Particulate matter sensor and air handling device

Abstract

The application discloses a particulate matter sensor and an air treatment device. The particulate matter sensor comprises a shell, a gas flow passage for a to-be-detected gas containing particulate matter is formed in the shell; a gas flow generating piece is in communication with the gas flow passage, the gas flow generating piece can drive the to-be-detected gas to pass through the gas flow passage, and a preset wind speed V of the gas flow generating piece satisfies 0.5 m / s≤V≤3 m / s; and an optical detection assembly is arranged in the shell, the optical detection assembly is used for generating a detection light beam, the detection light beam forms a light detection area at an intersection with the gas flow passage, the light detection area has a preset area S, S satisfies 16 mm 2 ≤S≤100 mm 2 , and the optical detection assembly outputs an electrical signal about a particulate matter concentration value according to the detection light beam scattered by the particulate matter.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and more particularly to a particulate matter sensor and an air handling device. Background Technology

[0002] In related technologies, particulate matter sensors typically require a long response time when detecting large-diameter particles, such as PM30 (particulate matter with an aerodynamic diameter of approximately 30 μm), making it difficult to achieve rapid detection of particles and hindering further improvement in the efficiency of particulate matter sensors. Utility Model Content

[0003] This application discloses a particulate matter sensor and an air handling device to solve the problems of long response time and insufficient detection accuracy of particulate matter.

[0004] In a first aspect, embodiments of this application disclose a particulate matter sensor, comprising: a housing having an airflow channel formed within it for a gas to be detected containing particulate matter to pass through; an airflow generator connected to the airflow channel, the airflow generator driving the gas to be detected through the airflow channel, wherein a preset wind speed V of the airflow generator satisfies: 0.5 m / s ≤ V ≤ 3 m / s; and an optical detection component disposed in the housing, the optical detection component generating a detection beam, the detection beam forming a light detection area at its intersection with the airflow channel, the light detection area having a preset area S, S satisfying: 16 mm. 2 ≤S≤100mm 2 The optical detection component outputs an electrical signal relating to the particle concentration value based on the detection beam scattered by the particles.

[0005] In one possible implementation, the particle size detection range of the particulate sensor is: 5μm≤D≤40μm, where D is the aerodynamic diameter of the particulate matter.

[0006] In one possible implementation, the preset area S of the light detection region satisfies: 16 mm. 2 ≤S≤36mm 2 .

[0007] In one possible implementation, the preset wind speed V of the airflow generator satisfies: 1m / s≤V≤2m / s.

[0008] In one possible implementation, the light detection area is at least any one of a circular area, a rectangular area, a square area, or an elliptical area.

[0009] In one possible implementation, the wavelength λ of the detection beam satisfies: 620nm ≤ λ ≤ 850nm.

[0010] In one possible implementation, the optical detection assembly includes a light emitter for generating the detection beam; a beam-shaping lens group disposed in the optical path of the detection beam, the beam-shaping lens group being capable of expanding the detection beam into the light detection region having the preset area; and a photodetector for receiving the detection beam passing through the airflow channel, the photodetector being capable of outputting an electrical signal relating to the particulate matter concentration value.

[0011] In one possible implementation, the detection beam is a linear detection beam, and the linewidth W of the detection beam satisfies: 4.5mm ≤ W ≤ 10mm.

[0012] In one possible implementation, the detection performance of the photodetector is positively correlated with the preset wind speed V and / or the preset area S.

[0013] In one possible implementation, the light emitter, the beam shaping lens group, and the photodetector are arranged linearly, and the airflow channel is perpendicular to the light detection area.

[0014] In one possible implementation, the beam shaping lens group includes a double-sided aspherical mirror located on the light-emitting side of the light emitter, the double-sided aspherical mirror being used to expand the detection beam into a rectangular light detection area; and a collimating lens located on the light-emitting side of the double-sided aspherical mirror.

[0015] In one possible implementation, the particulate sensor further includes a control circuit electrically connected to the optical detection assembly to control the optical detection assembly to perform particulate detection.

[0016] In one possible implementation, the particulate sensor further includes a power supply module, comprising charging and discharging elements for storing and outputting electrical energy, the power supply module being electrically connected to the control circuit to supply power to the control circuit.

[0017] In one possible implementation, the particulate sensor further includes a communication module electrically connected to the control circuit, the communication module being used to transmit the electrical signal generated by the optical detection component to an external device.

[0018] Secondly, this application also provides an air treatment device, including the particulate matter sensor provided in the first aspect of this application.

[0019] In one possible implementation, the air handling device further includes a controller electrically connected to the particulate sensor.

