Motor vehicle exhaust monitoring system

Abstract

The present invention discloses a motor vehicle exhaust monitoring system, which belongs to the field of monitoring technology, and includes a sampling head assembly, a collection monitoring assembly and a micro air pump. The collection monitoring assembly includes a first six-way, an adsorption assembly, an absorption bottle, an integrated detector, a box-type sampling assembly and a second six-way. A one-way valve is provided between the adsorption assembly, the absorption bottle, the integrated detector and the box-type sampling assembly and the first six-way. A flow controller is provided between the adsorption assembly, the absorption bottle, the integrated detector and the box-type sampling assembly and the second six-way. The first pipeline is connected to the first six-way, the second pipeline is connected to the second six-way, the first pipeline is provided with a dilution assembly, and a heat preservation area is provided outside the pipeline between the sampling head assembly and the one-way valve, and a refrigeration area is provided outside the adsorption assembly and the absorption bottle. The present invention can realize rapid monitoring of exhaust gas, improve the monitoring range of exhaust gas components, and realize detailed analysis of each component of exhaust gas.

Description

Technical Field

[0001] The invention belongs to the field of monitoring technology, and in particular relates to a motor vehicle exhaust monitoring system. Background Art

[0002] Motor vehicle exhaust pollution refers to the pollution to the atmosphere caused by exhaust gas emitted when the fuel of motor vehicles cannot be completely burned. The main pollutants are carbon monoxide, carbon dioxide, nitrogen oxides, volatile organic compounds (VOCs) and particulate matter (PM). For the sake of human survival environment, preventing and controlling automobile pollution has become a problem that must be solved.

[0003] Monitoring the types, concentrations and emission trends of pollutants emitted by motor vehicle exhaust helps to understand the status of environmental pollution and provides an important basis for formulating environmental protection policies, planning environmental protection measures and evaluating environmental protection effects. In addition, by analyzing monitoring data, high-emission vehicles and areas with excessive emissions can be found, so that targeted emission reduction measures can be taken, such as strengthening vehicle management, optimizing traffic structure, and promoting clean energy, to reduce the impact of exhaust emissions on the environment.

[0004] Previously, the mainstream measures to control vehicle exhaust emissions were annual vehicle exhaust inspections and daily road inspections and patrol inspections. Traditional inspection methods have problems such as difficulty in conducting road inspections, low inspection efficiency, and greater pollution caused by vehicle idling during inspections.

[0005] At present, the current motor vehicle exhaust data is monitored through particulate matter capture and the joint action of multiple sensors; or spectral absorption technology is used. At the moment when the vehicle passes normally, the remote sensing system sends out a detection light that passes through the air mass and then returns to the detection unit through the right-angle displacement reflection unit. The system then calculates and completes various tests on the motor vehicle exhaust.

[0006] The above technical means can realize the rapid monitoring of exhaust gas, but the monitoring types are not comprehensive enough, the exhaust gas cannot be sampled online, and the exhaust gas components cannot be analyzed in detail online; in addition, the host of the multi-sensor online monitoring is some distance away from the exhaust outlet, and the exhaust gas is transported to the sensor through a transmission pipe, and some targets are lost or changed during the transmission; and in the spectral detection technology, not only are the detection components relatively small, but the accuracy is not high enough. In summary, the monitoring of the components of motor vehicle exhaust is not enough, and the monitoring accuracy of some components is also insufficient. Summary of the invention

[0007] The purpose of the present invention is to provide a motor vehicle exhaust monitoring system to solve the problems existing in the background technology.

