Pollution testing equipment and method for heavy duty vehicles and off-highway machines

Abstract

The present application discloses a heavy vehicle and non-road machinery pollutant testing device and testing method, and relates to the technical field of vehicle exhaust pollutant concentration measurement. The device comprises a sampling unit, which comprises a first collecting pipe and a second collecting pipe. The first collecting pipe is in communication with an engine exhaust pipe at an end away from a first connecting pipe. A first reversing valve is arranged at the connection of the first collecting pipe with the first connecting pipe and a second connecting pipe, and a second reversing valve is arranged at the connection of the second collecting pipe with the first connecting pipe and the second connecting pipe. A flow detection module and a first temperature sensor module are installed on the first collecting pipe. A heating unit is arranged on the first connecting pipe, the second connecting pipe and the second collecting pipe. A PN measurement unit and a NOx measurement unit are in communication with the second collecting pipe. A control unit is in communication connection with the first reversing valve, the second reversing valve, the flow detection module, the first temperature sensor module and the heating unit. The water content is effectively reduced, and the detection accuracy and reliability are improved.

Description

Technical Field

[0001] This invention generally relates to the field of vehicle exhaust pollutant concentration measurement technology, and specifically to testing equipment and methods for testing pollutants from heavy-duty vehicles and non-road machinery. Background Technology

[0002] The coordinated regulation and control of particulate matter (PN) and NOx emissions from traditional motor vehicles is crucial for air pollution monitoring and control. However, current vehicle-specific testing technologies have significant limitations. Since the implementation of the China V emission standard, heavy-duty vehicles have adopted Diesel Particulate Filters (DPFs), which can comprehensively control black smoke emissions. However, they cannot detect whether PN particulate matter emissions in smokeless emissions meet standards. Therefore, government environmental management departments are researching the introduction of particulate matter detection technologies for regulation, with rapid particulate matter number testing equipment replacing traditional opacities as the preferred method for detecting particulate matter emissions from in-use vehicles.

[0003] In recent years, hydrogen ammonia fuel has been successfully applied in internal combustion engines, opening a new path to "zero carbon" combustion. However, hydrogen ammonia fuel engines produce a significant proportion of water vapor during combustion, far exceeding that of conventional fuels (up to 60%). The generation of water vapor significantly interferes with existing chemiluminescent detector (CLD) and non-dispersive ultraviolet (NDUV) methods for testing NOx pollutants. Therefore, we propose a testing device and method suitable for heavy-duty vehicles and non-road machinery to address these issues. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a testing device and testing method for pollutants from heavy vehicles and non-road machinery that can effectively reduce moisture content and improve detection accuracy and reliability.

[0005] In a first aspect, the present invention provides a testing device for pollutants from heavy vehicles and non-road machinery, comprising: The sampling unit includes: a first sampling tube, a second sampling tube, and a first connecting tube and a second connecting tube connected in parallel between the first sampling tube and the second sampling tube; the end of the first sampling tube away from the first connecting tube is connected to the engine exhaust pipe; a first reversing valve is provided at the connection between the first sampling tube and the first connecting tube and the second connecting tube, and a second reversing valve is provided at the connection between the second sampling tube and the first connecting tube and the second connecting tube; a flow detection module and a first temperature sensor module are also installed on the first sampling tube, the flow detection module is used to detect the exhaust flow rate, and the first temperature sensor module is used to detect the first exhaust temperature; A heating unit is installed on the first connecting pipe, the second connecting pipe, and the second collecting pipe, and is used to heat the corresponding pipes. The PN measurement unit and the NOx measurement unit are both connected to the end of the second acquisition tube away from the first connecting tube. The PN measurement unit is used to measure the PN concentration, and the NOx measurement unit is used to measure the NOx concentration. The control unit is communicatively connected to the first reversing valve, the second reversing valve, the flow detection module, the first temperature sensor module, and the heating unit. The control unit is used to control the rotation angle of the first reversing valve and the second reversing valve according to the exhaust flow rate and the first exhaust temperature, thereby controlling the exhaust gas from the engine exhaust pipe to enter the PN measurement unit and the NOx measurement unit through the connected pipeline path. The control unit is also used to control the heating unit to heat the corresponding pipeline according to the connected pipeline path and the target temperature of the PN measurement unit and the NOx measurement unit.

[0006] According to the technical solution provided by the present invention, the heating unit includes: The first heating module is disposed on the first connecting pipe; The second heating module is mounted on the second connecting pipe; The third heating module is installed on the second acquisition tube.

[0007] According to the technical solution provided by the present invention, the NOx measurement unit includes: The first measuring tube has one end connected to the end of the second collecting tube that is away from the second reversing valve; The first measuring tube is provided with a gas filter module, a second temperature sensor module, a NOx measuring module, and a first vacuum pump, arranged sequentially from the end closest to the second collecting tube to the end furthest from the second collecting tube.

[0008] According to the technical solution provided by the present invention, the PN measurement unit includes: The second measuring tube has one end connected to the end of the second acquisition tube that is away from the second reversing valve; The second measuring tube is provided with a primary filter module, a multi-stage diluter module, a third temperature sensor module, a PN measurement module, and a second vacuum pump, arranged sequentially from the end closest to the second acquisition tube to the end furthest from the second acquisition tube.

[0009] According to the technical solution provided by the present invention, the NOx measurement module is connected to a first wireless Bluetooth module, which is used to transmit the NOx concentration measured by the NOx measurement module to the vehicle OBD system, the wireless printer and the environmental protection platform. The PN measurement module is connected to a second wireless Bluetooth module, which is used to transmit the PN concentration measured by the PN measurement module to the vehicle OBD system, wireless printer, and environmental protection platform.

[0010] According to the technical solution provided by the present invention, it further includes: a thermal insulation component; The thermal insulation component includes at least: The first insulation layer is disposed on the outer wall of the first connecting pipe; The second insulation layer is disposed on the outer wall of the second connecting pipe; The third insulation layer is installed on the outer wall of the second collection tube.