[0020] Thus, the particulate matter provided in this embodiment of the application is controlled by maintaining the preset area S of the photodetection region formed by the detection beam at 16 mm. 2 ≤S≤100mm 2 By maintaining the wind speed V of the airflow generator at a preset wind speed of 0.5m / s≤V≤3m / s, the overall performance of the particulate matter sensor can be balanced. This allows particles of different sizes (PM10-PM30) to receive sufficient detection beam illumination to generate sufficiently strong scattering signals. At the same time, it significantly improves the response speed of the particulate matter sensor while increasing detection sensitivity. The larger area of ​​the light detection region combined with the higher wind speed can accelerate the passage rate of particles, enabling rapid detection of particulate matter concentration. This achieves a balance between rapid response, high-precision detection, and long-term reliability of the particulate matter sensor.

[0021] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the particulate matter sensor provided in the embodiments of this application;

[0024] Figure 2 One of the positional relationships between the detection area and the airflow channel of the optical detection component of the particulate sensor provided in the embodiments of this application;

[0025] Figure 3 The second diagram showing the positional relationship between the detection area and the airflow channel of the optical detection component of the particulate sensor provided in the embodiments of this application;

[0026] Figure 4 This is a schematic diagram of the optical path of the optical detection component of the particulate sensor provided in an embodiment of this application.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1-Particulate sensor; 10-Housing; 101-Airflow channel; 20-Airflow generator; 30-Optical detection assembly; 301-Light emitter; 302-Beam shaping lens group; 3021-Double-sided aspherical mirror; 3022-Collimating lens; 303-Photodetector. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the scope of protection of this application.

[0030] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0031] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0032] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0033] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0034] like Figure 1 As shown, this application provides a particulate matter sensor 1, which can be applied in scenarios requiring the detection of particulate matter concentration in the air, such as air purification equipment, environmental monitoring equipment, or industrial dust removal systems. This particulate matter sensor 1 is suitable for detecting the concentration of larger particle sizes, such as PM10, PM20, and PM30 (particulate matter with aerodynamic diameters of approximately 10 μm, 20 μm, and 30 μm, respectively).

[0035] like Figure 1 As shown, the particulate sensor 1 includes a housing 10. The housing 10 is the main structure of the particulate sensor 1, and the housing 10 can be made of engineering plastic or metal.

[0036] like Figure 1 As shown, an airflow channel 101 is formed inside the housing 10. This airflow channel 101 is for the gas to be detected containing particulate matter to pass through. The cross-sectional shape of the airflow channel 101 can be designed as a circle or an ellipse, or other shapes with smooth surfaces. The inner wall of the airflow channel 101 can be polished to reduce airflow resistance and is made of a material with good light transmittance, such as antistatic coated quartz glass.

[0037] like Figure 1 As shown, the airflow channel 101 can be a single channel. The airflow channel 101 has an air inlet and an air outlet at its two ends, respectively.

[0038] The airflow channel 101 can have a large cross-sectional area, thereby reducing the accumulation of particulate matter within it and ensuring that the particulate matter after concentration detection is promptly discharged from the airflow channel 101. Especially for larger particle sizes (PM30), due to their greater weight, a larger cross-sectional area in the airflow channel 101 provides a smooth airflow path, reducing the sedimentation and accumulation of larger particles. Specifically, the cross-sectional area of ​​the airflow channel 101 should be smaller than the preset area of ​​the light detection area described later.

[0039] In one possible implementation, the airflow channel 101 can be a channel that extends at least partially in a straight line. An airflow channel 101 that extends at least partially in a straight line can reduce the accumulation of particulate matter within the airflow channel 101. Especially for larger particles, which are more prone to settling and accumulation in curved or complex flow channels due to their greater weight, a straight airflow channel 101 can provide a smoother airflow path.

[0040] The particulate matter sensor 1 also includes an airflow generator 20. The airflow generator 20 can be disposed inside or outside the housing 10, or it can be configured in a space processing device in which the particulate matter sensor 1 is installed. The intake port of the airflow generator 20 is connected to the outlet port of the airflow channel 101. The airflow generator 20 can drive the gas to be detected (from the indoor environment) through the airflow channel 101 at a certain flow rate to detect the concentration of particulate matter.

[0041] The airflow generator 20 can be a fan. The preset wind speed V generated by the airflow generator 20 satisfies: 0.5m / s≤V≤3m / s, thereby effectively drawing in larger particles from the indoor environment and allowing the gas to be detected to pass through the airflow channel 101 at a relatively fast flow rate.

