluorescent particle counting device is used to calibrate the laser radar telemetry data. The calibrated laser radar scan data is interpolated. Finally, the laser radar measurement data is background-subtracted and displayed as a three-dimensional pseudo-color image on a measurement and control terminal computer. This ultimately enables visual monitoring of the spatial distribution characteristics of bioaerosol concentration fields in small indoor spaces.

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

[0036] S1, using laser radar to scan and measure the airflow organization containing fluorescent tracers to obtain the intensity distribution of scattered fluorescent 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 laser radar system in step S1, a rough distribution of the measured bioaerosol concentration field is obtained.

[0038] S3, combining the measured bioaerosol concentration data obtained by the fluorescent particle counting device at a specific location and using the rough distribution of the bioaerosol concentration field, calibrate the measurement results of the lidar system according to 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 corresponding relationship between the measurement results of the lidar system and the measured concentration of bioaerosols, and outputs the reconstructed fine distribution of the aerosol concentration field;

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

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

[0042] At the same time, 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 laser radar and a fluorescent particle counting device;

[0043] The laser radar 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 of bioaerosol molecules;

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

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

[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 visualize the measurement results as a three-dimensional concentration field in real time.

[0049] The laser emission unit emits two laser beams, one for identifying bioaerosol clouds and the other for distinguishing between the scattered signal from the air background. Because 355nm ultraviolet laser light effectively excites bioaerosol molecules and is less affected by absorption by atmospheric molecules, it is used for identifying bioaerosol clouds. The 470nm laser light is used to distinguish the scattered signal from the air background. The laser beam from the 355nm semiconductor high-repetition-rate pulsed laser source 1 is expanded by a 355nm semiconductor high-repetition-rate pulsed laser source beam expansion mechanism 2. The laser beam from the 470nm semiconductor high-repetition-rate pulsed laser source 3 is expanded by a 355nm semiconductor high-repetition-rate pulsed laser source beam expansion mechanism 4. The two laser beams, after being expanded individually, are then combined by a laser beam combiner 5. The beams are then transmitted through a transmitting and receiving telescope 6 and a scanning unit 7 into the indoor airflow structure, where they scan and measure the airflow structure containing the fluorescent tracer. The backscattered fluorescence signal generated by the interaction between the laser and the fluorescent tracer in the airflow organization is received by the transmitting and receiving telescope 6, and the background stray light is suppressed by the aperture 8, and then enters the color separation and filtering mechanism 9 for signal reception wavelength screening. The screened fluorescence scattering signal and the airflow organization Mie scattering signal respectively enter the corresponding signal detection unit 10 for photoelectric conversion, and the laser backscattered echo signal is converted into an electric pulse signal and enters the signal acquisition unit 11. The signal acquisition unit converts the electric pulse signal into a digital signal and uploads it to the display and control terminal computer 12, and the signal is analyzed by the measurement and control software running on the display and control terminal computer.

[0050] The detection unit includes two fluorescence signal detection channels: a 470nm laser emission wavelength excites the target to produce scattered fluorescence at a wavelength of 520nm, hence the 520nm wavelength chosen for fluorescence detection; and a 355nm light source excites aerosol particles to emit a Mie scattering signal of the same wavelength, hence the 355nm wavelength used for both laser emission and Mie scattering signal detection. The 355nm Mie scattering signal is used to locate airflow organization and background obstacles, while the 520nm fluorescence detection is used to correct the fluorescence signal, improving the accuracy of the inversion of bioaerosol concentration fields.

[0051] The laser radar device can realize real-time measurement of the intensity of the fluorescence scattering signal of bioaerosols at a long distance. The intensity of the fluorescence scattering signal can only qualitatively reflect the concentration of bioaerosols. In order to realize the quantitative analysis of the concentration of bioaerosols along the direction of the laser target, the measurement data of the fluorescent particle counting device needs to be calibrated to the measurement results of the laser radar.

[0052] Fluorescent particle counting devices can measure the precise number of bioaerosol particles at a fixed point. The number of particles is the most direct reflection of the bioaerosol concentration. By using a laser radar and a fluorescent particle counting device to jointly measure the same target area and repeating the experiment with varying concentrations in the target area, the intensity of the fluorescence scattering signal can be calibrated with the number of bioaerosol particles, thereby enabling the use of a laser radar to accurately measure the bioaerosol concentration over a long distance. Figure 2 As shown, the fluorescent particle counting device primarily consists of an airflow control and sampling system, a laser light source, a photomultiplier tube (PMT) module, the PMT's associated high-voltage and amplification circuits, and a display and control terminal computer. The airflow control and sampling system uses a micropump to extract and sample gas. To ensure the most accurate aerosol particle counting possible, the diameter of the airflow inlet tube entering the measurement chamber is no larger than 1 mm, and the micropump flow rate into the measurement chamber is controlled to no more than 2 L / min. This maximizes single-particle measurement of the fluorescent tracer introduced into the airflow. The laser light source uses a continuous light laser diode with a wavelength of 470 nm as the fluorescence excitation wavelength. After the laser strikes the fluorescent tracer entering the measurement chamber, the fluorescence scattering signal is converged by a filter and lens assembly onto the photosensitive surface of the photomultiplier tube (PMT). After photoelectric conversion and analog-to-digital conversion, the signal is collected and analyzed by the display and control terminal computer.

