Passenger car engine exhaust aftertreatment system, aftertreatment control method and passenger car engine system

Abstract

The invention provides a passenger car engine exhaust aftertreatment system, a control method and a passenger car engine system. The passenger car engine exhaust aftertreatment system comprises a main exhaust pipeline, at least one branch exhaust pipeline, a tail gas purification coupling unit, a nitrogen and oxygen treatment unit, an on-off assembly and a nitrogen and oxygen sensor. The tail gas purification coupling unit is located on the main exhaust pipeline. The nitrogen-oxygen treatment unit is positioned on the branch exhaust pipeline; the on-off assembly is electrically connected with the engine controller and connected with the main exhaust gas inlet, the branch exhaust gas inlet and the engine exhaust port so as to control at least one of the main exhaust gas inlet and the branch exhaust gas inlet to communicate with the engine exhaust port, and the branch exhaust gas outlet is located between the tail gas purification coupling unit and the on-off assembly and communicates with a main exhaust pipeline. The nitrogen and oxygen sensor is electrically connected with the engine controller and located on the main exhaust pipeline. According to the invention, the fluctuation anti-interference capability of NOx pollutants can be improved, and the emission consistency and reliability of the NOx pollutants can be improved.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas treatment technology for passenger vehicle engines, and particularly to an exhaust gas aftertreatment system for passenger vehicle engines, an exhaust gas aftertreatment control method for passenger vehicle engines, and a passenger vehicle engine system. Background Technology

[0002] With increasingly stringent emission and fuel consumption regulations, major standards such as China VI b, Euro VII, the U.S. Environmental Protection Agency (EPA), and the California Air Resources Board (CARB) all impose stricter requirements on NOx emissions. x Strict limits have been imposed on concentration; Euro 7 explicitly requires Original Brand Manufacturers (OBMs) to report NO in real time. x Pollutants pose numerous challenges to the after-treatment of exhaust gases from passenger vehicle engines. Existing passenger vehicle exhaust after-treatment systems still contain NOx. x Uneven pollutant emissions, and regarding NO x The ability to resist fluctuations in pollutants needs improvement, making it difficult to guarantee that the engine system will maintain NO levels under different operating conditions. x Consistency and reliability of pollutant emissions, increasing NO x There is a risk of pollutant emissions exceeding standards. Summary of the Invention

[0003] This invention provides a passenger vehicle engine exhaust aftertreatment system, a passenger vehicle engine exhaust aftertreatment control method, and a passenger vehicle engine system, improving the performance of NO2 control. x The ability to resist fluctuations in pollutants ensures that the engine system maintains NO levels under different operating conditions. x Consistency and reliability of pollutant emissions.

[0004] The present invention provides an exhaust aftertreatment system for a passenger vehicle engine, comprising: a main exhaust pipe, at least one branch exhaust pipe, an exhaust gas purification coupling unit, a nitrogen oxide treatment unit, an on / off assembly, and a nitrogen oxide sensor.

[0005] The main exhaust pipe has a main exhaust inlet; at least one branch exhaust pipe has a branch exhaust inlet and a branch exhaust outlet; the exhaust gas purification coupling unit is located on the main exhaust pipe; the nitrogen oxide treatment unit is located on the branch exhaust pipe, and the nitrogen oxide treatment unit treats NO... x Storage and DeNO XThe switching assembly is electrically connected to the engine controller and to the main exhaust intake, branch exhaust intake, and engine exhaust port, respectively, to control at least one of the main exhaust intake and branch exhaust intake to connect to the engine exhaust port. The branch exhaust port is located between the exhaust gas purification coupling unit and the switching assembly and is connected to the main exhaust pipe. The nitrogen oxide sensor is electrically connected to the engine controller and is located on the main exhaust pipe to monitor the NO at the nitrogen oxide sensor in the main exhaust pipe in real time. x Pollutant concentration.

[0006] In one embodiment of the present invention, the exhaust gas purification coupling unit includes a three-way catalytic converter and a particulate filter, wherein the three-way catalytic converter is located upstream of the particulate filter.

[0007] In one embodiment of the present invention, the number of nitrogen oxide sensors is at least two, and they are located on the main exhaust pipes upstream and downstream of the exhaust gas purification coupling unit, respectively.

[0008] In one embodiment of the present invention, one of the two nitrogen and oxygen sensors is located upstream of the on / off assembly, and the other is located downstream of the exhaust gas purification coupling unit.

[0009] In one embodiment of the present invention, the on / off component is an electronically controlled valve, which includes an air inlet and at least two air outlets. The air inlet of the electronically controlled valve is used to connect to the engine exhaust port, one of the air outlets is connected to the main exhaust air inlet, and the other air outlet is connected to the branch exhaust air inlet. The electronically controlled valve is used to control at least one of the two air outlets to be connected to the air inlet.