[0042] If V < 1 m / s, larger particles (such as PM30) are more likely to settle on the inner wall of the airflow channel 101 due to gravity, leading to a decrease in the detection accuracy of the particulate sensor 1 after long-term use. Furthermore, V < 1 m / s may also cause a prolonged residence time of particles in the light detection area A, potentially exceeding 20 seconds for a single particle, which fails to meet the rapid response requirements of the particulate sensor 1. It is worth noting that below 6000 pcs / m 3 Under sparse particulate matter distribution conditions, even low-speed airflow cannot achieve relatively uniform passage of particulate matter through the light detection area A, resulting in an increased false detection rate of particulate matter sensor 1.

[0043] If V > 3 m / s, the velocity of the particles passing through the light detection area A may be too fast, and the duration for which the photoelectric detection component receives the scattered light generated by the particles may be too short. This could prevent the photoelectric detection component from fully acquiring the pulse signal, increasing the risk of false detection. Furthermore, if the preset wind speed is too high, the flow velocity of the gas to be detected will increase accordingly, potentially generating turbulence and noise. The power of the airflow generator 20 will also need to be increased accordingly, resulting in increased operating noise from the particulate sensor 1.

[0044] Therefore, maintaining the preset wind speed V of the airflow generator 20 at 0.5m / s≤V≤3m / s can effectively balance detection accuracy, response speed and operating noise, enabling the particulate matter sensor 1 to quickly obtain reliable detection results on particulate matter concentration values.

[0045] The particulate matter sensor 1 also includes an optical detection component 30. The optical detection component 30 is disposed within the housing 10. The optical detection component 30 may include a light emitter 301, which is capable of emitting a detection beam. The optical detection component 30 may also include a photodetector 303, which is capable of receiving the detection beam after it has passed through and been scattered by the particulate matter, and outputting an electrical signal regarding the particulate matter concentration value.

[0046] In one possible implementation, the optical detection component 30 may include a beam shaping element that can expand the detection beam emitted by the light emitter 301 to form a light detection region A with a preset area, so that the detection beam is scattered by particulate matter in the gas to be detected.

[0047] The detection beam can be visible light or near-infrared light with longer wavelengths. Larger particles have better scattering characteristics for red visible light and near-infrared light. The detection beam forms a light detection region A at its intersection with the airflow channel 101; that is, the detection beam intersects the airflow channel 101 in its propagation direction, forming the light detection region A. The light detection region A has a preset area S, which can be the projected area of ​​the light detection region A on a plane perpendicular to the propagation direction of the detection beam. The preset area of ​​the light detection region is the effective detection range of the optical detection component 30.

[0048] When the airflow channel 101 contains particulate matter, the particulate matter will cause Mie scattering of the detection beam, resulting in a change in the light intensity received by the photodetector 303. By measuring the degree of light intensity attenuation, the concentration of particulate matter can be obtained. The airflow channel 101 passes through the photodetector area A, and the preset area of ​​the photodetector area A should be larger than the cross-sectional area of ​​the airflow channel 101 to reduce the probability of missed detection.

[0049] In one possible implementation, the light emitter 301 or light source of the optical detection component 30 can be a surface light source, such as an LED array or a VCSEL (vertical-cavity surface-emitting laser) array. The VCSEL array can emit high-power, highly directional red or near-infrared light. The detection beam emitted by the VCSEL array can directly form a pre-defined detection area A, simplifying the structure of the optical detection component 30. Correspondingly, to complement the surface light source, the photodetector 303 can be a high-sensitivity photodetector or an array detector.

[0050] The preset area S formed by the detection beam satisfies: 16mm 2 ≤S≤100mm 2 The preset area S can be understood as the effective coverage area of ​​the detection beam on the cross-section of the airflow channel 101. The size of the preset area S will affect the acquisition quality of the scattered light formed by the detection beam.

[0051] If S < 16mm 2 For large-diameter particulate matter such as PM30, if the preset area S of the optical detection region A is too small, it may cause signal distortion when the particulate matter partially blocks the detection beam, or result in incomplete signal acquisition when the particulate matter passes through the edge of the airflow channel 101. Furthermore, at 6000 pcs / m 3 In low-concentration environments, if the preset area S is too small, the number of particles captured per unit time is limited, and a longer sampling time is required to obtain a more accurate particle concentration value.

[0052] If S > 100mm 2This can lead to energy dispersion of the detection beam, resulting in reduced light intensity per unit area. The intensity of scattered light generated by relatively small particles such as PM10 scattering the detection beam may be insufficient, reducing the signal-to-noise ratio. Secondly, if the preset area S is too large, the uniformity of light intensity at the edge of the detection area A formed by the detection beam will decrease, and the light intensity at the edge will be significantly attenuated relative to the central area, affecting the accuracy of the detection results.

