A method and system for controlling an exhaust aftertreatment system of a hydrogen fueled engine

Abstract

The application discloses a kind of hydrogen fuel engine exhaust gas post-processing system control method and system, it is related to hydrogen fuel engine technical field, the method includes: when the state of first bypass valve is monitored to exhaust gas enters LNT, the H2 concentration of exhaust gas and engine working condition are acquired;Call pre-constructed adsorption / regeneration MAP chart, determine the working mode corresponding to LNT according to the H2 concentration of exhaust gas and engine working condition, wherein, working mode includes lean NOx adsorption or rich H2 reduction regeneration mode;When LNT is in rich H2 reduction regeneration mode, the NOx adsorption amount is acquired and the H2 consumption required for LNT regeneration is determined according to NOx adsorption amount to determine H2 injection amount control LNT to carry out post-injection, and the opening of second bypass valve is controlled to regulate intake oxygen concentration and temperature, to ensure the reduction efficiency of selective catalytic reduction device.The application improves the purification efficiency of exhaust gas.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell engine technology, and in particular to a control method and system for an exhaust gas aftertreatment system of a hydrogen fuel cell engine. Background Technology

[0002] Hydrogen fuel cell engine lean combustion NO x The Lightning Torque Netting (LNT) technology combined with an H2 concentration control system represents the most advanced approach for deeply purifying NOx emissions from exhaust gases and achieving efficient hydrogen utilization. To meet increasingly stringent emission requirements, exhaust aftertreatment systems comprised of Droplet Filters (DPFs), LNTs, and Selective Catalytic Reduction (SCR / ASC) units have become a core component of hydrogen fuel cell engines. DPFs primarily capture trace amounts of solid particles generated during combustion; LNTs efficiently adsorb NOx using alkaline earth metal materials under lean-burn conditions. x SCR / ASC uses urea as a reducing agent to catalytically reduce residual NOx.

[0003] In existing technologies, control is mostly based on ideal exhaust emission conditions or traditional after-treatment devices, such as the inventions titled "An Exhaust After-treatment Device and Control Method for a Hydrogen Internal Combustion Engine" (Publication No. CN117703570A, Publication Date: March 15, 2024), "Control Method, Device and Vehicle" (Publication No. CN116658280A, Publication Date: August 29, 2023), "Vehicle Exhaust System, Vehicle Exhaust System Control Method and Vehicle" (Publication No. CN116517666A, Publication Date: August 1, 2023), and "A NO..." X The invention patent "Emission Control Method and Related Device" (Publication No. CN118309544A, Publication Date: July 9, 2024) only considers the impact of a single factor on exhaust gas treatment.

[0004] However, in practical applications of hydrogen fuel cell engines, DPF, LNT, and SCR / ASC interact with each other. For example, as the adsorption process proceeds, NO accumulates in the LNT. x It will gradually become saturated, causing a decrease in the catalytic efficiency of the selective catalytic reduction device, which in turn leads to the problem of low exhaust gas treatment efficiency. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a control method and system for exhaust gas aftertreatment system of hydrogen fuel cell engine, which aims to solve the problem of low exhaust gas treatment efficiency in the prior art.

[0006] This invention proposes a control method for an exhaust gas aftertreatment system of a hydrogen fuel cell engine, used to control the exhaust gas emissions of the aftertreatment system. The aftertreatment system includes a particulate filter, a low-temperature nitrogen (LNT), and a selective catalytic reduction (SCR) device arranged sequentially. A first bypass valve for controlling the on / off state of the LNT is provided at the inlet of the LNT. The LNT is connected to the intake system via an EGR (Exhaust Gas Recycling) pipeline. A second bypass valve for controlling the on / off state of the LNT and the intake system is provided on the EGR pipeline. The method includes:

[0007] When exhaust gas enters LNT through the status monitoring of the first bypass valve, the H2 concentration of the exhaust gas and the engine operating condition are obtained.

[0008] The pre-built adsorption / regeneration MAP is invoked, and the corresponding operating mode of LNT is determined based on the H2 concentration in the exhaust gas and the engine operating conditions. The operating modes include lean-burn NO2. x Adsorption or H2-rich reduction and regeneration mode;

[0009] When the LNT is in the fuel-rich H2 reduction and regeneration mode, NO is obtained. x Adsorption amount and according to NO x The amount of adsorption determines the amount of H2 required for LNT regeneration, which in turn determines the amount of H2 injection to control the post-injection of LNT. The opening of the second bypass valve is also controlled to regulate the intake oxygen concentration and temperature, thereby ensuring the reduction efficiency of the selective catalytic reduction unit.

[0010] Furthermore, in the above-mentioned control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine, the method further includes:

[0011] Real-time monitoring of the exhaust temperature at the LNT inlet and determination of whether the exhaust temperature exceeds the preset temperature threshold.

[0012] If the exhaust temperature is greater than the preset temperature threshold, the first bypass valve is opened, the second bypass valve is closed, and the after-injection is stopped.

[0013] If the exhaust temperature is lower than the preset temperature threshold, the first bypass valve is closed, and the LNT status parameters are obtained to determine NO. x Does the adsorption amount exceed the preset adsorption threshold?

[0014] If NO x If the adsorption amount exceeds the preset adsorption amount threshold, the post-spray is activated, and the regeneration spray amount is calculated based on the pre-constructed LNT adsorption / regeneration MAP, while the main spray amount is reduced to compensate.

[0015] If NO x If the adsorption amount is lower than the preset adsorption threshold, then spraying will stop.

[0016] Furthermore, in the above-mentioned control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine, the method further includes:

[0017] The exhaust gas H2 concentration detected by the H2 sensor is obtained. If the exhaust gas H2 concentration is less than the first preset H2 concentration threshold, the LNT adsorption state is maintained, the incremental post-injection is started, and the recovery ratio of the EGR recovery pipeline is adjusted.

