A VOCs waste gas detection device and detection method

Abstract

The application relates to the technical field of gas detection, in particular to a VOCs waste gas detection device and a detection method. The detection device comprises a conduit, a rotating drum, a transmission mechanism and a detection unit. The conduit is connected to the outlet end of a waste gas emission device, and the rotating drum is rotationally arranged at the end of the conduit far from the waste gas emission device. The transmission mechanism is arranged in the rotating drum, and the waste gas in the conduit is used to drive the rotating drum to rotate. The detection unit is arranged in the rotating drum and is used for detecting the waste gas in the rotating drum. The VOCs waste gas detection device can be used for real-time detection of vehicle exhaust during automobile driving, so that the detection result is more accurate.

Description

Technical Field

[0001] This invention relates to the field of gas detection technology, specifically to a VOCs exhaust gas detection device and detection method. Background Technology

[0002] The vehicle exhaust emission testing system is a testing system developed based on AVL, HORIBA series and domestic emission testers. It is mainly used in automobile manufacturers, 4S service stations and vehicle inspection agencies. The system generally consists of a gas analyzer, a computer control system, an OBD diagnostic system and report output equipment. It can measure pollutants such as HC, CO, CO2, O2, NOx and calculate the excess air index.

[0003] Some existing gas analyzers, when analyzing and testing vehicle exhaust, typically position the car in a fixed location and let it idle before measuring the exhaust emissions. This can lead to discrepancies between the measured data and the exhaust emission data during actual driving, resulting in inaccurate results. Furthermore, the concentration of exhaust gases varies at different locations within the exhaust pipe during emission, which can also contribute to inaccurate test results. Summary of the Invention

[0004] This invention provides a VOCs exhaust gas detection device and method, which can detect vehicle exhaust gas in real time while the car is in motion, making the detection results more accurate.

[0005] The VOCs exhaust gas detection device and detection method of the present invention adopt the following technical solution:

[0006] A VOCs exhaust gas detection device includes a conduit, a rotating drum, a transmission mechanism, and a detection unit. The conduit is connected to the outlet end of the exhaust gas emission device, and the rotating drum is rotatably positioned at the end of the conduit away from the exhaust gas emission device. The transmission mechanism is located inside the rotating drum, and the transmission mechanism drives the rotating drum to rotate by passing exhaust gas into the rotating drum through the conduit. The detection unit is located inside the rotating drum and is used to detect the exhaust gas passing into the rotating drum.

[0007] Furthermore, the detection unit includes a reflector, a transmitter, a receiver, and a movable limiting assembly. The reflector is coaxially fixed inside the rotating cylinder, and both the transmitter and the receiver are set inside the reflector through the movable limiting assembly.

[0008] The transmitter is configured to emit light, which is reflected inside the reflector tube and then received by the receiver. The receiver is configured to perform spectral analysis on the received light and determine the concentration of harmful gases in the exhaust gas based on the analysis results. The movable limiting component is configured to change the position of the transmitter and receiver inside the reflector tube to change the number of times the light emitted by the transmitter is reflected inside the reflector tube.

[0009] Furthermore, a rotating ring is fixed at the end of the duct away from the exhaust gas emission device. The rotating cylinder is inserted into the rotating ring and rotatably connected to it. A speed encoder is installed on the side wall of the rotating ring. The speed encoder is electrically connected to the transmitter to control the frequency of the light emitted by the transmitter, and the frequency of the light emitted by the transmitter is positively correlated with the intake speed of the exhaust gas entering the rotating cylinder. A gear ring is provided on the outer side wall of the rotating cylinder, and a speed measuring gear that meshes with the gear ring is installed on the input shaft of the speed encoder.

[0010] Furthermore, the movable limiting assembly includes a fixed shaft, a sliding sleeve, a telescopic rod, a limiting structure, and a reset mechanism. The fixed shaft is fixed on the rotating drum, the sliding sleeve is slidably mounted on the fixed shaft, and there are two telescopic rods symmetrically arranged about the fixed shaft. One end of each telescopic rod is hinged to the sliding sleeve, and the other end passes through the rotating drum and is fixedly connected to the transmitter and the receiver, respectively. The part of the telescopic rod that passes through the rotating drum is rotatably connected to the rotating drum.