[0011] According to the technical solution provided by the present invention, it further includes: a power supply module, which is electrically connected to the sampling unit, the heating unit, and the control unit, and is used to supply power to the corresponding devices.

[0012] According to the technical solution provided by the present invention, the length of the second connecting pipe is at least 2 meters longer than the length of the first connecting pipe.

[0013] Secondly, the present invention provides a testing method for pollutants from heavy-duty vehicles and non-road machinery, based on the aforementioned testing equipment for pollutants from heavy-duty vehicles and non-road machinery. The testing method includes the following steps: Connect the first acquisition tube to the engine exhaust pipe, start the test equipment, and adjust the test equipment to the first state; the first state refers to the state in which the first acquisition tube is connected to the first connecting tube and disconnected from the second connecting tube, and at the same time the first connecting tube is connected to the second acquisition tube and the second connecting tube is disconnected from the second acquisition tube; When collecting exhaust gas from the engine exhaust pipe, the exhaust flow rate detected by the flow detection module and the first exhaust temperature detected by the first temperature sensor module are obtained. When it is determined that the exhaust flow rate is greater than or equal to the minimum flow rate and the first exhaust temperature is less than the minimum temperature, the rotation angle of the first reversing valve and the second reversing valve is adjusted until the test equipment is in the second state; the second state refers to the state in which the first collection pipe is connected to the second connecting pipe and disconnected from the first connecting pipe, and at the same time the second connecting pipe is connected to the second collection pipe and the first connecting pipe is disconnected from the second collection pipe; Obtain the second exhaust temperature detected by the second temperature sensor module or the third exhaust temperature detected by the third temperature sensor module; Based on the connection and disconnection of the first acquisition tube with the first connecting tube and the second connecting tube, when it is determined that the second exhaust temperature is less than the minimum temperature limit, or when it is determined that the third exhaust temperature is less than the minimum temperature limit, the heating unit is controlled to heat the corresponding pipeline. When it is determined that the second exhaust temperature is greater than or equal to the minimum temperature limit and the third exhaust temperature is greater than or equal to the minimum temperature limit, the PN concentration is measured using the PN measurement unit, and the NOx concentration is measured using the NOx measurement unit.

[0014] According to the technical solution provided by the present invention, after measuring the NOx concentration using the NOx measurement unit, the method further includes the following steps: The PN concentration and the NOx concentration are uploaded to the vehicle OBD system, the wireless printer, and the environmental protection platform.

[0015] In summary, this invention discloses a specific structure for a testing device for pollutants from heavy-duty vehicles and non-road machinery. The invention designs a sampling unit comprising: a first sampling tube, a second sampling tube, and a first connecting tube and a second connecting tube disposed between the two; wherein, the end of the first sampling tube furthest from the first connecting tube is connected to an engine exhaust pipe; a first reversing valve is provided at the connection point between the first sampling tube and the first and second connecting tubes; a second reversing valve is provided at the connection point between the second sampling tube and the first and second connecting tubes; a flow detection module and a first temperature sensor module are also installed on the first sampling tube; a heating unit is provided on the first sampling tube, the second connecting tube, and the second sampling tube; a PN measurement unit and a NOx measurement unit are connected to the end of the second sampling tube furthest from the first connecting tube; a control unit is communicatively connected to the first reversing valve, the second reversing valve, the flow detection module, the first temperature sensor module, and the heating unit. The control unit controls the rotation angle of the first reversing valve and the second reversing valve based on the exhaust flow detected by the flow detection module and the first exhaust temperature detected by the first temperature sensor module. This controls the exhaust gas from the engine exhaust pipe to enter the PN measurement unit and the NOx measurement unit through the connected pipeline path. At the same time, the control unit also controls the heating unit to heat the corresponding pipeline based on the connected pipeline path and the target temperature of the PN measurement unit and the NOx measurement unit.

[0016] This invention determines whether the exhaust gas flow rate and the first exhaust temperature meet the requirements for subsequent measurement by judging the exhaust gas flow rate and the first exhaust temperature. If they do not meet the requirements, a gas transmission path of first collection pipe - second connecting pipe - second collection pipe is selected for the exhaust gas. If they meet the requirements, a gas transmission path of first collection pipe - first connecting pipe - second collection pipe is selected for the exhaust gas. Furthermore, when the first exhaust temperature does not meet the target temperature, a heating unit is used to heat the corresponding pipeline to avoid water vapor condensation in the corresponding pipeline. This can effectively reduce the water content, prevent water vapor from interfering with NOx measurement, and improve detection accuracy and reliability. Attached Figure Description

[0017] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of a testing device for pollutants from heavy vehicles and non-road machinery.

[0019] Figure 2 This is a schematic diagram of the data transmission structure between the first and second wireless Bluetooth modules.

[0020] Figure 3 This is a flowchart illustrating a testing method for pollutants applicable to heavy-duty vehicles and non-road machinery.

[0021] Figure 4 This is a schematic diagram showing the communication connection between the control unit and various modules and devices.