[0018] If the H2 concentration in the exhaust gas exceeds the second preset H2 concentration threshold, emergency regeneration is triggered, the EGR recovery pipeline is fully opened, and nitrogen dilution is initiated.

[0019] If the H2 concentration in the exhaust gas is within the range of the first preset H2 concentration threshold and the second preset H2 concentration threshold, according to the NO of LNT x The adsorption capacity is controlled by the post-treatment system according to a preset decision.

[0020] Furthermore, in the above-mentioned control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine, the step of controlling the NO emission based on LNT... x The steps for controlling the adsorption amount of the post-treatment system according to a preset decision include:

[0021] According to NO x The amount of adsorption determines the opening degree of the corresponding second bypass valve, thereby controlling the level of LNT regeneration mode.

[0022] Furthermore, in the above-mentioned control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine, the step of controlling the NO emission based on LNT... x Before the step of controlling the adsorption amount of the post-treatment system according to a preset decision, the following steps are also included:

[0023] Monitor the exhaust temperature of the LNT. When the exhaust temperature is abnormal, open the first bypass valve and suspend regeneration to avoid thermal damage. When the exhaust temperature is normal, close the first bypass valve, maintain preheating, or execute the regeneration command.

[0024] Furthermore, in the above-mentioned control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine, the step of constructing a LNT adsorption / regeneration MAP includes:

[0025] Based on the LNT reaction temperature, NO input to LNT is incorporated. x Calculate NO concentration and inlet gas flow rate. x Adsorption rate and adsorption amount;

[0026] Machine learning or mathematical modeling methods are used to establish reaction prediction models, and these models are used to extrapolate NO emissions from LNTs. x Concentration, summarizing NO concentration under different operating conditions for LNT. x Pattern of change;

[0027] Combined with NO x The required H2 content for reduction was determined by calibrating the temperature-operating condition-NO content. x The LNT adsorption / regeneration MAP is obtained by correlating the adsorption / regeneration H2 demand with the MAP diagram.

[0028] Furthermore, in the above-mentioned control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine, the step of constructing the LNT adsorption / regeneration MAP map further includes:

[0029] The LNT reaction temperature and LNT input NO were obtained respectively. x Concentration, inlet flow rate, exhaust gas H2 concentration, real-time opening of the second bypass valve, and LNT catalyst aging factor are used as input factors;

[0030] Using the input factor as the input layer, construct a multi-parameter and NO... x A coupled prediction model for processing efficiency, the model output layer includes LNT NO. x Adsorption saturation time, minimum H2 injection rate required for regeneration, and optimal second bypass valve opening range;

[0031] After each preset running time or a preset number of complete adsorption-regeneration cycles, extract the NO from the LNT inlet. x Concentration, LNT export NO x The measured data of concentration, residual H2 concentration in exhaust gas, and exhaust temperature are compared with the output values ​​of the coupled prediction model to calculate the deviation. If the absolute value of the deviation exceeds the threshold, the model weights are updated through the backpropagation algorithm, and the temperature-operating condition-NO in the LNT adsorption / regeneration MAP diagram is corrected simultaneously. x Mapping relationship between adsorption / regeneration and H2 demand;

[0032] Establish a collaborative correction link between the MAP diagram and the selective catalytic reduction unit, and adjust the NO output of the selective catalytic reduction unit. x The sensor's real-time detection data serves as a closed-loop feedback signal; if NO is detected... x If the concentration exceeds the preset threshold, the H2 injection correction coefficient will be automatically increased under the corresponding operating condition in the MAP diagram, and the opening range of the second bypass valve will be narrowed to ensure the coordinated matching of LNT regeneration effect and selective catalytic reduction unit purification efficiency.

[0033] Another object of the present invention is to provide a control system for an exhaust gas aftertreatment system of a hydrogen fuel cell engine, characterized in that it controls the exhaust gas emissions of the exhaust gas aftertreatment system, the aftertreatment system comprising a particulate filter, a light-turbine nitrogen (LNT), and a selective catalytic reduction (SCR) device arranged sequentially, wherein a first bypass valve for controlling the on / off state of the LNT is provided at the inlet of the LNT, the LNT is connected to the intake system via an EGR recovery pipeline, and a second bypass valve for controlling the on / off state of the LNT and the intake system is provided on the EGR recovery pipeline, the system comprising:

[0034] The acquisition module is used to acquire the H2 concentration of the exhaust gas and the engine operating condition when the exhaust gas enters the LNT through the status monitoring of the first bypass valve.

[0035] The module invokes a pre-built adsorption / regeneration MAP and determines the corresponding LNT operating mode based on the H2 concentration in the exhaust gas and the engine operating conditions. The operating modes include lean-burn NO2. x Adsorption or H2-rich reduction and regeneration mode;

[0036] The control module is used to obtain the NOx adsorption amount and, based on the NOx adsorption, determine the NOx adsorption capacity when the LNT is in the H2-rich reduction and regeneration mode. x The amount of adsorption determines the amount of H2 required for LNT regeneration, which in turn determines the amount of H2 injection to control the post-injection of LNT. The opening of the second bypass valve is also controlled to regulate the intake oxygen concentration and temperature, thereby ensuring the reduction efficiency of the selective catalytic reduction unit.

[0037] Another object of the present invention is to provide a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0038] Another object of the present invention is to provide an electronic device including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the program to implement the steps of the method described above.