[0010] In one embodiment of the present invention, there is one branch exhaust pipe, and the electronically controlled valve is an electronically controlled three-way valve. The electronically controlled three-way valve includes an air inlet, a first air outlet, and a second air outlet. The air inlet of the electronically controlled three-way valve is used to connect to the engine exhaust port, the first air outlet is connected to the main exhaust air inlet, and the second air outlet is connected to the branch exhaust air inlet. The electronically controlled three-way valve is used to control at least one of the first air outlet and the second air outlet to be connected to the air inlet.

[0011] In one embodiment of the present invention, the branch exhaust outlet is connected to the main exhaust pipe via a three-way connecting pipe.

[0012] In one embodiment of the present invention, the tee connector is a Y-type tee connector.

[0013] In one embodiment of the present invention, the system includes a temperature sensor electrically connected to the engine controller for real-time monitoring of the engine's exhaust temperature, wherein:

[0014] The temperature sensor is located upstream of the on / off component.

[0015] This invention also provides a method for controlling exhaust aftertreatment of passenger vehicle engines, used to control the aforementioned exhaust aftertreatment system for passenger vehicle engines. The system further includes a temperature sensor and two nitrogen oxide sensors. The temperature sensor is used to monitor the exhaust temperature of the engine in real time. One of the two nitrogen oxide sensors is located upstream of the on / off assembly, and the other is located downstream of the exhaust gas purification coupling unit. The control method includes:

[0016] Obtain the exhaust temperature of the main exhaust pipe collected by the temperature sensor;

[0017] Determine whether the exhaust temperature meets the preset conditions;

[0018] If so, the on / off control assembly connects both the main exhaust intake and the branch exhaust intake to the engine exhaust port;

[0019] If not, then obtain the NO data collected by the two nitrogen and oxygen sensors. x Pollutant concentrations and calculation of NO x Post-processing efficiency M;

[0020] According to NO x The preset threshold range of the aftertreatment efficiency M is selectively controlled by the on / off component to connect at least one of the main exhaust intake and the branch exhaust intake to the engine exhaust port.

[0021] In one embodiment of the present invention, determining whether the exhaust temperature meets a first preset condition specifically includes:

[0022] Determine if the exhaust temperature meets the preset temperature;

[0023] Determine whether the duration of exhaust temperature meets the preset time.

[0024] In one embodiment of the present invention, the preset temperature is less than 220°C.

[0025] In one embodiment of the present invention, the preset time is greater than or equal to 30 seconds.

[0026] In one embodiment of the present invention, if not, then the NO collected by the two nitrogen and oxygen sensors is obtained. x Pollutant concentrations and calculation of NO x Post-processing efficiency M specifically includes:

[0027] The NO2 sensor upstream of the exhaust gas purification coupling unit collects NO2 data. x The pollutant concentration is recorded as A;

[0028] The NO2 sensor downstream of the exhaust gas purification coupling unit collects NO2 data. x The pollutant concentration was recorded as B;

[0029] Calculate NO xPost-processing efficiency M = (AB) / A × 100%.

[0030] In one embodiment of the present invention, based on NO x Within a preset threshold range of the aftertreatment efficiency M, selectively controlling at least one of the main exhaust intake and the branch exhaust intake to connect to the engine exhaust port via an on / off component, specifically including:

[0031] If NO x When the after-treatment efficiency M is within the first preset threshold range, the on / off component controls both the main exhaust intake and the branch exhaust intake to be connected to the engine exhaust port.

[0032] If NO x When the after-treatment efficiency M falls within the second preset threshold range, the on / off component controls the connection between the branch intake and the engine exhaust port.

[0033] If NO x When the aftertreatment efficiency M falls within the third preset threshold range, the on / off component controls the connection between the main exhaust intake and the engine exhaust port.

[0034] In one embodiment of the present invention, the first preset threshold range is M less than or equal to 70%, the second preset threshold range is M greater than 70% and less than 90%, and the third preset threshold range is M greater than or equal to 92%.

[0035] The present invention also provides a passenger vehicle engine system, including an engine and the above-described passenger vehicle engine exhaust aftertreatment system.

[0036] The beneficial effects of this invention are:

[0037] The passenger vehicle engine exhaust aftertreatment system, passenger vehicle engine exhaust aftertreatment control method, and passenger vehicle engine system of the present invention, wherein the engine controller can be based on the NO collected by the nitrogen oxide sensor. x The pollutant concentration is selectively controlled under different operating conditions by switching on / off components to connect at least one of the main exhaust inlet and the branch exhaust inlet to the engine exhaust port. This allows the nitrogen oxide treatment unit on the branch exhaust pipe to share the pressure with the exhaust gas purification coupling unit on the main exhaust pipe, thereby improving the treatment of NO. x The ability to resist fluctuations in pollutants and improve NO x The efficiency of pollutant treatment is improved, costs are reduced, and the engine system can ensure NO emission levels under different operating conditions. x Consistency and reliability of pollutant emissions, meeting NO x Pollutant emission standards; and the branch exhaust outlet is located between the exhaust gas purification coupling unit and the on / off assembly and is connected to the main exhaust pipe, that is, the branch exhaust pipe and the main exhaust pipe are connected in parallel. Compared with the series connection, this can reduce the engine exhaust back pressure, maintain engine power, and simultaneously achieve NO xEfficient treatment of pollutants. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0039] In the attached diagram:

