Gas particle or aerosol detector and its detection system and detection method

Abstract

The present invention relates to the field of particle or aerosol detection. The gas particle or aerosol detector of the present invention adopts non-contact particle or aerosol measurement technology. When the gas passes through the gas channel of the quartz glass tube, each particle or aerosol in the gas will cause the intensity of the laser main beam to drop instantly, generating a negative pulse signal on the photoresistance detector; at the same time, the particle or aerosol also generates scattered light, generating a positive pulse signal on the scattered light detector; the height and width of these two pulses are proportional to the diameter of the particle or aerosol, and the number of pulses is the number of particles or aerosols. The gas particle or aerosol detection method of the present invention expands the range of the gas particle or aerosol detection system and improves the measurement accuracy by complementing and verifying each other through two signals; through decompression and non-contact detection, continuous measurement of other components of high-pressure gas is achieved, and detection efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of particle or aerosol detection in gas, and in particular to a gas particle or aerosol detector and a detection system and a detection method thereof. Background Art

[0002] Hydrogen is a clean and efficient secondary energy source. With the development of hydrogen energy technology and in response to increasingly severe global climate change, many developed countries have elevated the development of the hydrogen energy industry to the level of national energy strategy. At present, my country's hydrogen is mainly used for the synthesis of ammonia and methanol, as well as the production of refining products. About 3% of hydrogen is used as industrial gas for reducing gas, protective gas, reaction gas, etc. in metallurgy, steel, electronics, building materials, fine chemicals and other industries. Among them, proton exchange membrane fuel cells have broad application prospects in the field of transportation, especially large-scale replacement of fuel vehicles, which can not only achieve zero emissions of automobiles, but also correspondingly reduce my country's excessive dependence on oil resources, which is conducive to national energy transformation. Therefore, it can be foreseen that with the large-scale application and promotion of proton exchange membrane fuel cells, the demand for hydrogen in the future society will increase significantly.

[0003] In the prior art, particle counters are mainly used to detect tiny particle pollutants in liquid or gaseous media. Traditional optical particle counters use the principle of light scattering to determine the size of the particle size through the intensity of scattered light, thereby realizing the detection and calculation of particles. However, the precision detection results of existing particle counters have large errors, and the detection accuracy needs to be improved. In addition, the test of the particulate matter (or aerosol) content in the gas is mainly measured using the filter membrane weight gain method. The test procedure is cumbersome and requires multiple weighings under specific conditions. The concentration of the particulate matter (or aerosol) in the gas is calculated by the weight change before and after the filter membrane sampling. However, during the filtration process, it will affect the concentration of other easily adsorbed gas-phase impurities in the gas, and the content of other components cannot be tested continuously. In addition, the inspection test cycle is long and the efficiency is low. Summary of the invention

[0004] To solve the above problems, the present invention provides a gas particle or aerosol detector and a detection system thereof, which reduces the error of the detection result, improves the accuracy of the detection, shortens the detection and analysis time, and solves the problem of not being able to continuously test the content of other components.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a gas particle or aerosol detector, comprising a laser, a quartz glass tube, a scattered light detector and a photoresistance detector, the quartz glass tube is provided with a gas channel for gas to pass through, the laser emitted by the laser passes through the gas channel and the photoresistance detector in sequence, or passes through the gas channel and the scattered light detector in sequence, and the laser emitted by the laser is perpendicular to the gas channel;

[0006] When the gas passes through the gas channel of the quartz glass tube, each particle or aerosol in the gas will cause the intensity of the laser main beam to drop instantly, generating a negative pulse signal on the photoresistance detector; at the same time, the particles or aerosols also generate scattered light, generating a positive pulse signal on the scattered light detector.

[0007] Furthermore, the main beam of the laser passes through the center of the scattering detector and directly reaches the photoresistance detector, or the main beam is scattered by particulate matter or aerosol and reaches the scattering detector.

[0008] Furthermore, the particle or aerosol detector has a measuring range of 0.5-400 μm and a gas consumption of 0.5-10 L for a single test.

[0009] A gas particle or aerosol detection system is also provided, comprising a gas pipeline, a pipeline branch, a pressure reducing and limiting valve, a flow meter, and the above-mentioned gas particle or aerosol detector, wherein the pipeline branch is led out from the gas pipeline, and the pressure reducing and limiting valve, the flow meter, and the gas particle or aerosol detector are sequentially installed on the pipeline branch, so that the gas passes through the pressure reducing and limiting valve and the flow meter to reach the gas particle or aerosol detector, and the gas particle or aerosol detector is externally connected to a display host, and the display host displays the parameters output by the particle or aerosol detector.

