Urea abnormal consumption analysis method and device and vehicle

Abstract

The invention provides a urea abnormal consumption analysis method and device and a vehicle, and belongs to the technical field of diesel engine aftertreatment. The method comprises the steps that a heat energy window is determined based on preset energy and a current working condition point; the heat energy window comprises multiple working condition points, the terminal working condition point of the heat energy window is the current working condition point, and the accumulated heat of the multiple working condition points is equal to preset energy; determining a target ammonia nitrogen ratio, an actually measured ammonia nitrogen ratio, a target window exhaust temperature and an actually measured window exhaust temperature of the heat energy window; a first product of the target ammonia nitrogen ratio and the target window exhaust temperature and a second product of the actually measured ammonia nitrogen ratio and the actually measured window exhaust temperature are determined, the absolute value of the ratio of the first product to the second product serves as an exhaust temperature coefficient, and when the exhaust temperature coefficient is smaller than a preset exhaust temperature coefficient, it is determined that the urea abnormal consumption reason is exhaust temperature abnormity. The abnormal consumption of urea is analyzed by taking the heat energy window as a calculation unit, the influence of the exhaust temperature on the ammonia nitrogen ratio is considered, and the accuracy of an analysis result is improved.

Description

Technical Field

[0001] The invention relates to the technical field of diesel engine post-processing, and in particular to a method, a device and a vehicle for analyzing abnormal urea consumption. Background Art

[0002] NOx emitted from diesel engine exhaust is one of the important pollutants in the atmosphere. Currently, the mainstream method for reducing NOx in diesel engine exhaust is selective catalytic reduction (SCR), which injects urea into the exhaust tail pipe. Since urea will hydrolyze to form ammonia at a certain temperature, ammonia reacts with NOx to generate pollution-free water and nitrogen. Therefore, the amount of urea injected into the exhaust tail pipe directly affects the final emission of NOx in diesel engine exhaust. The National VI Emission Regulations have strict requirements for monitoring urea consumption.

[0003] There are currently two ways to determine urea consumption: 1) derive the volume of urea consumption by calculating the height change of the urea tank liquid level * the bottom area of ​​the urea tank; 2) derive the volume of urea consumption by accumulating and summing the actual urea injection volume of the urea nozzle. Although the above two methods can determine the urea deviation based on the urea consumption volume and the obtained urea demand, they cannot determine the cause of the abnormality when the urea consumption is abnormal.

[0004] Therefore, there is an urgent need to provide a method, device and vehicle for analyzing abnormal urea consumption, which can be used to analyze the cause of abnormal urea consumption when urea consumption is abnormal, and provide a reference for subsequent maintenance. Summary of the invention

[0005] In view of this, it is necessary to provide a method, device and vehicle for analyzing abnormal urea consumption, so as to solve the technical problem existing in the prior art that the cause of abnormal urea consumption cannot be analyzed.

[0006] On the one hand, in order to solve the above technical problems, the present invention provides a method for analyzing abnormal urea consumption, comprising: Determine a thermal energy window based on a preset energy and a current operating point; the thermal energy window includes a plurality of operating points, the end operating point of the thermal energy window is the current operating point, and the accumulated heat of the plurality of operating points is equal to the preset energy; Determining a target ammonia nitrogen ratio, a measured ammonia nitrogen ratio, a target window exhaust temperature, and a measured window exhaust temperature of the thermal energy window; Determine a first product of the target ammonia nitrogen ratio and the target window exhaust temperature and a second product of the measured ammonia nitrogen ratio and the measured window exhaust temperature, and use the absolute value of the ratio of the first product to the second product as an exhaust temperature coefficient. When the exhaust temperature coefficient is less than a preset exhaust temperature coefficient, determine that the cause of abnormal urea consumption is abnormal exhaust temperature.