[0039] The aftertreatment system proposed in this invention includes a particulate filter, a light-turbine nitrogen (LNT), and a selective catalytic reduction (SCR) device arranged sequentially. A first bypass valve is installed at the LNT inlet to control its on / off state. The LNT is connected to the intake system via an EGR (Exhaust Gas Regeneration) pipeline. A second bypass valve is installed on the EGR pipeline to control the connection between the LNT and the intake system. When exhaust gas enters the LNT through the first bypass valve, the system monitors the H2 concentration of the exhaust gas and the engine operating condition. A pre-constructed adsorption / regeneration MAP is then called to determine the corresponding operating mode of the LNT based on the H2 concentration of the exhaust gas and the engine operating condition. The operating mode includes lean-burn NO₂. x Adsorption or H2-rich reduction and regeneration mode; when LNT is in H2-rich reduction and regeneration mode, NO is obtained.x Adsorption amount and according to NO x The adsorption capacity determines the H2 consumption required for LNT regeneration, which in turn determines the H2 injection rate to control LNT post-injection. The opening of the second bypass valve is also controlled to regulate the intake oxygen concentration and temperature, ensuring the reduction efficiency of the selective catalytic reduction unit. This is achieved through actual measurements of H2 concentration and NO... x By dynamically adjusting the adsorption capacity and post-injection strategy, and through feedback regulation of engine exhaust temperature and EGR opening, the optimal operating environment for SCR is maintained while ensuring efficient LNT regeneration. This significantly reduces the risk of SCR catalyst deactivation due to H2 poisoning, greatly extends catalyst life, and improves efficiency. Ultimately, it achieves NO... x The goal is to synergistically optimize the conversion rate and H2 recovery rate, thus solving the problem of low efficiency in existing exhaust gas treatment technologies. Attached Figure Description

[0040] Figure 1 This is a flowchart of the control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine in the first embodiment of the present invention;

[0041] Figure 2 This is a flowchart illustrating the control logic of the exhaust gas aftertreatment system in the exhaust gas aftertreatment system control method of the hydrogen fuel cell engine in the first embodiment of the present invention.

[0042] Figure 3 This is a dynamic control flowchart of the LNT adsorption and regeneration mode in the control method of the exhaust gas aftertreatment system of a hydrogen fuel engine in the first embodiment of the present invention.

[0043] Figure 4 This is a flowchart illustrating the precise dynamic control of LNT adsorption and regeneration in the exhaust gas aftertreatment system control method of a hydrogen fuel cell engine in the first embodiment of the present invention.

[0044] Figure 5 This is a flowchart illustrating the construction and application of the LNT adsorption / regeneration MAP diagram in the control method of the exhaust gas aftertreatment system of a hydrogen fuel cell engine in the first embodiment of the present invention.

[0045] Figure 6 This is a structural block diagram of the control system of the exhaust gas aftertreatment system of the hydrogen fuel engine in the third embodiment of the present invention.

[0046] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0047] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0048] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0050] Example 1

[0051] Please see Figure 1 The figure shows a control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine according to the first embodiment of the present invention. The method is used to control the exhaust gas emissions of the exhaust gas aftertreatment system. The aftertreatment system includes a particulate filter, a low-temperature nitrogen (LNT), and a selective catalytic reduction (SCR) device arranged in sequence. A first bypass valve for controlling the on / off state of the LNT is provided at the inlet of the LNT. The LNT is connected to the intake system through an EGR recovery pipeline. A second bypass valve for controlling the on / off state of the LNT and the intake system is provided on the EGR recovery pipeline. The method includes steps S10 to S12.

[0052] Step S10: When exhaust gas enters LNT through the status monitoring of the first bypass valve, the H2 concentration of the exhaust gas and the engine operating condition are obtained.

[0053] The post-processing system consists of a particle trap and a lean NOx filter. x The LNT (Lean Nitrous Oxide Trap) and Selective Catalytic Reduction (SCR / ASC) unit are connected in series. The first bypass valve at the LNT inlet controls whether exhaust gas enters the LNT. The LNT is connected to the engine intake system through the EGR (Exhaust Gas Recycling) recovery line. The second bypass valve on the line controls the opening and closing of this circuit. By adding an EGR recovery line, H2 can be recovered.

[0054] Furthermore, the status signal of the first bypass valve is used to determine whether exhaust gas enters the LNT. Once it is confirmed that the exhaust gas has entered, the H2 concentration at the LNT inlet is monitored in real time by a high-precision H2 sensor, and the current operating parameters of the engine are obtained at the same time.

[0055] Step S11: The pre-constructed adsorption / regeneration MAP is invoked, and the operating mode corresponding to LNT is determined based on the H2 concentration in the exhaust gas and the engine operating conditions. The operating mode includes lean-burn NO2. x Adsorption or H2-rich reduction and regeneration mode.

[0056] This involves calling a pre-built adsorption / regeneration MAP, which is a parameter mapping table established based on a large amount of experimental or simulation data. The system will match the corresponding LNT operating mode in the MAP according to the real-time collected H2 concentration and engine operating conditions. The operating modes are divided into two core types: lean-burn NO. x The adsorption mode and the fuel-rich H2 reduction and regeneration mode are used to capture NO when the exhaust gas is in a lean-burn state. x The latter is used to reduce NO adsorbed in LNTs with H2 when needed. x .

[0057] Step S12: When the LNT is in the H2-rich reduction and regeneration mode, obtain NO. x Adsorption amount and according to NO x The amount of adsorption determines the amount of H2 required for LNT regeneration, which in turn determines the amount of H2 injection to control the post-injection of LNT. The opening of the second bypass valve is also controlled to regulate the intake oxygen concentration and temperature, thereby ensuring the reduction efficiency of the selective catalytic reduction unit.