[0010] Wherein, the display host is a computer, a tablet or a display screen.

[0011] The gas particle or aerosol detector is also connected to a gas concentration detector or other analytical instrument through another pipeline branch, so that the gas comes out of the gas channel of the quartz glass tube and enters another gas concentration detector or other analytical instrument for detection.

[0012] A gas particle or aerosol detection method is also provided, which uses the above-mentioned gas particle or aerosol detection system for detection, and the detection method steps are as follows:

[0013] S1, open the pressure reducing and limiting valve, so that the gas in the gas pipeline passes through the flow meter from the pipeline branch and enters the gas particle or aerosol detector;

[0014] S2, when the gas passes through the gas channel of the quartz glass tube, if there are particles or aerosols in the gas, each particle or aerosol will cause the intensity of the laser main beam to drop instantly, generating a negative pulse signal on the photoresistance detector; at the same time, the particles or aerosols also generate scattered light, generating a positive pulse signal on the scattered light detector;

[0015] S3, when the gas passes through the gas channel of the quartz glass tube, if the diameter of the particles or aerosols is greater than 5μm, the negative pulse signal is dominant, and if the diameter of the particles or aerosols is less than 5μm, the positive pulse signal is dominant;

[0016] S4, the height and width of the two pulses of the negative pulse signal and the positive pulse signal are proportional to the diameter of the particles or aerosols, and the number of pulses represents the number of particles or aerosols;

[0017] S5, the data output by the gas particle or aerosol detector is calculated by the display host and then displayed.

[0018] The project parameters displayed by the display host include the total number of particles or aerosols per liter of gas, a particle size distribution diagram, and a total volume of particles or aerosols.

[0019] Wherein, the pressure reducing and flow limiting valve is an electric control valve and is electrically connected to the PLC controller.

[0020] The gas flow is regulated by a pressure reducing and limiting valve, and the volume flow of the gas is calculated by a flow meter.

[0021] The beneficial effects of the present invention are as follows: the gas particle or aerosol detector of the present invention adopts non-contact particle or aerosol measurement technology. When the gas passes through the gas channel of the quartz glass tube, each particle or aerosol in the gas will cause the intensity of the laser main beam to drop instantly, generating a negative pulse signal on the photoresistance detector; at the same time, the particle or aerosol also generates scattered light, generating a positive pulse signal on the scattered light detector; the height and width of these two pulses are proportional to the diameter of the particle or aerosol, and the number of pulses is the number of particles or aerosols. Among them, if the diameter of the particle or aerosol is greater than 5μm, the negative pulse (photoresistance effect) signal is stronger; if the diameter of the particle or aerosol is less than 5μm, the positive pulse (scattering effect) signal is stronger.

[0022] The gas particle or aerosol detection method of the present invention complements and verifies each other through two signals, thereby expanding the range of the gas particle or aerosol detection system and improving the measurement accuracy; in addition, the gas particle or aerosol detection system of the present invention realizes continuous measurement of other components of high-pressure gas through decompression and non-contact detection, thereby improving detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the detector of the present invention.

[0024] Figure 2 It is a comparison diagram of the pulse signals of the scattered light detector and the photoresistance detector of the detector of this embodiment.

[0025] Figure 3 It is a schematic diagram of the structure of the detection system of the present invention.

[0026] Figure 4It is a typical numerical range chart of the test analysis report of this embodiment.

[0027] Figure 5 It is the particle size distribution table of the test analysis report of this embodiment.

[0028] Figure 6 It is a graph of the particle size distribution of the test analysis report of this embodiment.

[0029] Figure 7 It is a simplified particle size distribution table of the test analysis report of this embodiment.

[0030] Explanation of the accompanying figures: 1. Gas pipeline; 2. Pipeline branch; 3. Pressure reducing and limiting valve; 4. Flow meter; 5. Gas particle or aerosol detector; 51. Laser; 52. Quartz glass tube; 521. Gas channel; 53. Scattered light detector; 54. Light resistance detector; 6. Display host; 7. Other analytical instruments. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below through specific implementations in conjunction with the accompanying drawings. The present application can be implemented in a variety of different forms and is not limited to the implementation described in this embodiment. The purpose of providing the following specific implementations is to facilitate a clearer and more thorough understanding of the disclosure of the present application.

[0032] See also Figure 1-3 As shown, the present invention relates to a gas particle or aerosol detector, comprising a laser 51, a quartz glass tube 52, a scattered light detector 53 and a photoresistance detector 54, wherein the quartz glass tube 52 is provided with a gas channel 521 for gas to pass through, the laser emitted by the laser 51 passes through the gas channel 521 and the scattering detector 53 in sequence, or passes through the gas channel 521 and the photoresistance detector 54 in sequence, and the laser emitted by the laser 53 is perpendicular to the gas channel 521; wherein the main light beam of the laser 51 passes through the center of the scattering detector 53 directly to reach the photoresistance detector 54, or the main light beam is scattered by particles or aerosols to reach the scattering detector 53.