[0008] The objective of the present invention is achieved through the following technical solutions:

[0009] A motor vehicle exhaust monitoring system comprises a sampling head assembly, a collection monitoring assembly and a micro air pump, wherein one end of the sampling head assembly extends into an exhaust pipe of the motor vehicle, the other end of the sampling head assembly is connected to the collection monitoring assembly located outside the exhaust pipe of the motor vehicle through a first pipeline, and the other end of the collection monitoring assembly is connected to the micro air pump through a second pipeline;

[0010] The collection and monitoring component includes a first six-way, an adsorption component, an absorption bottle, an integrated detector, a box-type sampling component and a second six-way, the adsorption component, the absorption bottle, the integrated detector and the box-type sampling component are all located between the first six-way and the second six-way, the adsorption component, the absorption bottle, the integrated detector and the box-type sampling component are respectively connected to the first six-way and the second six-way through pipelines, a one-way valve is provided between the adsorption component, the absorption bottle, the integrated detector and the box-type sampling component and the first six-way, and a flow controller is provided between the adsorption component, the absorption bottle, the integrated detector and the box-type sampling component and the second six-way;

[0011] The first pipeline is connected to the first six-way pipe, and the second pipeline is connected to the second six-way pipe;

[0012] The first pipeline is provided with a dilution component, and a heat preservation area is provided outside the pipeline between the sampling head component and the one-way valve;

[0013] A refrigeration zone is arranged outside the adsorption assembly and the absorption bottle.

[0014] Furthermore, the sampling head assembly includes a sampling head body, a pressure sensor, a thermocouple and a telescopic claw, the sampling surface of the sampling head body is parallel to the airflow direction, and the telescopic claw is located near the outlet side of the exhaust pipe of the motor vehicle.

[0015] Furthermore, the dilution assembly includes a dilution gas bottle and a first electronic mass flow controller, one end of the first electronic mass flow controller is connected to the dilution gas bottle, and the other end of the first electronic mass flow controller is connected to the first pipeline through a tee.

[0016] Furthermore, the adsorption assembly includes a first multi-position selector valve, an enrichment tube, an adsorption tube and a second multi-position selector valve in sequence according to the gas flow direction, one end of each of the enrichment tubes is respectively connected to the first multi-position selector valve, each of the adsorption tubes is correspondingly connected to one of the enrichment tubes, and the other ends of the multiple adsorption tubes are respectively connected to the second selector valve.

[0017] Furthermore, a substitute standard gas bottle and a second electronic mass flow controller are provided between the first six-way valve and the adsorption assembly, one end of the second electronic mass flow controller is connected to the substitute standard gas bottle, and the other end of the second electronic mass flow controller is connected to the air inlet pipeline of the adsorption assembly through a three-way valve.

[0018] Furthermore, at least two absorption bottles are arranged in series, and absorption liquid is provided in the absorption bottles.

[0019] Furthermore, the integrated detector comprises a base, a flow channel, a microprobe and a needle valve, the flow channel is embedded in the base, a plurality of microprobes are connected to the flow channel, and the needle valve is located between the microprobe and the flow channel.

[0020] Furthermore, the box-type sampling assembly includes a sampling air inlet pipe, a sampling air outlet pipe, a vacuum box and a sampling air bag, the sampling air bag is located in the vacuum box, one end of the sampling air inlet pipe is connected to the first six-way pipe, the other end of the sampling air inlet pipe extends into the vacuum box and is connected to the sampling air bag, one end of the sampling air outlet pipe is connected to the vacuum box, and the other end of the sampling air outlet pipe is connected to the second six-way pipe.

[0021] Furthermore, the heat preservation zone is made of heat insulation material, and the heat insulation material is sleeved outside the pipeline between the sampling head assembly and the one-way valve.

[0022] Furthermore, the refrigeration zone adopts an insert made of aluminum alloy or copper, and the insert is coated on the outside of the enrichment tube, the adsorption tube and the absorption bottle.

[0023] The beneficial effects of the present invention are:

[0024] 1) The acquisition monitoring component can realize rapid monitoring or sampling monitoring of exhaust gas, improve the monitoring range of exhaust gas components, and realize detailed analysis of each component of exhaust gas.

[0025] 2) It is convenient to switch between different adsorption tubes and enrichment tubes, collect exhaust components in a targeted manner, and examine the relationship between the components and vehicle speed, so as to more effectively manage and control motor vehicle exhaust emissions.

