Diesel engine urea injection control method and system based on real-time parameter monitoring

Abstract

The application discloses a urea injection control method and system based on real-time parameter monitoring of a diesel engine, which is applied to a controller, and the method comprises the following steps: measuring the NOx concentration in real time through a NOx sensor arranged at the inlet of a two-stage SCR, and combining the engine operating state to query the NO2 proportion coefficient from a NO2 model to calculate the NO2 concentration; monitoring the temperature before the SCR and the NO2 concentration in real time as input parameters of a N2O generation difficulty model; according to the N2O generation characteristics, establishing a N2O generation difficulty model based on the temperature and the NO2 concentration, and calculating the N2O generation difficulty coefficient of the two-stage SCR; dynamically adjusting the first-stage urea injection amount according to the N2O generation difficulty coefficient; and monitoring the NOx conversion efficiency of the two-stage SCR. Therefore, the application can effectively reduce the N2O emission through real-time monitoring and adjustment, and meet the emission regulation requirements.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of diesel engine aftertreatment technology, and in particular to a urea injection control method and system for diesel engines based on real-time parameter monitoring. Background Technology

[0002] Diesel engines themselves do not produce N2O during combustion. However, the urea injected into the exhaust pipe undergoes pyrolysis to produce NH3, which then generates a large amount of polluting N2O gas as a side reaction. The chemical reactions by which NH3 generates N2O in the SCR and ASC catalytic units are as follows:

[0003] NO2 + NH3 → NH4NO3 + N2 + H2O

[0004] NH4NO3→N2O+H2O

[0005] NH3 + O2 → N2O + H2O

[0006] Among them, the SCR coating material, exhaust temperature, NO2 concentration, and urea injection volume all affect the amount of N2O generated. How to reduce N2O emissions is an urgent problem that the industry needs to solve. Summary of the Invention

[0007] This invention provides a urea injection control method and system for diesel engines based on real-time parameter monitoring. Through real-time monitoring and adjustment, it effectively reduces N2O emissions and meets emission regulations.

[0008] To achieve the above objectives, in a first aspect, the present invention provides a urea injection control method for a diesel engine based on real-time parameter monitoring, applied in a controller, the method comprising:

[0009] Step S100, through the NO arranged at the two-stage SCR inlet x Sensor, real-time measurement of NO x The concentration was determined by querying the NO2 proportion coefficient from the NO2 model in conjunction with the engine operating status, and the NO2 concentration was calculated.

[0010] Step S200: Monitor the temperature and NO2 concentration before SCR in real time, as input parameters for the N2O generation difficulty model;

[0011] Step S300: Based on the N2O generation characteristics, establish an N2O generation difficulty model based on temperature and NO2 concentration, and calculate the N2O generation difficulty coefficient of the two-stage SCR.

[0012] Step S400: Dynamically adjust the first-stage urea injection volume based on the difficulty coefficient of N2O generation.

[0013] Step S500: Monitor the NO of the two-stage SCR.x Conversion efficiency.

[0014] In one embodiment of the present invention, step S100 includes:

[0015] Step S101, by placing NO at the first-stage SCR inlet and the second-stage SCR inlet x Sensors automatically acquire real-time NO levels x The concentration data are denoted as Q1 and Q2, respectively.

[0016] Step S102: Monitor the engine's operating status in real time, including engine speed and circulating oil volume;

[0017] Step S103: Based on the real-time acquired engine speed and circulating oil volume, automatically retrieve the corresponding NO2 proportion coefficients from the pre-stored NO2 model, and record them as R1 and R2 respectively.

[0018] Step S104, using the measured NO x The concentrations Q1 and Q2, along with the queried NO2 proportion coefficients R1 and R2, are used to automatically calculate the NO2 concentrations at the inlet of the first-stage SCR and the inlet of the second-stage SCR, which are denoted as M1 and M2, respectively.

[0019] In one embodiment of the present invention, step S200 includes:

[0020] Step S201: Automatically monitor the temperature sensors arranged before the first-stage SCR and the second-stage SCR to obtain exhaust temperature data in real time, which are recorded as T1 and T2 respectively.

[0021] Step S202, from NO x The NO2 concentration data, namely M1 and M2, are obtained in the NO2 concentration monitoring step.

[0022] Step S203: The obtained exhaust temperatures T1 and T2 and NO2 concentrations M1 and M2 are integrated and automatically stored in the internal memory.

[0023] Step S204: Continuously monitor the changes in exhaust temperature and NO2 concentration, and update the stored data in real time as input parameters for the N2O generation difficulty model.

[0024] In one embodiment of the present invention, step S300 includes:

[0025] Step S301: Based on research data and experience, a mathematical model is established in advance to describe the relationship between the ease of N2O generation and exhaust temperature and NO2 concentration.

[0026] Step S302: The real-time monitored exhaust temperatures T1 and T2, as well as NO2 concentrations M1 and M2, are automatically input into the N2O generation difficulty model.

[0027] Step S303: Using the established mathematical model, the N2O generation difficulty coefficients of the first-stage SCR and the second-stage SCR are automatically calculated based on the input exhaust temperature and NO2 concentration, and are denoted as K1 and K2 respectively.

[0028] The lower the difficulty coefficient, the easier it is to generate N2O, which requires control; the higher the difficulty coefficient, the more difficult it is to generate N2O.

[0029] In one embodiment of the present invention, step S400 includes:

[0030] Step S401: Automatically obtain the N2O generation difficulty coefficients K1 and K2 of the first-level SCR and the second-level SCR from the N2O generation difficulty model;

[0031] Step S402: Based on N2O, generate difficulty coefficients K1 and K2 to determine the correction direction of urea injection;

[0032] Step S403: Based on the determined correction direction, automatically calculate the correction coefficient L for urea injection;

[0033] Step S404: Apply the calculated correction coefficient L to the injection volume of the first-stage urea to dynamically adjust the injection volume of the first-stage urea.

[0034] In one embodiment of the present invention, step S500 includes:

[0035] Step S501, automatically remove NO from the NO placed before and after the catalyst. x Real-time NO is obtained from the sensor x The concentration data are denoted as N1 and N2, respectively.

[0036] Step S502, using the obtained NO x Based on the concentration data, the total NO concentration of the two-stage SCR system is automatically calculated using the formula F=(N1-N2) / N1. x Conversion efficiency F;

[0037] Step S503: Compare the calculated conversion efficiency F with a preset threshold or historical data to determine whether the conversion efficiency has decreased.

[0038] In step S504, if the conversion efficiency F does not decrease, the current urea injection correction coefficient L is maintained, and the correction strategy continues to be executed; if the conversion efficiency F decreases, the urea injection correction coefficient L is automatically adjusted to 1, and the correction is canceled.

[0039] Secondly, the present invention provides a diesel engine urea injection control system based on real-time parameter monitoring, applied in a controller. The system includes: a first calculation module, a first monitoring module, a second calculation module, a dynamic adjustment module, and the second monitoring module. The first calculation module is used to control the urea injection of a diesel engine based on real-time parameter monitoring, using urea injection at the inlet of a two-stage SCR. x Sensor, real-time measurement of NO x The NO2 concentration is calculated by querying the NO2 proportion coefficient from the NO2 model in conjunction with the engine operating status. The first monitoring module monitors the temperature and NO2 concentration before the SCR in real time, using them as input parameters for the N2O formation difficulty model. The second calculation module establishes an N2O formation difficulty model based on temperature and NO2 concentration according to N2O formation characteristics, and calculates the N2O formation difficulty coefficient for the two-stage SCR. The dynamic adjustment module dynamically adjusts the first-stage urea injection quantity based on the N2O formation difficulty coefficient. The second monitoring module monitors the NO2 concentration of the two-stage SCR. x Conversion efficiency.

[0040] In one embodiment of the present invention, the first calculation module includes: a first acquisition unit, a first monitoring unit, a query unit, and a first calculation unit. The first acquisition unit is used to obtain information from the NO... (The sentence is incomplete and requires more context to translate accurately). x Sensors automatically acquire real-time NO levels x The concentration data are denoted as Q1 and Q2, respectively. The first monitoring unit is used to monitor the engine's operating status in real time, including engine speed and circulating oil volume. The query unit is used to automatically query the corresponding NO2 proportion coefficients from the pre-stored NO2 model based on the real-time acquired engine speed and circulating oil volume, denoted as R1 and R2, respectively. The first calculation unit is used to utilize the measured NO... x The concentrations Q1 and Q2, along with the queried NO2 proportion coefficients R1 and R2, are used to automatically calculate the NO2 concentrations at the inlet of the first-stage SCR and the inlet of the second-stage SCR, which are denoted as M1 and M2, respectively.