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

[0054] The present invention utilizes the constructed laser radar in combination with a fluorescent particle counting device for joint measurement, and finally integrates the remote sensing and point measurement data results to perform three-dimensional visual measurement inversion of indoor airflow organization and bioaerosol concentration field distribution.

[0055] The above content is a further detailed description of the present invention in conjunction with specific embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A three-dimensional visualization measurement method for airflow organization, characterized in that: The steps include: S1, using laser radar to scan and measure the airflow organization containing fluorescent tracers to obtain the intensity distribution of scattered fluorescent signals in space; S2, using a fluorescent particle counting device to perform air sampling at a specific location to obtain measured bioaerosol concentration data; combining the laser radar system in step S1 to obtain a rough distribution of the measured bioaerosol concentration field; S3, combining the measured bioaerosol concentration data obtained by the fluorescent particle counting device at a specific location and using the rough distribution of the bioaerosol concentration field, calibrate the measurement results of the lidar system according to 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 process of S1-S3, and finally obtains the corresponding relationship between the measurement result of the lidar system and the measured concentration of the bioaerosol, and outputs the reconstructed fine distribution of the aerosol concentration field; S5, displays the detailed distribution of bioaerosol concentration in the airflow organization in the form of a three-dimensional pseudo-color image, realizing the spatial three-dimensional visualization of the airflow organization and the bioaerosol concentration field distribution.

2. The three-dimensional visualization measurement method of airflow organization according to claim 1 is 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 on the real-life image according to the spatial size ratio.

3. A three-dimensional visualization measurement device for airflow organization, characterized in that: The measuring device can realize the visual measurement as claimed in claim 1; the measuring device includes a laser radar and a fluorescent particle counting device; The laser radar 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 to induce fluorescence scattering of bioaerosol molecules; The scanning unit is used to control the emission direction of the laser to measure the distribution of bioaerosol concentration in different directions; The signal detection unit is used to receive the fluorescence scattering echo signal generated by the bioaerosol molecules and convert it into an electrical pulse signal that can be processed by the measuring device; 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 visualize the measurement results as a three-dimensional concentration field in real time; The laser emitting unit emits two lasers, which are respectively used for the identification of bioaerosol clouds and non-biological aerosol clouds; the laser emitted by one 355nm semiconductor high repetition rate pulse laser light source is expanded by a 355nm semiconductor high repetition rate pulse laser light source beam expansion mechanism; the laser emitted by the other 470nm semiconductor high repetition rate pulse laser light source is expanded by a 355nm semiconductor high repetition rate pulse laser light source beam expansion mechanism, and the lasers of two different wavelengths are respectively expanded and then combined by a laser beam combining mechanism, and then emitted through the transmitting and receiving telescope and the scanning unit into the space where the indoor airflow organization is located, and the fluorescent tracer is detected. The airflow organization is scanned and measured; the backscattered fluorescent signal generated by the interaction between the laser and the fluorescent tracer in the airflow organization is received by the transmitting and receiving telescopes, and the background stray light is suppressed by the aperture, and then enters the color separation and filtering mechanism for signal receiving wavelength screening. The screened fluorescent scattering signal and the airflow organization Mie scattering signal enter the corresponding signal detection unit for photoelectric conversion, and the laser backscattered echo signal is converted into an electric pulse signal and enters the signal acquisition unit. The signal acquisition unit converts the electric pulse signal into a digital signal and uploads it to the display and control terminal computer, and the measurement and control software running on the display and control terminal computer performs signal analysis; The detection unit includes two fluorescence signal detection channels: 470nm as the laser emission wavelength and 520nm as the fluorescence detection wavelength; 355nm as both the laser emission wavelength and the Mie scattering signal detection wavelength; the 355nm Mie scattering signal is used for positioning the airflow organization and background obstacle targets, and the 520nm fluorescence detection is used to correct the fluorescence signal to improve the inversion accuracy of the bioaerosol concentration field; The fluorescent particle counting device collects measurement data and is used to calibrate the measurement results of the lidar.

4. The three-dimensional visualization measuring device for airflow organization according to claim 3 is characterized in that: The fluorescent particle counting device comprises 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 and sample the gas.

5. The three-dimensional visualization measuring device for airflow organization according to claim 4, characterized in that: In order to accurately count aerosol particles, the diameter of the airflow input pipe entering the measurement chamber is no more than 1mm, and the flow rate of the micro pump entering the measurement chamber is controlled to not exceed 2L / min.

6. The three-dimensional visualization measuring device for airflow organization according to claim 4, characterized in that: The laser light source uses a continuous light laser diode with a wavelength of 470nm as the fluorescence excitation wavelength.

Images