[0026] 3) A heat preservation area is set outside the pipeline between the box-type sampling assembly and the one-way valve to reduce the heat loss of exhaust gas through insulation materials to prevent temperature changes from affecting the accuracy of exhaust gas detection.

[0027] 4) A refrigeration zone is provided outside the adsorption component and the absorption bottle to ensure the efficiency of adsorption or absorption and improve the accuracy and measurement concentration range.

[0028] 5) Dilute the sample by diluting the component to avoid the exhaust gas concentration being too high and exceeding the measurement range, and reduce the adverse effects of high-concentration samples on the components such as residues.

[0029] 6) The monitoring system can analyze more than 100 indicators: enrichment tubes and adsorption tubes can collect weakly polar, non-polar substances with relatively stable physical properties, with a boiling point range from -50°C to 300°C, including benzene series, alkanes, olefins, esters, etc.; absorption liquids can collect substances that are difficult to analyze with enrichment tubes and adsorption tubes, such as ammonia and formaldehyde; air bags can collect total amount indicators, such as non-methane total hydrocarbons, etc.; integrated sensors can measure higher concentrations of pollutants such as carbon dioxide, sulfur dioxide, nitrogen oxides, and carbon monoxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a motor vehicle exhaust monitoring system according to the present invention;

[0031] Figure 2 It is a schematic diagram of the sampling head assembly in the present invention in a retracted state;

[0032] Figure 3 It is a schematic diagram of the sampling head assembly in the present invention in an open state;

[0033] Figure 4 A schematic diagram of the motor vehicle exhaust monitoring system of the present invention starting to collect data;

[0034] Figure 5 A schematic diagram of switching adsorption tubes during the collection process of the present invention;

[0035] Figure 6 This is a schematic diagram of the working of the dilution component during the collection process of the present invention;

[0036] Figure 7 A schematic diagram of adding substitutes during the collection process of the present invention;

[0037] Figure 8 A schematic diagram of switching adsorption tubes to add substitutes during the collection process of the present invention;

[0038] In the figure, the area surrounded by the single-dot chain line represents the heat preservation area, the area surrounded by the double-dot chain line represents the cooling area, and the dotted line represents the gas flow path;

[0039] In the figure, 1-exhaust pipe, 2-sampling head assembly, 21-sampling head body, 22-pressure sensor, 23-thermocouple, 24-telescopic claw, 3-adsorption assembly, 31-first multi-position selection valve, 32-enrichment tube, 33-adsorption tube, 34-second multi-position selection valve, 35-second electronic mass flow controller, 36-substitute standard gas bottle, 4-absorption bottle, 5-integrated detector, 51-base, 52-flow channel, 53-micro probe, 54-needle valve, 6-box sampling assembly, 61-vacuum box, 62-sampling gas bag, 7-micro vacuum pump, 8-dilution assembly, 81-first electronic mass flow controller, 82-dilution gas bottle, 9-first six-way, 10-second six-way, 11-first pipeline, 12-second pipeline, 13-check valve, 14-flow controller, 15-insulation area, 16-refrigeration area. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] like Figure 1 The present invention provides a motor vehicle exhaust monitoring system, comprising a sampling head assembly 2, a collection monitoring assembly and a micro air pump 7, wherein one end of the sampling head assembly 2 extends into the motor vehicle exhaust pipe 1, and the other end of the sampling head assembly 2 is connected to the collection monitoring assembly located outside the motor vehicle exhaust pipe 1 through a first pipeline 11, and the other end of the collection monitoring assembly is connected to the micro air pump 7 through a second pipeline 12;

[0043] The collection and monitoring component includes a first six-way 9, an adsorption component 3, an absorption bottle 4, an integrated detector 5, a box-type sampling component 6 and a second six-way 10. The adsorption component 3, the absorption bottle 4, the integrated detector 5 and the box-type sampling component 6 are all located between the first six-way 9 and the second six-way 10. The adsorption component 3, the absorption bottle 4, the integrated detector 5 and the box-type sampling component 6 are connected to the first six-way 9 and the second six-way 10 through pipelines, respectively. A one-way valve 13 is provided between the adsorption component 3, the absorption bottle 4, the integrated detector 5 and the box-type sampling component 6 and the first six-way 9, and a flow controller 14 is provided between the adsorption component 3, the absorption bottle 4, the integrated detector 5 and the box-type sampling component 6 and the second six-way 10;

