Plateau nitrous oxide emission evaluation method and system based on engine operating condition method

Abstract

The application discloses a kind of plateau nitrous oxide emission evaluation method and system based on engine operating mode, it is related to engine emission evaluation technical field under plateau environment, the method includes: in standard emission operating mode, according to plateau comprehensive correction factor, each original exhaust parameter is corrected, generate multiple new exhaust parameters;According to new exhaust parameter, the conversion rate of DOC component and mass generation flow are calculated;According to the molar ratio of urea injection under the condition of target altitude height operating mode and SCR component inlet temperature, the conversion rate of SCR component and mass generation flow are calculated;ASC component inlet temperature is calculated according to SCR component inlet temperature, and the conversion rate of ASC component and mass generation flow are calculated according to ASC component inlet temperature;DOC component mass generation flow, the mass generation flow of SCR component and the mass generation flow of ASC component are added, and the total mass flow of current condition is generated, and the total mass flow of current condition is evaluated.

Description

Technical Field

[0001] This invention belongs to the field of engine emission assessment technology in high-altitude environments, and more specifically, relates to a method and system for assessing nitrous oxide emissions in high-altitude environments based on engine operating conditions. Background Technology

[0002] In existing technologies, the emission characteristics of heavy-duty diesel engines, especially nitrous oxide (NOx), are addressed. Research on emissions primarily focuses on engine bench testing measurements, empirical emission factor methods, and mechanistic modeling based on single aftertreatment components. Traditional methods typically rely on real-vehicle or bench testing under standard operating cycles (such as WHTC, WHSC, NRTC, and NRSC) to evaluate emissions by directly collecting exhaust data. The emission levels of conventional pollutants such as CO, HC and particulate matter were determined, and estimates were made based on these levels. Emissions. However, this type of method suffers from problems such as long testing cycles, high costs, strong environmental dependence, and limited repeatability. Especially in high-altitude areas, the reduced air density and lower environmental pressure lead to significant changes in engine combustion characteristics and aftertreatment system reaction mechanisms, making it difficult to accurately extrapolate results from traditional plains tests. Furthermore, some studies employ the emission factor method, estimating emissions through statistical models. While this method can detect emissions, it lacks a deep understanding of the catalytic reaction mechanism and thermodynamic processes, making it difficult to reflect the differences between various aftertreatment technologies and limiting its predictive accuracy. In recent years, with the increasing complexity of diesel engine aftertreatment systems, multi-stage catalytic converters such as DOC, DPF, SCR, and ASC have been widely used. The emission generation pathways exhibit significant coupling and nonlinear characteristics, such as under low-temperature conditions in DOC. Side reactions with combustible components, in SCR Selective reduction and its side reaction formation and in ASC The oxidation process The contribution of emissions. However, most existing technologies only model single catalysts, lacking a systematic integrated analysis of the entire DOC–DPF–SCR–ASC process, making it difficult to achieve comprehensive analysis of emissions. A comprehensive assessment of the generation mechanism. Meanwhile, existing models typically assume standard atmospheric conditions, neglecting the impact of the plateau environment on exhaust temperature, exhaust flow rate, and... The combined effects of concentration and urea injection strategy, coupled with the lack of a unified high-altitude correction mechanism, result in insufficient applicability of the model under high-altitude conditions.

[0003] Therefore, there is an urgent need to propose a method based on engine operating conditions, taking into account the impact of high-altitude environments, and capable of collaborative modeling of multiple aftertreatment components. Emissions assessment methods to improve prediction accuracy, reduce development costs, and enhance the efficiency of technology optimization. Summary of the Invention

[0004] To address the above technical problems, this invention proposes a method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions, comprising: Under standard emission conditions, multiple raw exhaust parameters of the engine are obtained. Based on the target altitude and corresponding atmospheric pressure, a plateau comprehensive correction factor is calculated, and each raw exhaust parameter is corrected to generate multiple new exhaust parameters. Calculate the DOC component based on the new exhaust parameters. Generate conversion rate and Quality generates traffic; Based on the oxidation efficiency of DOC combustible components and new exhaust parameters, the inlet temperatures of the DPF and SCR components were calculated. Then, based on the SCR component inlet temperature and the urea injection molar ratio at the target altitude, the SCR component temperature was calculated. Generate conversion rate and Quality generates traffic; Calculate the ASC module inlet temperature based on the SCR module inlet temperature. Generate conversion rate and Quality generates traffic; DOC components Quality generation flow, SCR component Quality generation traffic and ASC components The quality-generated flow rate is summed to generate the current operating condition. Total mass flow rate, for the current operating conditions The total mass flow rate is evaluated.