[0033] See also Figure 2 As shown, its working principle is: when the gas passes through the gas channel 521 of the quartz glass tube 52, each particle or aerosol in the gas will cause the intensity of the laser main beam to drop instantly, and a negative pulse signal will be generated on the photoresistance detector 54; at the same time, the particles or aerosols also generate scattered light, and a positive pulse signal will be generated on the scattered light detector 53. The two signals complement and verify each other, thereby improving the measurement accuracy.

[0034] The present embodiment also relates to a gas particle or aerosol detection system using the above-mentioned gas particle or aerosol detector, including a gas pipeline 1, a pipeline branch 2, a pressure reducing and limiting valve 3, a flow meter 4, and a gas particle or aerosol detector 5. The pipeline branch 2 is led out from the gas pipeline 1, and the pressure reducing and limiting valve 3, the flow meter 4 and the gas particle or aerosol detector 5 are installed in sequence on the pipeline branch 2, so that the gas passes through the pressure reducing and limiting valve 3 and the flow meter 4 to reach the gas particle or aerosol detector 5. The gas particle or aerosol detector 5 is externally connected to a display host 6, and the display host 6 displays the parameters output by the particle or aerosol detector.

[0035] Among them, the gas particle or aerosol detector 5 is also connected to a gas concentration detector or other analytical instrument 7 through another pipeline branch 2, so that the gas comes out of the gas channel 521 of the quartz glass tube 52 and enters another gas concentration detector or other analytical instrument 7 for detection, thereby realizing the detection of gas particle or aerosol concentration or other parameters.

[0036] In this embodiment, the display host 6 can be a computer, a tablet or a display screen, which is not limited here.

[0037] This embodiment uses the above-mentioned gas particle or aerosol detection system for detection, and the detection method steps are as follows:

[0038] S1, open the pressure reducing and limiting valve 3, so that the gas in the gas pipeline 1 passes through the pipeline branch 2 through the flow meter 4 and enters the gas particle or aerosol detector 5;

[0039] S2, when the gas passes through the gas channel 521 of the quartz glass tube 52, if there are particles or aerosols in the gas, each particle or aerosol will cause the intensity of the laser main beam to drop instantly, generating a negative pulse signal on the photoresistance detector 54; at the same time, the particles or aerosols also generate scattered light, generating a positive pulse signal on the scattered light detector 53;

[0040] S3, when the gas passes through the gas channel 521 of the quartz glass tube 52, if the diameter of the particles or aerosols is greater than 5 μm, the negative pulse signal is dominant, and if the diameter of the particles or aerosols is less than 5 μm, the positive pulse signal is dominant;

[0041] S4, the height and width of the two pulses of the negative pulse signal and the positive pulse signal are proportional to the diameter of the particles or aerosols, and the number of pulses represents the number of particles or aerosols;

[0042] S5, the data output by the gas particle or aerosol detector 5 is calculated by the display host 6 and then displayed.

[0043] In step S5, the calculation method includes the following methods: analog signal digitization algorithm, processing and analyzing the digital signal, pulse identification and judgment algorithm, and calculating the particle size value according to the pulse height, and the formula for calculating the particle size value is as follows:

[0044] y=-0.00022X 2 +0.15141X-0.36667 (Light resistance calculation formula)

[0045] y=-0.00046X 2 +0.41291X+7.58232 (Light resistance calculation formula)

[0046] Wherein, X is the calculated signal height value, y is the particle size value (um), and the calculation method adopted by the display host 6 in this embodiment is an existing algorithm, which will not be repeated here.

[0047] In this embodiment, the pressure reducing and limiting valve 3 is an electric control valve and is electrically connected to the PLC controller and can be electrically controlled by the PLC controller. The user can adjust the gas flow rate through the pressure reducing and limiting valve 3 and calculate the volume flow rate of the gas through the flow meter 4.

[0048] It should be further explained that the technical indicators of the detection system of this embodiment are: a measuring range of 0.5-400μm; accuracy error: ≤3% (deviation between the test value and the nominal value of the standard sample); counting efficiency: >95%; flow measurement accuracy: ≤1%; gas consumption for a single test is 0.5-10L (related to the measurement accuracy and can be set by the controller); output project parameters: total number of particles or aerosols per liter of gas, particle size distribution diagram, number of particles or aerosols in special intervals, total volume of particles or aerosols, etc.