[0044] The first pipeline 11 is connected to the first six-way valve 9, and the second pipeline 12 is connected to the second six-way valve 10;

[0045] The first pipeline 11 is provided with a dilution component 8, and a heat preservation area 15 is provided outside the pipeline between the sampling head component 2 and the one-way valve 13;

[0046] The adsorption assembly 3 and the absorption bottle 4 are provided with a refrigeration area 16 outside.

[0047] Through the above technical scheme, the sampling head assembly 2 is extended into the exhaust pipe 1 of the motor vehicle, and the exhaust gas of the motor vehicle is extracted by the micro vacuum pump 7. At this time, the exhaust gas of the motor vehicle enters the collection and monitoring assembly through the sampling head assembly 2, wherein the semi-volatile organic matter and volatile organic matter in part of the exhaust gas are enriched by the adsorption assembly 3; the ammonia, formaldehyde, etc. in the exhaust gas are absorbed by the absorption bottle 4; the components and contents of oxygen, water, nitrogen oxides, sulfur dioxide, carbon monoxide, and the total amount of VOCs in the exhaust gas are detected by the integrated detector 5; the full-component exhaust gas is collected by the box-type sampling assembly 6 for the determination of non-methane total hydrocarbons, etc.

[0048] The acquisition and monitoring components of this solution can realize rapid monitoring of exhaust gas, while greatly improving the monitoring range of exhaust gas components and realizing detailed analysis of each exhaust gas component.

[0049] The specific working principle is as follows Figure 2-Figure 5 As shown, Figure 2 As shown, the sampling head assembly 2 is in a retracted state at this time. The sampling head assembly 2 of this solution includes a sampling head body 21, a pressure sensor 22, a thermocouple 23 and a telescopic claw 24, wherein the telescopic claw 24 includes a hollow metal tube, a claw and a spring. In the retracted state, the claw and the spring are in the hollow metal tube. It can be known that the telescopic claw 24 can adopt an electric control structure to realize electric telescopic. The electric telescopic claw 24 is a conventional technical means and will not be described in detail.

[0050] like Figure 3 As shown, at this time, the claws and the spring extend out of the hollow metal tube. Under the action of the spring, the claws open and abut against the inner wall of the exhaust pipe 1 to complete the fixation. At least three claws abut against the exhaust pipe 1 to improve the stability of the sampling head assembly 2.

[0051] like Figure 4 As shown, after the sampling head assembly 2 is extended and fixed, the sampling surface of the sampling head body 21 is parallel to the airflow direction, the sampling surface is rectangular or elliptical, the recommended specification is 20mm×5mm, and the filter membrane is made of quartz. After the micro vacuum pump 7 is started, the exhaust gas enters the first pipeline 11 through the sampling head body 21.

[0052] At this time, part of the exhaust gas passes through the pressure sensor 22 and the thermocouple 23. The thermocouple 23 records the temperature of the exhaust gas in real time, and the pressure sensor 22 reads the pressure value of the exhaust gas in real time. The pressure sensor 22 is made of metal high-temperature resistant material. The sensing surface of the pressure sensor 22 faces the airflow direction. The recommended outer diameter of the sensing surface is 5mm. The pressure sensor 22 calculates the flow rate of the exhaust pipe 1 according to the pressure, pressure area, temperature, etc. and records it in real time.

