An atmospheric oxidation indicator detection device

Abstract

This invention discloses an atmospheric oxidizing indicator detection device, relating to the field of atmospheric detection technology. The proposed solution includes a housing, and further comprises: a condenser tube installed within the housing for dehumidifying incoming air; a splitter, the inlet of which is connected to the outlet of the condenser tube, for splitting the dehumidified air sample into a first branch and a second branch; a photodetector unit, comprising a photoreaction tube, a first mixing tank, and a first detector connected in sequence, the inlet of the photoreaction tube being connected to the outlet of the first branch of the splitter; and a catalytic detection unit, comprising a catalytic reaction tube, a second mixing tank, and a second detector connected in sequence, the inlet of the catalytic reaction tube being connected to the outlet of the second branch of the splitter. This overcomes the inherent time difference problem of sequential measurements using a single detector.

Description

Technical Field

[0001] This invention relates to the field of atmospheric detection technology, and in particular to a device for detecting atmospheric oxidation indicator factors. Background Technology

[0002] Atmospheric oxidation capacity is a key indicator for measuring the atmosphere's self-purification capacity and photochemical pollution potential. It is usually characterized by detecting indicator factors such as total oxidants and total nitrogen oxides. Currently, the detection of various oxidizing substances in the atmosphere mostly adopts single-channel sequential measurement or simple parallel multi-detector schemes; however, when using a single detector to measure different parameters in turn by switching through valves, there is a time difference between the data of each parameter, which cannot achieve strict synchronization, resulting in errors when calculating dynamic indicators such as oxidant generation rate; Secondly, in order to study photochemical processes, some devices have attempted to introduce light-shielding components for simple comparisons, but they can usually only achieve a binary switch between "with light" and "without light," and cannot accurately and quantitatively simulate the continuously changing light intensity and spectral composition in the real atmosphere, which limits the depth of their mechanism research. In addition, in order to achieve illumination simulation, existing schemes often directly adjust the power of the light source, which can easily lead to spectral drift and unstable heating of the light source. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to solve the above-mentioned problems.

[0004] To achieve the above-mentioned technical objectives, the present invention provides an atmospheric oxidizing indicator detection device: It includes the outer casing, and also includes: A condenser tube, installed inside the housing, is used to dehumidify the incoming air; The splitter, whose inlet is connected to the outlet of the condenser tube, is used to split the dehumidified air sample into a first branch and a second branch. The optical change detection unit includes a photoresponse tube, a first mixing tank and a first detector connected in sequence, wherein the inlet of the photoresponse tube is connected to the first branch outlet of the splitter; The catalytic detection unit includes a catalytic reaction tube, a second mixing tank, and a second detector connected in sequence. The inlet of the catalytic reaction tube is connected to the outlet of the second branch of the splitter. A light-modulation simulation mechanism, mounted on the housing and positioned corresponding to the photoresponse tube, is used to provide simulated illumination to an air sample flowing through the photoresponse tube.

[0005] Preferably, the condenser tube has a U-shaped structure, a cooling fin is provided on the outer bottom of the condenser tube, and a drain nozzle is fixed at the lowest point of the bottom of the condenser tube.

[0006] Preferably, the distributor includes a distributor valve, a main pipe and two branch pipes, the inlet of the main pipe is connected to the outlet of the condenser, and the outlets of the two branch pipes are respectively connected to the inlets of the photoreaction tube and the catalytic reaction tube.

[0007] Preferably, the light-changing simulation mechanism includes a light source section and a dimming section; The light source unit includes a heat sink and a light source disposed on the side of the heat sink facing the photoresist tube; The dimming unit is located between the light source unit and the photoresponse tube, and includes an intensity adjustment plate and a spectral adjustment plate that can be rotated independently. The intensity adjustment plate has regions with different transmittance, and the spectral adjustment plate has regions with different spectral transmission characteristics.