[0058] When the LNT is determined to enter the fuel-rich H2 reduction and regeneration mode, the system will obtain the current NO of the LNT. x The adsorption capacity can be derived by combining a preset calculation model with sensor data. Based on NO... x Based on the amount of adsorption, the system further calculates the H2 consumption required for LNT regeneration, thereby determining the corresponding H2 injection rate. Precise hydrogen injection is achieved by controlling the LNT-related post-injection devices. Simultaneously, the system adjusts the opening of the second bypass valve, changing the gas recirculation ratio in the EGR recovery pipeline to regulate the oxygen concentration and intake temperature of the engine intake system, optimizing the reaction atmosphere. During this process, NO is released... x A closed-loop system for H2 emission monitoring provides feedback to adjust injection rates and EGR opening, preventing under- or over-reaction and ensuring downstream selective catalytic reduction (SCR) units operate at optimal conditions, maintaining high NOx reduction efficiency. Finally, SCR / ASC is used for final control, achieving coordinated control of the entire process from "adsorption-regeneration" to "end-of-pipe purification." In practical implementation, the control strategy is as follows: Figure 2As shown.

[0059] In summary, the exhaust gas aftertreatment system control method for a hydrogen fuel cell engine in the above embodiments of the present invention includes a particulate filter, a low-temperature nitrogen (LNT), and a selective catalytic reduction (SCR) device arranged sequentially. A first bypass valve for controlling the on / off state of the LNT is provided at its inlet. The LNT is connected to the intake system via an EGR recovery pipeline, and a second bypass valve for controlling the on / off state of the LNT and the intake system is provided on the EGR recovery pipeline. When exhaust gas is detected entering the LNT through the status monitoring of the first bypass valve, the H2 concentration of the exhaust gas and the engine operating condition are obtained. A pre-constructed adsorption / regeneration MAP is invoked, and the corresponding operating mode of the LNT is determined based on the H2 concentration of the exhaust gas and the engine operating condition. The operating mode includes lean NO₂. x Adsorption or H2-rich reduction and regeneration mode; when LNT is in H2-rich reduction and regeneration mode, NO is obtained. x Adsorption amount and according to NO x The adsorption capacity determines the H2 consumption required for LNT regeneration, which in turn determines the H2 injection rate to control LNT post-injection. The opening of the second bypass valve is also controlled to regulate the intake oxygen concentration and temperature, ensuring the reduction efficiency of the selective catalytic reduction unit. This is achieved through actual measurements of H2 concentration and NO... x By dynamically adjusting the adsorption capacity and post-injection strategy, and through feedback regulation of engine exhaust temperature and EGR opening, the optimal operating environment for SCR is maintained while ensuring efficient LNT regeneration. This significantly reduces the risk of SCR catalyst deactivation due to H2 poisoning, greatly extends catalyst life, and improves efficiency. Ultimately, it achieves NO... x The goal is to synergistically optimize the conversion rate and H2 recovery rate, thus solving the problem of low efficiency in existing exhaust gas treatment technologies.

[0060] Example 2

[0061] This embodiment also proposes a control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine. The difference between the control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine in this embodiment and the control method for the exhaust gas aftertreatment system of a hydrogen fuel cell engine in Embodiment 1 is as follows:

[0062] The method further includes:

[0063] Real-time monitoring of the exhaust temperature at the LNT inlet and determination of whether the exhaust temperature exceeds the preset temperature threshold.

[0064] If the exhaust temperature is greater than the preset temperature threshold, the first bypass valve is opened, the second bypass valve is closed, and the after-injection is stopped.

[0065] If the exhaust temperature is lower than the preset temperature threshold, the first bypass valve is closed, and the LNT status parameters are obtained to determine NO. xDoes the adsorption amount exceed the preset adsorption threshold?

[0066] If NO x If the adsorption amount exceeds the preset adsorption amount threshold, the post-spray is activated, and the regeneration spray amount is calculated based on the pre-constructed LNT adsorption / regeneration MAP, while the main spray amount is reduced to compensate.

[0067] If NO x If the adsorption amount is lower than the preset adsorption threshold, then spraying will stop.

[0068] Among them, the LNT inlet exhaust temperature and NO were added. x A closed-loop control logic for the adsorption capacity threshold enables dynamic control of LNT adsorption and regeneration modes. Specifically, the system monitors exhaust temperature data in real time using a temperature sensor located at the LNT inlet and compares this data with a preset temperature threshold.

[0069] If the monitored exhaust temperature is greater than the preset temperature threshold, it indicates that the current exhaust temperature is too high. Continuing to allow the exhaust gas to flow through the LNT or to perform regeneration operations may cause thermal aging or damage to the LNT catalyst. At this time, the system will execute a protection strategy, opening the first bypass valve to allow the exhaust gas to bypass the LNT directly, closing the second bypass valve to cut off the EGR recovery circuit, and stopping the H2 after-injection operation to avoid abnormal reactions at high temperatures.

[0070] If the exhaust temperature is lower than the preset temperature threshold, it indicates that the temperature conditions are suitable for LNT operation. The system will close the first bypass valve to ensure that all exhaust gas enters the LNT, and then acquire the LNT's status parameters, which include, but are not limited to, NO. x The core purpose of the derived data related to adsorption capacity is to determine the current NO content. x Does the adsorption amount exceed the preset adsorption threshold?

[0071] If the NOx adsorption exceeds the preset adsorption threshold, it indicates that the LNTs are nearing adsorption saturation and the regeneration process needs to be initiated. The system will activate the H2 post-injection device and calculate the precise regeneration injection amount based on the pre-constructed LNT adsorption / regeneration MAP and the current operating conditions. To avoid excessive total hydrogen injection affecting engine combustion stability, the system will simultaneously reduce the hydrogen injection amount of the main injection system as compensation, ensuring that the engine power output is not significantly affected.