[0011] The fixed shaft has multiple defined positions. The sliding sleeve is configured to slide along the fixed shaft under the action of the centrifugal force of the rotating drum and is limited to any defined position under the action of the limiting structure. The reset mechanism is provided between the sliding sleeve and the fixed shaft and is configured to make the sliding sleeve tend to move towards the defined position in the radial direction.

[0012] Furthermore, the limiting structure includes an elastic element and a limiting groove. The elastic element is fixed on the inner wall of the sliding sleeve, and the limiting groove is opened on the side wall of the fixed shaft. The sliding sleeve is engaged in the limiting groove by the elastic element.

[0013] Furthermore, the reset mechanism includes a reset spring, one end of which is fixedly connected to the end of the sliding sleeve away from the rotating cylinder, and the other end is fixedly connected to the end of the fixed shaft away from the rotating cylinder.

[0014] Furthermore, the transmission mechanism includes a transmission cylinder and transmission blades. The transmission cylinder is coaxially fixed inside the rotating cylinder, and the transmission blades are fixed on the inner wall of the transmission cylinder. Multiple transmission blades are provided, and the multiple transmission blades are evenly arranged around the central axis of the transmission cylinder.

[0015] Furthermore, the conduit is equipped with a water-cooling jacket.

[0016] Furthermore, the duct is provided with a solid filter block, which is located after the water cooling jacket in the direction of exhaust gas flow within the duct.

[0017] A method for detecting VOCs exhaust gas, using the aforementioned VOCs exhaust gas detection device.

[0018] The beneficial effects of this invention are:

[0019] This invention discloses a VOCs exhaust gas detection device. With the sealing plate closed, exhaust gas from a vehicle enters a rotating drum through a duct. After entering the drum, the exhaust gas is driven to rotate by a transmission mechanism. The rotation of the drum causes some disturbance to the exhaust gas, resulting in a more uniform distribution of the exhaust gas within the drum. The detection unit can detect the exhaust gas generated during vehicle operation. Compared to existing detection methods that obtain results by idling the vehicle, the detection results of this invention are more consistent with actual vehicle driving conditions. Furthermore, the more uniform distribution of exhaust gas within the rotating drum further improves the accuracy of the detection results.

[0020] Furthermore, a portion of the light emitted by the transmitter at specific wavelengths is absorbed by the exhaust gas. By analyzing the spectrum of the received light with the receiver, the types and amounts of gases in the exhaust gas can be detected, making the detection process simple and quick. Moreover, the movable limiting component can change the positions of the transmitter and receiver within the emission tube, resulting in more diverse reflection patterns of the emitted light within the reflector tube. Based on the received data from these various reflections, the receiver measures the average content of multiple gases in the exhaust gas, making the data obtained by this invention more accurate.

[0021] Furthermore, the sliding sleeve, subjected to the centrifugal force of the rotating drum, can slide on the fixed shaft and be limited to a specific position on the fixed shaft by the limiting structure. The centrifugal force of the rotating drum is positively correlated with its rotational speed, which in turn is positively correlated with the intake speed of the exhaust gas. Therefore, the centrifugal force on the slider is positively correlated with the speed at which the exhaust gas enters the rotating drum. When the intake speed is slow, the sliding sleeve is located in a limited position closer to the rotating drum, resulting in fewer reflections of the emitted light within the reflecting tube. When the intake speed is fast, the sliding sleeve is located in a limited position farther from the rotating drum, resulting in more reflections of the emitted light within the reflecting tube. In this case, the light path reflected within the rotating drum is denser than when low-speed exhaust gas is introduced, thus enabling the receiver to receive more comprehensive spectral data and more accurate analysis results.