[0040] Figure 1 This is a schematic diagram of the principle structure of a passenger vehicle engine exhaust aftertreatment system according to an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the overall flow structure of a passenger vehicle engine exhaust aftertreatment control method according to an embodiment of the present invention;

[0042] Figure 3 Provided for an embodiment of the present invention Figure 2 A flowchart illustrating the sub-steps of step S2;

[0043] Figure 4 Provided for an embodiment of the present invention Figure 2 A flowchart illustrating the sub-steps of step S4 in the middle section;

[0044] Figure 5 Provided for an embodiment of the present invention Figure 2 A flowchart illustrating the sub-steps of step S5.

[0045] The attached figures are labeled as follows:

[0046] 100. Engine; 1. Main exhaust pipe; 2. Branch exhaust pipe; 3. Exhaust gas purification coupling unit; 31. Three-way catalytic converter; 32. Particulate filter; 4. Nitrogen oxide treatment unit; 5. On / off assembly; 51. Inlet; 52. First outlet; 53. Second outlet; 6. Temperature sensor; 7. Nitrogen oxide sensor; 8. T-connector. Detailed Implementation

[0047] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0048] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0049] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0050] The engine itself is sensitive to NO x For certain operating conditions, such as high EGR rates and low-temperature exhaust conditions, engine carbon and oxygen pollutants are controlled at relatively high levels, but NO... x Pollutant levels will be lower; under low EGR rate and high-temperature exhaust conditions, engine carbon and oxygen pollutants will be controlled at low levels, but NO... x Pollutant levels will be high; below 5°C in ambient temperature, EGR is often shut off due to the risk of condensation, and EGR can no longer be relied upon to adjust NO levels. x Pollutant concentration, NO x Uneven pollutant emissions make calibration complex and can easily increase NO levels. x Excessive pollutant emissions pose a danger. To address this problem, the present invention provides the following solution.

[0051] Please see Figure 1 The present invention provides an exhaust aftertreatment system for a passenger vehicle engine, which has an engine controller and an engine exhaust port, including: a main exhaust pipe 1, at least one branch exhaust pipe 2, an exhaust gas purification coupling unit 3, a nitrogen and oxygen treatment unit 4, an on / off assembly 5, and two nitrogen and oxygen sensors 7.

[0052] Please see Figure 1 The main exhaust pipe 1 has a main exhaust inlet; at least one branch exhaust pipe 2 has a branch exhaust inlet and a branch exhaust outlet; the exhaust gas purification coupling unit 3 is located on the main exhaust pipe 1; the exhaust gas purification coupling unit 3 is used to treat exhaust pollutants passing through the main exhaust pipe 1, and can adopt various structural forms readily conceived by those skilled in the art, such as an oxidation catalyst, a separately set three-way catalytic converter 31, etc.; however, in one embodiment of the present invention, the exhaust gas purification coupling unit 3 may include a three-way catalytic converter 31 and a particulate filter 32, with the three-way catalytic converter 31 located upstream of the particulate filter 32, thus utilizing the three-way catalytic converter 31 to preferentially treat carbon monoxide (CO), hydrocarbons (CH), and nitrogen oxides (NO) in the exhaust gas.x The three-way catalytic converter 31 can carry out efficient catalytic conversion and avoid particulate matter covering the active sites, thus reducing catalytic efficiency. At the same time, the three-way catalytic converter 31 can increase the exhaust temperature and optimize the airflow distribution, creating suitable working conditions for the downstream particulate filter 32, promoting efficient capture and passive regeneration of particulate matter, thereby significantly reducing particulate matter load, extending the service life of the particulate filter 32, and achieving a synergistic purification effect of gaseous pollutants and particulate pollutants.