[0053] Continue as Figure 4 As shown, the tail gas passes through the first pipeline 11 and the first six-way 9 and enters the adsorption component 3, the absorption bottle 4, the integrated detector 5 and the box-type sampling component 6 respectively. At the same time, since a one-way valve 13 is provided between the adsorption component 3, the absorption bottle 4, the integrated detector 5 and the box-type sampling component 6 and the first six-way 9, the tail gas backflow can be effectively avoided to affect the detection; at the same time, a flow controller 14 is provided between the adsorption component 3, the absorption bottle 4, the integrated detector 5 and the box-type sampling component 6 and the second six-way 10, and the flow controller 14 can be used to control the amount of tail gas required in each flow path, so as to determine the sampling volume and ensure the effect of collection and monitoring. The front end of the flow controller 14 is connected in series with a purification material or a filter to protect the core component of the flow controller 14. Preferably, the collection flow rate in the adsorption component 3 is generally 50mL / min; the absorption bottle is generally 0.3L / min; the sampling air bag is generally 0.1L / min.

[0054] When the tail gas enters the adsorption assembly 3, it is in a low temperature state through the refrigeration zone, and the temperature is generally 2~5°C. The tail gas enters the designated enrichment pipe 32 through the first multi-position selector valve 31 in turn, and the semi-volatile organic compounds (SVOC) in the tail gas are enriched through the enrichment pipe 32. At the same time, the enrichment pipe 32 is also used to condense the gaseous water in the tail gas. The enrichment pipe 32 is made of inert stainless steel or borosilicate glass. Preferably, the size of the enrichment pipe 32 is 10mm in outer diameter, 6~8mm in inner diameter, 15cm in length, and 3~4cm inlet end is left empty. At the same time, the enrichment pipe 32 is filled with 40~60 mesh borosilicate glass balls or quartz sand, and the two ends are fixed by deactivated glass fiber wool or metal screen. When the tail gas enters the corresponding adsorption pipe 33 through the enrichment pipe 32, the volatile organic compounds (VOCs) in the tail gas are enriched through the adsorption pipe 33. The adsorption pipe 33 is made of inert stainless steel or borosilicate glass. Preferably, the adsorption tube 33 has an outer diameter of 6 mm, an inner diameter of 4 mm, and a length of 10 cm. It is filled with a variety of adsorbents, all of which are 60-80 mesh. From the inlet end to the outlet end, the adsorption capacity of the adsorbent increases from weak to strong. Preferably, the adsorbent is graphitized carbon black, carbon molecular sieve, etc.

[0055] When the tail gas enters the absorption bottle 4, the absorption bottle 4 is filled with absorption liquid, specifically various aqueous solutions. The absorption liquid in each bottle of absorption liquid can be different. Ammonia, formaldehyde, etc. in the tail gas are absorbed through the absorption bottle 4. For example, acid solution is used to absorb ammonia, and pure water is used to absorb formaldehyde.

[0056] When the exhaust gas enters the integrated detector 5, it enters the flow channel 52 in the base 51, and the exhaust gas components are analyzed and recorded by the microprobe 53 in the flow channel 52. At the same time, the needle valve 54 between the flow channel 52 and the microprobe 53 accurately controls the exhaust gas flow rate in the flow channel 52, so that the flow rate is within the most accurate detection range. The base 51 is made of inert materials, such as polyetheretherketone or polyvinylidene fluoride materials, to reduce the impact on the target object. Several types of substances are quickly monitored by the microprobe 53. The detection principle of the microprobe 53 can adopt constant potential electrolysis, ultraviolet, laser, photoionization, resistance and capacitance, etc. The substances monitored by the microprobe 53 include at least oxygen, water, nitrogen oxides, sulfur dioxide, carbon dioxide, carbon monoxide, and the total amount of VOCs.

[0057] When the exhaust gas enters the box-type sampling assembly 6, the box-type sampling assembly 6 includes a sampling air inlet pipe, a sampling air outlet pipe, a vacuum box 61 and a sampling air bag 62. The sampling air bag 62 is located in the vacuum box 61. One end of the sampling air inlet pipe is connected to the first six-way pipe 9, and the other end of the sampling air inlet pipe extends into the vacuum box 61 and is connected to the sampling air bag 62. One end of the sampling air outlet pipe is connected to the vacuum box 61, and the other end of the sampling air outlet pipe is connected to the second six-way pipe 10.