[0022] The diagram shows the following components: 1. Engine exhaust pipe; 2. First acquisition pipe; 3. Flow detection module; 4. First temperature sensor module; 5. First reversing valve; 6. First connecting pipe; 7. First heating module; 8. First insulation layer; 9. Second reversing valve; 10. Third heating module; 11. Third insulation layer; 12. First measuring pipe; 13. Gas filter module; 14. Second temperature sensor module; 15. NOx measurement module; 16. First wireless Bluetooth module; 17. First vacuum pump; 18. Second connecting pipe; 19. Second insulation layer; 20. Second heating module; 21. Second acquisition pipe; 22. Second measuring pipe; 23. Primary filter module; 24. Multi-stage diluter module; 25. Third temperature sensor module; 26. PN measurement module; 27. Second wireless Bluetooth module; 28. Second vacuum pump; 29. ​​Control unit; 30. Power module; 31. Vehicle OBD system; 32. Wireless printer; 33. Environmental protection platform. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] The 2020 Environmental Status Bulletin shows that diesel vehicles account for 80% of total vehicle NOx emissions. However, remote platforms for monitoring emissions from heavy-duty diesel vehicles cannot yet identify and warn of failures in key emission control components or screen suspicious vehicles. Beijing has implemented rapid on-site NOx testing standards to detect high-emission vehicles, but the compliance and accuracy of the equipment still need improvement. Furthermore, according to incomplete statistics, the monitoring of smoke opacity at Beijing's entry points has been increasing year by year. 288,500 vehicles were sampled in 2019, 224,100 in 2020, and 267,600 in 2021, with the failure rate indeed decreasing annually, at 10%, 5%, and 3% respectively. These sampling results indicate, on the one hand, that vehicle emission control levels have improved and stabilized; on the other hand, they also place higher demands on testing methods. To address these existing problems, this invention designs the following testing equipment and method.

[0026] It should be noted that the testing equipment and methods proposed in this invention are applicable to heavy-duty vehicles and non-road machinery. Heavy-duty vehicles refer to M- and N-class vehicles with a maximum gross vehicle weight greater than 3500 kg. These vehicles consist of a heavy-duty tractor and a heavy-duty trailer, and generally employ a series-axle hydraulic suspension system. They are typically used to transport large cargo exceeding the limits stipulated by road traffic regulations in terms of size and weight. Heavy-duty vehicles mainly include trucks, semi-trailer tractors, ordinary buses, dump trucks, and city buses. Non-road machinery refers to machinery and transportable equipment equipped with engines. Common examples include tractors, agricultural transport vehicles (agricultural machinery license plates), combine harvesters, irrigation and drainage machinery, loaders, cranes, excavators, lawnmowers, bulldozers, road rollers, asphalt pavers, off-highway trucks, loaders, road rollers, asphalt pavers, forklifts, machinery manufacturing, construction machinery, mining machinery, garden machinery, and other machinery manufacturing and production equipment. They primarily use diesel or gasoline engines.

[0027] Example 1 Please refer to Figure 1 The diagram shown is a structural schematic of a first embodiment of a testing device for pollutants from heavy vehicles and non-road machinery provided by the present invention, comprising: The sampling unit includes: a first sampling tube 2, a second sampling tube 21, and a first connecting tube 6 and a second connecting tube 18 disposed between the first sampling tube 2 and the second sampling tube 21; the end of the first sampling tube 2 away from the first connecting tube 6 is connected to the engine exhaust pipe 1. The air inlet of the first collection tube 2 is, for example, Figure 1 The left-side opening of the first collection pipe 2 is connected to the engine exhaust pipe 1; the outlet of the first collection pipe 2 is, for example, [missing information]. Figure 1 The right-side inlet of the pipe is connected to the air inlet of the first connecting pipe 6 and the air inlet of the second connecting pipe 18; the air inlet of the second collection pipe 21 is, for example, Figure 1 The left-side opening of the tube is connected to the air outlet of the first connecting tube 6 and the air outlet of the second connecting tube 18; the air outlet of the second collecting tube 21 is, for example, Figure 1 The right-side port is connected to the corresponding ports of the PN measurement unit and the NOx measurement unit.

[0028] The first connecting pipe 6 and the second connecting pipe 18 are connected in parallel between the first collecting pipe 2 and the second collecting pipe 21. A first reversing valve 5 is provided at the connection between the first collecting pipe 2 and the first connecting pipe 6 and the second connecting pipe 18, and a second reversing valve 9 is provided at the connection between the second collecting pipe 21 and the first connecting pipe 6 and the second connecting pipe 18. The first reversing valve 5 is used to control the opening and closing of the first collection pipe 2 and the first connecting pipe 6 and the second connecting pipe 18, thereby controlling the exhaust gas to be transported from the first collection pipe 2 to the first connecting pipe 6 or the second connecting pipe 18; the second reversing valve 9 is used to control the opening and closing of the second collection pipe 21 and the first connecting pipe 6 and the second connecting pipe 18, thereby controlling the exhaust gas in the first connecting pipe 6 or the second connecting pipe 18 to enter the second collection pipe 21; here, the first reversing valve 5 and the second reversing valve 9 are, for example, two-position three-way valves.

[0029] The first acquisition tube 2 is also equipped with a flow detection module 3 and a first temperature sensor module 4. The flow detection module 3 is used to detect the exhaust flow rate, and the first temperature sensor module 4 is used to detect the first exhaust temperature of the exhaust gas in the first acquisition tube 2. Among them, the flow detection module 3 is, for example, an MF4003 gas mass flow meter. The first temperature sensor module 4 is, for example, a Messiko temperature sensor, or a Combiwell 692010 1*PT100.

[0030] A heating unit is provided on the first connecting pipe 6, the second connecting pipe 18 and the second collecting pipe 21, and is used to heat the corresponding pipes. Among them, such as Figure 1 As shown, the heating unit includes: The first heating module 7 is disposed on the first connecting pipe 6; the first heating module 7 is used to heat the gas in the first connecting pipe 6.

[0031] The second heating module 20 is disposed on the second connecting pipe 18; the second heating module 20 is used to heat the gas in the second connecting pipe 18.

[0032] The third heating module 10 is disposed on the second collection tube 21; the third heating module 10 is used to heat the gas in the second collection tube 21.