[0007] In a possible implementation, determining a target ammonia nitrogen ratio and a measured ammonia nitrogen ratio in a thermal energy window includes: Obtaining the urea injection amount at each of the operating points, and determining the target original engine NOx mass flow rate and the measured original engine NOx mass flow rate at each of the operating points; Determining a total target source NOx mass flow rate of the thermal energy window based on the target source NOx mass flow rate; Determining a total measured original engine NOx mass flow rate in the thermal energy window based on the measured original engine NOx mass flow rate; determining a total urea injection amount in the thermal energy window based on the urea injection amount; The ratio of the total urea injection amount to the total measured original machine NOx mass flow rate is used as the measured ammonia nitrogen ratio, and the ratio of the total urea injection amount to the total target original machine NOx mass flow rate is used as the target ammonia nitrogen ratio.

[0008] In a possible implementation, the determining of the target original engine NOx mass flow rate and the measured original engine NOx mass flow rate at each operating point includes: Obtaining the exhaust gas flow rate and the target original engine NOx volume percentage and the measured original engine NOx volume percentage at each operating point; The target source engine NOx mass flow is determined based on the target source engine NOx volume percentage and the exhaust gas flow rate, and the measured source engine NOx mass flow is determined based on the measured source engine NOx volume percentage and the exhaust gas flow rate.

[0009] In a possible implementation, the target ammonia nitrogen ratio is:

[0010]

[0011] The measured ammonia nitrogen ratio is:

[0012]

[0013] In the formula, is the target ammonia nitrogen ratio; For the k Urea injection amount at each operating point; For the k Target original engine NOx mass flow rate at each operating point; i and j They are the starting point number and the ending point number of the thermal energy window respectively; is the measured ammonia nitrogen ratio; For the kThe measured original engine NOx mass flow rate at each operating point; The target original engine NOx volume ratio; It is the measured NOx volume percentage of the original engine; is the exhaust gas flow rate.

[0014] In a possible implementation, determining the target window exhaust temperature and the measured window exhaust temperature includes: Determine a plurality of target exhaust temperatures at the plurality of operating points and a plurality of measured exhaust temperatures at the plurality of operating points; The average value of the target exhaust temperatures of the multiple operating points is used as the target window exhaust temperature, and the actually measured exhaust temperatures of the multiple operating points are used as the actually measured window exhaust temperature.

[0015] In a possible implementation, the method further includes: Determining the power of each of the operating points; Determining a target source engine NOx window emission based on the power and the target source engine NOx mass flow rate, and determining a measured source engine NOx window emission based on the power and the measured source engine NOx mass flow rate; Determining the original engine NOx specific emission deviation based on the target original engine NOx window emission and the measured original engine NOx window emission; When the original engine NOx emission specific deviation is greater than the threshold deviation, it is determined that the cause of the abnormal urea consumption is that the original engine NOx deviates from the design value.

[0016] In a possible implementation manner, determining the power of each operating point includes: The rotation speed and torque at each operating point are obtained, and the power is determined based on the rotation speed and the torque.

[0017] In a possible implementation, the original engine NOx emission ratio deviation is:

[0018]

[0019]

[0020]

[0021] In the formula, It is the NOx emission deviation of the original engine; is the measured NOx window emission of the original engine; | | is the absolute value symbol; is the target original engine NOx mass flow rate; is power; is the rotation speed; For torque.

[0022] On the other hand, the present invention also provides a device for analyzing abnormal urea consumption, comprising: A thermal energy window determination unit, configured to determine a thermal energy window based on a preset energy and a current operating point; the thermal energy window includes a plurality of operating points, the end operating point of the thermal energy window is the current operating point, and the accumulated heat of the plurality of operating points is equal to the preset energy; An ammonia nitrogen ratio and window exhaust temperature determination unit, for determining a target ammonia nitrogen ratio, a measured ammonia nitrogen ratio, a target window exhaust temperature and a measured window exhaust temperature of the thermal energy window; The abnormal urea consumption analysis unit is used to determine a first product of the target ammonia nitrogen ratio and the target window exhaust temperature and a second product of the measured ammonia nitrogen ratio and the measured window exhaust temperature, and use the absolute value of the ratio of the first product to the second product as an exhaust temperature coefficient. When the exhaust temperature coefficient is less than a preset exhaust temperature coefficient, it is determined that the cause of the abnormal urea consumption is abnormal exhaust temperature.