[0053] Therefore, the preset area S of the light detection region A is maintained at 16 mm. 2 ≤S≤100mm 2 This reduces the risk of incomplete signal acquisition due to an excessively small photodetector area A. A photodetector area A of a suitable size can also maintain sufficient light intensity density, ensuring both the scattering signal strength of larger particles such as PM30 and a detectable signal level for smaller particles such as PM10. The preset area S of the aforementioned region also balances the detection sensitivity and signal-to-noise ratio of the particulate matter sensor 1, giving it better anti-interference capabilities.

[0054] It should be noted that the preset area S of the optical detection region A formed by the detection beam is set to 16mm. 2 Up to 100mm 2 Within the range, and by keeping the preset wind speed of the airflow generator 20 between 0.5 m / s and 3 m / s, it is possible to ensure that particles of different sizes (PM10-PM30) receive appropriate detection beam irradiation time, so that particles of different sizes can generate sufficient scattering signal intensity, and improve the detection speed and response efficiency of the particle sensor 1.

[0055] Table 1

[0056]

[0057]

[0058] The test data above shows that the optimized combination of preset area and preset wind speed improves the detection performance of particulate matter sensor 1. When using a 16mm... 2 When the optical detection area A is used in conjunction with a wind speed of 1.8 m / s (serial number 2), the detection time of particulate matter sensor 1 is reduced by 31.6% to 8.42 seconds compared to a wind speed of 0.5 m / s (serial number 1), while maintaining a detection sensitivity of 5.23 μm. The optical detection area A is then expanded to 100 mm. 2 With a wind speed of 3 m / s (serial number 3), the detection time was further reduced to 2.87 seconds, demonstrating a significant improvement in response speed. Particularly noteworthy is the improvement in high-concentration environments (14000 pcs / m³). 3Under serial number 4), particulate matter sensor 1 can achieve an extremely fast response of 1.03 seconds, indicating that particulate matter sensor 1 has good detection performance under various working conditions.

[0059] The test data in Table 1 also proves that: when the light detection area A is too small (8mm) 2 Furthermore, when the wind speed is low (0.2 m / s, item 7), the detection time for a single particle is significantly extended to 53.23 seconds, demonstrating the importance of combining the preset area of ​​the optical detection region A and the preset wind speed of the airflow generator 20 in the embodiments of this application. It is evident that the preset area is 16 mm². 2 ≤S≤100mm 2 The combination of the light detection area A and the airflow generator 201 with a wind speed of 0.5 m / s-3 m / s not only enables rapid detection of PM10-PM30 particles (1.03-12.31 seconds), but also enables the detection of smaller particles (detectable particle size of approximately 5.23 μm), giving the particulate sensor 1 both fast response and high sensitivity.

[0060] Thus, the particulate matter provided in this embodiment of the application is controlled by maintaining the preset area of ​​the photodetection region A formed by the detection beam at 16mm. 2 ≤S≤100mm 2 By maintaining the preset wind speed of the airflow generator 20 at 0.5m / s≤V≤3m / s, the overall performance of the particulate matter sensor 1 can be balanced. This allows particulate matter of different sizes (PM10-PM30) to receive sufficient detection beam illumination to generate a sufficiently strong scattering signal. At the same time, it significantly improves the response speed while increasing the detection sensitivity. The larger light detection area A, combined with the higher wind speed, can accelerate the passage rate of particulate matter, thereby achieving rapid detection of particulate matter concentration. This achieves a balance between the rapid response, high-precision detection, and long-term reliability of the particulate matter sensor 1.

[0061] In some embodiments, the aerodynamic equivalent diameter D of the particles that the particulate sensor 1 can detect satisfies: 5μm≤D≤40μm.

[0062] The particulate sensor 1 provided in this application embodiment can detect particulate matter with an aerodynamic equivalent diameter D that satisfies: 5μm≤D≤40μm, covering a wide range of particle sizes from fine to coarse particles. This enables the particulate sensor 1 to simultaneously detect particulate matter of different size ranges such as PM10, PM20, and PM30, thus meeting the diverse detection needs of the particulate sensor 1 in complex environments.

[0063] In some embodiments, the preset area S of the light detection region A satisfies: 16mm² 2 ≤S≤36mm 2In this way, the preset area of ​​the light detection region A is effectively controlled within the above range, which can balance detection efficiency and detection sensitivity. This avoids the problem of insufficient signal acquisition caused by an excessively small light detection region A, and reduces the light intensity dispersion defect caused by an excessively large light detection region A.