[0022] Furthermore, the drive blades can drive the rotating drum to rotate at different speeds based on the intake speed of the exhaust gas. Different drum speeds result in different speeds measured by the speed encoder. The speed encoder can then control the frequency of the light emitted by the transmitter based on the measured speed. The faster the speed encoder measures, the higher the frequency of the emitted light. Higher frequency light is reflected more densely within the reflector, resulting in more spectral data received by the receiver, thus making the measured data more accurate. Attached Figure Description

[0023] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a VOCs exhaust gas detection device provided in an embodiment of the present invention;

[0025] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure in the OO direction;

[0026] Figure 3 for Figure 2 A magnified structural diagram of part A in the middle;

[0027] Figure 4 for Figure 2 A magnified structural diagram of part B in the middle section;

[0028] Figure 5 for Figure 2 A magnified structural diagram of section C;

[0029] Figure 6 for Figure 2 A schematic diagram of the cross-sectional structure in the DD direction when the sliding sleeve is located near the limiting groove of the rotating drum in the provided VOCs exhaust gas detection device;

[0030] Figure 7 for Figure 6 A magnified structural diagram of section E in the middle;

[0031] Figure 8 for Figure 2 A schematic diagram of the cross-sectional structure in the DD direction when the sliding sleeve is located away from the limiting sleeve of the rotating drum in the provided VOCs exhaust gas detection device;

[0032] Figure 9 for Figure 8 A schematic diagram of the cross-sectional structure of section F in the middle.

[0033] In the diagram: 100, conduit; 110, sealing plate; 120, swivel ring; 121, speed encoder; 130, water-cooling jacket; 140, solid filter block; 200, rotating drum; 210, gear ring; 300, transmission mechanism; 310, transmission cylinder; 320, transmission blade; 410, reflector; 420, transmitter; 430, receiver; 441, fixed shaft; 442, sliding sleeve; 443, telescopic rod; 4441, elastic element; 4442, limiting groove; 445, return spring; 500, conductive ring. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] like Figures 1 to 9 As shown, a VOCs exhaust gas detection device includes a conduit 100, a rotating drum 200, a transmission mechanism 300, and a detection unit. The conduit 100 is connected to the outlet end of an exhaust gas emission device, and the rotating drum 200 is rotatably disposed at the end of the conduit 100 away from the exhaust gas emission device. The transmission mechanism 300 is disposed inside the rotating drum 200 and drives the rotating drum 200 to rotate by exhaust gas flowing into the rotating drum 200. The detection unit is disposed inside the rotating drum 200 and is used to detect the exhaust gas flowing into the rotating drum 200.

[0038] Specifically, the exhaust emission device can be the vehicle's exhaust pipe, and the duct 100 can be a T-shaped pipe with three ports. One end of the straight section of the duct 100 is fixedly connected to the exhaust outlet of the exhaust emission device, and the other end is connected to an openable and closable sealing plate 110. The drain section of the duct 100 is directly rotatably connected to the rotating drum 200.

[0039] When this invention is installed on the exhaust pipe of a vehicle, if the content of harmful gases in the vehicle exhaust needs to be detected, the sealing plate 110 is closed, allowing the exhaust gas to enter the rotating drum 200 through the drain pipe of the conduit 100. If the content of harmful gases in the vehicle exhaust is not being detected, the sealing plate 110 remains open. When the sealing plate 110 is closed, this invention can detect the composition of harmful gases in the vehicle exhaust regardless of whether the vehicle is in motion. When the sealing plate 110 is open, as little exhaust gas as possible is allowed to enter the rotating drum 200, which helps to ensure smooth exhaust emission.

[0040] The transmission mechanism 300 is a mechanical structure powered by the exhaust gas, which drives the rotating drum 200 to rotate. The faster the exhaust gas intake speed, the faster the rotating drum 200 rotates. The detection unit can be an existing exhaust gas analyzer, such as an AVL exhaust gas analyzer. When the rotating drum 200 rotates, it can create a certain disturbance to the exhaust gas entering the drum 200, making the exhaust gas more evenly distributed within the drum 200. This, in turn, allows the detection unit to obtain more accurate detection results when detecting harmful gas components in the exhaust gas.