[0005] Furthermore, the calculation of the plateau comprehensive correction factor includes:

[0006] in, Target altitude The comprehensive correction factor for high altitude, To match the target altitude The corresponding atmospheric pressure, Standard atmospheric pressure The pressure-exhaust coupling index, The temperature-height attenuation coefficient. For reference altitude.

[0007] Furthermore, calculate the DOC components. The conversion rate includes:

[0008] in, For time DOC components Generate conversion rate, For DOC components under standard emission conditions Generate the saturation limit value of conversion rate. For DOC components Generation rate coefficient, For time At the target altitude Mass fraction of combustible components at the DOC component inlet. For time At the target altitude DOC component entry point concentration, For DOC components Reference for the generation reaction concentration, For time At the target altitude Lower DOC component inlet exhaust temperature, For The temperature window function for the catalytic activity of the DOC component is a parameter; Calculate DOC components Quality generated traffic includes:

[0009] in, For time DOC components Quality generates traffic. For time At the target altitude Down Quality generates traffic.

[0010] Furthermore, the calculation of the DPF module inlet temperature and the SCR module inlet temperature includes: Calculating the DPF component inlet temperature includes:

[0011] Calculating the SCR module inlet temperature includes:

[0012] in, For time DPF module inlet temperature The weighted lower heating value of the combustible components. For time Oxidation conversion efficiency of combustible components in DOC components For the specific heat capacity of the exhaust gas, For time SCR module inlet temperature For time At the target altitude The carbon soot mass fraction at the DOC component inlet. Due to the low calorific value of carbon soot, For time DPF module carbon soot oxidation and regeneration efficiency This refers to the heat loss and temperature drop of the connecting pipe section from the DPF module outlet to the SCR module inlet.

[0013] Furthermore, the calculation of the SCR component Generate conversion rate and Quality generated traffic includes: Calculate the SCR component The conversion rate includes:

[0014] in, For time SCR component Generate conversion rate, For SCR components under standard emission conditions Generate conversion rate, For urea injection molar ratio The generated modulation amplitude coefficient, The transition sensitivity coefficient is the urea injection molar ratio. For time urea injection molar ratio, for The inflection point value at which the conversion rate is most sensitive to the urea injection molar ratio. For The temperature window function for the catalytic activity of the SCR component is a parameter; Calculate the SCR component Quality generated traffic includes:

[0015] in, For time SCR component Quality generates traffic. For time After being converted by the DOC component, it enters the SCR component. Mass flow rate.

[0016] Furthermore, calculating the ASC module inlet temperature based on the SCR module inlet temperature includes:

[0017] in, For time The inlet temperature of the ASC component at that time. The molar heat of reaction for the main reaction of the SCR component. For time SCR component conversion efficiency For time At the target altitude The exhaust mass flow rate is below This refers to the heat loss and temperature drop of the connecting pipe section from the SCR module outlet to the ASC module inlet.

[0018] Furthermore, the ASC module's inlet temperature is used to calculate the ASC module's... Generate conversion rate and Quality generated traffic includes: Calculate the ASC component The conversion rate includes:

[0019] in, For time The ASCII component Generate conversion rate, For ASC components under maximum catalytic activity conditions Generate conversion rate limit value. For ASCII component with parameters The generated temperature response function, For The urea injection molar ratio response function with parameters. For time Time ASC component entry Quality score, For ASCII component entry point for parameters Mass fraction response function; Calculate the ASC component Quality generated traffic includes:

[0020] in, For time The ASCII component Quality generates traffic. For time After being converted by the SCR component, it enters the ASC component. Mass flow rate.

[0021] Furthermore, regarding the current operating conditions The total mass flow rate is evaluated by including: if the current operating conditions are... If the total mass flow rate is less than or equal to the first threshold, then nitrous oxide emissions are compliant. If the current operating conditions... If the total mass flow rate is greater than the first threshold and less than or equal to the second threshold, then nitrous oxide emissions are slightly exceeded. If the current operating conditions... If the total mass flow rate is greater than the second threshold and less than or equal to the third threshold, then nitrous oxide emissions are moderately excessive. If the current operating conditions... If the total mass flow rate exceeds the third threshold, then the nitrous oxide emissions are severely excessive.

