CN117030950B

CN117030950B - Measuring device, exhaust system and vehicle

Info

Publication number: CN117030950B
Application number: CN202311272019.7A
Authority: CN
Inventors: 王雪鹏; 李萧丽; 张海瑞; 曾凡; 郑凯
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2023-09-28
Filing date: 2023-09-28
Publication date: 2024-01-12
Anticipated expiration: 2043-09-28
Also published as: CN117030950A

Abstract

The invention relates to the technical field of concentration measurement, in particular to a measuring device, an exhaust system and a vehicle. The measuring device comprises a shell, a rotating shaft, a plurality of measuring pipelines, a transfer pipeline and a measuring unit, wherein a through channel is arranged in the shell, the rotating shaft is rotatably arranged in the through channel, the measuring pipelines are arranged on the peripheral wall of the rotating shaft, the measuring pipelines are provided with air inlets and air outlets, the distances between the air inlets of the measuring pipelines and the central axis of the through channel are unequal, the distance between the air outlets and the central axis is the same, the transfer pipeline is provided with a collecting pipe along the radial direction of the rotating shaft, one end of the collecting pipe is communicated with the transfer pipeline, and the other end of the collecting pipe can be respectively communicated with a plurality of air outlets. Because the distances from the air inlets of the measuring pipelines to the central axes of the through channels on the rotating shaft are unequal, real-time sampling from different positions can be ensured when the rotating shaft rotates, and the comprehensiveness and accuracy of data are greatly enhanced.

Description

Measuring device, exhaust system and vehicle

Technical Field

The invention relates to the technical field of concentration measurement, in particular to a measuring device, an exhaust system and a vehicle.

Background

With the rapid development of modern industrialization, the demand for environmental protection is also increasing. Diesel engines have received a great deal of attention as a main power source for a wide variety of mechanical devices, and the problem of exhaust emissions. Particularly with the progress of diesel combustion technology, although the combustion process is more adequate, there is a concomitant significant increase in the nitrogen oxide (NOx) content of the emissions, which makes environmental performance of diesel engines a new challenge. In order to solve the above problems, SCR (selective catalytic reduction) is widely used for exhaust gas treatment of diesel engines. The SCR technology mainly uses a specific catalyst to convert NOx in the exhaust into harmless nitrogen and water under the action of a reducing agent (such as urea aqueous solution), thereby greatly reducing the content of NOx in the exhaust.

However, in order to further optimize the SCR technology and ensure efficient operation under various conditions, it is particularly critical to accurately measure the concentration distribution of the emissions in the SCR tank, which is an important indicator for evaluating whether the structural design of the SCR tank is reasonable. Conventional concentration measurement methods, such as providing a removable sensor within the SCR tank, while providing some convenience for concentration measurement, have significant limitations. These sensors can only measure the concentration at a specific location in the SCR tank within a given time, and cannot achieve simultaneous measurement of multiple locations on the same cross-section or locations on different cross-sections. The point-to-point measurement mode is complex in operation, and the structural design evaluation of the SCR box is possibly inaccurate due to the fact that comprehensive concentration distribution information cannot be obtained.

Disclosure of Invention

The invention aims to at least solve the problem that the concentration of a plurality of positions cannot be measured independently in a certain time. The aim is achieved by the following technical scheme:

a first aspect of the invention proposes a measuring device for measuring the concentration of SCR emissions, comprising:

the shell is internally provided with a through channel penetrating through the shell;

a rotation shaft rotatably provided in the through passage;

the measuring pipes are arranged on the peripheral wall of the rotating shaft along the circumferential direction of the rotating shaft, the measuring pipes comprise air inlets and air outlets, the air inlet direction of each air inlet is parallel to the axial direction of the through channel, the distances between the air inlets of the measuring pipes and the central axis of the through channel are unequal, and the interval distances between the air outlets of the measuring pipes and the central axis are equal;

the transmission pipeline is provided with a collecting pipe along the radial direction of the rotating shaft, one end of the collecting pipe is communicated with the transmission pipeline, and the other end of the collecting pipe can be respectively communicated with any air outlet;

and the measuring unit is communicated with the transmission pipeline.