[0064] For example, please refer to the test data in Table 1, when the area of ​​the light detection region A is 16 mm². 2 In cases (2 and 5), a balance was achieved between detection time (4.78-12.31 seconds) and detection particle size (5.23 μm)—compared to the smaller 8 mm. 2 Area 7 can shorten the detection time by more than 76%, compared to 100mm. 2 The optical detection areas (numbers 3 and 4) enhance the detection sensitivity of particle sensor 1 for small-diameter particles (the measurable particle size is optimized from 8.37 μm to 5.23 μm). This reduces signal distortion caused by insufficient preset area (the 44.44-second detection time of number 7) and avoids the light intensity dispersion problem caused by excessively large preset area (the measurable particle size of numbers 3 and 4 is increased to 8.37 μm), enabling particle sensor 1 to detect particles in the range of 6000-14000 pcs / m². 3 It exhibits a stable and rapid response time within the concentration range, with the response speed optimized to 4.78 seconds.

[0065] Specifically, the preset area S of the light detection region A can be 16 mm². 2 25mm 2 36mm 2 .

[0066] In some embodiments, the preset wind speed V of the airflow generator 20 satisfies: 1m / s≤V≤2m / s.

[0067] Maintaining the preset wind speed of the airflow generator 20 at 1ms-2ms allows the particles to have a suitable residence time, enabling the particle sensor 1 to further optimize its response speed and stably detect particles with a diameter of 5.23μm, thereby further improving the response speed and detection accuracy of the particle sensor 1.

[0068] Specifically, the preset wind speed V of the airflow generator 20 can be 1m / s, 1.3m / s, 1.5m / s, 1.8m / s, or 2m / s.

[0069] In some embodiments, such as Figure 2 and Figure 3 As shown, the light detection area A is at least one of a circular area, a rectangular area, a square area, or an elliptical area.

[0070] The optical detection area A can be configured into different geometric shapes such as circle, rectangle, ellipse or square to adapt to the diverse detection needs of particulate matter sensor 1. Among them, a square optical detection area A can make the detection beam energy uniformly distributed in the X / Y direction, reducing the light intensity difference within the optical detection area A.

[0071] In some embodiments, the wavelength λ of the detection beam satisfies: 620nm ≤ λ ≤ 850nm. This wavelength range of red to near-infrared spectrum can effectively excite large-diameter particles (such as PM10-PM30) to produce a significant Mie scattering effect. Its longer wavelength characteristics can penetrate large-diameter particles, reduce signal interference caused by multiple scattering, and reduce the influence of ambient light interference.

[0072] Specifically, the wavelength of the detection beam can be 630nm, 650nm, 690nm, 730nm, 760nm, 7900nm, or 850nm.

[0073] Furthermore, the wavelength λ of the detection beam can be a laser source with a wavelength of 650nm. This wavelength is located in the central region of the above wavelength range and has good scattering efficiency for particles of 10m-40μm. Moreover, it matches the peak response wavelength of common photodetectors 303 (such as silicon photodiodes which have high sensitivity around 650nm), which can further improve the signal-to-noise ratio of particle sensor 1.

[0074] In some embodiments, such as Figure 4 As shown, the optical detection assembly 30 includes a light emitter 301, a photodetector 303, and a beam shaping lens group 302.

[0075] The light emitter 301 is used to generate the detection beam. The light emitter 301 can be a laser emitter or an LED light source. Laser emitters have advantages such as good beam quality, strong directionality, and concentrated energy, making them particularly suitable for high-precision particulate matter detection. LED light sources can use high-brightness red LEDs, which are characterized by low cost, long lifespan, and ease of integration.

[0076] In some embodiments, the detection beam is a linear detection beam, and the linewidth W of the detection beam satisfies: 4.5mm ≤ W ≤ 10mm. Specifically, the linewidth W of the detection beam can be 45mm, 5mm, 7mm, 8mm, 9mm, or 10mm.

[0077] The extended characteristics of the linear beam cause particles to generate more distinctive scattered signal pulses when passing through the detection beam, improving the signal-to-noise ratio and discriminability. The linewidth W of the detection beam satisfies: 4.5mm ≤ W ≤ 10mm, thus making it easier to obtain a rectangular optical detection area A that conforms to the preset area S, where S satisfies: 16mm. 2 ≤S≤36mm2 .

[0078] The beam shaping lens group 302 is disposed in the optical path of the detection beam, and the beam shaping lens group 302 can expand the linear detection beam into a light detection area A with a preset area.

[0079] For example, the beam shaping lens group may include at least one cylindrical lens and one aspherical lens to convert the Gaussian beam emitted by the light emitter into a uniformly distributed rectangular light spot.