[0022] This invention also proposes a high-altitude nitrous oxide emission assessment system based on engine operating condition method, comprising: The correction module is used to acquire multiple raw exhaust parameters of the engine under standard emission conditions, calculate the plateau comprehensive correction factor based on the target altitude and corresponding atmospheric pressure, and correct each raw exhaust parameter to generate multiple new exhaust parameters. The DOC component exhaust calculation module is used to calculate the DOC component's exhaust parameters based on the new exhaust parameters. Generate conversion rate and Quality generates traffic; The SCR component exhaust calculation module is used to calculate the DPF component inlet temperature and SCR component inlet temperature based on the DOC combustible component oxidation efficiency and new exhaust parameters. It also calculates the SCR component's inlet temperature and the urea injection molar ratio at the target altitude. Generate conversion rate and Quality generates traffic; The ASC module exhaust calculation module is used to calculate the ASC module inlet temperature based on the SCR module inlet temperature, and then calculate the ASC module exhaust temperature based on the SCR module inlet temperature. Generate conversion rate and Quality generates traffic; The evaluation module is used to evaluate the DOC components. Quality generation flow, SCR component Quality generation traffic and ASC components The quality-generated flow rate is summed to generate the current operating condition. Total mass flow rate, for the current operating conditions The total mass flow rate is evaluated.

[0023] Furthermore, the calculation of the plateau comprehensive correction factor includes:

[0024] in, Target altitude The comprehensive correction factor for high altitude, To match the target altitude The corresponding atmospheric pressure, Standard atmospheric pressure The pressure-exhaust coupling index, The temperature-height attenuation coefficient. For reference altitude.

[0025] Overall, such as Figure 3 As shown, the above technical solutions conceived by this invention have the following beneficial effects compared with the prior art: Significantly reduce development costs and shorten development cycles: Eliminate the reliance on physical bench testing for each iteration, and... Emissions assessment is moved to the digital calculation stage, significantly reducing the number of sample manufacturing and high-altitude bench tests.

[0026] Improving the targeting and precision of high-altitude adaptability development: By introducing a comprehensive high-altitude correction factor and corresponding component model corrections, the impact of the high-altitude environment on exhaust parameters, catalyst temperature, and... The impact of the generated path is systematically incorporated into the evaluation framework, which is a fundamental improvement over the simple extrapolation of plain test results.

[0027] Achieving proactive risk assessment and emission compliance prediction: Quantitatively predicting the risks of each solution before product finalization. Emission levels, identifying high-risk configurations, providing quantitative basis for emission compliance decisions, and effectively preventing emissions from becoming a risk factor. Risk of rework due to exceeding standards. Attached Figure Description

[0028] Figure 1 This is a flowchart of the method in Embodiment 1 of the present invention; Figure 2 This is a system structure diagram of Embodiment 2 of the present invention; Figure 3 This is a rendering of the invention. Detailed Implementation

[0029] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0030] The method provided by this invention can be implemented in a terminal environment that may include one or more of the following components: a processor, a storage medium, and a display screen. The storage medium stores at least one instruction, which is loaded and executed by the processor to implement the method described in the following embodiments.

[0031] A processor may include one or more processing cores. The processor uses various interfaces and lines to connect various parts of the terminal, and performs various functions and processes data by running or executing instructions, programs, code sets or instruction sets stored in the storage medium, and by calling data stored in the storage medium.

[0032] Storage media can include random access memory (RAM) or read-only memory (ROM). Storage media can be used to store instructions, programs, code, code sets, or instructions.

[0033] The display screen is used to show the user interface of each application.

[0034] In addition, those skilled in the art will understand that the structure of the terminal described above does not constitute a limitation on the terminal. The terminal may include more or fewer components, or combine certain components, or have different component arrangements. For example, the terminal may also include radio frequency circuits, input units, sensors, audio circuits, power supplies, and other components, which will not be described in detail here.

[0035] Glossary: ​​DOC: Diesel Oxidation Catalyst. Diesel particulate filter, SCR (Selective Catalytic Reduction), ASC (Ammonia Slip Catalyst).