[0041] Thirdly, the present invention provides an electronic device, comprising:

[0042] At least one processor; and

[0043] A memory that is communicatively connected to the at least one processor;

[0044] The memory stores instructions that can be executed by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the urea injection control method for diesel engines based on real-time parameter monitoring as described above.

[0045] Fourthly, the present invention provides a computer-readable storage medium including a computer program and instructions, which, when the computer program or the instructions are executed on a computer, cause the computer to perform the urea injection control method for a diesel engine based on real-time parameter monitoring as described above.

[0046] Compared with the prior art, the urea injection control method and system for diesel engines based on real-time parameter monitoring according to the present invention has the following advantages:

[0047] 1. Through real-time monitoring and adjustments, N2O emissions were effectively reduced, meeting emission regulations.

[0048] 2. While reducing N2O emissions, it is possible to maintain NO emissions. x Its high conversion efficiency ensures overall emission compliance;

[0049] 3. It achieves automatic acquisition, processing and output without human intervention, thus improving the intelligence level of system operation. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of an existing diesel engine aftertreatment system;

[0051] Figure 2 This is a flowchart illustrating a diesel engine urea injection control method based on real-time parameter monitoring, as described in Embodiment 1 of the present invention.

[0052] Figure 3 This is a schematic diagram of a diesel engine urea injection control system based on real-time parameter monitoring, according to Embodiment 2 of the present invention.

[0053] Figure 4 This is a schematic diagram of the structure of an electronic device according to Embodiment 3 of the present invention;

[0054] Figure 5 This is a schematic diagram of the working logic of a diesel engine urea injection control method based on real-time parameter monitoring according to a specific embodiment of the present invention. Detailed Implementation

[0055] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit the scope of the invention. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the embodiments of the present invention, and not all structures.

[0056] Example 1

[0057] Figure 2This is a flowchart illustrating a diesel engine urea injection control method based on real-time parameter monitoring, as described in Embodiment 1 of the present invention. Figure 2 As shown, Embodiment 1 provides a urea injection control method for diesel engines based on real-time parameter monitoring, applied in a controller. The method includes:

[0058] Step S100, through the NO arranged at the two-stage SCR inlet x Sensor, real-time measurement of NO x The concentration was determined by querying the NO2 proportion coefficient from the NO2 model in conjunction with the engine operating status, and the NO2 concentration was calculated.

[0059] Specifically, step S100 is a key initiation step in the urea injection control method, which involves NO injection at the inlet of the two-stage SCR system. x Sensor measures NO in real time x The NO2 concentration is calculated by dynamically querying the NO2 percentage coefficient from a pre-stored NO2 model, taking into account the engine's operating status. This process is not only highly automated but also highly accurate, reflecting the NO2 concentration in engine exhaust in real time. x The distribution of NO2 provides crucial information for precise control of urea injection. This step lays a solid foundation for reducing N2O emissions and optimizing SCR system performance. The controller mentioned can be, for example, an on-board controller (ECU).

[0060] Step S200: Monitor the temperature and NO2 concentration before SCR in real time, as input parameters for the N2O generation difficulty model;

[0061] Specifically, step S200 accurately captures key factors affecting N2O generation by real-time monitoring of exhaust temperature and NO2 concentration before SCR, and imports this data as input parameters into the N2O generation ease model. This step ensures the accuracy and timeliness of the model predictions, which is crucial for dynamically adjusting the urea injection strategy to reduce N2O emissions.

[0062] Step S300: Based on the N2O generation characteristics, establish an N2O generation difficulty model based on temperature and NO2 concentration, and calculate the N2O generation difficulty coefficient of the two-stage SCR.

[0063] Specifically, step S300 constructs an N2O generation difficulty model based on N2O generation characteristics, using exhaust temperature and NO2 concentration as variables. This model allows the system to accurately calculate the N2O generation difficulty coefficient for a two-stage SCR system, providing a scientific basis for optimizing urea injection strategies and reducing N2O emissions.

[0064] Step S400: Dynamically adjust the first-stage urea injection volume based on the difficulty coefficient of N2O generation.

[0065] Specifically, step S400 intelligently adjusts the first-stage urea injection rate in real time based on the N2O generation difficulty coefficient. When the generation difficulty coefficient indicates that N2O is easily generated, the urea injection is reduced; conversely, it is appropriately increased to balance NO. x Transformation and N2O suppression ensure emissions meet standards while optimizing urea consumption.

[0066] Step S500: Monitor the NO of the two-stage SCR. x Conversion efficiency;

[0067] Specifically, step S500 focuses on monitoring the NO of the two-stage SCR system. x Conversion efficiency is monitored in real time to ensure that the treatment effect meets the expected standards. This step aims to promptly detect and address any decline in efficiency, maintain efficient system operation, and ensure that exhaust emissions continue to meet standards.

[0068] In this embodiment, step S100 includes:

[0069] Step S101, by placing NO at the first-stage SCR inlet and the second-stage SCR inlet x Sensors automatically acquire real-time NO levels x The concentration data are denoted as Q1 and Q2, respectively.

[0070] Specifically, a high-precision NO is installed at the inlet of the first-stage SCR system. x A high-precision NO sensor is also installed at the inlet of the second-stage SCR system. x Sensors; ensure that the sensor is installed in a reasonable location and can accurately reflect the NO entering each stage of the SCR system. x Concentration. Two NOs x The sensors measure the NO at their respective inlets in real time. x Concentration. The sensor will measure the NO concentration. x Concentration data is converted into electrical signals and transmitted to the control system (which has a built-in control system) via data lines. The data acquisition module in the control system receives and processes these electrical signals, converting them into specific NO concentrations. x Concentration value. The control system will reduce the NO concentration at the inlet of the first-stage SCR. x The concentration value is labeled Q1. Similarly, the NO at the inlet of the second-stage SCR is... x The concentration values ​​are labeled Q2. These data will be used in subsequent calculations and analyses.

[0071] For example, a diesel engine, under normal operating conditions, employs a two-stage SCR (Selective Catalytic Reduction) system in its exhaust gas treatment system. At a certain moment, the control system uses NO₂ located at the inlet of the first and second stage SCRs. xThe sensor acquired real-time NO x Concentration data: NO at the inlet of the first-stage SCR x Concentration (Q1): 300 ppm, indicating that the NO in the exhaust gas before treatment by the first-stage SCR system is [value missing]. x The concentration is 300 ppm. This value will serve as one of the basic data points for calculating the NO2 concentration at the inlet of the first-stage SCR. The NO2 concentration at the inlet of the second-stage SCR... x Concentration (Q2): 250 ppm. After treatment by the first-stage SCR system, the NO in the exhaust gas... x The concentration decreased to 250 ppm. This value is equally important because it reflects the treatment effect of the first-stage SCR system and will serve as one of the fundamental data points for calculating the NO2 concentration at the inlet of the second-stage SCR. These real-time NO2 concentrations... x The concentration data (Q1 and Q2) can be further combined with the engine's operating status and other relevant parameters to perform subsequent calculations and analyses, such as querying the NO2 proportion coefficient, calculating the NO2 concentration, and assessing the ease of N2O formation, thereby providing a scientific basis for dynamically adjusting the urea injection volume.

[0072] Step S102: Monitor the engine's operating status in real time, including engine speed and circulating oil volume, as the basis for subsequent calculation of the NO2 proportion coefficient.

[0073] Specifically, the engine is equipped with a speed sensor and a fuel quantity sensor (or similar devices, such as a fuel injection control unit). The speed sensor measures the engine speed in real time and converts the speed signal into an electrical signal, which is then transmitted to the control system. The fuel quantity sensor (or related device) monitors the amount of fuel circulating in the engine and similarly converts the fuel quantity information into an electrical signal, which is also transmitted to the control system. The data acquisition module in the control system receives the electrical signals from the speed sensor and the fuel quantity sensor and converts these signals into specific values, namely the engine's real-time speed and the amount of fuel circulating. The control system stores the received speed and fuel quantity data in its internal memory for later retrieval and use. As the engine runs, this data is continuously updated to reflect the engine's current actual operating status.