[0008] Preferably, the dimming unit further includes a middle partition, an upper cover plate, and a lower cover plate. The intensity adjustment plate and the spectral adjustment plate are rotatably mounted on opposite sides of the middle partition plate and are respectively encapsulated by the upper cover plate and the lower cover plate. The intensity adjustment plate and the spectral adjustment plate are driven to rotate by independent stepper motors.

[0009] Preferably, a light guide cover is fitted around the outside of the photoreactor tube, and the inner wall of the light guide cover is a reflective surface.

[0010] Preferably, the light source is an LED light strip that includes the ultraviolet band; the heat sink is provided with heat dissipation fins and a cooling fan on the side facing away from the light source, and the outer casing has a ventilation opening corresponding to the position of the cooling fan.

[0011] Preferably, the catalytic reaction tube is filled with a catalyst and is equipped with a heating structure.

[0012] Preferably, the system further includes an analysis module, which is communicatively connected to the first detector and the second detector to synchronously receive and process the detection signals from both detectors in order to calculate atmospheric oxidative parameters.

[0013] Preferably, a gear is fixed to the output end of the stepper motor, and a driven internal gear ring is fixed to the middle of the intensity adjustment plate or the spectrum adjustment plate, and the gear meshes with the driven internal gear ring.

[0014] As can be seen from the above technical solutions, this application has the following beneficial effects: 1. The same air sample is split into two streams in real time by a splitter and enters the photodetector and catalytic detector units that work in parallel, so that the concentration data of total oxidant and total reactive nitrogen oxides have consistent timestamps, overcoming the time difference problem inherent in sequential measurement using a single detector; 2. A mechanical dimming unit consisting of an intensity adjustment plate and a spectral adjustment plate independently driven by a stepper motor is used. By controlling the rotation angle of the filter plate, the light intensity can be continuously and steplessly adjusted precisely, and different spectral characteristics can be selected, thereby quantitatively simulating complex real atmospheric light environments with varying spectra from weak to strong. 3. A constant power light source combined with a physical filter is used to change the final illumination conditions on the reaction tube, avoiding problems such as spectral drift, heat generation fluctuations, and accelerated light decay caused by directly adjusting the light source drive current to change the light intensity. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 A schematic diagram of the overall structure of an atmospheric oxidizing indicator detection device provided by the present invention; Figure 2 This is a cross-sectional structural schematic diagram of an atmospheric oxidizing indicator detection device provided by the present invention; Figure 3 This is a partial cross-sectional view of an atmospheric oxidizing indicator detection device provided by the present invention. Figure 4 A schematic diagram of the exploded structure of the optical variable detection unit of an atmospheric oxidizing indicator detection device provided by the present invention; Figure 5 A schematic diagram of the overall structure of the catalytic detection unit of an atmospheric oxidizing indicator detection device provided by the present invention; Figure 6 A schematic diagram of the overall structure of the condenser and splitter of an atmospheric oxidizing indicator detection device provided by the present invention; Figure 7 This is a partial cross-sectional view of the optical variation simulation mechanism of an atmospheric oxidizing indicator detection device provided by the present invention. Figure 8 A schematic diagram of the simulated component explosion structure of an atmospheric oxidizing indicator detection device provided by the present invention; Figure 9 A schematic diagram of the overall structure of a stepper motor for an atmospheric oxidizing indicator detection device provided by the present invention.

[0017] Explanation of reference numerals in the attached figures: 10. Outer casing; 11. Air inlet; 20. Condenser coil; 21. Refrigeration element; 22. Drain nozzle; 30. Flow divider; 31. Flow divider valve; 32. Main pipe; 33. Branch pipe; 40. Optical variation detection unit; 41. Optical reaction tube; 411. Light guide cover; 42. First mixing tank; 43. First detector; 50. Catalytic detection unit; 51. Catalytic reaction tube; 52. Second mixing tank; 53. Second detector; 60. Light-changing simulation mechanism; 61. Heat sink; 611. LED light strip; 612. Heat sink fins; 613. Cooling fan; 62. Simulation component; 621. Middle partition; 622. Intensity adjustment plate; 6221. Driven internal gear ring; 623. Spectrum adjustment plate; 624. Upper cover plate; 625. Lower cover plate; 63. Stepper motor; 631. Gear. Detailed Implementation