[0036] Example 1 like Figure 1 As shown, this embodiment proposes a method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions, including: Step 101: Under standard emission conditions, acquire multiple raw exhaust parameters of the engine, calculate the plateau comprehensive correction factor based on the target altitude and corresponding atmospheric pressure, and correct each raw exhaust parameter to generate multiple new exhaust parameters. Specifically, the calculation of the plateau comprehensive correction factor includes:

[0037] in, Target altitude The comprehensive correction factor for high altitude, To match the target altitude The corresponding atmospheric pressure, Standard atmospheric pressure The pressure-exhaust coupling index (which can be 0.6–0.9) is calibrated using engine high-altitude bench test data and reflects the overall sensitivity of intake volume changes to DOC component inlet exhaust parameters. The temperature-height attenuation coefficient characterizes the extent to which the reduction in intake air temperature corrects the combustion temperature field (it can be 0.05–0.20). For reference altitude.

[0038] Step 102: Calculate the DOC component based on the new exhaust parameters. Generate conversion rate and Quality generates traffic; Specifically, calculating DOC components The conversion rate includes:

[0039] in, For time DOC components Generate conversion rate, For DOC components under standard emission conditions Generate the saturation limit value of conversion rate. For DOC components Generation rate coefficient, For time At the target altitude Mass fraction of combustible components (THC+CO) at the DOC component inlet. For time At the target altitude DOC component entry point concentration, For DOC components Reference for the generation reaction concentration, For time At the target altitude Lower DOC component inlet exhaust temperature, For The temperature window function for the catalytic activity of the DOC component is a parameter; Preferably, calculation include:

[0040] in, For time The mass fraction of combustible components at the DOC component inlet under standard emission conditions (one of the original exhaust parameters). The first adjustment coefficient for the plateau comprehensive correction factor can be 0.5–2.0.

[0041] Preferably, calculation include:

[0042] in, This is the coefficient for the first steepest temperature transition. For DOC components The lower limit temperature of generation, This is the coefficient for the second steepest temperature transition. For DOC components The upper limit temperature and all four parameters were calibrated using steady-state characteristic test data of individual DOC components.

[0043] Preferably, calculation include:

[0044] in, For time The exhaust temperature at the DOC component inlet under standard emission conditions (one of the original exhaust parameters). This is the temperature correction factor (which can be 0.05–0.15). To achieve the average exhaust temperature under standard emission conditions, For time Engine load at that time This is the maximum load on the engine.

[0045] Calculation time At the target altitude Downdraft mass flow rate :

[0046] in, For time The exhaust mass flow rate under standard emission conditions (one of the original exhaust parameters).

[0047] Calculate DOC components Quality generated traffic includes:

[0048] in, For time DOC components Quality generates traffic. For time At the target altitude Down Quality generates traffic.

[0049] Step 103: Based on the oxidation efficiency of DOC combustible components and the new exhaust parameters, calculate the inlet temperature of the DPF module and the inlet temperature of the SCR module. Based on the inlet temperature of the SCR module and the urea injection molar ratio under the target altitude conditions, calculate the SCR module's... Generate conversion rate and Quality generates traffic; Specifically, calculating the inlet temperature of the DPF module and the inlet temperature of the SCR module includes: Calculating the DPF component inlet temperature includes:

[0050] Calculating the SCR module inlet temperature includes:

[0051] in, For time DPF module inlet temperature The weighted lower heating value of the combustible components is calculated by weighting the mole fractions of each component. For time Oxidation conversion efficiency of combustible components in DOC components For the specific heat capacity of the exhaust gas, For time SCR module inlet temperature For time At the target altitude The carbon soot mass fraction at the DOC component inlet. Due to the low calorific value of carbon soot, For time DPF module carbon soot oxidation and regeneration efficiency This refers to the heat loss and temperature drop of the connecting pipe section from the DPF module outlet to the SCR module inlet.

[0052] Preferably, calculation include:

[0053] in, For time The carbon soot mass fraction at the DOC component inlet under standard emission conditions (one of the original exhaust parameters). The first adjustment coefficient for the plateau comprehensive correction factor can be 0.3–1.5.

[0054] Specifically, calculating the SCR component Generate conversion rate and Quality generated traffic includes: Calculate the SCR component The conversion rate includes:

[0055] in, For time SCR component Generate conversion rate, For SCR components under standard emission conditions Generate conversion rate, For urea injection molar ratio The generated modulation amplitude coefficient (can be 0.3–1.0). The transition sensitivity coefficient for the urea injection molar ratio (can be 2–8). For time urea injection molar ratio, for The inflection point value at which the conversion rate is most sensitive to the urea injection molar ratio (representing...) (The critical position most sensitive to urea injection rate) For The temperature window function for the catalytic activity of the SCR component is a parameter; Preferably, calculation include:

[0056] in, For SCR components The lower limit temperature of generation, For SCR components The upper limit temperature for generation.