[0058] The extraction flow rate is controlled by the corresponding flow controller 14, so that a pressure difference is generated between the vacuum box 61 and the sampling air bag 62, and the sampling air bag 62 extracts and collects the tail gas through the pressure difference. A transparent observation window is provided outside the vacuum box 61 to facilitate observation of the extraction of the internal sampling air bag 62. The film of the sampling air bag 62 is made of polyvinyl fluoride or polyvinyl alcohol composite material to reduce the adsorption of some substances.

[0059] Through the collection and monitoring components, multiple means can be used to collect and detect exhaust gas at the same time, thereby improving the detection accuracy of exhaust gas components and improving the detection effect.

[0060] like Figure 5As shown, the adsorption capacity of the adsorption tube 33 is limited. By switching the first multi-position selector valve 31 and the second multi-position selector valve 34, different enrichment tubes 32 and adsorption tubes 33 can be selected. Specifically, in two cases, it is necessary to switch the sampling adsorption tube 33: 1. If it is necessary to examine the organic matter content emitted by the vehicle under different driving conditions, it is necessary to replace different adsorption tubes 33 according to the driving state of the vehicle; 2. According to the real-time monitoring of the total amount of volatile organic compounds (VOCs), if it exceeds 500μmol / mol, the adsorption tube 33 needs to be replaced. By comparing the relationship between the components in different adsorption tubes 33 (including highly toxic components and components that have a great impact on ozone pollution) and exhaust emissions at different vehicle speeds, motor vehicle exhaust emissions can be more effectively managed and controlled.

[0061] At the same time, it can be known that, due to the limited adsorption capacity of the adsorption tube 33, when the total amount of monitored volatile organic compounds (VOCs) exceeds 500 μmol / mol, a dilution method can be used for collection. The specific dilution method is shown in Example 2.

[0062] Furthermore, an insulation zone 15 is provided outside the pipeline between the sampling head assembly 2 and the one-way valve 13. The insulation zone 15 is made of insulation material. The insulation material is sleeved outside the pipeline between the sampling head assembly 2 and the one-way valve 13. The insulation material reduces the heat loss of the exhaust gas and prevents temperature changes from affecting the accuracy of exhaust gas detection.

[0063] Furthermore, a refrigeration zone 16 is provided outside the adsorption assembly 3 and the absorption bottle 4. The refrigeration zone 16 adopts semiconductor refrigeration. The refrigeration zone 16 adopts an insert made of aluminum alloy or copper, and the insert is coated on the outside of the enrichment tube 32, the adsorption tube 33 and the absorption bottle 4. The refrigeration zone 16 ensures the efficiency of adsorption or absorption, and improves the accuracy and the measurement concentration range.

[0064] At the same time, it can be known that this solution collects and analyzes the entire amount of exhaust gas, and is not limited to the collection and analysis of one or several components of the exhaust gas. The monitoring system can analyze more than 100 indicators: enrichment tubes and adsorption tubes can collect weakly polar or non-polar substances with relatively stable physical properties, with a boiling point range from -50°C to 300°C, including benzene series, alkanes, olefins, esters, etc.; absorption liquids can collect substances that are difficult to analyze with enrichment tubes and adsorption tubes, such as ammonia and formaldehyde; sampling gas bags can collect total amount indicators, such as non-methane total hydrocarbons, etc.; integrated sensors can measure higher concentrations of pollutants such as carbon dioxide, sulfur dioxide, nitrogen oxides, and carbon monoxide.

[0065] Example 2

[0066] Based on Example 1, refer to Figure 6The first pipeline 11 is provided with a dilution component 8, and the dilution component 8 includes a dilution gas bottle 82 and a first electronic mass flow controller 81, one end of the first electronic mass flow controller 81 is connected to the dilution gas bottle 82, and the other end of the first electronic mass flow controller 81 is connected to the first pipeline 11 through a tee.