[0049] In this embodiment, if the particle or aerosol diameter is greater than 5 μm, the negative pulse (light blocking effect) signal is stronger; if the particle or aerosol diameter is less than 5 μm, the positive pulse (scattering effect) signal is stronger. The gas particle or aerosol detection method of the present invention expands the range of the gas particle or aerosol detection system and improves the measurement accuracy by complementing and verifying each other through two signals.

[0050] As a specific example, see Figure 4-7 As shown, the example diagram of the test analysis report obtained by using the detection system and method of this embodiment can allow the user to intuitively see the parameter analysis results of the test gas.

[0051] It should be further explained that the laser 51, scattered light detector 53, photoresistance detector 54, pressure reducing and limiting valve 3, flow meter 4 and other instruments mentioned in this embodiment can all be purchased from the market and are existing technical products in the field, and will not be described in detail here.

[0052] The above implementation modes are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering and technical personnel in the field shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A gas particle or aerosol detector, characterized in that: It comprises a laser, a quartz glass tube, a scattered light detector and a photoresistance detector, wherein the quartz glass tube is provided with a gas channel for gas to pass through, the laser emitted by the laser passes through the gas channel and the photoresistance detector in sequence, or passes through the gas channel and the scattered light detector in sequence, and the laser emitted by the laser and the gas channel are perpendicular to each other; When the gas passes through the gas channel of the quartz glass tube, each particle or aerosol in the gas will cause the intensity of the laser main beam to drop instantly, generating a negative pulse signal on the photoresistance detector; at the same time, the particles or aerosols also generate scattered light, generating a positive pulse signal on the scattered light detector.

2. A gas particle or aerosol detector according to claim 1, characterized in that: The main beam of the laser passes through the center of the scattering detector and directly reaches the photoresistance detector.

3. A gas particle or aerosol detector according to claim 1, characterized in that: The particle or aerosol detector has a measuring range of 0.5-400 μm and a gas consumption of 0.5-10 L for a single test.

4. A gas particle or aerosol detection system, characterized in that: It includes a gas pipeline, a pipeline branch, a pressure reducing and limiting valve, a flow meter, and the gas particle or aerosol detector according to any one of claims 1 to 3, wherein the pipeline branch is led out from the gas pipeline, and the pressure reducing and limiting valve, the flow meter and the gas particle or aerosol detector are sequentially installed on the pipeline branch, so that the gas passes through the pressure reducing and limiting valve and the flow meter to reach the gas particle or aerosol detector, and the gas particle or aerosol detector is externally connected to a display host, and the display host displays the parameters output by the particle or aerosol detector.

5. A gas particle or aerosol detection system according to claim 4, characterized in that: The display host is a computer, a tablet or a display screen.

6. A gas particle or aerosol detection system according to claim 4, characterized in that: The gas particle or aerosol detector is also connected to the gas concentration detector through another pipeline branch, so that the gas comes out of the gas channel of the quartz glass tube and enters another gas concentration detector for detection.

7. A method for detecting gas particles or aerosols, characterized in that: The gas particle or aerosol detection system of claim 4 is used for detection, and the detection method steps are as follows: S1, open the pressure reducing and limiting valve, so that the gas in the gas pipeline passes through the flow meter from the pipeline branch and enters the gas particle or aerosol detector; S2, when the gas passes through the gas channel of the quartz glass tube, if there are particles or aerosols in the gas, each particle or aerosol will cause the intensity of the laser main beam to drop instantly, generating a negative pulse signal on the photoresistance detector; at the same time, the particles or aerosols also generate scattered light, generating a positive pulse signal on the scattered light detector; S3, when the gas passes through the gas channel of the quartz glass tube, if the diameter of the particles or aerosols is greater than 5μm, the negative pulse signal is dominant, and if the diameter of the particles or aerosols is less than 5μm, the positive pulse signal is dominant; S4, the height and width of the two pulses of the negative pulse signal and the positive pulse signal are proportional to the diameter of the particles or aerosols, and the number of pulses represents the number of particles or aerosols; S5, the data output by the gas particle or aerosol detector is calculated by the display host and then displayed.

8. A gas particle or aerosol detection method according to claim 7, characterized in that: The project parameters displayed by the display host include the total number of particles or aerosols per liter of gas, a particle size distribution diagram, and the total volume of particles or aerosols.

9. A gas particle or aerosol detection method according to claim 7, characterized in that: The pressure reducing and flow limiting valve is an electric control valve and is electrically connected to a PLC controller.

10. A gas particle or aerosol detection method according to claim 7, characterized in that: The gas flow is regulated by a pressure reducing limiting valve and the volume flow of the gas is calculated by a flow meter.

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