[0057] Calculate the SCR component Quality generated traffic includes:

[0058] in, For time SCR component Quality generates traffic. For time After being converted by the DOC component, it enters the SCR component. Mass flow rate.

[0059] Step 104: Calculate the ASC module inlet temperature based on the SCR module inlet temperature, and then calculate the ASC module's... Generate conversion rate and Quality generates traffic; Specifically, calculating the ASC module inlet temperature based on the SCR module inlet temperature includes:

[0060] in, For time The inlet temperature of the ASC component at that time. For the main reaction of the SCR component ( The molar heat of reaction, where a positive value indicates exothermic and a negative value indicates endothermic. For time SCR component Conversion efficiency For time At the target altitude The exhaust mass flow rate below, This refers to the heat loss and temperature drop of the connecting pipe section from the SCR module outlet to the ASC module inlet.

[0061] Specifically, the ASC module's inlet temperature is used to calculate the ASC module's... Generate conversion rate and Quality generated traffic includes: Calculate the ASC component The conversion rate includes:

[0062] in, For time The ASCII component Generate conversion rate, For ASC components under maximum catalytic activity conditions Generate conversion rate limit value. For ASCII component with parameters The generated temperature response function (this function uses a modified Arrhenius type function). For The urea injection molar ratio response function is given by parameter (this function is a logistic type monotonically increasing function). For time Time ASC component entry Quality score, For ASCII component entry point for parameters Quality fraction response function (this function uses a piecewise linear interpolation function); Preferably, calculation include:

[0063] in, For time Under standard emission conditions Mass fraction (one of the original exhaust parameters).

[0064] Calculate the ASC component Quality generated traffic includes:

[0065] in, For time The ASCII component Quality generates traffic. For time After being converted by the SCR component, it enters the ASC component. Mass flow rate.

[0066] Step 105, transfer the DOC component Quality generation flow, SCR component Quality generation traffic and ASC components The quality-generated flow rate is summed to generate the current operating condition. Total mass flow rate, for the current operating conditions The total mass flow rate is evaluated.

[0067] Specifically, regarding the current working conditions The total mass flow rate is evaluated by including: if the current operating conditions are... If the total mass flow rate is less than or equal to the first threshold, then nitrous oxide emissions are compliant. If the current operating conditions... If the total mass flow rate is greater than the first threshold and less than or equal to the second threshold, then nitrous oxide emissions are slightly exceeded. If the current operating conditions... If the total mass flow rate is greater than the second threshold and less than or equal to the third threshold, then nitrous oxide emissions are moderately excessive. If the current operating conditions... If the total mass flow rate exceeds the third threshold, then the nitrous oxide emissions are severely excessive.

[0068] Example 2 like Figure 2 As shown, this embodiment proposes a high-altitude nitrous oxide emission assessment system based on engine operating condition method, including: The correction module is used to acquire multiple raw exhaust parameters of the engine under standard emission conditions, calculate the plateau comprehensive correction factor based on the target altitude and corresponding atmospheric pressure, and correct each raw exhaust parameter to generate multiple new exhaust parameters. The DOC component exhaust calculation module is used to calculate the DOC component's exhaust parameters based on the new exhaust parameters. Generate conversion rate and Quality generates traffic; The SCR component exhaust calculation module is used to calculate the DPF component inlet temperature and SCR component inlet temperature based on the DOC combustible component oxidation efficiency and new exhaust parameters. It also calculates the SCR component's inlet temperature and the urea injection molar ratio at the target altitude. Generate conversion rate and Quality generates traffic; The ASC module exhaust calculation module is used to calculate the ASC module inlet temperature based on the SCR module inlet temperature, and then calculate the ASC module exhaust temperature based on the SCR module inlet temperature. Generate conversion rate and Quality generates traffic; The evaluation module is used to evaluate the DOC components. Quality generation flow, SCR component Quality generation traffic and ASC components The quality-generated flow rate is summed to generate the current operating condition. Total mass flow rate, for the current operating conditions The total mass flow rate is evaluated.

[0069] Since Example 2 is based on Example 1, it will not be described again.