[0053] Please see Figure 1 The nitrogen oxide treatment unit 4 is located on the branch exhaust pipe 2; the nitrogen oxide treatment unit 4 is used to treat exhaust pollutants passing through the branch exhaust pipe 2, and can also be called a nitrogen oxide precipitator. The working principle of the nitrogen oxide precipitator can include: the first stage NO x Storage (lean-burn condition), that is, occurring in oxygen-rich exhaust gas (λ>1), under the action of precious metal catalysts such as platinum (Pt), NO... X It reacts with Ba(CO3)2 to produce Ba(NO3)2, and NO... X Stored in Ba(CO3)2, NO is achieved. x The "capture"; Phase Two DeNO X The conversion (fuel-rich condition) means that after a period of time, when the Ba(NO3)2 storage reaches its limit, it needs to be converted through regeneration. Specifically, this can be achieved by creating an oxygen-deficient environment (i.e., λ < 1) through post-injection of fuel from the engine injectors. Incomplete combustion produces CO, and CO and Ba(NO3)2 are reduced to CO2 and N2, thus achieving NO conversion. x The "store first, reduce later" approach, compared to selective catalytic reduction (SCR) systems, allows nitrogen oxide scavengers to effectively remove NO under lean-burn conditions. X It efficiently enriches and stores NO, and releases and reduces it under fuel-rich conditions, that is, when the three-way catalytic converter 31 is in the low catalytic zone, it captures NO. x Pollutants share the pressure of the three-way catalytic converter 31, and when the three-way catalytic converter 31 is in the high catalytic zone, the captured NO is released. x Pollutants are reduced to CO2 and N2, thereby improving the overall system's ability to handle NO. x The ability to resist fluctuations in pollutants, achieving NO x The system efficiently treats pollutants without requiring additional urea storage and injection devices, resulting in a compact, cost-effective, and easy-to-maintain system. It is particularly suitable for the limited space, variable operating conditions, and frequent start-stop characteristics of urban roads in passenger vehicles, and can significantly reduce the cost of vehicle lightweighting and electrification while ensuring purification efficiency.

[0054] Please see Figure 1The on / off assembly 5 is electrically connected to the engine controller and to the main exhaust intake, branch exhaust intake, and engine exhaust port, respectively, to control at least one of the main exhaust intake and branch exhaust intake to be connected to the engine exhaust port. The branch exhaust port is located between the exhaust gas purification coupling unit 3 and the on / off assembly 5 and is connected to the main exhaust pipe 1. The nitrogen oxide sensor 7 is electrically connected to the engine controller and is located on the main exhaust pipe 1 to monitor the NO at the nitrogen oxide sensor 7 in the main exhaust pipe 1 in real time. x Pollutant concentration, so that the engine controller can use the NO collected by the nitrogen oxide sensor 7 to... x The pollutant concentration is selectively controlled by the on / off assembly 5 to connect at least one of the main exhaust intake port 51 and the branch exhaust intake port 51 to the engine exhaust port under different operating conditions. This allows the nitrogen oxide treatment unit on the branch exhaust pipe 2 to share the pressure of the three-way catalytic converter 31 on the main exhaust pipe 1, thereby improving the treatment of NO. x The ability to resist fluctuations in pollutants and improve NO x The efficiency of pollutant treatment is improved, costs are reduced, and the engine system can ensure NO emission levels under different operating conditions. x Consistency and reliability of pollutant emissions, meeting NO x It meets pollutant emission standards and can reduce engine exhaust back pressure, maintaining engine power at 100 kW while achieving NOx emission reduction. x Efficient treatment of pollutants.

[0055] The on / off component 5 can adopt various structural forms readily conceived by those skilled in the art, such as a pneumatic shut-off valve, a hydraulic gate valve, etc.; however, for ease of implementation, in one embodiment of the present invention, the on / off component 5 can be an electrically controlled valve, which includes an air inlet 51 and at least two air outlets. The air inlet 51 of the electrically controlled valve is used to connect to the engine exhaust port, one of the air outlets is connected to the main exhaust air inlet, and the other air outlet is connected to the branch exhaust air inlet. The electrically controlled valve is used to control at least one of the two air outlets to be connected to the air inlet 51. Compared with pneumatic shut-off valves and hydraulic gate valves, the electrically controlled valve does not require a pneumatic or hydraulic auxiliary system. When connected to the engine controller, it can achieve millisecond-level fast response and high-precision digital control, significantly reducing system complexity and maintenance costs. It is especially suitable for complex situations such as limited space and variable operating conditions in passenger vehicles.

[0056] Please see Figure 1In one embodiment of the present invention, the number of branch exhaust pipes 2 can be one, and the electronically controlled valve is an electronically controlled three-way valve. The electronically controlled three-way valve includes an inlet 51, a first outlet 52, and a second outlet 53. The inlet 51 of the electronically controlled three-way valve is used to connect to the engine exhaust port, the first outlet 52 is connected to the main exhaust inlet, and the second outlet 53 is connected to the branch exhaust inlet. The electronically controlled three-way valve is used to control at least one of the first outlet 52 and the second outlet 53 to be connected to the inlet 51. It is conceivable that in other embodiments, the number of branch exhaust pipes 2 can be flexibly set as needed, including but not limited to 1, 2, 3, 4, etc.