[0072] If NO x If the adsorption capacity is lower than the preset adsorption capacity threshold, it indicates that the LNT still has sufficient adsorption space and regeneration is unnecessary. The system will then stop the H2 post-spraying operation to maintain the lean NO from the LNT. x Adsorption mode.

[0073] For example, such as Figure 3As shown, this process starts with LNT temperature detection. First, it determines whether the temperature exceeds 450℃: if T>450℃, the first bypass valve (bypass valve V1) is opened, the second bypass valve of the EGR (bypass valve V2) is closed, and post-spraying is stopped (to avoid high-temperature damage to the LNT); if T≤450℃, V1 is closed, the LNT status parameters are obtained, and its NO is further determined. x Does the adsorption capacity exceed 80%? If the adsorption capacity is >80%, the post-injection is started, and the regeneration injection quantity is calculated based on the MAP diagram. At the same time, the main injection quantity is reduced to compensate (adjust the air-fuel ratio and create a rich regeneration environment). If the adsorption capacity is ≤80%, the post-injection is stopped (maintaining the lean-burn adsorption state) to achieve dynamic switching between LNT adsorption and regeneration modes.

[0074] Furthermore, in some optional embodiments of the present invention, precise dynamic regulation of LNT adsorption and regeneration is further achieved based on dynamic control, specifically:

[0075] The exhaust gas H2 concentration detected by the H2 sensor is obtained. If the exhaust gas H2 concentration is less than the first preset H2 concentration threshold, the LNT adsorption state is maintained, the incremental post-injection is started, and the recovery ratio of the EGR recovery pipeline is adjusted.

[0076] If the H2 concentration in the exhaust gas exceeds the second preset H2 concentration threshold, emergency regeneration is triggered, the EGR recovery pipeline is fully opened, and nitrogen dilution is initiated.

[0077] If the H2 concentration in the exhaust gas is within the range of the first preset H2 concentration threshold and the second preset H2 concentration threshold, according to the NO of LNT x The adsorption capacity is controlled by the post-treatment system according to a preset decision.

[0078] In this system, considering the significant amount of H2 spillage during the reaction, an EGR recovery pipeline is added to introduce emitted H2 into the intake manifold for fuel recovery, thus avoiding the safety issues associated with H2 combustion during emission treatment. To implement the LNT-coupled EGR system, the system first acquires real-time H2 concentration data in the exhaust gas using an H2 sensor and compares this data with two preset H2 concentration thresholds (a first preset H2 concentration threshold and a second preset H2 concentration threshold, with the first threshold being lower than the second threshold).

[0079] If the H2 concentration in the exhaust gas is less than the first preset H2 concentration threshold, it indicates that the amount of H2 available for reduction in the current exhaust gas is insufficient, and the system will maintain the lean NO of the LNT. x During the adsorption process, an incremental post-injection operation is initiated to replenish the H2 supply to meet subsequent regeneration needs. The recovery ratio of the EGR recovery pipeline is also adjusted to optimize the intake conditions and improve adsorption efficiency.

[0080] If the H2 concentration in the exhaust gas exceeds the second preset H2 concentration threshold, it indicates that the H2 content in the exhaust gas is too high, which may pose a safety hazard or cause a decrease in SCR reduction efficiency. The system will immediately trigger an emergency regeneration procedure, control the EGR recovery pipeline to fully open, and simultaneously start the nitrogen dilution device to reduce the H2 concentration in the exhaust gas to a safe range, ensuring the stable operation of the aftertreatment system.

[0081] If the H2 concentration in the exhaust gas is between the first preset H2 concentration threshold and the second preset H2 concentration threshold, it indicates that the H2 concentration is within a suitable range. The system will then adjust the LNT based on the current NO content. x The adsorption capacity is adjusted according to preset control decisions to regulate the post-treatment system and balance the adsorption effect and regeneration efficiency.

[0082] Among them, accurately detecting or calculating the current NO of LNT x The adsorption capacity is divided into different ranges based on the amount of adsorption, and each range corresponds to a specific opening range of the second bypass valve. By adjusting the opening of the second bypass valve, the return flow rate of the gas in the EGR recovery pipeline can be changed, thereby regulating the oxygen concentration and intake temperature of the engine intake system, and ultimately controlling the LNT regeneration mode level.

[0083] Regeneration mode level is usually based on NO x The adsorption capacity is divided into different levels. The lower the adsorption capacity, the lower the regeneration level, and the lower the required H2 amount and oxygen concentration control precision. The higher the adsorption capacity, the higher the regeneration level, and it is necessary to create conditions more conducive to the reduction reaction by adjusting the opening of the bypass valve.

[0084] In addition, before making a decision, the exhaust temperature of the LNT is monitored through LNT temperature detection closed-loop protection. When the exhaust temperature is abnormal, the first bypass valve is opened and regeneration is suspended to avoid thermal damage. When the exhaust temperature is normal, the first bypass valve is closed, preheating is maintained, or the regeneration command is executed.

[0085] For example, such as Figure 4 As shown, the H2 sensor first monitors the H2 concentration in the exhaust gas. If H2 < 1.5%, the system maintains LNT adsorption, starts incremental post-injection, and adjusts the EGR recovery ratio to optimize adsorption conditions. If H2 > 2.5%, emergency regeneration is triggered, controlling the EGR to be fully open and initiating nitrogen dilution to quickly reduce the H2 concentration and prevent emissions from exceeding standards. When H2 is in the critical range of 1.5% to 2.5%, it enters the LNT-NO... xThe adsorption capacity is tiered for decision-making. When the adsorption capacity is <80%, regeneration is temporarily suspended to maintain adsorption. In the range of 20% to 80%, standard regeneration (EGR opening 50%) or early regeneration (EGR opening 60%) is performed proportionally. When the adsorption capacity is >80%, enhanced regeneration (EGR opening 70%) is performed to prevent adsorption saturation. Before the regeneration decision is executed, a closed-loop protection is implemented through LNT temperature detection. If the temperature is abnormal, the bypass valve V1 is opened and regeneration is suspended to avoid thermal damage. If the temperature is normal, the bypass valve V1 is closed, preheating is maintained, or the regeneration command is executed. The entire logic is based on H2 concentration as the initial trigger, adsorption capacity to refine the regeneration intensity, and temperature detection as the final protection, achieving precise dynamic control of LNT adsorption and regeneration in a step-by-step manner.