[0074] For example, a diesel engine is running at a stable speed for a long-distance transport mission. At this time, the control system obtains the following real-time data through the speed sensor and fuel level sensor: Engine speed: 1800 rpm, indicating that the engine is currently running at a medium speed, suitable for stable long-distance driving. Circulating fuel volume: 50 liters / hour, meaning the engine consumes approximately 50 liters of fuel per hour to maintain its operation. The control system stores this data in its internal memory and retrieves it as needed. For example, when calculating the NO2 proportion coefficient in step S103, the control system will look up the corresponding proportion coefficient from the pre-stored NO2 model based on the current engine speed and circulating fuel volume. If the model shows that NO2 accounts for a certain proportion at the current speed and fuel volume, the control system will determine the proportion coefficient. x The proportion of NO2 in the system is approximately 15%, so this information will be used to calculate the NO2 concentration at the inlet of the first and second stage SCR systems. Through this real-time monitoring and data acquisition and processing, the control system can accurately grasp the engine's operating status, providing precise basic data support for subsequent urea injection control.

[0075] Step S103: Based on the real-time acquired engine speed and circulating oil volume, automatically retrieve the corresponding NO2 proportion coefficients from the pre-stored NO2 model, and record them as R1 and R2 respectively.

[0076] Specifically, ensure that the control system has received and stored the real-time acquired engine speed and circulating fuel volume data (as described in step S102). Verify that the pre-stored NO2 model is available and contains data points covering the current engine speed and circulating fuel volume range. The control system determines the query conditions in the NO2 model based on the current engine speed and circulating fuel volume. Use an appropriate query algorithm (such as interpolation, lookup tables, etc.) to find the NO2 proportion coefficient in the NO2 model that best matches the current engine state. If the model is discrete (e.g., in lookup table form), it may be necessary to calculate the NO2 proportion coefficient for non-directly corresponding points through interpolation. Store the queried NO2 proportion coefficient in the control system for subsequent calculations. If any problems are encountered during the query process (such as missing data points, model range mismatch, etc.), the control system should be able to identify and take appropriate error handling measures.

[0077] For example, a diesel engine is currently running at 1800 rpm and has a fuel circulation rate of 50 liters per hour. The control system uses this real-time data to look up the corresponding NO2 percentage coefficient in a pre-stored NO2 model. Assume the NO2 model is a two-dimensional lookup table containing NO2 percentage coefficients for different combinations of engine speed and fuel circulation rate. The control system first determines the positions of the current engine speed (1800 rpm) and fuel circulation rate (50 liters per hour) in the lookup table. If these two values ​​match a data point in the lookup table, the corresponding NO2 percentage coefficient is directly read. If they do not match, the control system uses interpolation (such as bilinear interpolation) to calculate the NO2 percentage coefficient closest to the current value. Assume that after querying and interpolation, the obtained NO2 percentage coefficient is 0.15 (i.e., NO... x The NO2 content is 15%. This NO2 content coefficient will be used in subsequent steps to calculate the NO2 concentration at the inlet of the first and second stage SCRs (as described in step S104). Through this query process, the control system can accurately obtain the NO2 content coefficient based on the real-time operating status of the engine, providing key parameters for subsequent urea injection control.

[0078] Step S104, using the measured NO x The concentrations Q1 and Q2, along with the queried NO2 proportion coefficients R1 and R2, are used to automatically calculate the NO2 concentrations at the inlet of the first-stage SCR and the inlet of the second-stage SCR, which are denoted as M1 and M2, respectively; where M1 = Q1 × R1, M2 = Q2 × R2.

[0079] Specifically, ensure that the NO values ​​of the first and second level SCR entry points have been obtained. x Concentration data, denoted as Q1 and Q2 (units are usually ppm). Ensure that the NO2 percentage coefficients corresponding to the current engine speed and circulating oil volume have been retrieved through step S103, denoted as R1 and R2 (unitless, representing NO2 in NO...). x The NO2 concentration at each SCR inlet is calculated using the formula Mi=Qi×Ri, where i represents the stage number (1 or 2). For the first-stage SCR inlet, M1=Q1×R1 is calculated, and for the second-stage SCR inlet, M2=Q2×R2 is calculated. The calculated NO2 concentrations (M1 and M2) are stored in the control system for later use.

[0080] For example, the operating data of a diesel engine at a certain moment is as follows:

[0081] Level 1 SCR Entry NO x Concentration Q1 = 300 ppm;

[0082] Second-level SCR entry NO xConcentration Q2 = 250 ppm;

[0083] The NO2 proportion coefficients obtained through step S103 are: Level 1 R1 = 0.15, Level 2 R2 = 0.12;

[0084] Next, proceed with the calculation according to step S104:

[0085] The NO2 concentration at the inlet of the first-stage SCR is M1 = Q1 × R1 = 300 ppm × 0.15 = 45 ppm;

[0086] The NO2 concentration at the inlet of the second-stage SCR is M2 = Q2 × R2 = 250 ppm × 0.12 = 30 ppm;

[0087] This yields the NO2 concentrations at the inlets of the first and second stage SCRs. These data will be used in subsequent steps to assess the ease of N2O formation and adjust the urea injection rate accordingly. By refining step S104, it can be ensured that the actual operating conditions of the engine (reflected by the NO2 proportion coefficient) are taken into account when calculating the NO2 concentration, thus providing more accurate basic data for subsequent urea injection control.

[0088] In this embodiment, step S200 includes:

[0089] Step S201: Automatically monitor the temperature sensors arranged before the first-stage SCR and the second-stage SCR to obtain exhaust temperature data in real time, which are recorded as T1 and T2 respectively.

[0090] Specifically, high-precision temperature sensors are installed at the inlets of the first and second stage SCR systems. These sensors ensure accurate measurement and reflection of the exhaust temperature at the SCR system inlet. The temperature sensors detect the temperature at the SCR inlet in real time and convert the temperature value into an electrical signal. These electrical signals are transmitted to the data acquisition module in the control system via data lines. The data acquisition module receives the electrical signals from the temperature sensors and converts them into a specific temperature value (usually in degrees Celsius). The converted temperature value is stored in the internal memory of the control system for subsequent analysis and use. The control system continuously monitors the output of the temperature sensors and updates the stored temperature data in real time. If the temperature value changes significantly or exceeds the preset range, the control system should be able to trigger corresponding alarms or adjustment measures.

[0091] For example, a diesel engine is running, and its exhaust gas treatment system includes a two-stage SCR (Selective Catalytic Reduction) system. Temperature sensors are installed at the inlet of the first and second stage SCR systems to monitor exhaust temperature. At a certain moment, the temperature sensor at the first stage SCR inlet detects an exhaust temperature of 400 degrees Celsius and converts this temperature value into an electrical signal, which is then sent to the control system. Simultaneously, the temperature sensor at the second stage SCR inlet also detects an exhaust temperature, let's say 350 degrees Celsius, and similarly sends this temperature value to the control system. Upon receiving the electrical signals from the two temperature sensors, the control system converts them into specific temperature values: 400 degrees Celsius and 350 degrees Celsius, respectively. These temperature values ​​are stored in the control system's internal memory and labeled as the first-stage SCR inlet temperature T1 and the second-stage SCR inlet temperature T2. In step S300, these temperature values, along with the NO2 concentration, are used as input parameters to calculate the N2O generation difficulty coefficient of the two-stage SCR system. Based on the effect of temperature on N2O formation (generally, N2O formation decreases at high temperatures, but excessively high or low temperatures can affect the catalytic efficiency of SCR), the control system will assess the ease of N2O formation under current conditions and adjust the urea injection rate accordingly. By refining step S201, real-time and accurate monitoring of the temperature at the SCR inlet can be ensured, providing reliable data support for subsequent N2O formation assessment and control.

[0092] Step S202, from NO x The NO2 concentration data, namely M1 and M2, are obtained in the NO2 concentration monitoring step as important parameters affecting N2O emissions.