[0057] Please see Figure 1 To facilitate the connection of the branch exhaust port to the main exhaust pipe 1, in one embodiment of the present invention, the branch exhaust port can be connected to the main exhaust pipe 1 via a tee connector 8. In one embodiment of the present invention, the tee connector 8 can be a Y-type tee connector 8, which, compared with the traditional T-type tee, can significantly reduce the flow resistance and turbulence loss at the merging point, reduce eddy current generation and pressure drop, and at the same time has a more compact structure, making it easier to install the pipes and more suitable for the limited space in passenger vehicles.

[0058] Please see Figure 1 In one embodiment of the present invention, the number of nitrogen oxide sensors 7 can be at least two, and they are respectively located on the main exhaust pipe 1 upstream and downstream of the exhaust gas purification coupling unit 3. One of the two nitrogen oxide sensors 7 is located upstream of the on / off assembly 5, and the other is located downstream of the exhaust gas purification coupling unit 3, that is, downstream of the particulate filter 32. Compared with other arrangement positions, placing one nitrogen oxide sensor 7 upstream of the on / off assembly 5 can achieve the detection of NO in the original exhaust gas. x Real-time and accurate monitoring of pollutant concentrations yields better monitoring results. Placing another nitrogen oxide sensor 7 downstream of the particulate filter 32 allows for more accurate monitoring of NO in the exhaust gas after passing through the three-way catalytic converter 31 and the particulate filter 32. x Pollutant concentration, thus facilitating more accurate calculation of NO. x This improves post-processing efficiency, thereby ensuring the stable operation of the entire system.

[0059] Please see Figure 1 In one embodiment of the present invention, the system may include a temperature sensor 6, which is electrically connected to the engine controller for real-time monitoring of the exhaust temperature of the engine 100. The engine controller can then adjust the exhaust temperature based on the temperature collected by the temperature sensor and the NO2 collected by the two nitrogen oxide sensors. xThe pollutant concentration is selectively controlled by the on / off component to connect at least one of the main exhaust intake and the branch exhaust intake to the engine exhaust port under different operating conditions. Compared with a single nitrogen oxide sensor, this significantly improves the system's adaptability to complex operating conditions and control accuracy, avoids misjudgments caused by single-point data deviations, further optimizes the on / off timing, and enhances system redundancy and diagnostic capabilities.

[0060] Please see Figure 1 In one embodiment of the present invention, the temperature sensor 6 can be located upstream of the on / off component 5. Compared with other arrangement positions, arranging the temperature sensor 6 upstream of the on / off component 5 can realize real-time and accurate monitoring of the original exhaust temperature, resulting in better monitoring effect and thus ensuring stable operation of the entire system.

[0061] Please see Figures 2 to 5 The present invention also provides a control method for exhaust aftertreatment of passenger vehicle engines, used to control the aforementioned exhaust aftertreatment system for passenger vehicle engines. The exhaust aftertreatment system further includes a temperature sensor 6 and two nitrogen oxide sensors 7. The specific structure and arrangement of the temperature sensor 6 and the nitrogen oxide sensors 7 are the same as described above, and will not be repeated here. The control method includes:

[0062] Step S1: Obtain the exhaust temperature of the main exhaust pipe 1 collected by temperature sensor 6;

[0063] In this step, the engine controller acquires the exhaust temperature of the main exhaust pipe 1 collected by the temperature sensor 6; it is conceivable that in other embodiments, the vehicle control unit may also acquire the exhaust temperature of the main exhaust pipe 1 collected by the temperature sensor 6.

[0064] Step S2: Determine whether the exhaust temperature meets the preset conditions;

[0065] In this step, the engine controller determines whether the exhaust temperature meets the preset conditions; it is conceivable that in other embodiments, the vehicle's control unit may also determine whether the exhaust temperature meets the preset conditions.

[0066] To more accurately determine whether the exhaust temperature meets the preset conditions, please refer to [link / reference needed]. Figure 3 In one embodiment of the present invention, step S2 may specifically include:

[0067] Step S21: Determine whether the exhaust temperature meets the preset temperature;

[0068] In this step, the preset temperature can be flexibly set according to actual usage requirements, such as less than 200℃, less than 250℃, less than 300℃, etc.; however, since the three-way catalytic converter 31 and the particulate filter 32 are in the high-efficiency catalytic zone above about 220 degrees and in the low-efficiency catalytic zone below about 220 degrees, in one embodiment of the present invention, the preset temperature is preferably less than 220℃, so that the engine controller can identify whether the three-way catalytic converter 31 and the particulate filter 32 are currently in the high-efficiency catalytic zone or the low-efficiency catalytic zone by judging the exhaust temperature;

[0069] Step S22: Determine whether the duration of exhaust temperature meets the preset time.

[0070] In this step, the preset time can be flexibly set according to actual usage requirements, such as greater than or equal to 20S, greater than or equal to 35S, greater than or equal to 38S, etc. However, in one embodiment of the present invention, the preset time is preferably greater than or equal to 30S, so as to take into account the response delay of temperature sensor 6 and the stability of exhaust temperature, avoid misjudgment caused by exhaust pulsation or short-term heat load fluctuation, and ensure overall control accuracy. Compared with a longer threshold of 35S or 38S, the invalid waiting time can be reduced, and compared with a shorter threshold of 20S, the misjudgment can be significantly reduced.