According to the measuring device disclosed by the invention, the plurality of measuring pipelines are arranged on the peripheral wall of the rotating shaft, the rotating shaft rotates to drive the plurality of measuring pipelines to rotate, the collecting pipes are arranged on the transmission pipelines, and after the measuring pipelines rotate, the collecting pipes can be respectively communicated with the air outlets of different measuring pipelines, so that the emissions in different measuring pipelines can be respectively collected, and the distances between the air inlets of the measuring pipelines on the rotating shaft and the central axis of the through channel are unequal, so that real-time sampling from different positions is ensured when the rotating shaft rotates, and the data comprehensiveness and accuracy are greatly enhanced. Furthermore, the design of the transfer conduit and the collection conduit enables the emission samples collected from the respective measurement conduits to be collected and transferred to the measurement unit for analysis. This approach ensures a continuous data flow and provides an important basis for accurate measurement of concentration. Therefore, the measuring device can provide more accurate and comprehensive emission concentration data after SCR, is beneficial to better evaluating and optimizing SCR technology, and further improves the efficiency of tail gas treatment.

In addition, the measuring device according to the invention may have the following additional technical features:

in some embodiments of the invention, the measuring device further comprises a conveying pipeline, one end of the conveying pipeline is communicated with the measuring unit, and the other end of the conveying pipeline is communicated with the transmission pipeline;

one end of the transmission pipeline is in plug-in fit with the rotating shaft, and the other end of the transmission pipeline is in plug-in fit with the conveying pipeline;

a flange plate is arranged on the peripheral wall of the conveying pipeline, a boss is arranged on the peripheral wall of the conveying pipeline, and an elastic part with the elastic direction parallel to the axial direction is arranged between the flange plate and the boss;

a magnetic force component is arranged in the rotating shaft, a limiting groove is formed in the end face, facing the transmission pipeline, of the magnetic force component, and a limiting key is arranged at one end, facing the magnetic force component, of the transmission pipeline;

and in the power-on state of the magnetic component, the limit key is accommodated in the limit groove, the rotating shaft drives the transmission pipeline to rotate, and in the power-off state of the magnetic component, the elastic component drives the limit key to be separated from the limit groove.

In some embodiments of the invention, the axis of the rotating shaft coincides with the axis of the through passage.

In some embodiments of the invention, the end of the collection tube that is adapted to communicate with the air outlet is provided with a guide portion that is adapted to guide the air outlet.

In some embodiments of the invention, a plurality of brackets are provided on the rotating shaft, each of the measuring pipes being connected to the rotating shaft by one of the brackets.

In some embodiments of the invention, the measuring device further comprises a motor, the rotating shaft being in driving connection with an output shaft of the motor.

In some embodiments of the present invention, the measuring device further includes a sleeve, the sleeve is sleeved on the outer side of the motor, a supporting rib is arranged on the sleeve, one end of the supporting rib is connected with the sleeve, and the other end of the supporting rib is connected with the inner wall of the through channel.

In some embodiments of the invention, the housing is provided with mounting flanges at opposite ends.

A second aspect of the present invention proposes an exhaust system comprising:

an SCR tank comprising a gas line;

the measuring device is arranged on the pipeline and is used for measuring the concentration of the SCR emission in the gas pipeline, and the through channel is communicated with the pipeline.

A third aspect of the present invention proposes a vehicle comprising:

an exhaust system as described above;

an ECU (in-vehicle control system) for controlling a rotation angle of the rotating shaft.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:

fig. 1 schematically shows a schematic cross-sectional structure of a measuring device according to an embodiment of the invention;

fig. 2 schematically shows a schematic structural view of a housing according to an embodiment of the present invention;

fig. 3 schematically shows a schematic structural view of a conveying pipe according to an embodiment of the present invention;

fig. 4 schematically shows a schematic structural view of a transfer pipe according to an embodiment of the present invention;

fig. 5 schematically shows a schematic cross-sectional structure of a rotary shaft according to an embodiment of the present invention;

FIG. 6 schematically illustrates a schematic diagram of the mating relationship of a rotating shaft and a magnetic component as they are attracted in accordance with an embodiment of the present invention;

FIG. 7 schematically illustrates a schematic diagram of the mating relationship of a rotating shaft and a magnetic component when disconnected, according to an embodiment of the present invention;

FIG. 8 schematically shows a semi-sectional structural schematic of a measuring device according to an embodiment of the invention;

fig. 9 is a flow chart of a measurement method.