[0093] Specifically, in step S104, NO has already been passed. x The NO2 concentrations (M1 and M2) at the inlets of the first and second stage SCRs are calculated using the concentrations (Q1 and Q2) and NO2 proportion coefficients (R1 and R2). These data will be directly used in step S202 without further measurement. However, in practical applications, if the control system needs to continuously monitor the NO2 concentration, a dedicated NO2 sensor can be installed at the SCR inlet to acquire data in real time. The calculated or real-time acquired NO2 concentration values ​​(M1 and M2) are stored in the internal memory of the control system. The accuracy and integrity of the data must be ensured for subsequent analysis and use. If the control system uses a real-time sensor to acquire the NO2 concentration, it should be ensured that the sensor data can be updated to the control system in real time. If the NO2 concentration is obtained through calculation, when NO... xWhen the concentration or NO2 proportion coefficient changes, the NO2 concentration value should be recalculated and updated. The acquired NO2 concentration data should be validated to ensure it is within a reasonable range and consistent with expectations. If abnormal data is found, the sensor or calculation process should be checked promptly to troubleshoot the problem. The validated NO2 concentration data (M1 and M2) should be used as one of the input parameters for the N2O generation ease model. Together with other relevant parameters (such as exhaust temperature, urea injection rate, etc.), it is used to assess the ease of N2O generation and adjust the urea injection strategy accordingly.

[0094] For example, at a certain moment, the NO2 concentrations at the inlet of the first and second stage SCRs, calculated through step S104, are M1 = 45 ppm and M2 = 30 ppm, respectively. These data will be stored in the control system and used for subsequent N2O generation assessment. If the system uses a real-time sensor to monitor the NO2 concentration, when the sensor detects a change in the NO2 concentration (e.g., due to engine operating condition adjustments leading to NO2 concentration changes),... x (Due to changes in emission characteristics), the new NO2 concentration value will be automatically updated to the control system, replacing the old data. In step S300, the control system will use the updated NO2 concentration value (along with other parameters such as exhaust temperature) as input to run the N2O generation difficulty model. The model calculates the N2O generation difficulty coefficient under the current conditions based on the input parameters, and the control system adjusts the urea injection rate according to this coefficient to optimize NO generation. x Conversion efficiency and N2O emission performance. Through the detailed steps and examples above, the role and implementation method of step S202 in the urea injection control process can be clearly understood.

[0095] Step S203: The obtained exhaust temperatures T1 and T2 and NO2 concentrations M1 and M2 are integrated and automatically stored in the internal memory for subsequent processing and retrieval.

[0096] Specifically, prior to this step, the system has already used a temperature sensor and an NO2 concentration monitoring device (possibly via NO...). xThe system acquires the exhaust temperatures (T1 and T2) and NO2 concentrations (M1 and M2) at the inlet of the first and second stage SCRs in real time (either calculated from sensors and NO2 proportion coefficients, or directly measured by NO2 sensors). The system integrates these scattered data (T1, T2, M1, M2) into a complete dataset. This process involves data formatting, unit standardization, and outlier checking to ensure the accuracy and efficiency of subsequent processing. The integrated dataset should contain all necessary input parameters so that it can be directly used as input for the N2O generation difficulty model. The system automatically stores the integrated dataset in internal memory, which can be, for example, RAM, Flash memory, or other types of non-volatile storage devices.

[0097] Step S204: Continuously monitor the changes in exhaust temperature and NO2 concentration, and update the stored data in real time as input parameters for the N2O generation ease model to ensure that the parameters used for calculating the N2O generation ease model are up-to-date.

[0098] Specifically, the system uses a temperature sensor and an NO2 concentration monitoring device installed at the SCR inlet (which may be a direct NO2 sensor, or a NO2-based sensor). x The system continuously monitors changes in exhaust temperature and NO2 concentration (derived from sensors and NO2 proportion coefficient calculations). These sensors acquire data in real time and convert it into electrical or digital signals for subsequent processing. The system's data acquisition module receives signals from the sensors and converts them into processable temperature and NO2 concentration values. Preliminary processing of the acquired data, including filtering, noise reduction, and calibration, is performed to improve data accuracy and reliability. The latest processed temperature (T1 and T2) and NO2 concentration (M1 and M2) data are automatically updated to the internal memory, overwriting older data. This ensures that the stored data always reflects the current exhaust temperature and NO2 concentration status. The updated data serves as input parameters for the N2O generation difficulty model. When the model needs to calculate the N2O generation difficulty coefficient, it retrieves this latest data directly from the internal memory. Through continuous monitoring and real-time updating mechanisms, the system ensures that the parameters used for calculating the N2O generation difficulty model are always up-to-date. This is crucial for improving the model's predictive accuracy and the real-time performance of urea injection control. Through the continuous monitoring and real-time update mechanism in step S204, the urea injection control system can ensure that the latest exhaust temperature and NO2 concentration data are always used as input parameters for the N2O generation difficulty model under dynamically changing operating conditions, thereby improving the accuracy and real-time performance of urea injection control.

[0099] In this embodiment, step S300 includes:

[0100] Step S301: Based on research data and experience, a mathematical model is established in advance to describe the relationship between the ease of N2O generation and exhaust temperature and NO2 concentration.

[0101] Specifically, firstly, a large amount of experimental data needs to be collected, covering N2O formation under different exhaust temperatures and NO2 concentrations. This data can be obtained through laboratory experiments, engine bench tests, or actual vehicle operation. The collected data should be analyzed in detail to identify the influence of exhaust temperature and NO2 concentration on the ease of N2O formation. This may involve methods such as statistical analysis and regression analysis to determine the quantitative relationships between various factors. Based on the data analysis results, a mathematical model should be constructed to describe the relationship between the ease of N2O formation and exhaust temperature and NO2 concentration. This model can be a multinomial regression model, a neural network model, a support vector machine model, etc., the specific choice depending on the characteristics of the data and the purpose of modeling. The model should be validated using a dataset not used in model building to evaluate its predictive accuracy and generalization ability. If the model's predictions show a high degree of agreement with the actual data, the model is considered successfully built; otherwise, the model needs to be adjusted and optimized. The model should be optimized based on the validation results to improve its predictive accuracy and stability. Optimization methods may include adjusting model parameters, adding input features, and improving the model structure. The optimized model is embedded into the urea injection control system to calculate the N2O generation difficulty coefficient in real time and adjust the urea injection amount based on the coefficient.

[0102] For example, data on N2O formation under different exhaust temperatures (T) and NO2 concentrations (M) were obtained through a series of experiments. Data analysis revealed the following relationship between the ease of N2O formation (K) and exhaust temperature and NO2 concentration:

[0103]

[0104] Here, (a, b, c, d, e, f) are model parameters obtained through regression analysis. To construct this model, the experimental data can first be fitted using the least squares method to obtain the specific values ​​of the model parameters. Then, methods such as cross-validation are used to validate and optimize the model. Finally, a mathematical model that can accurately describe the relationship between the ease of N2O formation and exhaust temperature and NO2 concentration is obtained. In the urea injection control system, the real-time exhaust temperature (T1 and T2) and NO2 concentration (M1 and M2) data are input into this model to calculate the N2O formation difficulty coefficients (K1 and K2) for the two-stage SCR. Then, the urea injection rate is adjusted according to these coefficients to reduce N2O formation while maintaining NO2 concentration. x Highly efficient conversion.

[0105] Step S302: The real-time monitored exhaust temperatures T1 and T2, as well as NO2 concentrations M1 and M2, are automatically input into the N2O generation difficulty model.

[0106] Specifically, prior to this step, the system has already used a temperature sensor and an NO2 concentration monitoring device installed at the SCR inlet (which can be a direct NO2 sensor or a NO2-based sensor). x The system monitors exhaust temperature (T1 and T2) and NO2 concentration (M1 and M2) in real time using sensors and NO2 proportion coefficient calculations. Before inputting this data into the model, the system validates it to ensure its accuracy, completeness, and reasonableness. This includes checking whether the data is within the expected range and whether there are any outliers. Once the data passes validation, the system automatically uses these data (T1, T2, M1, M2) as input parameters, inputting them into the pre-established N2O generation difficulty model according to the format and order required by the model. After receiving the input parameters, the model calculates according to its internal algorithm and formulas, outputting the corresponding N2O generation difficulty coefficients (such as K1 and K2). These coefficients reflect the ease or difficulty of N2O generation in the SCR system under the current exhaust temperature and NO2 concentration conditions.

[0107] Step S303: Using the established mathematical model, the N2O generation difficulty coefficients of the first-stage SCR and the second-stage SCR are automatically calculated based on the input exhaust temperature and NO2 concentration, and are denoted as K1 and K2 respectively.