[0070] Example 3 This invention also proposes a storage medium storing multiple instructions for implementing the aforementioned method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions.

[0071] Optionally, in this embodiment, the storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals.

[0072] Optionally, in this embodiment, the storage medium is configured to store program code for performing the method steps of Embodiment 1.

[0073] Example 4 This invention also proposes an electronic device, including a processor and a storage medium connected to the processor. The storage medium stores multiple instructions, which can be loaded and executed by the processor to enable the processor to perform the aforementioned high-altitude nitrous oxide emission assessment based on engine operating conditions.

[0074] Specifically, the electronic device in this embodiment can be a computer terminal, which may include one or more processors and a storage medium.

[0075] The storage medium can be used to store software programs and modules, such as the high-altitude nitrous oxide emission assessment based on engine operating condition method in this embodiment of the invention. The processor executes the software programs and modules stored in the storage medium to perform various functional applications and data processing, thus realizing the aforementioned high-altitude nitrous oxide emission assessment based on engine operating condition method. The storage medium may include high-speed random access storage media, and may also include non-volatile storage media, such as one or more magnetic storage systems, flash memory, or other non-volatile solid-state storage media. In some instances, the storage medium may further include storage media remotely configured relative to the processor, which can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0076] The processor can execute the method steps of Embodiment 1 by calling the information and application stored in the storage medium through the transmission system.

[0077] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0078] In the several embodiments provided by this invention, it should be understood that the disclosed technical content can be implemented in other ways. The system embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, indirect coupling or communication connection between units or modules, and may be electrical or other forms.

[0079] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0080] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0081] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, optical disks, and other media capable of storing program code.

[0082] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions, characterized in that, include: Under standard emission conditions, multiple raw exhaust parameters of the engine are obtained. Based on the target altitude and corresponding atmospheric pressure, a plateau comprehensive correction factor is calculated, and each raw exhaust parameter is corrected to generate multiple new exhaust parameters. Calculate the DOC component based on the new exhaust parameters. Generate conversion rate and Quality generates traffic; Based on the oxidation efficiency of DOC combustible components and new exhaust parameters, the inlet temperatures of the DPF and SCR components were calculated. Then, based on the SCR component inlet temperature and the urea injection molar ratio at the target altitude, the SCR component temperature was calculated. Generate conversion rate and Quality generates traffic; Calculate the ASC module inlet temperature based on the SCR module inlet temperature. Generate conversion rate and Quality generates traffic; DOC components Quality generation flow, SCR component Quality generation traffic and ASC components The quality-generated flow rate is summed to generate the current operating condition. Total mass flow rate, for the current operating conditions The total mass flow rate is evaluated.

2. The method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions as described in claim 1, characterized in that, The calculation of the plateau comprehensive correction factor includes: ， in, Target altitude The comprehensive correction factor for high altitude, To match the target altitude The corresponding atmospheric pressure, Standard atmospheric pressure The pressure-exhaust coupling index, The temperature-height attenuation coefficient, For reference altitude.

3. The method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions as described in claim 1, characterized in that, Calculate DOC components The conversion rate includes: ， in, For time DOC components Generate conversion rate, For DOC components under standard emission conditions Generate the saturation limit value of the conversion rate. For DOC components Generation rate coefficient, For time At the target altitude Mass fraction of combustible components at the DOC component inlet. For time At the target altitude DOC component entry point concentration, For DOC components Reference for the generation reaction concentration, For time At the target altitude Lower DOC component inlet exhaust temperature, For The temperature window function for the catalytic activity of the DOC component is a parameter; Calculate DOC components Quality generated traffic includes: ， in, For time DOC components Quality generates traffic. For time At the target altitude Down Quality generates traffic.

4. The method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions as described in claim 3, characterized in that, Calculating the inlet temperature of the DPF module and the inlet temperature of the SCR module includes: Calculating the DPF component inlet temperature includes: ， Calculating the SCR module inlet temperature includes: ， in, For time DPF module inlet temperature The weighted lower heating value of the combustible components. For time Oxidation conversion efficiency of combustible components in DOC components For the specific heat capacity of the exhaust gas, For time SCR module inlet temperature For time At the target altitude The carbon soot mass fraction at the DOC component inlet. Due to the low calorific value of carbon soot, For time DPF module carbon soot oxidation and regeneration efficiency This refers to the heat loss and temperature drop of the connecting pipe section from the DPF module outlet to the SCR module inlet.