[0080] For example, the beam shaping lens group may include a combination of a pair of aspherical lenses and diffractive optical elements, wherein the first aspherical lens is used to collimate the laser beam, the second aspherical lens is used for pre-focusing, and then the detection beam is converted into a uniformly distributed circular spot by the diffractive optical elements.

[0081] The photodetector 303 receives the detection beam passing through the detection area A and outputs the particulate matter concentration of the gas to be detected. The photodetector 303 can be a high-sensitivity silicon photodiode with a spectral response range of 620nm-850nm. A filter can be provided at the front end of the photodetector 303, with the center wavelength of the filter matching the wavelength of the detection beam and a bandwidth controlled within ±5nm, effectively suppressing ambient light interference and improving the signal-to-noise ratio.

[0082] In some embodiments, the detection performance of the photodetector 303 is positively correlated with a preset wind speed V and / or a preset area S.

[0083] When selecting the photodetector 303, the preset wind speed of the airflow disturbance component and / or the preset area of ​​the light detection area A can be referenced to make the detection performance (effective sampling volume L / min) of the photodetector 303 positively correlated with the preset wind speed and / or the preset area of ​​the light detection area A.

[0084] When the particulate sensor 1 uses a higher preset wind speed or a larger light detection area A, a photodetector 303 with faster response characteristics and a wider dynamic range can be matched to adapt to the increased particulate matter throughput and signal acquisition requirements. Correspondingly, under conditions of medium wind speed and a relatively small light detection area A, a photodetector 303 with higher sensitivity and lower noise can be selected to more accurately correspond to the number of particles passing through the light detection area A per unit time, while improving the integrity and accuracy of signal acquisition.

[0085] Please refer to the test data in Table 1. The selection of photodetector 303 is positively correlated with airflow velocity and / or the area of ​​the light detection region A: when particulate sensor 1 uses a 100mm... 2When the light detection area A is combined with a relatively high wind speed of 3 m / s (serial numbers 3 and 4), the photodetector 303 can have a detection capability of 3.6 L / min, achieving rapid detection in 1.03-2.87 seconds; while when the particulate sensor 1 uses a 16mm... 2 When the optical detection area A is used with a relatively high wind speed of 0.5-1.8 m / s (serial numbers 1 and 2), the detection capability of 0.9-1.35 L / min is adapted to a high-sensitivity detector, thereby achieving fine detection of 5.23 μm particles.

[0086] In some embodiments, the light emitter 301, the beam shaping lens group 302, and the photodetector 303 are arranged linearly, and the airflow channel 101 is perpendicular to the light detection area A.

[0087] The light emitter 301, the beam shaping lens group 302, and the photodetector 303 are arranged linearly to form a light detection channel. The optical axis of the light detection channel is O1, which is perpendicular to the airflow channel 101, that is, the airflow channel 101 is perpendicular to the light detection area A.

[0088] The phrase "the flow channel is perpendicular to the light detection area A" can be understood as follows: the airflow channel 101 is perpendicular or approximately perpendicular to the light detection area A, that is, the optical axis O1 of the light detection channel and the central axis of the airflow channel 101 are at an angle of 80°, 85°, 89°, 90°, 91°, 95°, or 100°. "Approximately perpendicular" can be interpreted as the two being nearly perpendicular or existing at an angle within the aforementioned preset range.

[0089] The airflow channel 101 is perpendicular to the light detection area A, which allows the particles in the airflow to pass through the detection beam perpendicularly, reducing the signal distortion that may occur when the airflow channel 101 passes obliquely through the light detection area A, and improving the signal-to-noise ratio of the pulse signal collected by the photodetector 303.

[0090] In some embodiments, the beam shaping lens group 302 includes a double-sided aspherical mirror 3021 and a collimating mirror 3022. The double-sided aspherical mirror 3021 is located on the light-emitting side of the light emitter 301 and is used to expand the detection beam into a rectangular light detection area A.

[0091] The double-sided aspherical mirror 3021 can be manufactured using PMMA (polymethyl methacrylate) molding technology. Both the incident and emitting surfaces of the double-sided aspherical mirror are conicoids, i.e., aspherical surfaces, to expand the Gaussian beam emitted by the light emitter 301 into a rectangular uniform light spot, i.e., the light detection area. Specifically, the incident surface is used to collimate the beam in the fast axis direction, and the emitting surface expands the beam in the slow axis direction, reducing the divergence angle difference of the light detection area A in the X / Y directions.

[0092] Furthermore, the PMMA-molded double-sided aspherical mirror 3021 is lightweight and highly impact-resistant, which improves the durability of the particulate sensor 1.

[0093] Collimating lens 3022 is located on the light-emitting side of double-sided aspherical mirror 3021. It is used to collimate the light detection area A that has undergone preliminary shaping, which can improve the uniformity of light intensity of the detection beam in the light detection area A, thereby improving the light energy utilization rate of the light detection area A.