[0108] The lower the difficulty coefficient, the easier it is to generate N2O, requiring control; conversely, the higher the difficulty coefficient, the more difficult it is to generate N2O. The controller uses the calculated K1 and K2 values ​​in subsequent urea injection correction steps. During actual operation, the controller continuously collects new data and updates and optimizes the N2O generation difficulty model as needed to improve its accuracy and adaptability.

[0109] Specifically, this step first requires invoking a pre-established mathematical model. This model, built upon extensive experimental data and theoretical research, describes the complex relationship between the ease of N2O generation and parameters such as exhaust temperature and NO2 concentration. Real-time exhaust temperature (T1 and T2) and NO2 concentration (M1 and M2) data are obtained from the system's monitoring module. This data has been validated to ensure its accuracy and effectiveness. T1 and M1 are used as input parameters for the first-stage SCR, and T2 and M2 are used as input parameters for the second-stage SCR, respectively, and input into the mathematical model. The model processes and calculates these input parameters according to its internal algorithms and formulas, ultimately outputting the N2O generation difficulty coefficients K1 and K2 for the first and second-stage SCRs. The calculated K1 and K2 are then output to the control system for use in subsequent steps (such as urea injection adjustment).

[0110] For example, the real-time monitoring data of a certain diesel engine at a certain moment is as follows:

[0111] The first-stage SCR inlet exhaust temperature T1 = 400°C

[0112] Second-stage SCR inlet exhaust temperature T2 = 350°C

[0113] The NO2 concentration at the inlet of the first-stage SCR is M1 = 45 ppm.

[0114] The NO2 concentration at the inlet of the second-stage SCR is M2 = 30 ppm.

[0115] These data have been verified by the system and confirmed to be correct. Next, the system will use these data as input parameters to call the pre-established N2O generation difficulty model for calculation.

[0116] For example, if the model is based on a multinomial regression algorithm, its internal formula could be:

[0117]

[0118] The parameters a, b, c, d, e, and f were obtained from training data. For the first-stage SCR: input parameters T=400°C, M=45ppm, the value of K1 was calculated by substituting them into the model formula; for the second-stage SCR: input parameters T=350°C, M=30ppm, the value of K2 was calculated by substituting them into the model formula. After calculation, the results are: K1 = 0.6 (indicating that N2O generation is relatively easy in the first-stage SCR), K2 = 0.8 (indicating that N2O generation is relatively difficult in the second-stage SCR). These difficulty coefficients will serve as important bases for subsequent adjustments to the urea injection rate. For example, if K1 is small and K2 is large, the system may reduce the urea injection rate in the first stage to reduce N2O generation, and may increase the urea injection rate in the second stage to ensure NOx The system achieves efficient conversion. Conversely, it also achieves efficient conversion. Through this dynamic adjustment strategy, the system can optimize urea consumption and the overall performance of the SCR system while meeting emission regulations.

[0119] In this embodiment, step S400 includes:

[0120] Step S401: Automatically obtain the N2O generation difficulty coefficients K1 and K2 of the first-level SCR and the second-level SCR from the N2O generation difficulty model;

[0121] Specifically, in this step, the control system first accesses a pre-established N2O generation difficulty model. This model has already performed calculations based on the input exhaust temperatures (T1 and T2) and NO2 concentrations (M1 and M2), and outputs the corresponding N2O generation difficulty coefficients. The control system extracts the N2O generation difficulty coefficients for the first-stage SCR and the second-stage SCR from the model, denoted as K1 and K2, respectively. These coefficients represent the ease or difficulty of N2O generation in the two-stage SCR system under the current operating conditions.

[0122] In practical applications, step S401 is an automated step in the urea injection control system. When the engine is running, the control system monitors the exhaust temperature and NO2 concentration at the SCR inlet in real time and inputs this data into the N2O generation ease model. After the model completes its calculations, the control system automatically retrieves the K1 and K2 coefficients from the model and adjusts the urea injection quantity based on these coefficients. In this way, the system can dynamically optimize the performance of the SCR system according to the current operating conditions, reducing N2O generation while maintaining high NO2O efficiency. x Transformation. By automating the acquisition of the N2O generation difficulty coefficient, the urea injection control system can significantly improve the accuracy and real-time performance of emission control, thereby better meeting increasingly stringent emission regulations.

[0123] Step S402: Based on the N2O generation difficulty coefficients K1 and K2, determine the correction direction of urea injection; if K1 is smaller and K2 is larger, it means that the first-stage SCR is easy to generate N2O, and injection reduction correction is required; if K1 is larger and K2 is smaller, it means that the second-stage SCR is not easy to generate N2O, and injection increase correction can be performed.

[0124] Specifically, K1 represents the N2O generation difficulty coefficient of the first-stage SCR; a smaller value indicates easier N2O generation, and a larger value indicates greater generation difficulty. K2 represents the N2O generation difficulty coefficient of the second-stage SCR; similarly, a smaller value indicates easier N2O generation, and a larger value indicates greater generation difficulty. A smaller K1 and a larger K2 indicate that N2O is easily generated in the first-stage SCR, but relatively difficult to generate in the second-stage SCR. To reduce N2O generation in the first-stage SCR while ensuring NO... x The efficient conversion requires reducing the amount of urea injected in the first stage (i.e., injection reduction correction). After injection reduction, although the NO converted in the first stage of SCR... x It will decrease, but the second-stage SCR will receive NO. x An increase in concentration may lead to an increase in the urea injection rate to maintain total NO levels. x Conversion efficiency. Since N2O is not easily generated in the second-stage SCR, increasing the urea injection rate will not lead to a significant increase in N2O emissions. Larger K1 and smaller K2: Conversely, if K1 is larger and K2 is smaller, it indicates that N2O generation is relatively difficult in the first-stage SCR but easier in the second-stage SCR. In this case, to optimize overall emission performance, increasing the urea injection rate in the first-stage SCR (i.e., increased injection correction) can be considered to convert more NO. x And reduce NO reaching the second stage of SCR. x Concentration. Since the second-stage SCR does not readily generate N2O at this stage, reducing the urea injection rate will not lead to NO concentration. x The conversion efficiency decreases significantly, but this also helps reduce N2O emissions. Based on the comparison results of K1 and K2, the control system will formulate corresponding urea injection correction strategies. These strategies will guide the increase or decrease of urea injection volume to reduce N2O emissions while maintaining high NO efficiency. x The purpose of the conversion is to further refine the urea injection process. Additionally, the correction of urea injection is real-time and dynamic; the values ​​of K1 and K2 change with variations in engine operating conditions (such as load and speed). Therefore, the control system needs to continuously monitor these coefficients and adjust the urea injection quantity in real time as needed. Through the decision-making process in step S402, the urea injection control system can intelligently adjust the urea injection quantity based on the current SCR system status and emission performance requirements, thereby achieving better emission control results.

[0125] Step S403: Based on the determined correction direction, automatically calculate the correction coefficient L for urea injection; where, if a reduction in injection correction is required, output a correction coefficient L less than 1; if an increase in injection correction is required, output a correction coefficient L greater than 1.

[0126] Specifically, the correction coefficient L is a proportional factor used to adjust the urea injection quantity. When L is less than 1, it indicates that the urea injection quantity needs to be reduced (reduction correction); when L is greater than 1, it indicates that the urea injection quantity needs to be increased (increase correction); when L equals 1, it indicates that no adjustment of the urea injection quantity is needed. Based on the correction direction determined in step S402, the control system will automatically calculate the value of the correction coefficient L. If a reduction correction is required (i.e., K1 is smaller and K2 is larger), the control system will output a correction coefficient L less than 1 according to a preset algorithm or lookup table. The specific value of L depends on the specific values ​​of K1 and K2 and the system's control strategy; generally, the smaller the L value, the greater the reduction in injection quantity. If an increase correction is required (i.e., K1 is larger and K2 is smaller), the control system will also output a correction coefficient L greater than 1 according to a preset algorithm or lookup table. The specific value of L also depends on K1, K2, and the control strategy; the larger the L value, the greater the increase in injection quantity. The calculated correction coefficient L will be directly applied to the calculation of the urea injection quantity. Specifically, the original planned urea injection amount is multiplied by the correction factor L to obtain the adjusted urea injection amount.