[0023] In another aspect, the present invention further provides a vehicle, comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the abnormal urea consumption analysis method described in any one of the possible implementations above.

[0024] The beneficial effects of the present invention are as follows: the abnormal urea consumption analysis method provided by the present invention first determines the thermal energy window, and uses the thermal energy window as a calculation unit to analyze the abnormal urea consumption. Compared with analyzing a single operating point, the influence of a single extreme operating condition on the analysis result is avoided, and the accuracy of the target ammonia nitrogen ratio, the measured ammonia nitrogen ratio, the target window exhaust temperature and the measured window exhaust temperature is improved, thereby improving the accuracy and stability of the abnormal urea consumption analysis result. In addition, the present invention uses the ammonia nitrogen ratio and the window exhaust temperature as related factors of the exhaust temperature coefficient, takes into account the influence of the exhaust temperature on the ammonia nitrogen ratio, improves the representativeness of the calculated exhaust temperature coefficient, and thereby improves the accuracy of the analysis result of analyzing the cause of abnormal urea consumption based on the exhaust temperature coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A schematic flow chart of an embodiment of the abnormal urea consumption analysis method provided by the present invention; Figure 2 For the present invention Figure 1 A schematic flow chart of an embodiment of determining the target ammonia nitrogen ratio and the measured ammonia nitrogen ratio in step S102; Figure 3 For the present invention Figure 2 A schematic flow chart of an embodiment of determining the target original engine NOx mass flow rate and the actual original engine NOx mass flow rate in step S201; Figure 4 For the present invention Figure 1 A schematic flow chart of an embodiment of determining the target window exhaust temperature and the measured window exhaust temperature in step S102; Figure 5 A schematic flow chart of an embodiment of the present invention for determining whether the cause of abnormal urea consumption is that the original engine NOx deviates from the design value; Figure 6 A schematic diagram of the structure of an embodiment of the abnormal urea consumption analysis device provided by the present invention; Figure 7 A schematic structural diagram of an embodiment of a vehicle provided by the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0028] It should be understood that the schematic drawings are not drawn to scale. The flowchart used in the present invention shows the operations implemented according to some embodiments of the present invention. It should be understood that the operations of the flowchart can be implemented out of order, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present invention, can add one or more other operations to the flowchart, and can also remove one or more operations from the flowchart. Some of the block diagrams shown in the accompanying drawings are functional entities, which do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0029] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] The present invention provides a method, device and vehicle for analyzing abnormal urea consumption, which are respectively described below.

[0031] The embodiment of the present invention provides a method for analyzing abnormal urea consumption, such as Figure 1 As shown, the abnormal urea consumption analysis method includes: S101, determining a thermal energy window based on a preset energy and a current operating point; the thermal energy window includes a plurality of operating points, the end operating point of the thermal energy window is the current operating point, and the accumulated heat of the plurality of operating points is equal to the preset energy; S102, determining a target ammonia nitrogen ratio, a measured ammonia nitrogen ratio, a target window exhaust temperature, and a measured window exhaust temperature in a thermal energy window; S103, determining a first product of the target ammonia nitrogen ratio and the target window exhaust temperature and a second product of the measured ammonia nitrogen ratio and the measured window exhaust temperature, and taking the absolute value of the ratio of the first product to the second product as an exhaust temperature coefficient; when the exhaust temperature coefficient is less than a preset exhaust temperature coefficient, determining that the cause of abnormal urea consumption is abnormal exhaust temperature.

[0032] Among them, the specific process of determining the thermal energy window in step S101 is: calculate the heat of the current operating point, accumulate the heat of the previous operating conditions from the current operating point, and when the accumulated heat is greater than or equal to the preset energy, take the frontmost operating point as the starting point of the thermal energy window, and the current operating point as the end point of the thermal energy window.

[0033] Specifically, the heat calculation formula for each operating point is: Q=C*m*(TT 0 ) In the formula, Q The heat for each operating point; C is the specific heat capacity of air, which can be obtained by looking up the table based on the measured exhaust temperature; m is the exhaust quality; T is the exhaust temperature; T 0 is the air temperature.