[0067] Through the above technical solution, when the tail gas concentration is too high and may exceed the upper limit of the determination, it may have an adverse effect on the collection and monitoring components. At this time, the sample is diluted by nitrogen. The dilution gas bottle 82 has a capacity of 1~2L and a full pressure of about 8MPa, and is filled with high-purity nitrogen. Nitrogen is introduced through the first electronic mass flow controller 81 at a set flow rate u / N. The total flow rate controlled by each flow controller 14 is u / T, and the dilution multiple is (u / T) / ((u / T)-(u / N)).

[0068] It is known that the diluent gas cylinder 82 may also contain diluent gas such as zero-grade air.

[0069] Example 3

[0070] Based on Example 1, refer to Figure 7-Figure 8 A substitute standard gas bottle 36 and a second electronic mass flow controller 35 are also provided between the first six-way valve 9 and the adsorption assembly 3. One end of the second electronic mass flow controller 35 is connected to the substitute standard gas bottle 36, and the other end of the second electronic mass flow controller 35 is connected to the air inlet pipeline of the adsorption assembly 3 through a three-way valve.

[0071] like Figure 7 As shown, the addition of substitute gas facilitates the measurement of exhaust gas, ensuring the accuracy and reliability of exhaust gas detection. According to the volume of exhaust gas entering the adsorption assembly 3, the volume of the added substitute gas is adjusted by the second electronic mass flow controller 35, and the final volume of the sample gas collected by the adsorption tube 33 is the integral volume of the corresponding flow controller 14 minus the integral volume of the second electronic mass flow controller 35.

[0072] like Figure 8 As shown, the adsorption capacity of the adsorption tube 33 is limited. By switching the first multi-position selector valve 31 and the second multi-position selector valve 34, different adsorption tubes 33 can be selected. The specific switching of the adsorption tube 33 is the same as the switching of the first embodiment.

[0073] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A motor vehicle exhaust monitoring system, characterized in that: It comprises a sampling head assembly (2), a collection monitoring assembly and a micro air pump (7), wherein one end of the sampling head assembly (2) extends into the exhaust pipe (1) of a motor vehicle, the other end of the sampling head assembly (2) is connected to the collection monitoring assembly located outside the exhaust pipe (1) of the motor vehicle via a first pipeline (11), and the other end of the collection monitoring assembly is connected to the micro air pump (7) via a second pipeline (12); The collection and monitoring component comprises a first six-way pipe (9), an adsorption component (3), an absorption bottle (4), an integrated detector (5), a box-type sampling component (6) and a second six-way pipe (10); the adsorption component (3), the absorption bottle (4), the integrated detector (5) and the box-type sampling component (6) are all located between the first six-way pipe (9) and the second six-way pipe (10); the adsorption component (3), the absorption bottle (4), the integrated detector (5) and the box-type sampling component (6) are respectively connected to the first six-way pipe (9) and the second six-way pipe (10) through pipelines; a one-way valve (13) is provided between the adsorption component (3), the absorption bottle (4), the integrated detector (5) and the box-type sampling component (6) and the first six-way pipe (9); and a flow controller (14) is provided between the adsorption component (3), the absorption bottle (4), the integrated detector (5) and the box-type sampling component (6) and the second six-way pipe (10); The first pipeline (11) is connected to the first six-port (9), and the second pipeline (12) is connected to the second six-port (10); The first pipeline (11) is provided with a dilution component (8), and a heat preservation area (15) is provided outside the pipeline between the sampling head component (2) and the one-way valve (13); The adsorption assembly (3) and the absorption bottle (4) are provided with a refrigeration area (16) outside; The adsorption assembly (3) comprises, in order according to the gas flow direction, a first multi-position selector valve (31), an enrichment tube (32), an adsorption tube (33), and a second multi-position selector valve (34); one end of each of the enrichment tubes (32) is connected to the first multi-position selector valve (31), each of the adsorption tubes (33) is connected to a corresponding enrichment tube (32), and the other ends of each of the adsorption tubes (33) are connected to the second multi-position selector valve (34); The plurality of absorption bottles (4) are arranged in series, and the absorption bottles (4) are provided with absorption liquid; When the tail gas enters the adsorption component (3), it is in a low temperature state through the refrigeration zone (16), at which time the temperature is 2-5°C. The tail gas sequentially passes through the first multi-position selector valve (31) and enters the designated enrichment tube (32). The semi-volatile organic matter in the tail gas is enriched through the enrichment tube (32). At the same time, the enrichment tube (32) is also used to condense the gaseous water in the tail gas. The enrichment tube (32) is made of inert stainless steel or borosilicate glass. The dimensions of the enrichment tube (32) are 10 mm in outer diameter, 6-8 mm in inner diameter, and 15 cm in length. The inlet end is 3-4 cm empty. At the same time, the enrichment tube (32) is used to condense the gaseous water in the tail gas. The tube (32) is filled with 40-60 mesh borosilicate glass balls or quartz sand, and both ends are fixed by deactivated glass fiber wool or metal screen. When the tail gas passes through the enrichment tube (32) and enters the corresponding adsorption tube (33), the volatile organic matter in the tail gas is enriched by the adsorption tube (33). The adsorption tube (33) is made of inert stainless steel or borosilicate glass. The adsorption tube 33 has an outer diameter of 6 mm, an inner diameter of 4 mm, and a length of 10 cm. The adsorbent is filled therein, and the mesh is 60-80. From the inlet end to the outlet end, the adsorption capacity of the adsorbent increases from weak to strong. The adsorbent is made of graphitized carbon black or carbon molecular sieve. The integrated detector (5) comprises a base (51), a flow channel (52), a microprobe (53) and a needle valve (54); the flow channel (52) is embedded in the base (51); a plurality of microprobes (53) are connected to the flow channel (52); and the needle valve (54) is located between the microprobe (53) and the flow channel (52).