The reference numerals are as follows:

100. a measuring device;

10. a housing; 11. a mounting flange;

20. a rotation shaft; 21. a magnetic force component; 211. a limit groove; 22. a bracket;

30. measuring a pipeline;

40. a transfer pipe; 41. a collection pipe; 411. a guide part; 42. a boss; 43. a limit key;

50. a measuring unit; 60. a sleeve; 61. a support rib; 70. a delivery conduit; 71. a flange plate;

80. an elastic member; 90. a motor; 91. an output shaft.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless an order of performance is explicitly stated. It should also be appreciated that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For ease of description, spatially relative terms, such as "inner," "outer," "lower," "below," "upper," "above," and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used herein interpreted accordingly.

As shown in fig. 1 and 8, according to an embodiment of the present invention, there is provided a measuring apparatus 100 including a housing 10, a rotation shaft 20, a plurality of measuring pipes 30, a transfer pipe 40, and a measuring unit 50, first, the housing 10 is provided therein with a through passage penetrating the housing 10, and the rotation shaft 20 is rotatably provided in the through passage. Then, a plurality of measuring pipes 30 are arranged on the outer circumferential wall of the rotary shaft 20 in a circumferential direction of the rotary shaft 20, the measuring pipes 30 have an air inlet and an air outlet, an air inlet direction of the air inlet is parallel to an axial direction of the through passage, and distances between the air inlet of the plurality of measuring pipes 30 and a central axis of the through passage are unequal, and a distance between the air outlet of the plurality of measuring pipes 30 and the central axis of the through passage is the same. The transfer duct 40 is provided with a collection pipe 41 in the radial direction of the rotary shaft 20, and one end of the collection pipe 41 communicates with the transfer duct 40, and the other end can communicate with either one of the air outlets. Finally, the measuring unit 50 communicates with the transfer duct 40.

According to the measuring device 100 of the present invention, the plurality of measuring pipes 30 are disposed on the outer peripheral wall of the rotating shaft 20, the rotating shaft 20 rotates to drive the plurality of measuring pipes 30 to rotate, the collecting pipe 41 is disposed on the transmitting pipe 40, and after the measuring pipes 30 rotate, the collecting pipe 41 can be respectively communicated with the air outlet of any one of the measuring pipes 30, so that the emissions in different measuring pipes 30 can be respectively collected, and since the distances between the air inlet of the measuring pipe 30 on the rotating shaft 20 and the central axis of the through passage are unequal, it is ensured that the real-time sampling can be performed from different positions when the rotating shaft 20 rotates, and the comprehensiveness and accuracy of the data are greatly enhanced. Furthermore, the design of the transfer duct 40 and the collection duct 41 enables the emission samples collected from the respective measuring duct 30 to be collected and transferred to the measuring unit 50 for analysis. This approach ensures a continuous data flow and provides an important basis for accurate measurement of concentration. Therefore, the measuring device 100 of the present invention can provide more accurate and comprehensive emission concentration data after SCR, which is helpful for better evaluating and optimizing SCR technology and further improving the efficiency of exhaust treatment.

Specifically, the plurality of measurement pipes 30 are arranged on the outer peripheral wall of the rotating shaft 20 along the circumferential direction of the rotating shaft 20, and the arrangement modes can be set at intervals or can be set in a fitting manner, and the arrangement modes need to be selected according to specific situations.

Specifically, as shown in fig. 2, the housing 10 is made of a corrosion-resistant, high-strength stainless steel material, so that stability is ensured under various environments. The housing 10 is cylindrical and smooth in the inside to reduce air flow resistance.

Specifically, the rotary shaft 20 is made of a metal material having high strength and high torsion resistance, such as titanium alloy. The use of high precision bearings for mounting the rotating shaft 20 ensures that the rotating shaft 20 remains stationary during long periods of operation. The rotation shaft 20 may be driven by an external motor 90, and it is also conceivable to use a brushless motor 90 to improve efficiency and reduce noise.

In particular, the measuring ducts 30 are evenly distributed along the peripheral wall of the rotating shaft 20, ensuring that emissions in different directions can be measured. The air inlet of the device can be designed into a small-caliber form, which is helpful for improving the entering speed of the discharged matters and increasing the measuring precision.

Specifically, both ends of the transfer pipe 40 may employ quick connectors, which may directly connect the transfer pipe 40 with the measuring unit 50 or the rotating shaft 20, so as to facilitate daily maintenance and replacement. For example, the end of the transfer duct 40 is provided with a plug, and the end of the measuring unit 50 or the rotary shaft 20 connected to the transfer duct 40 is provided with a socket, and when the plug is inserted into the socket, a special mechanical structure tightly locks them, ensuring that the discharged material or liquid does not leak. A sealing ring (e.g. an O-ring) is provided at the contact point of the plug and the socket, which ensures that no leakage of medium occurs when the joint is connected. In addition, the quick-connect connector is provided with a self-locking mechanism, such as a spring or ball detent, which automatically locks when the plug is fully inserted into the socket, ensuring a secure connection.