[0034] Among them, the ammonia nitrogen ratio refers to the ratio of urea to NOx, abbreviated as ANR.

[0035] In a specific embodiment of the present invention, the temperature rejection coefficient is:

[0036] In the formula, is the exhaust temperature coefficient; Exhaust temperature for target window; is the target ammonia nitrogen ratio; To measure the window exhaust temperature; is the measured ammonia nitrogen ratio; | | is the absolute value symbol.

[0037] Specifically, the preset exhaust temperature coefficient is 0.8.

[0038] It should be understood that the preset exhaust temperature coefficient can be set or adjusted according to the actual application scenario and is not limited to the above specific values.

[0039] It should be noted that: when the cause of abnormal urea consumption is exhaust temperature, it is necessary to check whether the insulation of the engine exhaust pipe and post-treatment is abnormal.

[0040] Compared with the prior art, the abnormal urea consumption analysis method provided in the embodiment of the present invention first determines the thermal energy window, and uses the thermal energy window as a calculation unit to analyze the abnormal urea consumption. Compared with analyzing a single operating point, it avoids the influence of a single extreme operating condition on the analysis result, improves the accuracy of the target ammonia nitrogen ratio, the measured ammonia nitrogen ratio, the target window exhaust temperature and the measured window exhaust temperature, and thus improves the accuracy and stability of the abnormal urea consumption analysis result. In addition, the present invention uses the ammonia nitrogen ratio and the window exhaust temperature as related factors of the exhaust temperature coefficient, takes into account the influence of the exhaust temperature on the ammonia nitrogen ratio, improves the representativeness of the calculated exhaust temperature coefficient, and thus improves the accuracy of the analysis result of analyzing the cause of abnormal urea consumption based on the exhaust temperature coefficient.

[0041] In some embodiments of the present invention, Figure 2 As shown, the step S102 of determining the target ammonia nitrogen ratio and the measured ammonia nitrogen ratio of the thermal energy window includes: S201, obtaining the urea injection amount at each operating point, and determining the target original engine NOx mass flow rate and the measured original engine NOx mass flow rate at each operating point; S202, determining a total target original engine NOx mass flow rate in a thermal energy window based on the target original engine NOx mass flow rate; S203, determining the total measured original engine NOx mass flow rate in the thermal energy window based on the measured original engine NOx mass flow rate; S204, determining a total urea injection amount in the thermal energy window based on the urea injection amount; S205. The ratio of the total urea injection amount to the total measured original NOx mass flow rate is used as the measured ammonia nitrogen ratio, and the ratio of the total urea injection amount to the total target original NOx mass flow rate is used as the target ammonia nitrogen ratio.

[0042] The urea injection amount in step S201 can be obtained by detecting a flow meter disposed at the urea nozzle.

[0043] In some embodiments of the present invention, Figure 3 As shown, the step S201 of determining the target original engine NOx mass flow rate and the measured original engine NOx mass flow rate at each operating point includes: S301, obtaining the exhaust gas flow rate and the target original engine NOx volume ratio and the measured original engine NOx volume ratio at each operating point; S302, determining a target original engine NOx mass flow rate based on the target original engine NOx volume percentage and the exhaust gas flow rate, and determining an actual original engine NOx mass flow rate based on an actual original engine NOx volume percentage and the exhaust gas flow rate.

[0044] The measured original engine NOx volume percentage in step S301 can be obtained by measuring with a NOx sensor.

[0045] The process of obtaining the target original engine NOx volume percentage is as follows: first determine the current speed and current torque of the current operating point, and interpolate in the map table based on the current speed and current torque to obtain the target original engine NOx volume percentage.

[0046] Specifically, the interpolation method is minimum linear interpolation.