[0086] Further steps in constructing the LNT adsorption / regeneration MAP include:

[0087] Based on the LNT reaction temperature, NO input to LNT is incorporated. x Calculate NO concentration and inlet gas flow rate. x Adsorption rate and adsorption amount;

[0088] Machine learning or mathematical modeling methods are used to establish reaction prediction models, and these models are used to extrapolate NO emissions from LNTs. x Concentration, summarizing NO concentration under different operating conditions for LNT. x Pattern of change;

[0089] Combined with NO x The required H2 content for reduction was determined by calibrating the temperature-operating condition-NO content. x The LNT adsorption / regeneration MAP is obtained by correlating the adsorption / regeneration H2 demand with the MAP diagram.

[0090] Among them, such as Figure 5 As shown, the reaction temperature of LNT is used as the core basic parameter because temperature has the most significant impact on the adsorption and regeneration efficiency of LNT. Simultaneously, the input NO to LNT is considered... x Taking into account factors such as concentration and engine intake airflow rate, the NO concentration of LNT under different parameter combinations was determined through experimental testing or simulation calculations. x Adsorption rate and adsorption capacity data are used to establish the correlation between basic parameters and adsorption effect.

[0091] Next, machine learning algorithms or mathematical modeling methods, such as regression analysis and neural network models, are used to establish a reaction prediction model for LNTs. This model takes basic parameters as input, simulates the chemical reaction process inside the LNT, and extrapolates the NOx emission concentration of the LNT under different operating conditions. It then summarizes the NOx adsorption and regeneration variation laws of LNTs under various engine operating conditions, providing theoretical support for the construction of MAP diagrams.

[0092] Finally, by combining the H2 content data required for the NOx reduction reaction and through a large number of calibration experiments, the H2 demand of LNT in the adsorption and regeneration states under different temperatures and engine operating conditions was determined. This resulted in a MAP diagram showing the correlation between temperature, operating conditions, NOx adsorption / regeneration, and H2 demand, namely the LNT adsorption / regeneration MAP diagram, which provides a basis for parameter lookup for real-time control of the system.

[0093] In addition, some optional embodiments of this method have added logic for multi-parameter coupling, dynamic model updating, and collaborative correction with SCR to improve the accuracy and adaptability of the MAP diagram.

[0094] The specific construction steps are as follows: First, expand the range of input factors and obtain the LNT reaction temperature and LNT input NO. x Key parameters such as concentration, inlet gas flow rate, exhaust gas H2 concentration, real-time opening of the second bypass valve, and LNT catalyst aging factor all affect the working efficiency of LNT. Including these parameters can improve the comprehensiveness of the model.

[0095] Using these expanded input factors as the input layer of the model, a multi-parameter and NO model is constructed. x The coupled prediction model for processing efficiency explicitly includes three core metrics in its output layer: LNT NO. x The adsorption saturation time, the minimum H2 injection rate required for regeneration, and the optimal opening range of the second bypass valve directly provide key parameters for system control.

[0096] During system operation, after each preset running time or after completing a preset number of full adsorption-regeneration cycles, NO at the LNT inlet will be automatically extracted. x Concentration, LNT export NO x Measured data on concentration, residual H2 concentration in exhaust gas, and exhaust temperature are used to calculate the deviation between these measured data and the output values ​​of the coupled prediction model. If the absolute value of the deviation exceeds a preset threshold, it indicates a significant difference between the model prediction and actual operation. The system will then update the model's weight parameters through a backpropagation algorithm and simultaneously correct the mapping relationship between temperature, operating conditions, NOx adsorption / regeneration, and H2 demand in the LNT adsorption / regeneration MAP diagram to ensure that the MAP diagram can adapt to long-term operational changes in the engine.

[0097] Finally, a collaborative correction link between the MAP diagram and the selective catalytic reduction unit was established to address the NO emission at the outlet of the selective catalytic reduction unit. x The sensor detects data in real time as a closed-loop feedback signal. If NO is detected... xIf the concentration exceeds the preset threshold, it indicates that the current LNT regeneration effect or SCR purification efficiency does not meet the requirements. The system will automatically increase the H2 injection quantity correction coefficient under the corresponding operating condition in the MAP diagram, increase the H2 injection quantity to enhance the LNT regeneration effect, and at the same time reduce the opening range of the second bypass valve to optimize the intake conditions, ensuring that the LNT regeneration effect and the selective catalytic reduction device purification efficiency are synergistically matched, thereby improving the exhaust gas purification capacity of the entire aftertreatment system.