[0041] The operating principle of this invention is as follows:

[0042] First, connect one end of the straight section of the conduit 100 to the car exhaust pipe. If it is necessary to detect the concentration of harmful gases in the car exhaust, close the sealing plate 110 so that all the car exhaust flows into the rotating drum 200 through the drain section of the conduit 100.

[0043] After the exhaust gas enters the rotating drum 200, it can drive the rotating drum 200 to rotate through the transmission mechanism 300. When the rotating drum 200 rotates, it can cause a certain disturbance to the exhaust gas entering the rotating drum 200, so that the exhaust gas is more evenly distributed in the rotating drum 200.

[0044] The detection unit installed inside the rotating drum 200 can detect the exhaust gas generated during vehicle operation. Compared with the existing detection results obtained by idling the vehicle, the detection results of the present invention are more consistent with the actual driving conditions of the vehicle. Furthermore, since the exhaust gas is more evenly distributed inside the rotating drum 200, the accuracy of the detection results is further improved.

[0045] In some embodiments, the detection unit includes a reflector 410, a transmitter 420, a receiver 430, and a movable limiting assembly. The reflector 410 is coaxially fixed inside the rotating drum 200, and both the transmitter 420 and the receiver 430 are disposed inside the reflector 410 via the movable limiting assembly.

[0046] The transmitter 420 is configured to emit light, which is reflected within the reflector 410 and received by the receiver 430. The receiver 430 is configured to perform spectral analysis on the received light and determine the concentration of harmful gases in the exhaust gas based on the analysis results. A movable limiting component is configured to change the positions of the transmitter 420 and receiver 430 within the reflector 410, thereby altering their positions and allowing the light emitted by the transmitter 420 to undergo more diverse reflections within the reflector 410. This results in the receiver 430 receiving more diverse spectral data, which, after analysis and processing by the receiver 430, yields more accurate detection data.

[0047] Specifically, the reflector 410 is a through-type concentric cylinder disposed within the rotating cylinder 200. The outer wall of the reflector 410 is fixedly connected to the inner wall of the rotating cylinder 200, and the inner wall of the reflector 410 is a smooth reflective surface. The emitter 420 can be an infrared emitter 420 or other types of light emitters 420, depending on the actual requirements. For example, an infrared emitter 420 is selected for detecting inorganic substances such as CO, CONO, SONH3, or alkanes, alkenes, and other hydrocarbons and organic substances such as CHC2H4; an ultraviolet emitter 420 is selected for detecting inorganic substances containing sulfur, nitrogen, and chlorine. The receiver 430 is an electronic device capable of performing spectral analysis on the light emitted by the emitter 420.

[0048] In this embodiment, a portion of the light emitted by the transmitter 420 at specific wavelengths is absorbed by the exhaust gas. By analyzing the spectrum of the received light through the receiver 430, the types and amounts of gases in the exhaust gas can be detected, making the detection process simple and quick. Moreover, after the light undergoes multiple reflections through the reflector 410, the types and amounts of various gases in the exhaust gas can be measured more accurately based on the number of reflections and the final received spectral data.

[0049] In some embodiments, the movable limiting assembly includes a fixed shaft 441, a sliding sleeve 442, a telescopic rod 443, a limiting structure, and a reset mechanism. The fixed shaft 441 is a rod whose axial direction is perpendicular to the axial direction of the rotating drum 200. The rotating drum 200 has a movable opening that penetrates the reflector 410. One end of the fixed shaft 441 is fixed at the center of the movable opening, and the other end extends away from the rotating drum 200.

[0050] The sliding sleeve 442 is slidably mounted on the fixed shaft 441. There are two telescopic rods 443, which are symmetrically arranged about the fixed shaft 441. One end of each telescopic rod 443 is hinged to the sliding sleeve 442, and the other end passes through the movable opening and is fixedly connected to the transmitter 420 and the receiver 430 respectively.

[0051] The fixed shaft 441 has multiple defined positions. The sliding sleeve is configured to slide along the fixed shaft under the action of the centrifugal force of the rotating drum and can be limited to any of the defined positions by the limiting structure. The limiting structure is set between the sliding sleeve 442 and the fixed shaft 441. The multiple defined positions on the fixed shaft are configured such that the light emitted by the transmitter 420 can only be received by the receiver 430 after being reflected by the reflector 410 when the sliding sleeve 442 is in the defined position.