[0033] Furthermore, the distribution of each heating module on the outer wall of the corresponding pipe can be either fully enclosed or partially enclosed. For example, the heating modules can be densely wound circular resistance wires wrapped around the outer wall of the corresponding pipe, forming a fully enclosed arrangement; or they can be multiple ceramic heating coils arranged on the outer wall of the corresponding pipe, which can be evenly or non-uniformly distributed, forming a partially enclosed arrangement. Moreover, since each heating module is located on the outer wall of its respective pipe, controlling the exhaust gas temperature does not affect the exhaust gas flow rate within the corresponding pipe.

[0034] Each heating module can use the PID (proportion integration differentiation) control algorithm to achieve precise temperature control.

[0035] The PN measurement unit and the NOx measurement unit are both connected to the end of the second acquisition tube 21 that is away from the first connecting tube 6. The PN measurement unit is used to measure the PN concentration, and the NOx measurement unit is used to measure the NOx concentration. Specifically, the NOx measurement unit includes: The first measuring tube 12 has one end connected to the end of the second collecting tube 21 away from the second reversing valve 9; wherein, the air inlet of the first measuring tube 12 is, for example, Figure 1 The left-side inlet of the tube is connected to the outlet of the second collection tube 21. The outlet of the first measuring tube 12 is, for example, [missing information]. Figure 1 The right-side port of the outlet is connected to the external atmospheric environment and is used to release the NOx into the external atmospheric environment after the NOx measurement unit has completed the measurement of NOx concentration.

[0036] The first measuring tube 12 is provided with a gas filter module 13, a second temperature sensor module 14, a NOx measuring module 15 and a first vacuum pump 17 sequentially from the end closest to the second collecting tube 21 to the end furthest from the second collecting tube 21.

[0037] It should be noted that the gas filter module 13 is used to remove particulate impurities from the exhaust gas entering the first measuring tube 12; the type of gas filter module 13 is, for example, YG45H-16C Y-type filter.

[0038] The second temperature sensor module 14 is used to detect the second exhaust temperature of the exhaust gas in the first measuring tube 12; the type of the second temperature sensor module 14 is, for example, a Messiko temperature sensor, Combiwell 692010 1*PT100.

[0039] The first vacuum pump 17 is used to pump exhaust gas through the first collection pipe 2 into the first connecting pipe 6 or the second connecting pipe 18, the second collection pipe 21 and the first measuring pipe 12 in sequence, and after measuring the NOx concentration, the exhaust gas is discharged into the external atmosphere.

[0040] The NOx measurement module 15 is used to detect the NOx concentration in the exhaust gas inside the first measuring tube 12. Here, the NOx concentration refers to the sum of the NO concentration and the NO2 concentration. Furthermore, the NOx measurement module 15 primarily uses UV-Differential Optical Absorption Spectroscopy (UV-DOAS) to detect the NOx concentration in the exhaust gas inside the first measuring tube 12. The specific principle is as follows: utilizing the different absorption characteristics of the same gas in different spectral bands, and the superposition effect of absorption by different gases in the same spectral band, multiple gases can be measured simultaneously through continuous spectrum analysis. The NOx measurement module 15 can use a holographic grating to disperse the light absorbed by the gas being measured, and use an array sensor to convert the dispersed optical signal into an electrical signal to obtain the continuous absorption spectrum of the medium, thus achieving simultaneous measurement of multiple gases.

[0041] Furthermore, the differential optical absorption spectroscopy algorithm can process continuous spectral data to obtain gas concentration. After the light beam passes through the gas environment of length L, the light energy will attenuate due to the absorption of light by the gas. The absorption of light intensity by the gas at wavelength λ can be accurately expressed by the Beer-Lambert relationship, as shown in the following formula: ; in, Let be the relative intensity of the emitted light at wavelength λ. Let λ be the relative intensity of the incident light at wavelength λ, and L be the optical path length. Let i be the concentration of the i-th gas. Let be the absorption coefficient of the i-th gas. The extinction coefficient is caused by factors such as particle scattering.

[0042] The differential absorption algorithm in the measurement experiment of the NOx measurement module 15 decomposes the gas absorption into two parts: ;in, This refers to the portion that changes rapidly with wavelength. The portion of absorption that changes slowly with wavelength is the part that is absorbed; while the extinction effect caused by factors such as particle scattering also changes slowly with wavelength. Obviously, the portion of absorption that changes rapidly with wavelength is only related to gas absorption. By calculating the corresponding values, the concentrations of NO and NO2 can be obtained.

[0043] Specifically, the PN measurement unit includes: The second measuring tube 22 has one end connected to the end of the second acquisition tube 21 away from the second reversing valve 9; wherein, the air inlet of the second measuring tube 22 is, for example, Figure 1 The left-side inlet of the tube is connected to the outlet of the second collection tube 21, and the outlet of the second measuring tube 22 is, for example, [missing information]. Figure 1 The right-side port of the PN measurement unit is connected to the external atmospheric environment and is used to discharge the PN concentration into the external atmospheric environment after the PN measurement unit completes the measurement.

[0044] The second measuring tube 22 is provided with a primary filter module 23, a multi-stage diluter module 24, a third temperature sensor module 25, a PN measurement module 26 and a second vacuum pump 28 sequentially from the end closest to the second collecting tube 21 to the end furthest from the second collecting tube 21.

[0045] It should be noted that the primary filter module 23 is used to remove volatile particles from the exhaust gas entering the second measuring tube 22 using volatile particulate removal technology; the type of primary filter module 23 is, for example, Thermo Fisher Scientific 57-002758 particulate filter.

[0046] The multistage diluter module 24 is used to dilute PN in the exhaust gas after it has been filtered by the primary filter 23 in multiple stages; the type of multistage diluter module 24 is, for example, the FAD-1200 fully automatic organic diluent dispenser.

[0047] The third temperature sensor module 25 is used to detect the third exhaust temperature of the exhaust gas in the second measuring tube 22; the type of the third temperature sensor module 25 is, for example, a Messiko temperature sensor, Combiwell 692010 1*PT100.