[0071] Step S3: If so, the on / off component 5 controls both the main exhaust inlet 51 and the branch exhaust inlet 51 to be connected to the engine exhaust port.

[0072] In this step, when the exhaust temperature meets the preset condition, that is, the temperature monitored by temperature sensor 6 is less than 220℃ and the duration is greater than or equal to 30 seconds, it is determined that the three-way catalytic converter 31 and the particulate filter 32 are in the inefficient catalytic zone. The on / off component 5 directly controls the main exhaust intake and the branch exhaust intake to be connected to the engine exhaust port, so that the nitrogen oxide treatment unit 4 on the branch exhaust pipe 2 shares the pressure of the exhaust gas purification coupling unit 3 on the main exhaust pipe 1, thereby improving the NO of the entire system. x Pollutant treatment efficiency, meeting NO x Pollutant emission standards.

[0073] Step S4: If not, then obtain the NO data collected by the two nitrogen and oxygen sensors 7. x Pollutant concentrations and calculation of NO x Post-processing efficiency M;

[0074] In this step, if the exhaust temperature does not meet the preset condition, that is, the temperature monitored by temperature sensor 6 is greater than or equal to 220℃ and the duration is greater than or equal to 30 seconds, it is determined that the three-way catalytic converter 31 and the particulate filter 32 are in the high-efficiency catalytic zone, and it is necessary to continue to obtain NO collected by the two nitrogen oxide sensors 7. x Pollutant concentrations and calculation of NO x Post-processing efficiency M. For ease of calculation of NO.x For post-processing efficiency M, please refer to [link / reference]. Figure 4 In one embodiment of the present invention, step S4 may specifically include:

[0075] Step S41: Obtain NO from the nitrogen oxide sensor 7 upstream of the exhaust gas purification coupling unit 3. x The pollutant concentration is recorded as A;

[0076] To facilitate explanation of this step, for example, the NO2 sensor 7 upstream of the exhaust gas purification coupling unit 3 collects the NO2 data. x Pollutant concentration A is 100 ppm;

[0077] Step S42: Obtain NO from the nitrogen oxide sensor 7 downstream of the exhaust gas purification coupling unit 3. x The pollutant concentration was recorded as B;

[0078] To facilitate explanation of this step, for example, the NO2 sensor 7 downstream of the exhaust gas purification coupling unit 3 collects the NO2 data. x Pollutant concentration B is 20 ppm;

[0079] Step S43, Calculate NO x Post-processing efficiency M = (AB) / A × 100%.

[0080] To facilitate explanation of this step, for example, NO x Post-processing efficiency M = (100-20) / 100 × 100% = 80%.

[0081] Step S5, based on NO x The preset threshold range of the aftertreatment efficiency M is selectively controlled by the on / off component 5 to connect at least one of the main exhaust port and the branch exhaust port to the engine exhaust port.

[0082] In this step, the division of the preset threshold range can be flexibly set according to actual usage requirements, such as dividing it into two efficiency intervals, three efficiency intervals, or four efficiency intervals, to achieve matching of differentiated exhaust path control strategies. However, to improve the robustness and response accuracy of the control, please refer to [the relevant documentation / reference]. Figure 5 In one embodiment of the present invention, step S5 specifically includes:

[0083] Step S51, if NO x When the after-treatment efficiency M is within the first preset threshold range, the on / off component 5 controls both the main exhaust intake and the branch exhaust intake to be connected to the engine exhaust port.

[0084] In this step, if NO xIf the aftertreatment efficiency M is within the first preset threshold range, it indicates that the exhaust gas purification capacity of the three-way catalytic converter 31 and the particulate filter 32 is severely insufficient. At this time, the on / off component 5 needs to control the main exhaust intake and the branch exhaust intake to connect in parallel to the engine exhaust port, so as to realize the dual-pipeline coordinated exhaust to maximize the purification treatment area and balance NO. x Pollutant emissions;

[0085] Step S52, if NO x When the after-treatment efficiency M is within the second preset threshold range, the on / off component 5 controls the connection between the branch intake and the engine exhaust port.

[0086] In this step, if NO x When the aftertreatment efficiency M is within the second preset threshold range, it indicates that the exhaust gas purification efficiency of the three-way catalytic converter 31 and the particulate filter 32 is under partial load. At this time, the on / off component 5 needs to control the connection between the branch intake port and the engine exhaust port only, and use the bypass branch to achieve targeted enhanced treatment, share the pressure, and balance NO. x Pollutant emissions;

[0087] Step S53, if NO x When the after-treatment efficiency M is within the third preset threshold range, the on / off component 5 controls the connection between the main exhaust intake and the engine exhaust port.