[0052] The reset mechanism is located between the fixed shaft 441 and the sliding sleeve 442. The reset mechanism causes the sliding sleeve 442 to tend to move toward a defined position in the radial direction, that is, the reset mechanism causes the sliding sleeve 442 to tend to move toward the rotating drum 200 on the fixed shaft 441.

[0053] In this embodiment, the faster the exhaust gas enters the conduit 100, the faster the transmission mechanism 300 drives the rotating drum 200 to rotate. The rotation speed of the rotating drum 200 is positively correlated with the intake speed of the exhaust gas. The centrifugal force of the rotating drum 200 is also positively correlated with the rotation speed of the rotating drum 200. Therefore, the centrifugal force on the sliding sleeve 442 is positively correlated with the speed at which the exhaust gas enters the rotating drum 200.

[0054] When the exhaust gas enters the rotating drum 200 at a slow speed, the sliding sleeve 442 is located at a limited position close to the rotating drum 200 on the fixed shaft 441, and the light emitted by the transmitter 420 is reflected less times in the reflecting tube 410. When the exhaust gas enters the rotating drum 200 at a faster speed, the sliding sleeve 442 is located at a limited position far from the rotating drum 200, and the light emitted by the transmitter 420 is reflected more times in the reflecting tube 410. At this time, the light path reflected by the emitted light in the rotating drum 200 is denser than when the exhaust gas is introduced at a low speed, which enables the receiver 430 to receive more comprehensive spectral data and more accurate analysis results.

[0055] For example, in this embodiment, two limiting positions can be provided on the fixed shaft 441, one near the rotating drum 200 and the other far from the rotating drum 200. When the exhaust gas velocity in the duct 100 is slow, the sliding sleeve 442 is restricted to the limiting position near the rotating drum 200. At this time, the light emitted by the transmitter 420 can be received by the receiver 430 after being reflected twice by the reflector 410. When the exhaust gas velocity in the duct 100 is fast, the sliding sleeve 442 is restricted to the limiting position far from the rotating drum 200. The light emitted by the transmitter 420 can be received by the receiver 430 after being reflected four times by the reflector 410.

[0056] The more times the light is reflected inside the rotating drum 200, the denser the light distribution inside the rotating drum 200, the longer the path the light travels inside the rotating drum 200, and the wider the exhaust gas distribution area that the light passes through inside the rotating drum 200. As a result, the receiver 430 receives more spectral data, which makes the data results obtained by the receiver 430 when performing spectral analysis on the received light more accurate.

[0057] In this embodiment, the setting of the active limiting component allows the light emitted by the transmitter 420 in this invention to have more reflections, thereby enabling the average value of the content of multiple gases in the exhaust gas to be measured based on the various different data received by the receiver 430, making the data measured by this invention more accurate.

[0058] Furthermore, the limiting structure includes an elastic element 4441 and a limiting groove 4442. The elastic element 4441 is fixed on the inner wall of the sliding sleeve 442, and the limiting groove 4442 is opened on the side wall of the fixed shaft 441. The sliding sleeve 442 is engaged in the limiting groove 4442 on the fixed shaft 441 by the elastic element 4441.

[0059] In this embodiment, the elastic element 4441 can be a metal sheet with rebound capability, and the limiting groove 4442 can be a groove formed on the side wall of the fixed shaft 441, with a smooth groove surface. Multiple limiting structures can be provided on the fixed shaft 441. By changing the position of the sliding sleeve 442 on the fixed shaft 441, the elastic element 4441 can be engaged with multiple limiting grooves 4442 at different positions. This allows the light emitted by the transmitter 420 to have various different reflection patterns within the reflector tube 410, resulting in various different data received by the receiver 430, thus enabling more accurate measurement of the type and content of gases in the exhaust gas by this invention.