[0048] The second vacuum pump 28 is used to pump exhaust gas through the first collection pipe 2 into the first connecting pipe 6 or the second connecting pipe 18, the second collection pipe 21 and the second measuring pipe 22 in sequence, and after measuring the PN concentration, the exhaust gas is discharged into the external atmosphere.

[0049] The PN measurement module 26 is used to detect the PN concentration of the exhaust gas in the second measuring tube 22. PN concentration refers to the total number concentration of particulate matter. For example, the PN measurement module 26 can use condensation single particle counting technology (i.e., diffusion charging method) to obtain the PN concentration in the exhaust gas. The specific process is as follows: The particulate matter total number concentration PN measurement module based on diffusion charging method mainly includes a particulate matter charging unit, a particulate matter charge measurement unit, and a number concentration inversion algorithm unit. That is, firstly, the particulate matter charging method such as corona discharge is used to charge the particulate matter to be measured. Then, the particulate matter charge measurement unit is used to measure the charge of the charged particulate matter. Finally, the number concentration inversion algorithm unit realizes the inversion calculation from the particulate matter charge to the total number concentration of particulate matter.

[0050] like Figure 4 As shown, the control unit 29 is communicatively connected to the first reversing valve 5, the second reversing valve 9, the flow detection module 3, the first temperature sensor module 4, and the heating unit. The control unit 29 is used to control the rotation angle of the first reversing valve 5 and the second reversing valve 9 according to the exhaust flow rate and the first exhaust temperature, thereby controlling the exhaust gas from the engine exhaust pipe 1 to enter the PN measurement unit and the NOx measurement unit according to the connected pipeline path. The control unit 29 is also used to control the heating unit to heat the corresponding pipeline according to the connected pipeline path and the target temperature of the PN measurement unit and the NOx measurement unit.

[0051] The control unit 29 is, for example, an Intel Core i5-12400F. The target temperature refers to the temperature required for the PN measurement unit and NOx measurement unit to perform their respective measurement tests.

[0052] It should be noted that the length of the second connecting pipe 18 is at least 2 meters longer than the length of the first connecting pipe 6. When the exhaust flow rate is large, the NOx concentration does not decrease significantly with the increase of the connecting pipe length. In this case, in order to meet the requirements of rapid measurement, the second connecting pipe 8 is needed to transport the exhaust gas. That is, using a longer connecting pipe to transport the exhaust gas helps to increase the exhaust temperature more quickly, thereby meeting the subsequent concentration measurement requirements. Here, the lengths of the second connecting pipe 18 and the first connecting pipe 6 can be set according to actual needs.

[0053] Specifically, after the testing equipment is started, it is in a first state, which means that the first acquisition tube 2 and the first connecting tube 6 are connected, while the first acquisition tube 2 and the second connecting tube 18 are disconnected. Furthermore, it is set that when the rotation angle of the first reversing valve 5 is 0 degrees, it indicates that the first acquisition tube 2 and the first connecting tube 6 are connected; when the rotation angle of the first reversing valve 5 is 180 degrees, it indicates that the first acquisition tube 2 and the second connecting tube 18 are connected. Similarly, when the rotation angle of the second reversing valve 9 is 0 degrees, it indicates that the first connecting tube 6 and the second acquisition tube 21 are connected; when the rotation angle of the second reversing valve 9 is 180 degrees, it indicates that the second connecting tube 18 and the second acquisition tube 21 are connected.

[0054] The control unit 29 acquires the exhaust flow rate detected by the flow detection module 3 and the first exhaust temperature detected by the first temperature sensor module 4, and then judges the two. When the exhaust flow rate is greater than or equal to the minimum flow rate limit and the first exhaust temperature is less than the minimum temperature limit, it indicates that the current exhaust flow rate is large, but the temperature does not meet the requirements. The length of the first connecting pipe 6 is shorter than the length of the second connecting pipe 18. If the first connecting pipe 6 is still used to transport gas, the final rapid measurement requirements will not be met. Therefore, it is necessary to switch to the second connecting pipe 18 to heat the exhaust gas. Since the exhaust flow rate is large, even if the second connecting pipe 18 is switched, the NOx concentration will not decrease significantly with the increase of the connecting pipe length. At the same time, the rapid measurement requirements can still be met. Therefore, when the exhaust flow rate is greater than or equal to the minimum flow rate limit and the first exhaust temperature is less than the minimum temperature limit, the second connecting pipe 18 needs to be used to transport the exhaust gas, which helps to increase the exhaust temperature more quickly. The way to switch the connecting pipe is to adjust the rotation angle of the first reversing valve 5 and the second reversing valve 9 so that the first acquisition pipe 2, the second connecting pipe 18 and the second acquisition pipe 21 are connected.

[0055] When the exhaust flow rate is less than the minimum flow rate limit, the connecting pipe cannot be switched regardless of whether the first exhaust temperature is less than the minimum temperature limit, to avoid the NOx concentration from significantly decreasing as the length of the connecting pipe increases. At this time, the rotation angle of the first reversing valve 5 and the second reversing valve 9 is not adjusted, and the exhaust gas still enters the first connecting pipe 6 through the first collection pipe 2. If the temperature is greater than or equal to the minimum temperature limit, there is no need to heat the first connecting pipe 6. If the temperature is less than the minimum temperature limit, the first connecting pipe 6 is heated to prevent the exhaust gas from condensing.

[0056] When the exhaust flow rate is greater than or equal to the minimum flow rate and the first exhaust temperature is greater than or equal to the minimum temperature, it means that the test equipment currently in the first state can meet the requirements of rapid testing, so there is no need to adjust the rotation angle of the first reversing valve 5 and the second reversing valve 9.

[0057] By determining the exhaust flow rate and the first exhaust temperature, a suitable delivery pipeline can be selected for the exhaust gas. This can avoid the decay of NOx concentration while ensuring rapid measurement requirements. At the same time, when the first exhaust temperature is lower than the minimum temperature limit, a heating unit is required to heat the gas to prevent water vapor condensation in the corresponding pipeline. This can effectively reduce the water content and improve the detection accuracy and reliability.