[0094] In some embodiments, as shown in the figure, the particulate matter sensor 1 includes a control circuit. The control circuit includes a microcontroller, which can be an MCU (Micro Controller Unit). The microcontroller is connected to a photodetector 303 to receive electrical signals generated by the photodetector 303. The microcontroller calculates the concentration value of the particulate matter using a pre-stored algorithm model. The algorithm model can be based on Mie scattering theory.

[0095] The control circuit may also include a light source driving circuit connected to the light emitter 301 to control the operating state of the light emitter 301. The control circuit may also include a signal processing circuit connected to the photodetector 303 and the microcontroller to amplify, reduce noise, and perform analog-to-digital conversion on the electrical signal generated by the photodetector 303.

[0096] In some embodiments, the control circuit further includes a drive circuit. The drive circuit is connected to the airflow generator 20 and the microcontroller. The microcontroller can control the operating parameters of the airflow generator 20 through the drive circuit to keep the wind speed of the airflow generator 20 within a preset wind speed range.

[0097] In some embodiments, as shown in the figure, the particulate sensor 1 further includes a power supply module. The power supply module includes charging and discharging elements to store and output electrical energy. The power supply module is electrically connected to a control circuit and is used to supply power to the control circuit. The power supply module can be a battery.

[0098] The particulate matter sensor 1 can be mounted on an external device. For example, the particulate matter sensor 1 can be applied to an air handling unit, which can adjust the operating parameters of its components (such as a fan assembly) based on the particulate matter concentration value output by the particulate matter sensor 1. When the external device is operating, it can charge the power supply module to ensure the module has sufficient power.

[0099] By configuring a separate power supply module in the particulate matter sensor 1, the operation of the particulate matter sensor 1 is no longer limited by the operation of external devices. Because the particulate matter sensor 1 has an independent power supply module, even when the external devices are not working, the particulate matter sensor 1 can still independently complete the detection of particulate matter concentration in the indoor environment. That is, the particulate matter sensor 1 can work autonomously, thereby achieving uninterrupted or long-term detection of particulate matter concentration in the indoor environment.

[0100] In some embodiments, as shown in the figure, the particulate sensor 1 further includes a communication module. The communication module is used for data interaction with external devices. The communication module can be a wireless communication module such as a Wi-Fi module, Bluetooth module, or ZigBee module. The communication module can also be a wired communication module.

[0101] External devices can be air handling equipment, or users' mobile terminals or IoT gateways in smart home systems.

[0102] The communication module can be electrically connected to the microcontroller of the control circuit to receive the particulate matter concentration value calculated by the microcontroller. The particulate matter sensor 1 can establish a communication connection with external devices through the communication module.

[0103] For example, the external device is an air handling unit, and the communication module can be a wired communication module or a wireless communication module. The particulate matter sensor 1 can transmit the particulate matter concentration value it detects to the controller of the air handling unit equipped with the particulate matter sensor 1, and the controller adjusts the operating parameters of the working components of the air handling unit according to the particulate matter concentration value.

[0104] It is worth noting that the particulate matter sensor 1 is equipped with an independent power supply module. Therefore, a communication module is configured for the particulate matter sensor 1. When the particulate matter sensor 1 is working autonomously (for example, when the air handling equipment equipped with the particulate matter sensor 1 is shut down), the particulate matter concentration value can be directly transmitted to the user's mobile terminal or IoT gateway through the wireless communication module.

[0105] For example, when the air handling equipment is shut down or running, users can remotely view the particulate matter concentration value of the indoor environment through an application on a mobile terminal.

[0106] For example, when the air conditioner equipped with particulate matter sensor 11 is shut down or running, the IoT gateway can control other smart home devices within the IoT to work together. For instance, when the particulate matter concentration exceeds the standard, the IoT gateway can control the air purifier to work independently or in conjunction with the air conditioner, thereby achieving intelligent adjustment of the indoor air quality.

[0107] In some embodiments, the housing 10 may be provided with an air inlet and an air outlet. The air inlet is connected to the air inlet of the airflow channel 101, and the air outlet is connected to the exhaust port of the airflow generator 20. The air inlet and the air outlet may be provided on the same side wall of the housing 10, or they may be provided on two opposite side walls of the housing 10.

[0108] By placing the air inlet and outlet on the same side wall of the housing 10, the space requirements of the air handling unit can be reduced when the particulate sensor 1 is used in an air handling unit. With the particulate sensor 1 having air inlet and outlet on the same side, the air handling unit can reserve ventilation space on one side, improving the installation flexibility of the particulate sensor 1, making it particularly suitable for compact air handling units.