[0060] Furthermore, the reset mechanism includes a reset spring 445, which is a compression spring. One end of the reset spring 445 is fixedly connected to the end of the sliding sleeve 442 away from the rotating cylinder 200, and the other end is fixedly connected to the end of the fixed shaft 441 away from the rotating cylinder 200.

[0061] In this embodiment, when the speed of the automobile exhaust gas introduced into the rotating drum 200 is slow, the rotating drum 200 rotates slowly, and the elastic element 4441 on the sliding sleeve 442 is engaged in the limiting groove 4442 which is closer to the rotating drum 200. At this time, the pressure on the elastic element 4441 and the return spring 445 is relatively small.

[0062] When the exhaust gas blown into the rotating drum 200 has a higher velocity, the rotating drum 200 rotates faster. As the fixed shaft 441 rotates with the rotating drum 200, the centrifugal force on the sliding sleeve 442 increases. When the centrifugal force exceeds the sum of the limiting force of the limiting groove 4442 on the elastic element 4441 and the elastic force of the return spring 445, the sliding sleeve 442 will slide on the fixed shaft 441 toward the limiting groove 4442 away from the rotating drum 200. During the sliding process, the restoring force of the return spring 445 gradually increases. When the sliding sleeve 442 abuts against the end of the fixed shaft 441 away from the rotating drum 200, the elastic element 4441 in the sliding sleeve is engaged in the limiting groove 4442 away from the rotating drum 200. Thereafter, no matter how much the rotation speed of the rotating drum 200 increases, the elastic element 4441 remains engaged in the limiting groove 4442 away from the rotating drum 200.

[0063] When the exhaust gas velocity blown into the rotating drum 200 slows down, the centrifugal force on the sliding sleeve 442 decreases as the fixed shaft 441 rotates with the rotating drum 200. When the elastic force of the return spring 445 is greater than the sum of the limiting force of the limiting groove 4442 on the elastic element 4441 and the centrifugal force, the sliding sleeve 442 is reset to the limited position close to the rotating drum 200 under the action of the return spring 445, and the elastic element 4441 is engaged in the limiting groove 4442 at the corresponding limited position.

[0064] In some embodiments, the transmission mechanism 300 includes a transmission cylinder 310 and transmission blades 320. The transmission cylinder 310 is a hollow cylinder coaxially arranged with the rotating cylinder 200, and is fixed inside the rotating cylinder 200, positioned above the reflector cylinder 410 within the rotating cylinder 200. The transmission blades 320 are fixed to the inner wall of the transmission cylinder 310, and multiple transmission blades 320 are provided, which are evenly arranged around the central axis of the transmission cylinder 310.

[0065] The side of the drive blade 320 away from the reflector 410 is a flat inclined surface or a spiral inclined surface. The exhaust gas blown into the rotating drum 200 from the duct 100 blows onto the inclined surface (flat inclined surface and spiral inclined surface) on the drive blade 320, thereby driving the rotating drum 200 to rotate through the drive blade 320.

[0066] The drive blade 320 can be a helical inclined plate, with the side facing away from the reflector 410 being a helical inclined surface. When the drive blade 320 rotates, it can turbulently blow the exhaust gas into the rotating drum 200, which helps to make the exhaust gas distribution in the rotating drum 200 more uniform. As a result, when the light emitted by the transmitter 420 passes through the more uniformly distributed exhaust gas, the wavelength of the light absorbed by the gas is more uniform, making the data received by the receiver 430 more stable. Ultimately, the gas type and gas content obtained from the data received by the receiver 430 are more accurate.

[0067] In addition, when the exhaust gas is introduced into the rotating drum 200, the rotation of the drum 200 will cause turbulence to the exhaust gas, causing it to rotate in a spiral direction within the drum 200. There is a speed difference between the spiral rotation speed of the exhaust gas and the rotation speed of the drum 200. Therefore, the light emitted by the transmitter 420 can pass through the exhaust gas at different positions each time. After the transmitter 420 emits light multiple times, the light emitted multiple times can pass through the exhaust gas at more different positions within the rotating drum 200, which enables the receiver 430 to receive more comprehensive data and more accurate detection results.