[0058] The minimum flow rate can be set based on the vehicle's exhaust mass flow rate, with a range of, for example, 20-40 g / s. The minimum temperature can be set according to actual needs, with a range of, for example, 130-170℃.

[0059] Furthermore, such as Figure 2 As shown, the NOx measurement module 15 is connected to a first wireless Bluetooth module 16, which is used to transmit the NOx concentration measured by the NOx measurement module 15 to the vehicle OBD system 31, the wireless printer 32 and the environmental protection platform 33. The PN measurement module 26 is connected to a second wireless Bluetooth module 27, which is used to transmit the PN concentration measured by the PN measurement module 26 to the vehicle OBD system 31, the wireless printer 32, and the environmental protection platform 33.

[0060] The signal input terminal of the first wireless Bluetooth module 16 is communicatively connected to the signal output terminal of the NOx measurement module 15, and the signal output terminal of the first wireless Bluetooth module 16 is communicatively connected to the vehicle OBD system 31, the wireless printer 32, and the environmental protection platform 33. Similarly, the signal input terminal of the second wireless Bluetooth module 27 is communicatively connected to the signal output terminal of the PN measurement module 26, and the signal output terminal of the second wireless Bluetooth module 27 is communicatively connected to the vehicle OBD system 31, the wireless printer 32, and the environmental protection platform 33.

[0061] The vehicle-mounted OBD system 31 is used to receive the NOx concentration measured by the NOx measurement module 15 and the PN concentration measured by the PN measurement module 26. The measurement personnel and vehicle owners can obtain the NOx concentration and PN concentration of the vehicle exhaust through the vehicle-mounted OBD system 31.

[0062] The wireless printer 32 is used to print out the NOx concentration measured by the NOx measurement module 15 and the PN concentration measured by the PN measurement module 26 in real time.

[0063] The environmental protection platform 33 is used to store the NOx concentration measured by the NOx measurement module 15 and the PN concentration measured by the PN measurement module 26, so as to facilitate later query and application.

[0064] Furthermore, such as Figure 1 As shown, it also includes: thermal insulation components; Insulation components include at least: The first insulation layer 8 is disposed on the outer wall of the first connecting pipe 6; The second insulation layer 19 is disposed on the outer wall of the second connecting pipe 18; The third insulation layer 11 is located on the outer wall of the second collection tube 21.

[0065] The first insulation layer 8, the second insulation layer 19, and the third insulation layer 11 are, for example, high-temperature resistant rubber and plastic insulation boards, used to insulate the corresponding pipelines and further enhance the temperature control effect of the corresponding heating modules. Furthermore, due to the presence of each insulation layer, each heating module can be pre-embedded between the outer wall of the corresponding pipeline and the corresponding insulation layer.

[0066] Furthermore, such as Figure 4 As shown, it also includes a power supply module 30, which is electrically connected to the sampling unit, heating unit, and control unit 29, and is used to supply power to the corresponding devices.

[0067] Among them, the power module 30 is, for example, a high-performance lithium battery with a power display function, which can continuously and stably measure for 6 hours, and is not limited by the on-site power supply conditions, making it especially suitable for outdoor testing.

[0068] Example 2 This invention provides a testing method for pollutants from heavy-duty vehicles and non-road machinery, implemented based on a testing device for pollutants from heavy-duty vehicles and non-road machinery as described in Example 1. Figure 3 As shown, the testing method includes the following steps: S10. Connect the first acquisition pipe 2 to the engine exhaust pipe 1, start the test equipment, and adjust the test equipment to the first state; the first state refers to the state in which the first acquisition pipe 2 is connected to the first connecting pipe 6 and disconnected from the second connecting pipe 18, while the first connecting pipe 6 is connected to the second acquisition pipe 21 and the second connecting pipe 18 is disconnected from the second acquisition pipe 21. After the first acquisition tube 2 and the engine exhaust pipe 1 are connected, the control unit 29 starts the power module 30 to supply power to each module and device. At this time, the first reversing valve 5 connects the first acquisition tube 2 and the first connecting tube 6, and the second reversing valve 9 connects the first connecting tube 6 and the second acquisition tube 21, that is, the test equipment is in the first state.

[0069] S20. When collecting exhaust gas in engine exhaust pipe 1, acquire the exhaust flow rate detected by flow detection module 3 and the first exhaust temperature detected by first temperature sensor module 4. The control unit 29 acquires the exhaust flow rate detected by the flow detection module 3 and the first exhaust temperature detected by the first temperature sensor module 4.

[0070] S30. When it is determined that the exhaust flow rate is greater than or equal to the minimum flow rate and the first exhaust temperature is less than the minimum temperature, adjust the rotation angle of the first reversing valve 5 and the second reversing valve 9 until the test equipment is in the second state; the second state refers to the state in which the first acquisition pipe 2 is connected to the second connecting pipe 18 and disconnected from the first connecting pipe 6, and at the same time the second connecting pipe 18 is connected to the second acquisition pipe 21 and the first connecting pipe 6 is disconnected from the second acquisition pipe 21. When the exhaust flow rate is greater than or equal to the minimum flow rate limit and the first exhaust temperature is less than the minimum temperature limit, it indicates that the current exhaust flow rate is large, but the temperature does not meet the requirements. The length of the first connecting pipe 6 is shorter than the length of the second connecting pipe 18. If the first connecting pipe 6 is still used to transport the gas, the final rapid measurement requirements will not be met. Therefore, it is necessary to switch to the second connecting pipe 18 to heat the exhaust gas. Since the exhaust flow rate is large, even if the second connecting pipe 18 is switched, the NOx concentration will not decrease significantly with the increase of the connecting pipe length. At the same time, the rapid measurement requirements can still be met. Therefore, when the exhaust flow rate is greater than or equal to the minimum flow rate limit and the first exhaust temperature is less than the minimum temperature limit, the second connecting pipe 18 should be used to transport the exhaust gas, which helps to increase the exhaust temperature more quickly. The way to switch the connecting pipes is to adjust the rotation angle of the first reversing valve 5 and the second reversing valve 9 so that the first sampling pipe 2, the second connecting pipe 18 and the second sampling pipe 21 are connected.