[0127] For example, if the originally planned urea injection quantity is X units and the correction factor L is 0.8 (indicating a need to reduce injection), then the adjusted urea injection quantity will be 0.8X units; if the correction factor L is 1.2 (indicating a need to increase injection), then the adjusted urea injection quantity will be 1.2X units. The calculation of the correction factor L should be real-time. That is, as engine operating conditions change (such as load, speed, etc.), the control system should continuously monitor the values ​​of K1 and K2 and calculate and adjust the correction factor L in real time as needed to ensure optimal urea injection quantity. When calculating the correction factor L, the control system can also consider safety limits on urea injection quantity. For example, even if an increase in injection is needed, the urea injection quantity should not exceed the system's maximum allowable value; similarly, even if a reduction in injection is needed, the urea injection quantity should not fall below the minimum value required to maintain the normal operation of the SCR system. By automatically calculating and applying the correction factor L, the urea injection control system can flexibly adjust the urea injection quantity according to the current SCR system status and emission performance requirements, thereby achieving better emission control results.

[0128] In step S404, the calculated correction coefficient L is applied to the injection rate of the first-stage urea, and the actual urea injection rate is adjusted by multiplying by L. In this way, in the first-stage SCR, the injection rate of urea is dynamically adjusted according to the difficulty of N2O generation.

[0129] Among these measures, after adjusting the urea injection rate, the NO content of the two-stage SCR system was continuously monitored. xConversion efficiency and N2O emissions. If conversion efficiency decreases or N2O emissions increase, the controller will automatically adjust the correction factor L to ensure overall emissions compliance and system performance optimization.

[0130] Specifically, prior to this step, the system has already determined the correction direction for urea injection based on the N2O generation difficulty coefficients K1 and K2, and calculated the corresponding correction coefficient L. This L value is a scaling factor used to adjust the urea injection quantity. Before the correction coefficient L, the system calculates a basic first-stage urea injection quantity based on the current engine operating conditions (such as speed, load, etc.) and other relevant parameters. This basic injection quantity is based on meeting the NO... x The actual injection rate is set based on conversion efficiency requirements. In step S404, the system multiplies the calculated correction coefficient L by the base first-stage urea injection rate to obtain the adjusted actual injection rate. That is: Actual injection rate = Base injection rate × L. In this way, the urea injection rate can be dynamically adjusted according to the difficulty of N2O formation. If L is less than 1, the actual injection rate will decrease, which helps to reduce N2O formation in the first-stage SCR; if L is greater than 1, the actual injection rate will increase, which can help to improve NO conversion efficiency. x The conversion efficiency is assessed (although this is typically done under the condition that the second-stage SCR does not readily generate N2O). The adjusted urea injection rate is then sent to the urea injection system for injection. This ensures that urea is injected into the SCR system at the optimized rate to achieve the desired emission control effect. After urea injection, the system continuously monitors the performance and emissions of the SCR system. If the adjusted injection rate does not achieve the expected results (e.g., NO2O), the system will take action. x If conversion efficiency decreases or N2O emissions increase, the system may reassess the N2O generation difficulty coefficients K1 and K2 and recalculate the correction coefficient L for further adjustments.

[0131] In practical applications, the execution of step S404 is highly automated, requiring no manual intervention. The urea injection control system calculates the optimal urea injection quantity in real time based on engine operating conditions and SCR system status, and ensures stable and optimized emission performance through a dynamic adjustment mechanism. This intelligent control method not only improves the accuracy of emission control but also effectively reduces urea consumption and operating costs.

[0132] In this embodiment, step S500 includes:

[0133] Step S501, automatically remove NO from the NO placed before and after the catalyst. x Real-time NO is obtained from the sensor x The concentration data are denoted as N1 and N2, respectively.

[0134] Specifically, step S501 is a crucial step in the urea injection control process, involving real-time monitoring of the catalytic conversion efficiency of the SCR system. In this step, the system first automatically removes NO from the urea injection system located before and after the catalyst (i.e., the SCR system). x Real-time NO is obtained from the sensor x Concentration data. Specifically, NO before the catalyst. x The sensor measures NO in the raw exhaust gas before it is treated by the SCR system. x The concentration, this data is labeled as N1. And the NO after the catalyst... x The sensor measures the NO in the exhaust gas after it has been treated by the SCR system. x Concentration, this data is labeled as N2. These two NO... x Concentration data is crucial for evaluating the conversion efficiency of an SCR system. By comparing the values ​​of N1 and N2, the system can calculate the SCR system's response to NO. x The conversion efficiency, that is, what percentage of NO... x Urea is successfully converted into harmless nitrogen and water when passing through the SCR system. This conversion efficiency is one of the key indicators for measuring the performance of the SCR system and an important basis for adjusting the urea injection control strategy. After acquiring N1 and N2 data, the system usually immediately calculates the conversion efficiency and uses the results in subsequent urea injection rate adjustment decisions. If the conversion efficiency is lower than a preset threshold, it indicates that the current urea injection rate may be insufficient or excessive, requiring corresponding adjustments to optimize the performance of the SCR system. Therefore, step S501 is not only a necessary step in the urea injection control process but also one of the key links to ensure the efficient and stable operation of the SCR system.

[0135] Step S502, using the obtained NO x Based on the concentration data, the total NO concentration of the two-stage SCR system is automatically calculated using the formula F=(N1-N2) / N1. x Conversion efficiency F;

[0136] Specifically, step S502 is a core calculation step in the urea injection control process, which is based on the NO levels before and after the catalyst obtained in step S501. x Concentration data (N1 and N2) are used to evaluate the performance of the SCR system. In this step, the system uses a simple mathematical formula to calculate the total NO in the two-stage SCR. x Conversion efficiency F. Specifically, the formula F=(N1-N2) / N1 is used to quantify the SCR system's efficiency for NO. x The conversion capacity, where N1 represents the NO before the catalyst (i.e., untreated). x The concentration, while N2 represents the NO concentration after the catalyst (i.e., after treatment by the SCR system). xConcentration. By executing this formula, the system can automatically calculate the F-value, which is the concentration of NO in the two-stage SCR system. x The overall conversion efficiency. This efficiency value reflects the NO removal efficiency of the SCR system. x The ability to remove pollutants is one of the key indicators for evaluating the performance of a system. A high F-value indicates that the SCR system can effectively remove NO. x When urea is converted into harmless substances, emission control is effective; conversely, a low F-value may indicate system problems, such as insufficient urea injection, catalyst aging, or blockage, requiring further inspection and adjustment. Therefore, step S502 is not merely a simple mathematical calculation, but a crucial feedback loop in the urea injection control system. It helps the system understand the real-time operating status of the SCR system and adjust the urea injection strategy as needed to ensure emission compliance and optimize system performance.

[0137] Step S503: Compare the calculated conversion efficiency F with a preset threshold or historical data to determine whether the conversion efficiency has decreased.

[0138] Specifically, the system compares and analyzes the conversion efficiency F with a preset threshold or historical data. The preset threshold is the minimum conversion efficiency standard set according to emission regulations and system performance requirements, while historical data records the system's conversion efficiency performance under different operating conditions. By comparing, the system can quickly determine whether the current conversion efficiency is lower than the threshold or has decreased compared to historical data, thereby assessing whether the SCR system is operating normally and whether the urea injection strategy needs to be adjusted to maintain or improve the conversion efficiency.

[0139] Step S504: If the conversion efficiency F does not decrease, maintain the current urea injection correction coefficient L and continue implementing the correction strategy; if the conversion efficiency F decreases, it indicates that the current correction strategy may be detrimental to NO. x Upon conversion, the controller will automatically adjust the urea injection correction coefficient L to 1 and cancel the correction to ensure NO x Emissions compliance;

[0140] Among them, NO will be continuously monitored after the correction is cancelled. x Conversion efficiency and N2O emissions. If conversion efficiency recovers or N2O emissions decrease, the controller can reconsider whether urea injection correction is needed.

[0141] Specifically, step S504 is a key decision point in urea injection control. When the conversion efficiency F remains stable or improves, the system confirms that the current urea injection correction strategy is effective, therefore maintaining the correction coefficient L unchanged and continuing to optimize N2O and NO. x Emissions. However, once a decrease in conversion efficiency F is detected, the system immediately assesses that the current correction may be interfering with NO emissions.x The normal conversion process was immediately disrupted, and protective measures were taken: the urea injection correction coefficient L was automatically reset to 1, meaning all urea quantity adjustments based on the difficulty of N2O generation were cancelled, and the basic injection strategy was quickly restored to ensure NO... x Emissions quickly returned to compliance levels. This adjustment is not permanent; the system will continuously monitor conversion efficiency and N2O emissions, seeking opportunities for recovery or improvement. If monitoring data shows an increase in conversion efficiency or a decrease in N2O emissions, it indicates that environmental conditions or system status may have changed. In this case, the controller will reassess whether it is appropriate to introduce urea injection correction to balance NO. x The need for conversion and N2O suppression is to achieve more refined emission control.