[0109] This application also provides an air treatment device, which includes the particulate sensor 1 provided in any of the above embodiments. The air treatment device provided in this application has the beneficial effects of any of the above embodiments regarding the particulate sensor 1 because it has the particulate sensor 1 as in any of the above embodiments, which will not be described in detail here.

[0110] In some embodiments, the air handling equipment may be an air purifier, or an air conditioner, fresh air system, humidifier, etc. with air purification function.

[0111] In some embodiments, the air inlet of the particulate sensor 1 is positioned toward the air inlet window of the air handling unit to accurately obtain the air quality of the indoor environment.

[0112] In some embodiments, the air handling unit may include a controller electrically connected to the particulate sensor 1. The controller can receive particulate concentration values ​​for different particle sizes detected by the particulate sensor 1. The controller can control the operation of the fan assembly of the air handling unit. For example, if the particulate concentration in the indoor environment exceeds a threshold, the fan assembly can be controlled to operate at a higher power to accelerate the treatment (e.g., purification) of the indoor air and reduce the particulate concentration as quickly as possible.

[0113] In some embodiments, the air handling equipment further includes a power supply interface, which can be connected to the power supply module of the power supply and the particulate matter sensor 1, and the power supply interface can supply power to the control circuit of the particulate matter sensor 1.

[0114] In some embodiments, the controller of the air handling equipment is electrically connected to the microcontroller of the control circuit.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A particulate matter sensor, characterized in that, include: The housing has an internal airflow channel for the gas to be detected, which contains particulate matter. An airflow generator is connected to the airflow channel and can drive the gas to be detected through the airflow channel. The preset wind speed V of the airflow generator satisfies: 0.5m / s≤V≤3m / s. An optical detection component is disposed in the housing. The optical detection component is used to generate a detection beam. The detection beam forms a light detection area at the intersection with the airflow channel. The light detection area has a preset area S, where S satisfies: 16 mm. 2 ≤S≤100mm 2 The optical detection component outputs an electrical signal relating to the particle concentration value based on the detection beam scattered by the particles.

2. The particulate matter sensor according to claim 1, characterized in that, The particle size detection range of the particulate sensor is: 5μm≤D≤40μm, where D is the aerodynamic diameter of the particulate matter.

3. The particulate matter sensor according to claim 1, characterized in that, The preset area S of the light detection region satisfies: 16mm² 2 ≤S≤36mm 2 ; and / or The preset wind speed V of the airflow generator satisfies: 1m / s≤V≤2m / s; and / or The light detection area is at least one of a circular area, a rectangular area, a square area, or an elliptical area.

4. The particulate matter sensor according to claim 1, characterized in that, The wavelength λ of the detection beam satisfies: 620nm≤λ≤850nm.

5. The particulate matter sensor according to claim 1, characterized in that, The optical detection component includes: A light emitter is used to generate the detection beam; A beam-shaping lens group is disposed in the optical path of the detection beam, and the beam-shaping lens group can expand the detection beam into the light detection area having the preset area; A photodetector is used to receive the detection beam passing through the airflow channel, and the photodetector is capable of outputting an electrical signal regarding the particulate matter concentration value.

6. The particulate matter sensor according to claim 5, characterized in that, The detection beam is a linear detection beam, and the linewidth W of the detection beam satisfies: 4.5mm ≤ W ≤ 10mm; and / or The detection performance of the photodetector is positively correlated with the preset wind speed V and / or the preset area S.

7. The particulate matter sensor according to claim 5, characterized in that, The light emitter, the beam shaping lens group, and the photodetector are arranged linearly, and the airflow channel is perpendicular to the light detection area.

8. The particulate matter sensor according to claim 5, characterized in that, The beam-shaping lens group includes: A double-sided aspherical mirror is located on the light-emitting side of the light emitter, and the double-sided aspherical mirror is used to expand the detection beam into a rectangular light detection area; A collimating lens is located on the light-emitting side of the double-sided aspherical mirror.

9. The particulate sensor according to any one of claims 1 to 8, characterized in that, The particulate sensor also includes: A control circuit is electrically connected to the optical detection component to control the optical detection component to perform particulate matter detection; A power supply module, including charging and discharging elements for storing and outputting electrical energy, the power supply module being electrically connected to the control circuit to supply power to the control circuit; and / or a communication module, the communication module being electrically connected to the control circuit, the communication module being used to transmit electrical signals generated by the optical detection component to an external device.

10. An air handling device, characterized in that, include: The particulate sensor as described in any one of claims 1 to 9; The controller is electrically connected to the particulate sensor.

Images