[0071] When the exhaust flow rate is less than the minimum flow rate limit, the connecting pipe cannot be switched regardless of whether the first exhaust temperature is less than the minimum temperature limit, to avoid the NOx concentration from significantly decreasing as the length of the connecting pipe increases. At this time, the rotation angle of the first reversing valve 5 and the second reversing valve 9 is not adjusted, and the exhaust gas still enters the first connecting pipe 6 through the first collection pipe 2. If the temperature is greater than or equal to the minimum temperature limit, there is no need to heat the first connecting pipe 6. If the temperature is less than the minimum temperature limit, the first connecting pipe 6 is heated to prevent the exhaust gas from condensing.

[0072] When the exhaust flow rate is greater than or equal to the minimum flow rate and the first exhaust temperature is greater than or equal to the minimum temperature, it means that the test equipment currently in the first state can meet the requirements of rapid testing, so there is no need to adjust the rotation angle of the first reversing valve 5 and the second reversing valve 9.

[0073] S40. Obtain the second exhaust temperature detected by the second temperature sensor module 14 or the third exhaust temperature detected by the third temperature sensor module 25. The control unit 29 acquires the second exhaust temperature detected by the second temperature sensor module 14 or the third exhaust temperature detected by the third temperature sensor module 25.

[0074] S50. Based on the on / off state of the first acquisition tube 2, the first connecting tube 6, and the second connecting tube 18, when it is determined that the second exhaust temperature is less than the minimum temperature limit, or when it is determined that the third exhaust temperature is less than the minimum temperature limit, the heating unit is controlled to heat the corresponding pipeline. Taking the second exhaust temperature as an example, the control unit 29 acquires the rotation angles of the first reversing valve 5 and the second reversing valve 9 in real time to determine whether the exhaust gas in the first acquisition pipe 2 is flowing through the first connecting pipe 6 or the second connecting pipe 8. At the same time, it acquires the second exhaust temperature through the second temperature sensor module 14. If the exhaust gas is flowing through the first connecting pipe 6 and the second exhaust temperature is less than the minimum temperature limit, the control unit 29 controls the power module 30 to supply power to the first heating module 7 and the third heating module 10, and adjusts the heating opening of the two heating modules so that the second exhaust temperature is greater than or equal to the minimum temperature limit. If the exhaust gas is flowing through the second connecting pipe 8 and the second exhaust temperature is less than the minimum temperature limit, the control unit 29 controls the power module 30 to supply power to the second heating module 20 and the third heating module 10, and adjusts the heating opening of the two heating modules so that the second exhaust temperature is greater than or equal to the minimum temperature limit. If the second exhaust temperature is greater than or equal to the minimum temperature limit, no heating operation is required from the corresponding heating module.

[0075] The determination of the third exhaust temperature is the same as that of the second exhaust temperature, and will not be elaborated further here.

[0076] S60. When it is determined that the temperature of the second exhaust gas is greater than or equal to the minimum temperature limit and the temperature of the third exhaust gas is greater than or equal to the minimum temperature limit, the PN concentration is measured using the PN measurement unit, and the NOx concentration is measured using the NOx measurement unit at the same time. The specific methods for measuring PN concentration by the PN measurement unit and measuring NOx concentration by the NOx measurement unit are the same as those described in Example 1, and will not be repeated here.

[0077] Furthermore, after measuring the NOx concentration using the NOx measurement unit, the following steps are also included: S70, Upload PN concentration and NOx concentration to vehicle OBD system 31, wireless printer 32 and environmental protection platform 33.

[0078] The first wireless Bluetooth module 16 on the NOx measurement module 15 and the second wireless Bluetooth module 27 on the PN measurement module 26 can upload the NOx and PN measurement results to the vehicle OBD system 31 in real time. The measurement personnel and vehicle owners can view the results on the vehicle OBD system 31. The results can also be uploaded to the wireless printer 32 for real-time printing. In addition, the measurement results can also be uploaded to the environmental protection platform 33 for later query and application.

[0079] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A testing device for pollutants from heavy vehicles and non-road machinery, characterized in that, include: The sampling unit includes: a first sampling tube (2), a second sampling tube (21), and a first connecting tube (6) and a second connecting tube (18) connected in parallel between the first sampling tube (2) and the second sampling tube (21); the length of the second connecting tube (18) is at least 2 meters longer than the length of the first connecting tube (6); the end of the first sampling tube (2) away from the first connecting tube (6) is connected to the engine exhaust pipe (1); a first reversing valve (5) is provided at the connection between the first sampling tube (2) and the first connecting tube (6) and the second connecting tube (18), and a second reversing valve (9) is provided at the connection between the second sampling tube (21) and the first connecting tube (6) and the second connecting tube (18); a flow detection module (3) and a first temperature sensor module (4) are also installed on the first sampling tube (2), the flow detection module (3) is used to detect the exhaust flow, and the first temperature sensor module (4) is used to detect the first exhaust temperature; A heating unit is provided on the first connecting pipe (6), the second connecting pipe (18) and the second collecting pipe (21) for heating the corresponding pipes; The PN measurement unit and the NOx measurement unit are both connected to the end of the second acquisition tube (21) away from the first connecting tube (6). The PN measurement unit is used to measure the PN concentration, and the NOx measurement unit is used to measure the NOx concentration. The control unit (29) is communicatively connected to the first reversing valve (5), the second reversing valve (9), the flow detection module (3), the first temperature sensor module (4), and the heating unit. The control unit (29) is used to control the rotation angle of the first reversing valve (5) and the second reversing valve (9) according to the exhaust flow rate and the first exhaust temperature, thereby controlling the exhaust gas of the engine exhaust pipe (1) to enter the PN measurement unit and the NOx measurement unit according to the connected pipeline path. The control unit (29) is also used to control the heating unit to heat the corresponding pipeline according to the connected pipeline path and the target temperature of the PN measurement unit and the NOx measurement unit.