[0142] Example 2

[0143] Figure 3 This is a schematic diagram of a urea injection control system for a diesel engine based on real-time parameter monitoring, as shown in Embodiment 2 of the present invention. Figure 3 As shown in Embodiment 2, a diesel engine urea injection control system based on real-time parameter monitoring is provided and applied in a controller. The system includes: a first calculation module 301, a first monitoring module 302, a second calculation module 303, a dynamic adjustment module 304, and a second monitoring module 305. The first calculation module 301 is used to control the urea injection of a diesel engine based on real-time parameter monitoring, using urea injection at the inlet of the two-stage SCR. x Sensor, real-time measurement of NO x The NO2 concentration is calculated by querying the NO2 proportion coefficient from the NO2 model in conjunction with the engine operating status. The first monitoring module 302 monitors the temperature and NO2 concentration before the SCR in real time, using them as input parameters for the N2O generation difficulty model. The second calculation module 303 establishes an N2O generation difficulty model based on temperature and NO2 concentration according to the N2O generation characteristics, and calculates the N2O generation difficulty coefficient for the two-stage SCR. The dynamic adjustment module 304 dynamically adjusts the first-stage urea injection quantity based on the N2O generation difficulty coefficient. The second monitoring module 305 monitors the NO2 concentration of the two-stage SCR. x Conversion efficiency.

[0144] In this embodiment, the first calculation module 301 includes: a first acquisition unit, a first monitoring unit, a query unit, and a first calculation unit. The first acquisition unit is used to obtain information from the NO arrays located at the first-level SCR entry point and the second-level SCR entry point. x Sensors automatically acquire real-time NO levels xThe concentration data are denoted as Q1 and Q2, respectively. The first monitoring unit is used to monitor the engine's operating status in real time, including engine speed and circulating oil volume. The query unit is used to automatically query the corresponding NO2 proportion coefficients from the pre-stored NO2 model based on the real-time acquired engine speed and circulating oil volume, denoted as R1 and R2, respectively. The first calculation unit is used to utilize the measured NO... x The concentrations Q1 and Q2, along with the queried NO2 proportion coefficients R1 and R2, are used to automatically calculate the NO2 concentrations at the inlet of the first-stage SCR and the inlet of the second-stage SCR, which are denoted as M1 and M2, respectively.

[0145] In this embodiment, the first monitoring module 302 includes: a second monitoring unit, a second acquisition unit, an integration unit, and a third monitoring unit. The second monitoring unit is used to automatically monitor the temperature sensors arranged before the first-stage SCR and the second-stage SCR, and acquire exhaust gas temperature data in real time, denoted as T1 and T2 respectively. The second acquisition unit is used to obtain NO... x The NO2 concentration data, namely M1 and M2, are acquired in real time during the NO2 concentration monitoring step. The integration unit is used to integrate the acquired exhaust temperature T1 and T2 and NO2 concentration M1 and M2 data, and automatically store them in the internal memory. The third monitoring unit is used to continuously monitor the changes in exhaust temperature and NO2 concentration, and update the stored data in real time as input parameters for the N2O generation ease model.

[0146] In this embodiment, the second calculation module 303 includes a modeling unit, an input unit, and a second calculation unit. The modeling unit is used to pre-establish a mathematical model describing the relationship between the ease of N2O generation and exhaust temperature and NO2 concentration based on research data and experience. The input unit is used to automatically input the real-time monitored exhaust temperatures T1 and T2 and NO2 concentrations M1 and M2 as input parameters into the N2O generation ease of model. The second calculation unit is used to automatically calculate the N2O generation ease coefficients for the first-stage SCR and the second-stage SCR, denoted as K1 and K2, respectively, using the established mathematical model and based on the input exhaust temperature and NO2 concentration. A smaller ease coefficient indicates that N2O is more easily generated and requires control, while a larger ease coefficient indicates that N2O generation is more difficult.

[0147] In this embodiment, the dynamic adjustment module 304 includes a third acquisition unit, a first judgment unit, a third calculation unit, and a dynamic adjustment unit. The third acquisition unit is used to automatically acquire the N2O generation difficulty coefficients K1 and K2 for the first-stage SCR and the second-stage SCR from the N2O generation difficulty model. The first judgment unit is used to determine the correction direction for urea injection based on the N2O generation difficulty coefficients K1 and K2. The third calculation unit is used to automatically calculate the correction coefficient L for urea injection according to the determined correction direction. The dynamic adjustment unit is used to apply the calculated correction coefficient L to the injection amount of the first-stage urea, dynamically adjusting the injection amount of the first-stage urea.

[0148] In this embodiment, the second monitoring module 305 includes: a fourth acquisition unit, a fourth calculation unit, a second judgment unit, and a correction unit. The fourth acquisition unit is used to automatically acquire NO from the NO2-containing gas arrays located before and after the catalyst. x Real-time NO is obtained from the sensor x The concentration data are denoted as N1 and N2, respectively. The fourth calculation unit is used to utilize the acquired NO... x Based on the concentration data, the total NO concentration of the two-stage SCR system is automatically calculated using the formula F=(N1-N2) / N1. x Conversion efficiency F. The second judgment unit is used to compare the calculated conversion efficiency F with a preset threshold or historical data to determine whether the conversion efficiency has decreased. The correction unit is used to maintain the current urea injection correction coefficient L and continue to execute the correction strategy if the conversion efficiency F has not decreased; if the conversion efficiency F has decreased, it automatically adjusts the urea injection correction coefficient L to 1 and cancels the correction.

[0149] The various variations and specific examples of the diesel engine urea injection control method based on real-time parameter monitoring provided in Embodiment 1 are also applicable to the diesel engine urea injection control system based on real-time parameter monitoring provided in this embodiment. Through the foregoing detailed description of a diesel engine urea injection control method based on real-time parameter monitoring, those skilled in the art can clearly understand the implementation method of a diesel engine urea injection control system based on real-time parameter monitoring in this embodiment. Therefore, for the sake of brevity, it will not be described in detail here.

[0150] Figure 5 This is a schematic diagram of the working logic of a diesel engine urea injection control method based on real-time parameter monitoring according to a specific embodiment of the present invention, as shown below. Figure 5 As shown, in a specific embodiment of the present invention, the working logic of the present invention is as follows:

[0151] S1, through NO arranged at the inlet of the first and second stage SCR x The sensor accurately measures the NO at this location. xConcentrations Q1 and Q2. Based on the real-time engine operating speed and circulating oil volume, the NO2 proportion coefficients R1 and R2 are retrieved from the NO2 model. The NO2 concentration at the inlet of the first-stage SCR is M1 = Q1 * R1, and the NO2 concentration at the inlet of the second-stage SCR is M2 = Q2 * R2.

[0152] S2 monitors parameters affecting N2O emissions in real time. The temperatures before the first and second stage SCRs are measured and output by temperature sensors located at this position, and the NO2 concentration is calculated and output by S1.

[0153] S3. Research indicates that SCR and ASC begin to rapidly generate N2O at 200℃, reaching their peak generation rate around 250℃, with less N2O generation above 300℃. Higher NO2 concentrations in the exhaust gas lead to greater N2O generation. Based on these N2O generation characteristics, an N2O generation ease model is established based on the temperature and NO2 concentration affecting N2O emissions. Using real-time exhaust temperature and NO2 concentration, the model calculates the N2O generation ease coefficient K1 for the first-stage SCR and K2 for the second-stage SCR. Smaller coefficients indicate easier N2O generation, requiring control measures.