[0018] The following description is exemplary in nature and is not intended to limit the scope, application, or use of this disclosure. It should be understood that in all these figures, the same or similar reference numerals indicate the same or similar parts and features. The figures are merely schematic representations of the concept and principles of embodiments of this disclosure and do not necessarily show the specific dimensions and scale of the various embodiments of this disclosure. Certain details or structures of embodiments of this disclosure may be exaggerated in particular portions of certain figures.

[0019] Example 1, see Figures 1-9 As shown, an atmospheric oxidizing indicator detection device is integrated into a box-type housing 10 for simultaneous comparative detection of oxidizing parameters in the atmosphere, such as total oxidant Ox and total nitrogen oxides NOy. An air inlet 11 is provided on one side wall of the housing 10, and an exhaust port is provided on the opposite side. The housing 10 includes a main open shell and a detachable cover plate to facilitate the installation and maintenance of internal components.

[0020] Furthermore, it also includes a condenser tube 20 and a light-changing detection unit 40 and a catalytic detection unit 50 distributed on both sides of the condenser tube 20. One end of the condenser tube 20 is connected to the air inlet 11, and the other end is connected to the light-changing detection unit 40 and the catalytic detection unit 50 respectively through a splitter 30. For example, external gas enters from the condenser tube 20 and is then split into two samples by the splitter 30, which enter the light-changing detection unit 40 and the catalytic detection unit 50 for detection respectively.

[0021] Specifically, the condenser tube 20 has a U-shaped structure and is fixedly installed inside the outer casing 10. The condenser tube 20 is preferably made of transparent quartz material, and its U-shaped bend at the bottom facilitates the collection of condensate. A cooling plate 21 is tightly attached to the outer side of the bottom of the U-shaped condenser tube 20. In this embodiment, the cooling plate 21 uses semiconductor refrigeration or circulating liquid cooling, which is not specifically limited here. The cooling plate 21 is used to actively reduce the tube wall temperature, causing water vapor in the air flowing through the condenser tube 20 to condense rapidly. A drain nozzle 22 is installed at the lowest point of the bottom of the U-shaped condenser tube 20 to drain... The nozzle 22 is connected to a controlled solenoid valve, which can discharge condensate from the system according to the liquid level sensor signal or timing strategy. The specific method and structure will not be described in detail here. The purpose is that ambient air usually contains a certain amount of water vapor. If it is not dehumidified, water vapor will have many adverse effects: such as condensation again in the subsequent optical detection chamber or reaction chamber due to temperature changes, forming droplets or mist, interfering with optical measurements, such as scattering laser light, absorbing light of specific wavelengths, and contaminating the optical window; and affecting the activity and lifespan of the catalyst during the catalytic reaction.

[0022] Furthermore, the diverter 30 includes a diverter valve 31, a main pipe 32, and two branch pipes 33. The inlet of the main pipe 32 is connected to the outlet of the condenser pipe 20. In this embodiment, the diverter valve 31 is a precision electric proportional valve or a set of two independent switching valves coordinated by a controller. No specific limitation is made here. The diverter valve 31 is installed at the inlet of the main pipe 32 to distribute the same air sample from the condenser pipe 20 to the two branch pipes 33 according to a preset ratio. The preset ratio is set by those skilled in the art according to actual needs. No specific limitation is made here. The two branch pipes 33 respectively guide the airflow to two independent light-changing detection units 40 and catalytic detection units 50.

[0023] Specifically, the light-changing detection unit 40 includes a light reaction tube 41, a first mixing vessel 42, and a first detector 43 connected in sequence. The light reaction tube 41 is a straight quartz tube. The surface of the first mixing vessel 42 is provided with a first interface for injecting reaction gas. The first interface extends to the outer shell 10. The reaction gas is nitric oxide, which is used to detect the concentration of nitrogen dioxide in the gas after the reaction. This concentration corresponds to the content of total oxidant in the original gas sample. The oxidant is labeled as Ox.