2. The motor vehicle exhaust monitoring system according to claim 1, characterized in that: The sampling head assembly (2) comprises a sampling head body (21), a pressure sensor (22), a thermocouple (23) and a telescopic claw (24); the sampling surface of the sampling head body (21) is parallel to the airflow direction; and the telescopic claw (24) is located close to the outlet side of the motor vehicle exhaust pipe (1).

3. The vehicle exhaust monitoring system according to claim 1, characterized in that: The dilution assembly (8) comprises a dilution gas bottle (82) and a first electronic mass flow controller (81), one end of the first electronic mass flow controller (81) is connected to the dilution gas bottle (82), and the other end of the first electronic mass flow controller (81) is connected to the first pipeline (11) via a tee.

4. The vehicle exhaust monitoring system according to claim 1, characterized in that: A substitute standard gas bottle (36) and a second electronic mass flow controller (35) are also provided between the first six-way valve (9) and the adsorption assembly (3); one end of the second electronic mass flow controller (35) is connected to the substitute standard gas bottle (36), and the other end of the second electronic mass flow controller (35) is connected to the air inlet pipeline of the adsorption assembly (3) via a three-way valve.

5. The vehicle exhaust monitoring system according to claim 1, characterized in that: The box-type sampling assembly (6) comprises a sampling air inlet pipe, a sampling air outlet pipe, a vacuum box (61) and a sampling air bag (62); the sampling air bag (62) is located in the vacuum box (61); one end of the sampling air inlet pipe is connected to the first six-way pipe (9); the other end of the sampling air inlet pipe extends into the vacuum box (61) and is connected to the sampling air bag (62); one end of the sampling air outlet pipe is connected to the vacuum box (61); and the other end of the sampling air outlet pipe is connected to the second six-way pipe (10).

6. The vehicle exhaust monitoring system according to claim 1, characterized in that: The heat preservation area (15) is made of heat insulation material, and the heat insulation material is sleeved outside the pipeline between the sampling head assembly (2) and the one-way valve (13).

7. The vehicle exhaust monitoring system according to claim 1, characterized in that: The refrigeration zone (16) adopts semiconductor refrigeration, and the refrigeration zone (16) adopts an embedded part made of aluminum alloy or copper, and the embedded part is coated on the outside of the enrichment tube (32), the adsorption tube (33) and the absorption bottle (4).

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