[0154] S4, establish a correction coefficient L for the first-stage urea injection based on the difficulty coefficient K1 of the first-stage SCR N2O generation and the difficulty coefficient K2 of the second-stage SCR N2O generation. 1) If K1 is small and K2 is large, the output first-stage urea injection correction coefficient L is less than 1. The original first-stage urea injection amount, multiplied by L, will result in reduced injection, thus reducing the amount of N2O generated. Simultaneously, due to the reduced first-stage SCR urea injection, the converted NO... x It also reduces NO reaching the second stage of SCR. x It will also increase, at which point the second stage will be activated by the NO installed at this location. x The sensor measured NO x As the concentration increases, the amount of urea injected can be increased according to the model to convert the increased NO. x Keep the final output NO x The amount of urea injected in the second stage remains unchanged. Although the amount of urea injected in the second stage increases, the amount of N2O generated by the second-stage SCR will not increase significantly due to the difficulty in generating N2O under current conditions. Therefore, the total N2O will be significantly reduced. 2) If K1 is large and K2 is small, the first-stage urea injection correction coefficient L, which is greater than 1, will be output, increasing the amount of urea injected in the first stage and converting more NO. x However, N2O will not increase significantly. The second stage is based on NO... x Reducing the concentration of urea reduces the amount of urea injected, thus reducing N2O generation.

[0155] S5, NO before and after the catalyst x The sensor measured NOx For concentrations N1 and N2, the overall conversion efficiency of the two-stage SCR is F = (N1 - N2) / N1. If the SCR conversion efficiency F does not decrease, maintain the correction for the first-stage urea injection.

[0156] S6, if the SCR conversion efficiency F decreases after adjusting the first-stage urea injection, NO x The risk of increased emissions indicates that urea injection correction to reduce N2O is not suitable under current conditions. The correction factor L for the first-stage urea injection is changed to 1, and the correction is cancelled.

[0157] Example 3

[0158] Figure 3 This is a schematic diagram of the structure of an electronic device according to Embodiment 3 of the present invention, as shown below. Figure 3 As shown, Embodiment 3 also provides an electronic device 400, which may include a processor 401 and a memory 402.

[0159] Memory 402 is used to store programs. Memory 402 may include volatile memory, such as random-access memory (RAM), such as static random-access memory (SRAM), double data rate synchronous dynamic random-access memory (DDR SDRAM), etc.; memory may also include non-volatile memory, such as flash memory. Memory 402 is used to store computer programs (such as application programs and functional modules that implement the above methods), computer instructions, etc. The computer programs and computer instructions can be partitioned and stored in one or more memories 402. Furthermore, the computer programs, computer instructions, data, etc., can be accessed by processor 401.

[0160] The aforementioned computer programs and instructions can be stored in one or more partitions of memory 402. Furthermore, the aforementioned computer programs and instructions can be invoked by processor 401.

[0161] The processor 401 is configured to execute the computer program stored in the memory 402 to implement the various steps in the methods described in the above embodiments.

[0162] For details, please refer to the relevant descriptions in the preceding method embodiments.

[0163] The processor 401 and the memory 402 can be independent structures or integrated structures. When the processor 401 and the memory 402 are independent structures, the memory 402 and the processor 401 can be coupled together via bus 403.

[0164] The electronic device in this embodiment can execute the technical solution in the above method. Its specific implementation process and technical principle are the same, and will not be repeated here.

[0165] Example 4

[0166] Embodiment 4 also provides a computer-readable storage medium including a computer program and instructions, which, when executed on a computer, cause the computer to perform the control method for preventing urea nozzle crystallization blockage according to any embodiment of the present invention.

[0167] Computer-readable storage media include various media that can store program code, such as USB flash drives, external hard drives, ROM, RAM, magnetic disks, or optical disks.

[0168] This embodiment also provides a computer program product, which includes: a computer program stored in a readable storage medium, at least one processor of an electronic device can read the computer program from the readable storage medium, and the at least one processor executes the computer program to cause the electronic device to perform the solution provided in any of the above embodiments.

[0169] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0170] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A urea injection control method for a diesel engine based on real-time parameter monitoring, applied in a controller, characterized in that, The method includes: Step S100, by placing NO at the first-stage SCR inlet and the second-stage SCR inlet x Sensor, real-time measurement of NO x The concentration is calculated by querying the NO2 proportion coefficient from the pre-stored NO2 model in conjunction with the engine operating status, and the NO2 concentrations at the first-stage SCR inlet and the second-stage SCR inlet are denoted as M1 and M2, respectively. Step S200: Real-time monitoring of the exhaust temperature before the first-stage SCR and the second-stage SCR, as well as the NO2 concentrations M1 and M2, as input parameters for the N2O generation difficulty model; Step S300: Establish an N2O generation difficulty model, wherein the N2O generation difficulty model is a mathematical model describing the relationship between the ease of N2O generation and exhaust temperature and NO2 concentration. N2O begins to generate rapidly at a temperature of 200℃, reaches its highest generation rate at around 250℃, and generates less at temperatures above 300℃. Furthermore, the higher the NO2 concentration in the exhaust, the more N2O is generated. Based on the model and the input exhaust temperature and NO2 concentration, calculate the N2O generation difficulty coefficient K1 for the first-stage SCR and the N2O generation difficulty coefficient K2 for the second-stage SCR. The smaller the difficulty coefficient, the easier it is to generate N2O; the larger the difficulty coefficient, the more difficult it is to generate N2O. Step S400: Based on the difficulty coefficients K1 and K2 generated by N2O, dynamically adjust the first-stage urea injection volume, specifically as follows: If K1 is smaller and K2 is larger, then the first-stage urea injection correction coefficient L, which is less than 1, is output to perform a reduction correction on the originally set first-stage urea injection quantity. If K1 is larger and K2 is smaller, then the first-stage urea injection correction coefficient L, which is greater than 1, is output to perform an increase in injection correction on the originally set first-stage urea injection quantity. Step S500, through NO arranged before and after the catalyst x Sensor acquires NO x Calculate the total NO from two-stage SCR processes based on concentrations N1 and N2. x Conversion efficiency F = (N1-N2) / N1; if conversion efficiency F does not decrease, the current urea injection correction coefficient L is maintained; if conversion efficiency F decreases, the urea injection correction coefficient L is adjusted to 1 and the correction is canceled.

2. A urea injection control system for a diesel engine based on real-time parameter monitoring, applied in a controller, characterized in that, The system includes: The first calculation module is used to process NO arranged at the first-level SCR inlet and the second-level SCR inlet. x Sensor, real-time measurement of NO x The concentration is calculated by querying the NO2 proportion coefficient from the pre-stored NO2 model in conjunction with the engine operating status, and the NO2 concentrations at the first-stage SCR inlet and the second-stage SCR inlet are denoted as M1 and M2, respectively. The first monitoring module is used to monitor the exhaust temperature before the first-stage SCR and the second-stage SCR, as well as the NO2 concentrations M1 and M2, in real time, as input parameters for the N2O generation difficulty model. The second calculation module is used to establish an N2O generation difficulty model. This model is a mathematical model describing the relationship between the ease of N2O generation and exhaust temperature and NO2 concentration. N2O begins to generate rapidly at 200℃, reaches its highest generation rate around 250℃, and generates less above 300℃. Furthermore, the higher the NO2 concentration in the exhaust, the more N2O is generated. Based on this model and the input exhaust temperature and NO2 concentration, the module calculates the N2O generation difficulty coefficient K1 for the first-stage SCR and the N2O generation difficulty coefficient K2 for the second-stage SCR. A smaller coefficient indicates easier N2O generation, while a larger coefficient indicates greater difficulty in generating N2O. The dynamic adjustment module is used to dynamically adjust the first-stage urea injection volume based on the N2O generation difficulty coefficients K1 and K2, specifically as follows: If K1 is smaller and K2 is larger, then the first-stage urea injection correction coefficient L, which is less than 1, is output to perform a reduction correction on the originally set first-stage urea injection quantity. If K1 is larger and K2 is smaller, then the first-stage urea injection correction coefficient L, which is greater than 1, is output to perform an increase in injection correction on the originally set first-stage urea injection quantity. The second monitoring module is used to monitor NO levels placed before and after the catalyst. x Sensor acquires NO x Calculate the total NO from two-stage SCR processes based on concentrations N1 and N2. x Conversion efficiency F = (N1-N2) / N1; if conversion efficiency F does not decrease, the current urea injection correction coefficient L is maintained; if conversion efficiency F decreases, the urea injection correction coefficient L is adjusted to 1 and the correction is canceled.

3. An electronic device, characterized in that, include: At least one processor; as well as A memory that is communicatively connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the urea injection control method for diesel engines based on real-time parameter monitoring as described in claim 1.

4. A computer-readable storage medium, characterized in that, It includes computer programs and instructions that, when the computer program or the instructions are run on a computer, cause the computer to perform the urea injection control method for diesel engines based on real-time parameter monitoring as described in claim 1.

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