[0098] In summary, the exhaust gas aftertreatment system control method for a hydrogen fuel cell engine in the above embodiments of the present invention includes a particulate filter, a low-temperature nitrogen (LNT), and a selective catalytic reduction (SCR) device arranged sequentially. A first bypass valve for controlling the on / off state of the LNT is provided at its inlet. The LNT is connected to the intake system via an EGR recovery pipeline, and a second bypass valve for controlling the on / off state of the LNT and the intake system is provided on the EGR recovery pipeline. When exhaust gas is detected entering the LNT through the status monitoring of the first bypass valve, the H2 concentration of the exhaust gas and the engine operating condition are obtained. A pre-constructed adsorption / regeneration MAP is invoked, and the corresponding operating mode of the LNT is determined based on the H2 concentration of the exhaust gas and the engine operating condition. The operating mode includes lean NO₂. x Adsorption or H2-rich reduction and regeneration mode; when LNT is in H2-rich reduction and regeneration mode, NO is obtained. x Adsorption amount and according to NO x The adsorption capacity determines the H2 consumption required for LNT regeneration, which in turn determines the H2 injection rate to control LNT post-injection. The opening of the second bypass valve is also controlled to regulate the intake oxygen concentration and temperature, ensuring the reduction efficiency of the selective catalytic reduction unit. This is achieved through actual measurements of H2 concentration and NO... x By dynamically adjusting the adsorption capacity and post-injection strategy, and through feedback regulation of engine exhaust temperature and EGR opening, the optimal operating environment for SCR is maintained while ensuring efficient LNT regeneration. This significantly reduces the risk of SCR catalyst deactivation due to H2 poisoning, greatly extends catalyst life, and improves efficiency. Ultimately, it achieves NO... x The goal is to synergistically optimize the conversion rate and H2 recovery rate, thus solving the problem of low efficiency in existing exhaust gas treatment technologies.

[0099] Example 3

[0100] Please see Figure 6The figure shows a control system for the exhaust gas aftertreatment system of a hydrogen fuel cell engine proposed in the third embodiment of the present invention. This control system is used to control the exhaust gas emissions from the exhaust gas aftertreatment system. The aftertreatment system includes a particulate filter, a low-temperature nitrogen (LNT), and a selective catalytic reduction (SCR) device arranged sequentially. A first bypass valve for controlling the on / off state of the LNT is provided at the LNT inlet. The LNT is connected to the intake system via an EGR recovery pipeline. A second bypass valve for controlling the on / off state of the LNT and the intake system is provided on the EGR recovery pipeline. The system includes:

[0101] The acquisition module 100 is used to acquire the H2 concentration of the exhaust gas and the engine operating condition when the exhaust gas enters the LNT through the status monitoring of the first bypass valve.

[0102] Module 200 is used to invoke a pre-built adsorption / regeneration MAP map and determine the corresponding operating mode of LNT based on the H2 concentration in the exhaust gas and the engine operating conditions. The operating mode includes lean-burn NO. x Adsorption or H2-rich reduction and regeneration mode;

[0103] Control module 300 is used to obtain the NOx adsorption amount and, based on the NOx adsorption, when the LNT is in the fuel-rich H2 reduction and regeneration mode. x The amount of adsorption determines the amount of H2 required for LNT regeneration, which in turn determines the amount of H2 injection to control the post-injection of LNT. The opening of the second bypass valve is also controlled to regulate the intake oxygen concentration and temperature, thereby ensuring the reduction efficiency of the selective catalytic reduction unit.

[0104] The functions or operation steps implemented by the above modules are largely the same as those in the above method embodiments, and will not be repeated here.

[0105] Example 4

[0106] In another aspect, the present invention provides a readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the steps of the method described in any one of Embodiments 1 to 2 above.

[0107] Example 5

[0108] In another aspect, the present invention provides an electronic device, the electronic device including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the program to implement the steps of any one of the methods described in Embodiments 1 to 2 above.

[0109] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0110] Those skilled in the art will understand that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable instructions for implementing logical functions, and can be embodied in any computer-readable storage medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable storage medium" can mean any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0111] More specific examples (a non-exhaustive list) of computer-readable storage media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable storage media can even be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0112] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0113] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0114] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method of controlling an exhaust gas aftertreatment system of a hydrogen fuel engine, characterized by, The application discloses a method for controlling exhaust emission of an exhaust emission aftertreatment system, the aftertreatment system comprising a particulate trap, an LNT and a selective catalytic reduction device arranged in sequence, the LNT being provided with a first bypass valve for controlling on-off of the LNT at an inlet of the LNT, the LNT being connected with an intake system through an EGR recovery pipeline, the EGR recovery pipeline being provided with a second bypass valve for controlling on-off of the LNT and the intake system, the method comprising the following steps: When exhaust gas is monitored to enter the LNT through the state of the first bypass valve, the H2 concentration of the exhaust gas and the engine working condition are acquired; The pre-constructed LNT adsorption / regeneration MAP is called to determine the corresponding working mode of the LNT according to the H2 concentration of the tail gas and the engine working condition, wherein the working mode includes lean NO x adsorption or rich H2 reduction regeneration mode; When the LNT is in the rich H2 reduction regeneration mode, the NO x adsorption amount and according to the NO x adsorption amount to determine the H2 consumption required for LNT regeneration to determine the H2 injection amount Control the LNT to perform post-injection, and control the opening degree of the second bypass valve to regulate the oxygen concentration and temperature of the intake air to ensure the reduction efficiency of the selective catalytic reduction device; The step of constructing the LNT adsorption / regeneration MAP diagram comprises the following steps: With LNT reaction temperature as the core basis, the input NO x concentration and intake flow rate, calculate NO x adsorption rate and adsorption capacity; The reaction prediction model is established by using machine learning or mathematical modeling method, and the LNT emission NO x concentration is deduced by using the reaction prediction model, and the NO x change rule of the LNT under different working conditions is summarized. NO x Reduction H2 content desired, calibrate temperature - operating conditions - NO x Adsorption / regeneration - H2 demand correlation to MAP gives LNT adsorption / regeneration MAP; The step of constructing the LNT adsorption / regeneration MAP diagram further comprises the following steps: LNT reaction temperature, LNT input NO x concentration, intake air flow rate, exhaust gas H2 concentration, second bypass valve real-time opening degree, LNT catalyst aging factor as input factors; The input factor is the input layer, and a multi-parameter and NO x The coupling prediction model of processing efficiency, and the model output layer includes the NO x Adsorption saturation time, minimum H2 injection amount required for regeneration, and optimal second bypass valve opening interval After each cumulative running for a preset time length or completing a preset number of complete adsorption-regeneration cycles, the LNT inlet NO x concentration, LNT outlet NO x concentration, tail gas residual H2 concentration, exhaust temperature, the measured data are deviated from the output values of the coupled prediction model, and if the absolute value of the deviation exceeds the threshold value, the model weight is updated through the back propagation algorithm, and the temperature-working condition-NO x adsorption / regeneration-H2 demand mapping relationship; The MAP map is established and a cooperative correction link of the selective catalytic reduction device is selected, so as to automatically correct the NO x The real-time detection data of the sensor is used as a closed-loop feedback signal, and if the detected NO x The concentration exceeds the preset threshold value, the H2 injection amount correction coefficient is increased under the corresponding working condition in the MAP map, and the second bypass valve opening interval is reduced, so as to ensure the cooperative matching of the LNT regeneration effect and the purification efficiency of the selective catalytic reduction device.