2. The testing equipment for pollutants from heavy vehicles and non-road machinery according to claim 1, characterized in that, The heating unit includes: The first heating module (7) is disposed on the first connecting pipe (6); The second heating module (20) is disposed on the second connecting pipe (18); The third heating module (10) is installed on the second acquisition tube (21).

3. The testing equipment for pollutants from heavy vehicles and non-road machinery according to claim 1, characterized in that, The NOx measurement unit includes: The first measuring tube (12) has one end connected to the end of the second collecting tube (21) away from the second reversing valve (9); The first measuring tube (12) is provided with a gas filter module (13), a second temperature sensor module (14), a NOx measuring module (15) and a first vacuum pump (17) sequentially from the end closest to the second collecting tube (21) to the end furthest from the second collecting tube (21).

4. The testing equipment for pollutants from heavy vehicles and non-road machinery according to claim 3, characterized in that, The PN measurement unit includes: The second measuring tube (22) has one end connected to the end of the second collecting tube (21) away from the second reversing valve (9); The second measuring tube (22) is provided with a primary filter module (23), a multi-stage diluent module (24), a third temperature sensor module (25), a PN measuring module (26) and a second vacuum pump (28) in sequence from the end closest to the second collecting tube (21) to the end furthest from the second collecting tube (21).

5. The testing equipment for pollutants from heavy vehicles and non-road machinery according to claim 4, characterized in that, The NOx measurement module (15) is connected to a first wireless Bluetooth module (16), which is used to transmit the NOx concentration measured by the NOx measurement module (15) to the vehicle OBD system (31), the wireless printer (32) and the environmental protection platform (33). The PN measurement module (26) is connected to a second wireless Bluetooth module (27), which is used to transmit the PN concentration measured by the PN measurement module (26) to the vehicle OBD system (31), the wireless printer (32), and the environmental protection platform (33).

6. The testing equipment for pollutants from heavy vehicles and non-road machinery according to claim 1, characterized in that, Also includes: Thermal insulation components; The thermal insulation component includes at least: The first insulation layer (8) is disposed on the outer wall of the first connecting pipe (6); The second insulation layer (19) is disposed on the outer wall of the second connecting pipe (18); The third insulation layer (11) is disposed on the outer wall of the second collection tube (21).

7. The testing equipment for pollutants from heavy vehicles and non-road machinery according to claim 1, characterized in that, Also includes: The power module (30) is electrically connected to the sampling unit, the heating unit, and the control unit (29) and is used to supply power to the corresponding devices.

8. The testing equipment for pollutants from heavy vehicles and non-road machinery according to claim 1, characterized in that, The length of the second connecting pipe (18) is at least 2 meters longer than the length of the first connecting pipe (6).

9. A method for testing pollutants from heavy-duty vehicles and non-road machinery, implemented based on a testing device for pollutants from heavy-duty vehicles and non-road machinery as described in any one of claims 1-8, characterized in that, The testing method includes the following steps: Connect the first acquisition tube (2) to the engine exhaust pipe (1), start the test equipment, and adjust the test equipment to the first state; the first state refers to the state in which the first acquisition tube (2) is connected to the first connecting tube (6) and disconnected from the second connecting tube (18), while the first connecting tube (6) is connected to the second acquisition tube (21) and the second connecting tube (18) is disconnected from the second acquisition tube (21); When collecting exhaust gas in the engine exhaust pipe (1), the exhaust flow detected by the flow detection module (3) and the first exhaust temperature detected by the first temperature sensor module (4) are obtained. When the exhaust flow rate is greater than or equal to the minimum flow rate and the first exhaust temperature is less than the minimum temperature, the rotation angle of the first reversing valve (5) and the second reversing valve (9) is adjusted until the test equipment is in the second state; the second state refers to the state in which the first collection pipe (2) is connected to the second connecting pipe (18) and disconnected from the first connecting pipe (6), and at the same time the second connecting pipe (18) is connected to the second collection pipe (21) and the first connecting pipe (6) is disconnected from the second collection pipe (21); when the exhaust flow rate is less than the minimum flow rate or the first exhaust temperature is greater than or equal to the minimum temperature, the rotation angle of the first reversing valve (5) and the second reversing valve (9) is not adjusted, and the test equipment is kept in the first state; Obtain the second exhaust temperature detected by the second temperature sensor module (14) or the third exhaust temperature detected by the third temperature sensor module (25); Based on the connection and disconnection between the first acquisition tube (2) and the first connecting tube (6) and the second connecting tube (18), when it is determined that the second exhaust temperature is less than the minimum temperature limit, or when it is determined that the third exhaust temperature is less than the minimum temperature limit, the heating unit is controlled to heat the corresponding pipeline. When it is determined that the second exhaust temperature is greater than or equal to the minimum temperature limit and the third exhaust temperature is greater than or equal to the minimum temperature limit, the PN concentration is measured using the PN measurement unit, and the NOx concentration is measured using the NOx measurement unit.

10. A method for testing pollutants from heavy-duty vehicles and non-road machinery according to claim 9, characterized in that, After measuring the NOx concentration using the NOx measurement unit, the following steps are also included: The PN concentration and the NOx concentration are uploaded to the vehicle OBD system (31), the wireless printer (32), and the environmental protection platform (33).

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