[0068] In some embodiments, a rotating ring 120 is fixed to the end of the conduit 100 away from the exhaust emission device (here, the exhaust emission device is a vehicle exhaust pipe), and a rotating cylinder 200 is inserted into the rotating ring 120 and rotatably connected to the rotating ring 120. A speed encoder 121 is mounted on the outer wall of the rotating ring 120, and the speed encoder 121 is electrically connected to the transmitter 420. A gear ring 210 is fixed on the outer wall of the rotating cylinder 200. The speed encoder 121 is located on one side of the gear ring 210, and a speed measuring gear is mounted on the input shaft of the speed encoder 121, which meshes with the gear ring 210.

[0069] Specifically, over a period of time, the greater the volume of exhaust gas entering the conduit 100, the faster the rotating drum 200 rotates, and the faster the speed measured by the speed encoder 121. The faster the speed measured by the speed encoder 121, the higher the frequency of light emitted by the transmitter 420 can be controlled, resulting in a denser concentration of reflected light within the reflector 410, and thus more spectral data received by the receiver 430. After processing and analyzing more spectral data, the receiver 430 can obtain more precise information about the types of gases and the more accurate the content of each type of gas in the exhaust gas, thus giving the invention higher detection accuracy.

[0070] In some embodiments, the duct 100 is provided with a water-cooling jacket 130 and a solid filter block 140. In the flow direction of the exhaust gas within the duct 100, the solid filter block 140 is located after the water-cooling jacket 130, that is, the exhaust gas first passes through the water-cooling jacket 130 and then through the solid filter block 140. The water-cooling jacket 130 is fitted onto the drainage section of the duct 100. The water-cooling jacket 130 can cool the vehicle exhaust gas entering the duct 100, avoiding adverse effects on the transmitter 420 and receiver 430 due to the high temperature of the exhaust gas.

[0071] For example, when the transmitter 420 is an infrared transmitter 420, the high-temperature exhaust gas affects the infrared wavelength, and the high-temperature exhaust gas may also damage the transmitter 420 and the receiver 430 due to excessive temperature.

[0072] The solid filter block 140 is installed inside the conduit 100 and is located in the part of the pipe connecting the drain pipe to the rotating drum 200. The solid filter block 140 can filter out fine solid particles such as soot and fly ash in automobile exhaust, preventing solid particles from affecting the light emitted by the transmitter 420 and ensuring the stable implementation of the present invention.

[0073] In this invention, eight conductive rings 500 are provided between the rotating drum 200 and the conduit 100, with four conductive rings 500 fixed to the conduit 100 and the other four conductive rings 500 fixed to the rotating drum 200. The conductive rings 500 connected to the conduit 100 and the conductive rings 500 connected to the rotating drum 200 are in contact. Both the transmitter 420 and the receiver 430 have two terminals, which are electrically connected to the four conductive rings 500 on the rotating drum 200. The two conductive rings 500 connected to the two terminals of the receiver 430 can transmit data to an external analysis device, which can be a data terminal such as a computer. The two conductive rings 500 connected to the two terminals of the transmitter 420 can provide power to the transmitter 420, enabling it to emit light.

[0074] A method for detecting VOCs exhaust gas, using the aforementioned VOCs exhaust gas detection device, requires, when detecting the types and contents of gases in the exhaust gas of a moving vehicle, first closing the sealing plate 110, and then performing the following operating steps:

[0075] Step 1: Fix the straight section of conduit 100 to the exhaust pipe end of the car and start the car;

[0076] Step 2: Before the exhaust gas enters the rotating drum 200 through the duct 100, it passes through the cooling and dust removal stages in sequence;

[0077] Step 3: After the exhaust gas enters the rotating drum 200, it drives the transmission blades 320 to rotate, and the transmission blades 320 drive the rotating drum 200 to rotate.

[0078] Step 4: When the elastic element 4441 inside the sliding sleeve 442 is engaged in the limiting groove 4442 away from the rotating cylinder 200, record the data measured by the receiver 430.