Specifically, the measurement principle of the measurement unit 50 is to measure the concentration according to the characteristics of the emission after SCR by using infrared spectroscopy or chemical adsorption. The output mode is that the measurement data is transmitted to an upper computer or a control system (such as ECU) through a digital interface, such as an RS-485 or USB interface. The measurement unit 50 is further provided with a calibration function, so that a user can perform calibration regularly, and measurement accuracy is ensured.

In some embodiments, as shown in fig. 3-7, the measurement device 100 further includes a delivery conduit 70, one end of the delivery conduit 70 being in communication with the measurement unit 50 and the other end being in communication with the transfer conduit 40. One end of the transfer pipe 40 is in plug-in fit with the rotary shaft 20, and the other end of the transfer pipe 40 is in plug-in fit with the conveying pipe 70. The outer peripheral wall of the conveying pipe 70 is provided with a flange plate 71, the outer peripheral wall of the conveying pipe 40 is provided with a boss 42, and an elastic component 80 with the elastic direction parallel to the axial direction of the through passage is arranged between the flange plate 71 and the boss 42. The inside of rotation axis 20 is equipped with magnetic force part 21, and magnetic force part 21 is equipped with spacing recess 211 on the terminal surface towards transmission pipeline 40, and transmission pipeline 40 is equipped with limit key 43 towards the one end of magnetic force part 21. In the power-on state of the magnetic component 21, the limit key 43 is accommodated in the limit groove 211, the rotation shaft 20 can drive the transmission pipeline 40 to rotate, and in the power-off state of the magnetic component 21, the elastic component 80 drives the limit key 43 to be separated from the limit groove 211.

In the above embodiment, as shown in fig. 6 and 7, the magnetic member 21 adsorbs the rotation shaft 20, the limit key 43 on the transmission pipe 40 is accommodated in the limit groove 211 of the magnetic member 21, the magnetic member 21 is fixed inside the rotation shaft 20, and when the limit key 43 is accommodated in the limit groove 211, the rotation shaft 20 rotates to drive the transmission pipe 40 to rotate, so that the rotation shaft 20 and the transmission pipe 40 rotate simultaneously, and at this time, the collecting pipe 41 always corresponds to the air outlet of one measurement pipe 30.

Specifically, the present embodiment employs the magnetic member 21 to achieve synchronous rotation of the rotary shaft 20 and the transmission pipe 40. The core of this design is the fixation inside the rotating shaft 20 by means of the magnetic member 21 and the cooperation of the limit key 43 with the limit groove 211. When the magnetic member 21 attracts the rotation shaft 20, the limit key 43 is firmly fixed in the limit groove 211 of the magnetic member 21. In this way, any rotation of the rotating shaft 20 is directly transmitted to the transmission duct 40, causing it to rotate therewith. This design ensures that the rotation shaft 20 and the transfer duct 40 can rotate synchronously and accurately. This synchronized rotation mechanism means that the collection tube 41 is always aligned with the air outlet of one measuring duct 30, regardless of the rotation shaft 20, so that the emissions from this air outlet can be continuously and accurately collected. More importantly, since the collection tube 41 is always aligned with the air outlet of one measurement duct 30, this enables the measurement device 100 to measure different circumferential points in the same radial direction, thereby obtaining more comprehensive and fine emission data. In addition, the user can conveniently control the rotation or fixation of the rotation shaft 20 and the transfer duct 40 by the adsorption and release mechanism of the magnetic member 21. When the measuring position needs to be changed, only the state of the magnetic force component 21 needs to be changed, so that the operation is simple and efficient. Meanwhile, due to the characteristic of the magnetic connection, mechanical abrasion of the whole system is greatly reduced, thereby prolonging the service life of the measuring device 100. In summary, the design of the present embodiment not only enhances the accuracy and flexibility of the measuring apparatus 100, but also improves the convenience of operation and the durability of the system by the introduction of the magnetic force member 21.