[0088] In this step, if NO x The aftertreatment efficiency M is within the third preset threshold range, indicating that the exhaust gas purification of the three-way catalytic converter 31 and the particulate filter 32 is in a high-efficiency state. At this time, the on / off component 5 controls the main exhaust intake port to connect with the engine exhaust port, and the bypass branch is closed.

[0089] Step S5, by dividing the system into three efficiency zones, each corresponding to a different exhaust gas connection path, achieves a dynamic optimal balance between purification efficiency and system energy consumption. In the low-efficiency zone, the dual-pipeline parallel operation maximizes the catalytic contact area, quickly reversing the trend of emission degradation and preventing NO emissions under transient conditions. xExceeding the limit risk; in the medium efficiency range, the bypass branch can be activated to specifically enhance the purification depth in the low and medium load range and improve the conversion efficiency under key operating conditions; in the high efficiency range, switching to single main road operation significantly reduces system back pressure and catalytic heat loss, reduces unnecessary energy waste and catalyst high-temperature aging, thereby ensuring emission compliance under all operating conditions, effectively extending the service life of the coupling unit, and significantly reducing the frequent opening and closing load of the on / off component 5, thus improving the overall control robustness and fuel economy of the aftertreatment system. The first preset threshold range, the second preset threshold range, and the third preset threshold range can be flexibly set according to actual usage needs. In one embodiment of the present invention, the first preset threshold range can be M less than or equal to 70%, the second preset threshold range can be M greater than 70% and less than 90%, and the third preset threshold range can be M greater than or equal to 92%. The sum of the first preset threshold range, the second preset threshold range, and the third preset threshold range is 100%. Compared with other division intervals, the valve actuation frequency can be reduced by 30%-40%, the overall fuel consumption can be improved by 1.5%-2.3%, and the robustness of the system in dealing with catalyst performance degradation can be greatly improved, which is especially suitable for passenger cars.

[0090] The present invention also provides a passenger vehicle engine system, including an engine and the aforementioned passenger vehicle engine exhaust aftertreatment system. Since the structure of the passenger vehicle engine exhaust aftertreatment system is the same as described above, it will not be repeated here.

[0091] In summary, the passenger vehicle engine exhaust aftertreatment system, control method, and passenger vehicle engine system of the present invention innovatively add NO while minimizing the increase in exhaust back pressure. x Capture branch paths to balance the storage portion exceeding NO limits. x Pollutants, improve the system's ability to handle NO x The pollutant fluctuation resistance allows for achieving higher NO levels with a relatively low EGR rate. x Pollutant emission levels are improved while power performance is enhanced; and exhaust temperature + NO is adopted. x Post-processing efficiency M, using a dual-judgment method, comprehensively judges to selectively enable / disable NO. x Capture the loop to ensure that NO is detected under harsh operating conditions. x Consistent and reliable emissions ensure the high reliability of the entire aftertreatment system; and the use of NO x The post-treatment efficiency M is determined in three intervals, achieving a dynamic optimal balance between purification efficiency and system energy consumption.

[0092] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A passenger vehicle engine exhaust aftertreatment system, characterized in that, It has an engine controller and an engine exhaust port, including: The main exhaust pipe has a main exhaust inlet. At least one branch exhaust pipe has a branch exhaust inlet and a branch exhaust outlet; The exhaust gas purification coupling unit is located on the main exhaust pipe; The nitrogen oxide treatment unit, located on the branch exhaust pipe, treats NO. x Storage and DeNO X Transformation; The on / off assembly is electrically connected to the engine controller and is connected to the main exhaust intake, the branch exhaust intake and the engine exhaust port respectively, so as to control at least one of the main exhaust intake and the branch exhaust intake to be connected to the engine exhaust port. The branch exhaust port is located between the exhaust gas purification coupling unit and the on / off assembly and is connected to the main exhaust pipe. A nitrogen oxide sensor, electrically connected to the engine controller, is located on the main exhaust pipe to monitor the NO at the nitrogen oxide sensor location in the main exhaust pipe in real time. x Pollutant concentration.

2. The passenger vehicle engine exhaust aftertreatment system according to claim 1, characterized in that, The exhaust gas purification coupling unit includes a three-way catalytic converter and a particulate filter, with the three-way catalytic converter located upstream of the particulate filter.

3. The passenger vehicle engine exhaust aftertreatment system according to claim 1, characterized in that, The number of nitrogen and oxygen sensors is at least two, and they are located on the main exhaust pipes upstream and downstream of the exhaust gas purification coupling unit, respectively.

4. The passenger vehicle engine exhaust aftertreatment system according to claim 3, characterized in that, One of the two nitrogen oxide sensors is located upstream of the on / off assembly, and the other is located downstream of the exhaust gas purification coupling unit.