5. The method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions as described in claim 4, characterized in that, Calculate the SCR component Generate conversion rate and Quality generated traffic includes: Calculate the SCR component The conversion rate includes: ， in, For time SCR component Generate conversion rate, For SCR components under standard emission conditions Generate conversion rate, For urea injection molar ratio The generated modulation amplitude coefficient, The transition sensitivity coefficient is the urea injection molar ratio. For time urea injection molar ratio, for The inflection point value at which the conversion rate is most sensitive to the urea injection molar ratio. For The temperature window function for the catalytic activity of the SCR component is a parameter; Calculate the SCR component Quality generated traffic includes: ， in, For time SCR component Quality generates traffic. For time After being converted by the DOC component, it enters the SCR component. Mass flow rate.

6. The method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions as described in claim 5, characterized in that, The calculation of the ASC module inlet temperature based on the SCR module inlet temperature includes: ， in, For time The inlet temperature of the ASC component at that time. The molar heat of reaction for the main reaction of the SCR component. For time SCR component Conversion efficiency For time At the target altitude The exhaust mass flow rate is below This refers to the heat loss and temperature drop of the connecting pipe section from the SCR module outlet to the ASC module inlet.

7. The method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions as described in claim 6, characterized in that, Calculate the ASC module based on the ASC module inlet temperature. Generate conversion rate and Quality generated traffic includes: Calculate the ASC component The conversion rate includes: ， in, For time The ASCII component Generate conversion rate, For ASC components under maximum catalytic activity conditions Generate conversion rate limit value. For ASCII component with parameters The generated temperature response function, For The urea injection molar ratio response function with parameters. For time Time ASC component entry Quality score, For ASCII component entry point for parameters Mass fraction response function; Calculate the ASC component Quality generated traffic includes: ， in, For time The ASCII component Quality generates traffic. For time After being converted by the SCR component, it enters the ASC component. Mass flow rate.

8. The method for assessing nitrous oxide emissions at high altitudes based on engine operating conditions as described in claim 1, characterized in that, For the current working conditions The total mass flow rate is evaluated by including: if the current operating conditions are... If the total mass flow rate is less than or equal to the first threshold, then nitrous oxide emissions are compliant. If the current operating conditions... If the total mass flow rate is greater than the first threshold and less than or equal to the second threshold, then nitrous oxide emissions are slightly exceeded. If the current operating conditions... If the total mass flow rate is greater than the second threshold and less than or equal to the third threshold, then nitrous oxide emissions are moderately excessive. If the current operating conditions... If the total mass flow rate exceeds the third threshold, then the nitrous oxide emissions are severely excessive.

9. A high-altitude nitrous oxide emission assessment system based on engine operating condition method, characterized in that, include: The correction module is used to acquire multiple raw exhaust parameters of the engine under standard emission conditions, calculate the plateau comprehensive correction factor based on the target altitude and corresponding atmospheric pressure, and correct each raw exhaust parameter to generate multiple new exhaust parameters. The DOC component exhaust calculation module is used to calculate the DOC component's exhaust parameters based on the new exhaust parameters. Generate conversion rate and Quality generates traffic; The SCR component exhaust calculation module is used to calculate the DPF component inlet temperature and SCR component inlet temperature based on the DOC combustible component oxidation efficiency and new exhaust parameters. It also calculates the SCR component's inlet temperature and the urea injection molar ratio at the target altitude. Generate conversion rate and Quality generates traffic; The ASC module exhaust calculation module is used to calculate the ASC module inlet temperature based on the SCR module inlet temperature, and then calculate the ASC module exhaust temperature based on the SCR module inlet temperature. Generate conversion rate and Quality generates traffic; The evaluation module is used to evaluate the DOC components. Quality generation flow, SCR component Quality generation traffic and ASC components The quality-generated flow rate is summed to generate the current operating condition. Total mass flow rate, for the current operating conditions The total mass flow rate is evaluated.

10. The high-altitude nitrous oxide emission assessment system based on engine operating condition method as described in claim 9, characterized in that, The calculation of the plateau comprehensive correction factor includes: ， in, Target altitude The comprehensive correction factor for high altitude, To match the target altitude The corresponding atmospheric pressure, Standard atmospheric pressure The pressure-exhaust coupling index, The temperature-height attenuation coefficient, For reference altitude.

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