[0024] More specifically, the catalytic detection unit 50 includes a catalytic reaction tube 51, a second mixing tank 52, and a second detector 53 connected in sequence. The catalytic reaction tube 51 is filled with a catalyst, such as a molybdenum catalyst, and is equipped with a heating structure. In this embodiment, the heating structure is such as a resistance wire, which is not specifically limited here. The surface of the second mixing tank 52 is provided with a second interface for injecting a reaction gas, which is ozone. The second interface extends to the outer shell 10. Its purpose is to catalytically reduce the total active nitrogen oxides in the gas sample to nitric oxide, which is used to detect the concentration of nitrogen dioxide in the gas after the reaction. This concentration corresponds to the total amount of active nitrogen oxides in the original gas sample. It is worth mentioning that nitric oxide and ozone are provided by an external storage tank through the first and second interfaces.

[0025] It should be noted that both the first detector 43 and the second detector 53 are high-sensitivity nitrogen dioxide concentration detectors, such as chemiluminescent nitrogen oxide analyzers or optical cavity ring-down spectrometers. The first detector 43 and the second detector 53 can use the same type and model of detector to maintain system consistency and facilitate calibration. Alternatively, different types of instruments suitable for trace nitrogen dioxide detection can be selected according to the concentration range and response speed requirements of their respective channels. No specific limitation is made here. The two are used to detect the nitrogen dioxide concentration in the outlet gas of the first mixing tank 42 and the second mixing tank 52 in real time, respectively. The difference is that the purpose of the optical variable detection unit 40 is to measure the amount of nitrogen dioxide generated after the original oxidant reacts with nitric oxide in the air sample; the catalytic detection unit 50 measures the amount of nitrogen dioxide generated after the original active nitrogen oxides in the air sample are catalytically reduced to nitric oxide and then react with ozone.

[0026] Furthermore, a light-changing simulation mechanism 60 is installed on the housing 10. The light-changing simulation mechanism 60 is used to provide controllable lighting conditions for the light-changing detection unit 40. Specifically, the light-changing simulation mechanism 60 is installed on the cover plate of the housing 10, which is convenient for independent disassembly and replacement. Specifically, the light-changing simulation mechanism 60 includes a light source section and a dimming section. The light source section includes a heat sink 61, an LED strip 611, heat sink fins 612, and a cooling fan 613. The LED strip 611 is fixed on the side of the heat sink 61 facing the photoresistor tube 41. The LED strip 611 emits composite light including the ultraviolet band. The other side of the heat sink 61 is uniformly covered with heat sink fins 612, which facilitates the heat transfer of the LED strip 611 to the heat sink fins 612. The cooling fan 613 is fixed on the heat sink 61. It is worth mentioning that the outer casing 10 has a ventilation opening at the corresponding position of the cooling fan 613 to form a heat dissipation airflow.

[0027] The dimming unit includes an analog component 62 and a stepper motor 63. The analog component 62 is installed between the light source and the photoresponse tube 41. The analog component 62 includes a partition plate 621. The upper and lower sides of the partition plate 621 are rotatably mounted with a spectral adjustment plate 623 and an intensity adjustment plate 622, and are encapsulated by an upper cover plate 624 and a lower cover plate 625 fixed on the partition plate 621 to form a sandwich structure, which ensures the stability of the rotation dimming of the spectral adjustment plate 623 and the intensity adjustment plate 622. Specifically, both the spectral adjustment plate 623 and the intensity adjustment plate 622 are disc-shaped, with different regions along their circumference. The different regions of the intensity adjustment plate 622 are filters with different transmittance (e.g., neutral gray), and the different regions of the spectral adjustment plate 623 are filters with different spectral transmittance characteristics. The purpose is to simulate different intensities and different spectra of light by adjusting the different regions of the spectral adjustment plate 623 and the intensity adjustment plate 622 to block the light source, without having to frequently change the light intensity through power adjustment, thus improving the lifespan of the LED strip 611. More specifically, the stepper motor 63 is fixed on the upper cover plate 624, and a gear 631 is fixed at its output end. A driven internal gear ring 6221 is fixed at the center of the intensity adjustment plate 622. The driven internal gear ring 6221 meshes with the gear 631. The stepper motor 63 drives the driven internal gear ring 6221 to rotate through the gear 631, thereby controlling the rotation of the intensity adjustment plate 622. The spectral adjustment plate 623 is driven by another motor in the same way.