Specifically, as shown in fig. 5, the magnetic member 21 is an electromagnet, which is fixed inside the rotating shaft 20, typically near one end of the rotating shaft 20. When energized, the magnetic force member 21 generates a magnetic field so that one end of the transfer duct 40 is closely adsorbed to the inside of the rotation shaft 20. The electromagnet needs to be connected to an external power supply system to supply the power required for its operation. The control system may be a simple switch for controlling the powering on and off of the electromagnet, or a more advanced microcontroller for precisely controlling the current intensity, the powering on time and the powering off time. In addition, sensors may be provided to monitor the position of the transfer tubing 40 to provide feedback to the control system to ensure that the electromagnet's field strength and duration are sufficient for rotation. The magnetic force component 21 works in the following principle: when the measuring position needs to be changed, the control system supplies power to the electromagnet so that the electromagnet generates a magnetic field. The limit key 43 of the transfer duct 40 is attracted to the limit groove 211 of the rotation shaft 20 due to the magnetic field. When the rotation shaft 20 rotates, the transfer duct 40 rotates in synchronization with the rotation shaft 20 due to the magnetic attraction force generated by the electromagnet. When the measured position reaches the predetermined position, the control system will turn off the power supply, causing the electromagnet to lose its magnetic force, and the transfer conduit 40 and the rotating shaft 20 can be moved independently of each other.

Specifically, one end of the conveying pipeline 70, which is close to the conveying pipeline 40, is provided with a flange plate 71, a boss 42 is arranged on the outer peripheral wall of the conveying pipeline 40, which is close to the conveying pipeline 70, an elastic component 80 is connected between the flange plate 71 and the boss 42, and the elastic component 80 can enable the conveying pipeline 70 and the conveying pipeline 40 to move and reset in the axial direction. First, the flange plate 71 is generally circular in shape with a plurality of through holes uniformly distributed around the periphery thereof for fixing with the boss 42. The boss 42 is generally annular and has a through hole in the middle that mates with the through hole of the flange plate 71. One guide post passes two through-holes, and this guide post can slide in two through-holes, and the both ends of guide post are equipped with the anticreep piece, prevent that the guide post from coming off in two through-holes, and the cover is equipped with elastomeric element 80 on the guide post, specifically can be the spring, and when the magnetic part adsorbed transfer pipeline 40, the spring can receive compression or tensile force, and when the magnetic part did not adsorb transfer pipeline 40, the spring will resume original state, promotes transfer pipeline 40 to reset or the forward movement.

In some embodiments, the axis of the rotating shaft 20 coincides with the axis of the through-passage, in order to ensure perfect coincidence of the axis of the rotating shaft 20 with the axis of the through-passage, a precision-made bearing system may be employed. Such a bearing system ensures that the rotation shaft 20 always remains coincident with the axis of the through passage during rotation. In addition, sensors are provided inside the through passage, and these sensors can monitor the position of the rotating shaft 20 in real time and compare with a preset position. As soon as a slight deviation is measured, the automatic calibration system will adjust immediately, ensuring that the rotation shaft 20 coincides again with the axis of the through channel. The measurement result will be more accurate since the axis of the rotation shaft 20 is perfectly aligned with the axis of the through passage. This alignment ensures consistency and continuity of the emissions samples as they flow from the respective measurement conduits 30 into the collection tube 41.

In some embodiments, as shown in fig. 4, the end of the collecting pipe 41 capable of communicating with the air outlet is provided with a guide 411, and this guide 411 is used to guide the air outlet. The guide 411 has a tapered structure that gradually expands so that the discharged matter discharged from the air outlet can more smoothly enter the collecting pipe 41. This configuration reduces the resistance to flow of emissions, ensuring more accurate collection of emissions. Meanwhile, the portion of the guide 411 is a slope that helps to guide the air outlet of the measuring tube 30 to gradually interface with the collection tube 41, reducing the possibility of collision and jamming during the interface. Alternatively, the edge of the guide 411 may be made of an elastic material (e.g., rubber), and such an elastic edge may provide a buffer, reduce hard collision, and ensure smooth docking process when the air outlet contacts the guide 411. In addition, a micro-porous filtering screen may be provided inside the guide part 411 for filtering large particulate matters or impurities, ensuring the purity of the collected emission sample.

Specifically, a spiral guide groove may be disposed on the inner wall of the collecting pipe 41 near the guide portion 411, so that the effluent flows spirally when entering, which improves the contact between the effluent and the inner wall of the pipe, and helps to uniformly distribute and collect the effluent.