2. The hydrogen fuel engine exhaust gas aftertreatment system control method of claim 1, wherein The method further comprises the following steps: The exhaust temperature at the inlet end of the LNT is monitored in real time, and it is judged whether the exhaust temperature is greater than a preset temperature threshold value; If the exhaust temperature is greater than the preset temperature threshold value, the first bypass valve is opened, the second bypass valve is closed, and post-injection is stopped; If the exhaust temperature is less than a preset temperature threshold, the first bypass valve is closed, a state parameter of the LNT is acquired, and whether NO x whether the adsorption amount exceeds a preset adsorption amount threshold: If NO x If the adsorption amount exceeds the preset adsorption amount threshold, start the post-injection, calculate the regeneration injection amount according to the pre-constructed LNT adsorption / regeneration MAP, and reduce the main injection amount for compensation. If NO x If the adsorption amount is lower than the preset adsorption amount threshold, the post injection is stopped.

3. The hydrogen fuel engine exhaust gas aftertreatment system control method of claim 2, wherein, The method further comprises the following steps: The H2 concentration of the exhaust gas monitored by the H2 sensor is acquired, if the H2 concentration of the exhaust gas is less than a first preset H2 concentration threshold value, the LNT adsorption state is maintained, the incremental post-injection is started, and the recovery ratio of the EGR recovery pipeline is adjusted; If the H2 concentration of the exhaust gas is greater than a second preset H2 concentration threshold value, emergency regeneration is triggered, the EGR recovery pipeline is controlled to be fully opened, and nitrogen dilution is started; If the exhaust H2 concentration is in the first preset H2 concentration threshold and the second preset H2 concentration threshold interval, the NOx conversion rate of the LNT is controlled according to the NOx conversion rate of the LNT x The adsorption amount controls the aftertreatment system according to the preset decision.

4. The hydrogen fuel engine exhaust gas aftertreatment system control method of claim 3, wherein The NOx according to LNT x The step of controlling the aftertreatment system according to the predetermined decision on the adsorption amount comprises; According to NO x The amount of adsorption determines the opening of the corresponding second bypass valve, thereby controlling the level of the LNT regeneration mode.

5. The hydrogen fuel engine exhaust gas aftertreatment system control method of claim 3, wherein, The NOx according to LNT x The step of controlling the aftertreatment system according to the predetermined decision further comprises: The exhaust temperature of the LNT is monitored, when the exhaust temperature is abnormal, the first bypass valve is opened and the regeneration is suspended to avoid thermal damage, when the exhaust temperature is normal, the first bypass valve is closed, the preheating is maintained or the regeneration instruction is executed.

6. An exhaust gas aftertreatment system control system for a hydrogen fuel engine, characterized by, The application discloses a method for controlling exhaust emission of an exhaust emission aftertreatment system, the aftertreatment system comprising a particulate trap, an LNT and a selective catalytic reduction device arranged in sequence, the LNT being provided with a first bypass valve for controlling on-off of the LNT at an inlet of the LNT, the LNT being connected with an intake system through an EGR recovery pipeline, the EGR recovery pipeline being provided with a second bypass valve for controlling on-off of the LNT and the intake system, the method comprising the following steps: An acquisition module is used for acquiring the H2 concentration of the exhaust gas and the engine working condition when exhaust gas is monitored to enter the LNT through the state of the first bypass valve. The calling module is configured to call a pre-constructed LNT adsorption / regeneration MAP diagram to determine a working mode of the LNT according to the H2 concentration of the tail gas and the engine working condition, wherein the working mode includes a lean NO x adsorption or rich H2 reduction regeneration mode. a control module configured to obtain a NOx adsorption amount when the LNT is in a rich H2 reduction regeneration mode and to control the LNT to perform post-injection based on the NOx adsorption amount and a H2 injection amount determined based on the NOx adsorption amount x The NOx adsorption amount determines the H2 consumption amount required for LNT regeneration to determine the H2 injection amount, controls the LNT to perform post-injection, and controls the opening degree of the second bypass valve to regulate the oxygen concentration and temperature of the intake air to ensure the reduction efficiency of the selective catalytic reduction device.

7. A readable storage medium, having stored thereon a computer program, characterized in that, The program is executed by the processor to realize the steps of the method according to any one of claims 1 to 5.

8. An electronic device, comprising: The computer program is stored in the memory and executed on the processor, and the processor realizes the steps of the method according to any one of claims 1 to 5 when executing the program.

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