[0028] Furthermore, a light guide cover 411 is also provided on the outside of the light reaction tube 41. The inner wall of the light guide cover 411 is coated with a high reflectivity to effectively constrain and reflect the light source onto the circumference of the light reaction tube 41, which not only improves the uniformity of illumination, but also avoids stray light from interfering with other parts of the device.

[0029] Working principle: During operation, ambient air enters the condenser tube 20 through the air inlet 11. Under the active cooling of the cooling plate 21, the moisture in the air is condensed, and the dry air sample enters the distributor 30 and is divided into two streams by the distributor valve 31. A stream of gas enters the catalytic detection unit 50, is converted into nitric oxide in the catalytic reaction tube 51, and then reacts with excess ozone supplied from the outside in the second mixing tank 52 to generate nitrogen dioxide. Finally, the total active nitrogen oxide concentration is measured by the second detector 53. Another gas stream enters the photoreaction tube 41 of the photodetector unit 40. According to the experimental requirements, the photosimulation mechanism 60 provides simulated light with a specific spectrum and intensity to the photoreaction tube 41 by driving the spectral adjustment plate 623 and the intensity adjustment plate 622. After the gas sample undergoes a photochemical reaction under this light condition, it enters the first mixing tank 42 to react with nitric oxide. Finally, the total oxidant content is measured by the first detector 43.

[0030] Example 2, based on the above examples, further includes an analysis module and a simulation module. The analysis module is connected to the first detector 43 and the second detector 53 via wired and / or wireless communication, and is used to synchronously receive and process the detection signals of both, and to perform real-time differential and correlation analysis on the total oxidant concentration value measured by the first detector 43 and the total reactive nitrogen oxide concentration value measured by the second detector 53 at the same time point. That is, by continuously tracking the difference in the total oxidant concentration obtained by the first detector 43 at consecutive time points, and combining it with the reference concentration data synchronously provided by the second detector 53, the real-time generation rate of atmospheric oxidants is calculated. The purpose is that the effectiveness of this calculation method depends entirely on the sample homology ensured by the splitter 30 in Example 1 and the simultaneous detection by the first detector 43 and the second detector 53, eliminating the time asynchrony error inherent in the sequential sampling and detection in traditional equipment.

[0031] The simulation module is connected to the control terminal of the light variation simulation mechanism 60. It has multiple built-in light parameter models corresponding to different real environmental conditions. The simulation module drives the stepper motor 63 in the light variation simulation mechanism 60 to control the rotation and positioning of the spectral adjustment plate 623 and the intensity adjustment plate 622. In this way, the simulated light environment with the required spectrum and light intensity can be programmed to reproduce within the light reaction tube 41 of the light variation detection unit 40. For example, light parameters corresponding to different real environments, such as "clear sky at noon" and "thin clouds at dusk", can be constructed. Based on these light parameters, the light environment under specific time, location or weather conditions can be programmed to reproduce. This allows researchers to directly evaluate the quantitative impact of different light scenarios on the potential for oxidation of atmospheric samples in the laboratory.

[0032] The exemplary implementation of the solution proposed in this disclosure has been described in detail above with reference to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the spirit of this disclosure, and various combinations can be made to the various technical features and structures proposed in this disclosure without exceeding the protection scope of this disclosure, which is determined by the appended claims.