[0079] Step 5: After processing and analyzing the data measured by receiver 430, the gas classification in the exhaust gas and the content of each gas are obtained, thus completing the exhaust gas detection.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A VOCs exhaust gas detection device, characterized in that, include: The duct is connected to the outlet end of the exhaust gas emission device; The rotating drum is located at the end of the duct furthest from the exhaust gas emission device. The transmission mechanism is located inside the rotating drum, and the transmission mechanism drives the rotating drum to rotate by the exhaust gas introduced into the rotating drum. The detection unit, located inside the rotating drum, is used to detect the exhaust gas introduced into the rotating drum; The detection unit includes a reflector, a transmitter, a receiver, and a movable limiting assembly. The reflector is coaxially fixed inside the rotating cylinder, and both the transmitter and the receiver are set inside the reflector through the movable limiting assembly. The transmitter is configured to emit light, which is reflected in the reflector tube and then received by the receiver. The receiver is configured to perform spectral analysis on the received light and determine the concentration of harmful gases in the exhaust gas based on the analysis results. The movable limiting component is configured to change the position of the transmitter and receiver in the reflector tube to change the number of times the light emitted by the transmitter is reflected in the reflector tube. The movable limiting assembly includes a fixed shaft, a sliding sleeve, a telescopic rod, a limiting structure, and a reset mechanism. The fixed shaft is fixed on the rotating drum, the sliding sleeve is slidably mounted on the fixed shaft, and there are two telescopic rods arranged symmetrically about the fixed shaft. One end of each telescopic rod is hinged to the sliding sleeve, and the other end passes through the rotating drum and is fixedly connected to the transmitter and the receiver, respectively. The part of the telescopic rod that passes through the rotating drum is rotatably connected to the rotating drum. The fixed shaft has multiple defined positions. The sliding sleeve is configured to slide along the fixed shaft under the action of the centrifugal force of the rotating drum and is limited to any defined position under the action of the limiting structure. The reset mechanism is provided between the sliding sleeve and the fixed shaft and is configured to make the sliding sleeve tend to move towards the defined position in the radial direction. The limiting structure includes an elastic element and a limiting groove. The elastic element is fixed on the inner wall of the sliding sleeve, and the limiting groove is opened on the side wall of the fixed shaft. The sliding sleeve is locked in the limiting groove by the elastic element. The reset mechanism includes a reset spring. One end of the reset spring is fixedly connected to the end of the sliding sleeve away from the rotating cylinder, and the other end is fixedly connected to the end of the fixed shaft away from the rotating cylinder. The fixed shaft is a rod whose axis is perpendicular to the axis of the rotating cylinder. The rotating cylinder has a movable opening that penetrates the reflector cylinder. One end of the fixed shaft is fixed at the center of the movable opening, and the other end extends away from the rotating cylinder.

2. The VOCs exhaust gas detection device according to claim 1, characterized in that: A rotating ring is fixed at the end of the duct away from the exhaust gas emission device. The rotating cylinder is inserted into the rotating ring and rotatably connected to it. A speed encoder is installed on the side wall of the rotating ring. The speed encoder is electrically connected to the transmitter to control the frequency of the light emitted by the transmitter, and the frequency of the emitted light is positively correlated with the intake speed of the exhaust gas entering the rotating cylinder. A toothed ring is provided on the outer side wall of the rotating cylinder, and a speed measuring gear that meshes with the toothed ring is installed on the input shaft of the speed encoder.

3. The VOCs exhaust gas detection device according to claim 1, characterized in that: The transmission mechanism includes a transmission cylinder and transmission blades. The transmission cylinder is coaxially fixed inside the rotating cylinder, and the transmission blades are fixed on the inner wall of the transmission cylinder. There are multiple transmission blades, which are evenly arranged around the central axis of the transmission cylinder.

4. The VOCs exhaust gas detection device according to claim 1, characterized in that: The conduit is equipped with a water-cooling jacket.

5. The VOCs exhaust gas detection device according to claim 4, characterized in that: The duct is equipped with a solid filter block, which is located after the water cooling jacket in the direction of exhaust gas flow within the duct.

6. A method for detecting VOCs exhaust gas, using the VOCs exhaust gas detection device according to any one of claims 1-5.

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