Specifically, to ensure that emissions do not leak at the interface, an elastomeric seal may be provided between the guide 411 and the air outlet. This seal ring can act as a seal when the collection tube 41 is docked with the air outlet, ensuring that emissions only flow from the air outlet into the collection tube 41.

In some embodiments, as shown in fig. 5, a plurality of brackets 22 are provided on the rotating shaft 20, and each measuring tube 30 is connected to the rotating shaft 20 through one bracket 22. The bracket 22 is of a U-shaped or L-shaped design to provide sufficient bottom and side support for the measurement duct 30 to ensure that the duct is stationary when rotated. The support 22 may be welded to the rotating shaft 20, or may be detachably connected to the rotating shaft 20, for example, a groove is formed on the rotating shaft 20, and a corresponding protruding block is formed on the support 22, and the two blocks are engaged to form a stable mechanical connection. By the firm support of the support 22, the measuring tube 30 remains stable during rotation, ensuring the accuracy of the measured data.

In some embodiments, as shown in fig. 8, the rotatable shaft 20 is rotatable due to a motor 90, the rotatable shaft 20 being drivingly connected to an output shaft 91 of the motor 90. The stepper motor 90 is selected in this embodiment, and since the stepper motor 90 can realize accurate rotation angle control, the method is suitable for applications requiring fixed angle rotation. Second, the output shaft 91 of the motor 90 and the rotation shaft 20 of the measuring device 100 are directly connected using a mechanical coupling, ensuring smooth transmission and reducing errors. Where it is desired to increase torque or adjust the speed ratio, it is contemplated that a gearbox or gear set may be used to provide the output shaft 91 of the motor 90 in geared connection with the rotating shaft 20.

Specifically, the motor 90 control uses a microprocessor or PLC to control the motor 90, and the rotation angle, speed, and acceleration can be precisely set. The position information of the rotating shaft 20 can be acquired in real time by combining the rotary encoder, so that closed-loop control is realized, and the precision of the system is improved.

It will be appreciated that controlling the fixed angle of rotation of the motor 90 requires an integrated system including a microcontroller, position sensor, driver and interface to the motor 90. The microcontroller is the "brain" of the overall control system, responsible for reading the sensor data, processing the data and driving the motor 90 to the designated location. The position sensor is typically a rotary encoder, which may be incremental or absolute. Wherein the incremental encoder outputs a number of pulses per revolution, and the microcontroller determines the angle at which the motor 90 has rotated by counting the pulses. The absolute encoder outputs the current angle value directly without calculation from a reference point. The motor 90 driver provides power to the motor 90 according to the instructions of the microcontroller. This is typically accomplished by a PWM (pulse width modulation) signal, the duty cycle of which determines the speed and direction of the motor 90. The control strategy is that when the system is started, if an incremental encoder is used, the motor 90 needs to be moved to a known reference point (e.g., zero) for calibration. The microcontroller will read the data from the position sensor and compare it to the target position. If the current position of the motor 90 is not the target position, the microcontroller will send a command to the motor 90 driver to rotate the motor 90 to the target position. By means of a PID (proportional-integral-derivative) control algorithm, it is ensured that the motor 90 reaches the target position quickly and accurately, while overshoot and oscillations are avoided. The embodiment of the motor 90 drive provides an accurate, stable rotational drive for the measuring device 100, ensuring the accuracy of the measurement and the reliability of the apparatus.

Specifically, as shown in fig. 8, a sleeve 60 is further sleeved outside the motor 90, a supporting rib 61 is arranged on the sleeve 60, one end of the supporting rib 61 is connected with the sleeve 60, and the other end is connected with the inner wall of the through channel. The sleeve 60 should be made of a high strength material, such as stainless steel or aluminum alloy, to ensure that it effectively protects the motor 90 and provides adequate structural stability under various operating conditions. The inner diameter of the sleeve 60 should be slightly larger than the outer diameter of the motor 90 to ensure that the motor 90 can be smoothly inserted into and removed from the sleeve 60 while also providing sufficient heat dissipation space for the motor 90. Heat radiating fins may be provided on the outer wall of the sleeve 60 to improve heat radiating efficiency. The support rib 61 may be of a curved or straight design depending on the manner of its connection to the inner wall of the through-channel and the mechanical strength to be provided. The material of the support rib 61 should have good tensile and compressive strength, such as carbon steel or aluminum alloy. The connection portion of the support rib 61 may be connected to the sleeve 60 and the inner wall of the through passage by bolts, welding or other suitable fixing means. By using the sleeve 60 and the support rib 61, it is possible to secure the stability of the motor 90 during operation and reduce the risk of damage to the motor 90 due to vibration or external impact.