Claims

1. An atmospheric oxidizing indicator detection device, comprising a housing (10), characterized in that, Also includes: A condenser tube (20) is installed inside the housing (10) for dehumidifying the incoming air; The splitter (30) has its inlet connected to the outlet of the condenser (20) and is used to split the dehumidified air sample into a first branch and a second branch. The light-changing detection unit (40) includes a light-reacting tube (41), a first mixing tank (42) and a first detector (43) connected in sequence. The inlet of the light-reacting tube (41) is connected to the first branch outlet of the splitter (30). The catalytic detection unit (50) includes a catalytic reaction tube (51), a second mixing tank (52) and a second detector (53) connected in sequence. The inlet of the catalytic reaction tube (51) is connected to the second branch outlet of the splitter (30). A light-changing simulation mechanism (60) is mounted on the housing (10) and positioned corresponding to the photoresponse tube (41) to provide simulated illumination to an air sample flowing through the photoresponse tube (41).

2. The atmospheric oxidation indicator detection device according to claim 1, characterized in that, The condenser tube (20) has a U-shaped structure. A cooling plate (21) is provided on the outer side of the bottom of the condenser tube (20). A drain nozzle (22) is fixed at the lowest point of the bottom of the condenser tube (20).

3. The atmospheric oxidation indicator detection device according to claim 2, characterized in that, The distributor (30) includes a distributor valve (31), a main pipe (32) and two branch pipes (33). The inlet of the main pipe (32) is connected to the outlet of the condenser (20), and the outlets of the two branch pipes (33) are respectively connected to the inlet of the photoreaction tube (41) and the inlet of the catalytic reaction tube (51).

4. The atmospheric oxidizing indicator detection device according to claim 1, characterized in that, The light-changing simulation mechanism (60) includes a light source section and a dimming section; The light source unit includes a heat sink (61) and a light source disposed on the side of the heat sink (61) facing the photoresist tube (41); The dimming unit is located between the light source unit and the photoresponse tube (41), and includes an intensity adjustment plate (622) and a spectrum adjustment plate (623) that can be rotated independently. The intensity adjustment plate (622) has regions with different transmittance, and the spectrum adjustment plate (623) has regions with different spectral transmission characteristics.

5. The atmospheric oxidizing indicator detection device according to claim 4, characterized in that, The dimming unit also includes a middle partition (621), an upper cover (624) and a lower cover (625). The intensity adjustment plate (622) and the spectrum adjustment plate (623) are rotatably mounted on opposite sides of the middle partition (621) and are respectively encapsulated by the upper cover (624) and the lower cover (625). The intensity adjustment plate (622) and the spectrum adjustment plate (623) are driven to rotate by independent stepper motors (63).

6. The atmospheric oxidizing indicator detection device according to claim 1, characterized in that, The light-reacting tube (41) is covered with a light guide cover (411), and the inner wall of the light guide cover (411) is a reflective surface.

7. The atmospheric oxidizing indicator detection device according to claim 4, characterized in that, The light source is an LED light strip (611) containing ultraviolet light; the heat sink (61) is provided with heat dissipation fins (612) and a cooling fan (613) on the side facing away from the light source, and the outer shell (10) is provided with a ventilation opening corresponding to the position of the cooling fan (613).

8. The atmospheric oxidation indicator detection device according to claim 1, characterized in that, The catalytic reaction tube (51) is filled with a catalyst and is equipped with a heating structure.

9. The atmospheric oxidizing indicator detection device according to claim 1, characterized in that, It also includes an analysis module, which is communicatively connected to the first detector (43) and the second detector (53) for synchronously receiving and processing the detection signals of both to calculate atmospheric oxidative parameters.

10. The atmospheric oxidizing indicator detection device according to claim 5, characterized in that, The output end of the stepper motor (63) is fixed with a gear (631), and the middle part of the intensity adjustment plate (622) or the spectrum adjustment plate (623) is fixed with a driven internal gear ring (6221), and the gear (631) meshes with the driven internal gear ring (6221).

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