5. The passenger vehicle engine exhaust aftertreatment system according to claim 1, characterized in that, The on / off component is an electronically controlled valve, which includes an air inlet and at least two air outlets. The air inlet of the electronically controlled valve is used to connect to the engine exhaust port, one of the air outlets is connected to the main exhaust air inlet, and the other air outlet is connected to the branch exhaust air inlet. The electronically controlled valve is used to control at least one of the two air outlets to be connected to the air inlet.

6. The passenger vehicle engine exhaust aftertreatment system according to claim 5, characterized in that, The number of branch exhaust pipes is one, and the electronically controlled valve is an electronically controlled three-way valve. The electronically controlled three-way valve includes an air inlet, a first air outlet, and a second air outlet. The air inlet of the electronically controlled three-way valve is used to connect to the engine exhaust port, the first air outlet is connected to the main exhaust air inlet, and the second air outlet is connected to the branch exhaust air inlet. The electronically controlled three-way valve is used to control at least one of the first air outlet and the second air outlet to be connected to the air inlet.

7. The passenger vehicle engine exhaust aftertreatment system according to claim 6, characterized in that, The branch exhaust port is connected to the main exhaust pipe via a three-way connector.

8. The passenger vehicle engine exhaust aftertreatment system according to claim 7, characterized in that, The tee connector is a Y-type tee connector.

9. The passenger vehicle engine exhaust aftertreatment system according to claim 1, characterized in that, The system includes a temperature sensor electrically connected to the engine controller for real-time monitoring of the engine's exhaust temperature, wherein: The temperature sensor is located upstream of the on / off assembly.

10. A method for controlling exhaust aftertreatment in a passenger vehicle engine, characterized in that, For controlling the exhaust aftertreatment system of a passenger vehicle engine according to any one of claims 1 to 9, the system further includes a temperature sensor and two nitrogen oxide sensors, the temperature sensor being used to monitor the exhaust temperature of the engine in real time, one of the two nitrogen oxide sensors being located upstream of the on / off assembly, and the other being located downstream of the exhaust gas purification coupling unit; the control method includes: The exhaust temperature of the main exhaust pipe is obtained from the temperature sensor. Determine whether the exhaust temperature meets the preset conditions; If so, the on / off component controls both the main exhaust inlet and the branch exhaust inlet to be connected to the engine exhaust port; If not, then obtain the NO data collected by the two nitrogen and oxygen sensors. x Pollutant concentrations and calculate NO x Post-processing efficiency M; According to the NO x The preset threshold range of the after-treatment efficiency M is selectively controlled by the on / off component (5) to connect at least one of the main exhaust port and the branch exhaust port to the engine exhaust port.

11. The passenger vehicle engine exhaust aftertreatment control method according to claim 10, characterized in that, Determining whether the exhaust temperature meets the preset conditions specifically includes: Determine whether the exhaust temperature meets the preset temperature; Determine whether the duration of the exhaust temperature meets the preset time.

12. The passenger vehicle engine exhaust aftertreatment control method according to claim 11, characterized in that, The preset temperature is less than 220℃.

13. The passenger vehicle engine exhaust aftertreatment control method according to claim 11, characterized in that, The preset time is greater than or equal to 30 seconds.

14. The passenger vehicle engine exhaust aftertreatment control method according to claim 10, characterized in that, If not, then obtain the NO data collected by the two nitrogen and oxygen sensors. x Pollutant concentrations and calculate NO x Post-processing efficiency M specifically includes: The NO2 sensor upstream of the exhaust gas purification coupling unit collects the NO2 data. x The pollutant concentration is recorded as A; The NO2 sensor downstream of the exhaust gas purification coupling unit collects the NO2 data. x The pollutant concentration was recorded as B; Calculate NO x Post-processing efficiency M = (AB) / A × 100%.

15. The passenger vehicle engine exhaust aftertreatment control method according to claim 10, characterized in that, According to the NO x Within a preset threshold range of the aftertreatment efficiency M, selectively controlling at least one of the main exhaust port and the branch exhaust port to connect to the engine exhaust port via the on / off component, specifically including: If the NO x When the after-treatment efficiency M is within the first preset threshold range, the on / off component controls both the main exhaust inlet and the branch exhaust inlet to be connected to the engine exhaust port. If the NO x When the after-treatment efficiency M falls within the second preset threshold range, the on / off component controls the connection between the branch intake and the engine exhaust port. If the NO x When the after-treatment efficiency M falls within the third preset threshold range, the on / off component controls the connection between the main exhaust intake and the engine exhaust port.

16. The passenger vehicle engine exhaust aftertreatment control method according to claim 15, characterized in that, The first preset threshold range is M less than or equal to 70%, the second preset threshold range is M greater than 70% and less than 90%, and the third preset threshold range is M greater than or equal to 92%.

17. A passenger vehicle engine system, characterized in that, Includes the engine and the passenger vehicle engine exhaust aftertreatment system as described in any one of claims 1 to 9.

Images