In other embodiments, the rotating shaft 20 may also be rotated using a pneumatic rotary cylinder. The pneumatic rotary cylinder applies force to the piston by using compressed air, and converts linear motion into rotary motion through a crank-link mechanism.

Specifically, the pneumatic rotary cylinder needs to be matched with a control valve, a position feedback system, a compressed air source and a control system. Among them, in order to control the direction and speed of the rotating shaft 20, we need to use directional control valves. By rapidly switching the flow direction of the compressed air, the rotational direction of the actuator can be controlled. By adjusting the air flow, the speed of rotation can be controlled. To ensure the accuracy of the pneumatic drive system, a position feedback system is required to measure the actual position of the rotating shaft 20. Common systems include rotary encoders or hall effect sensors that can provide real-time position feedback. The compressed air source can be externally connected with an air compressor to provide stable and reliable compressed air. The control system may be an ECU or the like and when rotation of the rotatable shaft 20 to a specific position is desired, the control logic will adjust the directional control valve based on information from the position feedback system to cause the actuator to rotate to the specified position.

It will be appreciated that the principle of operation of the shaft 20 driven pneumatically is: the control logic receives the rotation instruction and determines the movement direction and speed of the pneumatic rotary cylinder according to the feedback of the required position and the current position. The control valve adjusts the flow direction and flow rate of the compressed air according to the instruction and drives the pneumatic rotary cylinder. The pneumatic rotary cylinder drives the rotary shaft 20 to rotate, and the position feedback system monitors the position of the rotary shaft in real time. When the rotating shaft 20 approaches or reaches the target position, the control system adjusts or stops the supply of compressed air to stop the rotating shaft 20 at the correct position.

In some embodiments, the housing 10 is provided with mounting flanges 11 at opposite ends, the shape and size of the mounting flanges 11 being designed according to the diameter of the housing 10 and the equipment or piping to be connected. Typically, the mounting flange 11 may be circular or other suitable shape and have a series of pre-drilled holes for mounting using bolts or other fastening means. The mounting flange 11 provides a simple, quick and stable connection means so that the measuring device 100 can be easily connected to other systems or equipment.

The embodiment also provides an exhaust system, which comprises an SCR box and a measuring device 100, wherein the SCR box is provided with a gas pipeline with concentration to be measured, the measuring device 100 is arranged on the gas pipeline, and the through channel is communicated with the gas pipeline. In combination with the SCR box and the measurement device 100 of the present embodiment, the exhaust system may effectively reduce harmful gas emissions while providing real-time emissions data to help monitor and optimize vehicle performance.

In particular, as shown in fig. 1 and 8, the measuring device 100 may be installed at an inlet, an outlet, or an intermediate position of the SCR tank as needed to measure the gas that enters or exits. The measuring device 100 should be equipped with corresponding fastening brackets 22 or mounting flanges 11 to ensure its stability in high-speed, high-temperature, high-pressure working environments.

The present embodiment also provides a vehicle including the exhaust system described above and an ECU for controlling the rotation angle of the rotary shaft 20.

Specifically, the ECU may acquire real-time data from an ammonia concentration sensor, a temperature sensor, and a pressure sensor in the SCR tank. These data provide information about the state of the system to the ECU and thus provide data support for subsequent control decisions. Based on the data and preset parameters, the ECU may determine the rotation angle of the measurement device 100 to ensure that the gas sample can be collected from the correct location. This is achieved by interacting with the motor 90 to drive the rotation shaft 20 in the measuring device 100 in rotation. In addition, the ECU may adjust the injection amount of the urea solution injector based on the gas concentration data obtained from the measurement device 100 to ensure that the NOx conversion efficiency is within an optimal range. Finally, the ECU may control the power supply of the magnetic member 21 to adsorb or release the rotation shaft 20. This determines whether the measuring device 100 starts or stops rotating.

As shown in fig. 9, the present embodiment further provides a measurement method, including the following steps:

step 1, starting and self-checking:

when the measuring device 100 is started, a self-checking procedure is first performed;

checking whether the electromagnet and the rotating shaft 20 are normal;

and feeding back 'normal operation' or 'failure' by the system according to the self-checking result.

Step 2, reading the concentration of the current position:

the system first reads the SCR concentration corresponding to the current measurement tube position.

If desired, the rotating shaft 20 can be rotated to a specific position to read the average concentration over the current diameter.

Step 3, disconnection:

the electromagnet is de-energized, disconnecting the measurement conduit 30 from the collection tube 41.

Step 4, rotating to a designated position:

the ECU calculates the angle of the next target position according to the preset concentration reading;

the rotation shaft 20 is controlled to rotate to the specified angle.

And 5, establishing connection:

the electromagnet is energized to ensure that the measuring tube 30 on the given diameter circle is connected to the collection tube 41.

Step 6, reading the concentration of the designated position:

again reading the SCR concentration at the new location;

the average concentration over a given diameter can be read by rotating shaft 20 continuously.

Step 7, data processing and decision:

comparing the read concentration data with a set threshold value;

if the concentration exceeds the threshold, the ECU may decide whether it is necessary to rotate to another location again or perform another operation;

if the concentration is normal, the system continues to monitor the current position until the next detection period.

Step 8, exception handling:

if the readings of several continuous positions are abnormal, the system can give an alarm;

if some part, such as the electromagnet or the rotating shaft 20, fails, the system also gives an alarm and stops operating.

Step 9, ending and preparing the period:

once a measurement cycle is completed, the system may decide to pause briefly or begin the next cycle immediately, depending on the requirements.

The measuring method can continuously and accurately monitor the concentration of the SCR and make adjustment according to actual conditions so as to ensure that the emission meets the environmental requirements.

Specifically, the ECU adjusts the rotation angle of the rotary shaft 20 according to the acquired real-time data, including the steps of:

setting a reference rotation angle, for example, 0 degrees;

setting a concentration threshold (e.g., an ammonia concentration threshold);

reading a current ammonia concentration value from an ammonia concentration sensor of the SCR tank;

reading current values from the temperature sensor and the pressure sensor;

if the ammonia concentration exceeds a set threshold, it may be indicative of too much urea injection or insufficient reaction in certain areas, at which time the measurement position needs to be adjusted. Calculating a rotation angle theta according to the concentration difference;

if the temperature or the pressure is abnormal, calculating a rotation angle father theta according to the abnormal degree;

new rotation angle = reference rotation angle + theta;

transmitting a new rotation angle command to the motor 90 to realize the rotation of the rotation shaft 20;

after the rotation is completed, the ammonia concentration value is read again;

if the ammonia concentration returns to the normal range, maintaining the current angle;

if the ammonia concentration is still abnormal, the operation is repeated until the ammonia concentration returns to normal.

The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims

1. A measurement device for measuring concentration of selective catalytic reduction emissions, comprising:

a rotation shaft rotatably provided in the through passage, and having an axis coincident with an axis of the through passage;

the measuring unit is communicated with the transmission pipeline;

the conveying pipeline is communicated with the measuring unit at one end, and the conveying pipeline is communicated with the transmission pipeline at the other end;

in the power-on state of the magnetic component, the limit key is accommodated in the limit groove, the rotating shaft drives the transmission pipeline to rotate, in the power-off state of the magnetic component, the transmission pipeline and the rotating shaft can move independently, and the elastic component drives the limit key to be separated from the limit groove.

2. The measuring device according to claim 1, wherein the collecting pipe is provided with a guide portion at one end for communicating with the air outlet, and the guide portion is for guiding the air outlet.

3. The measuring device according to claim 1, wherein a plurality of brackets are provided on the rotating shaft, and each of the measuring pipes is connected to the rotating shaft through one of the brackets.

4. The measurement device of claim 1, further comprising a motor, the rotating shaft being drivingly connected to an output shaft of the motor.

5. The measuring device according to claim 4, further comprising a sleeve, wherein the sleeve is sleeved on the outer side of the motor, a supporting rib is arranged on the sleeve, one end of the supporting rib is connected with the sleeve, and the other end of the supporting rib is connected with the inner wall of the through channel.

6. The measurement device of claim 1, wherein the housing is provided with mounting flanges at opposite ends.

7. An exhaust system, comprising:

a selective catalytic reduction tank comprising a gas line;

the measuring device of any one of claims 1-6, disposed on the gas line for measuring the concentration of the selective catalytic reduction emissions within the gas line, the through passage being in communication with the line.

8. A vehicle, characterized by comprising:

the exhaust system of claim 7;

and the vehicle-mounted control system is used for controlling the rotation angle of the rotating shaft.