[0047] In a specific embodiment of the present invention, the target ammonia nitrogen ratio is:

[0048]

[0049] The measured ammonia nitrogen ratio is:

[0050]

[0051] In the formula, is the target ammonia nitrogen ratio; For the k Urea injection amount at each operating point, in g / h; For the k Target original engine NOx mass flow rate at each operating point; i and j They are the starting point number and the ending point number of the thermal energy window respectively; is the measured ammonia nitrogen ratio; For the k The measured original engine NOx mass flow rate at each operating point; is the target original engine NOx volume percentage, in ppm; The measured NOx volume percentage of the original engine, in ppm; is the exhaust gas flow rate, in kg / h.

[0052] In some embodiments of the present invention, Figure 4 As shown, determining the target window exhaust temperature and the measured window exhaust temperature in step S102 includes: S401, determining multiple operating point target exhaust temperatures and multiple operating point measured exhaust temperatures; S402: taking the average of the target exhaust temperatures of the multiple operating points as the target window exhaust temperature, and taking the actually measured exhaust temperatures of the multiple operating points as the actually measured window exhaust temperature.

[0053] The target exhaust temperature at each operating point can be obtained by interpolation in the MAP table according to the speed and torque at each operating point. The actual exhaust temperature at the operating point can be obtained by collecting data from the temperature sensor.

[0054] The above process can only check whether the cause of abnormal urea consumption is temperature discharge, and the cause is single. In order to further improve the comprehensiveness of the cause of abnormal urea consumption, in some embodiments of the present invention, Figure 5 As shown, the abnormal urea consumption analysis method also includes: S501, determining the power of each operating point; S502, determining a target original engine NOx window emission based on the power and the target original engine NOx mass flow rate, and determining a measured original engine NOx window emission based on the power and the measured original engine NOx mass flow rate; S503, determining the original engine NOx specific emission deviation based on the target original engine NOx window emission and the measured original engine NOx window emission; S504: When the original engine NOx emission specific deviation is greater than the threshold deviation, it is determined that the cause of the abnormal urea consumption is that the original engine NOx deviates from the design value.

[0055] The embodiment of the present invention determines the original machine NOx emission ratio deviation based on the determined target original machine NOx window emission and the measured original machine NOx window emission. Whether the cause of abnormal urea consumption is the deviation of the original machine NOx from the design value can be determined through the original machine NOx emission ratio deviation. Under the premise that the cause of abnormal urea consumption is the exhaust temperature, other causes of abnormal urea consumption can be analyzed, thereby improving the comprehensiveness and accuracy of the analysis of the cause of abnormal urea consumption.

[0056] It should be noted that if the cause of abnormal urea consumption is that the original engine NOx deviates from the design value, it is necessary to check the engine manufacturing consistency to ensure whether the abnormal urea consumption is caused by the engine with abnormal parameters.

[0057] In a specific embodiment of the present invention, the threshold deviation is 20%.

[0058] It should be understood that the threshold deviation can be set or calibrated according to the actual application scenario, which will not be described in detail here.

[0059] In a specific embodiment of the present invention, step S501 is specifically: The speed and torque at each operating point are obtained, and the power is determined based on the speed and torque.

[0060] In a specific embodiment of the present invention, the original engine NOx emission deviation is:

[0061]

[0062]

[0063]

[0064] In the formula, It is the NOx emission deviation of the original engine; is the measured NOx window emission of the original engine; | | is the absolute value symbol; is the target original engine NOx mass flow rate; is power; is the rotation speed; For torque.

[0065] In summary, the abnormal urea consumption method provided in the embodiment of the present invention accurately determines whether the cause of abnormal urea consumption is caused by excessive exhaust temperature deviation through actual exhaust temperature, actual ammonia nitrogen ratio, target exhaust temperature and target ammonia nitrogen ratio, and determines whether the cause of abnormal urea consumption is caused by excessive NOx deviation of the original machine through the deviation between the target original machine NOx window emission and the measured original machine NOx window emission, thereby realizing the analysis of the cause of abnormal urea consumption. In addition, the embodiment of the present invention uses the thermal energy window as the analysis unit, and compared with a single operating point, the thermal energy window includes multiple operating points, which can further improve the accuracy, representativeness and stability of the analysis results.

[0066] In order to better implement the abnormal urea consumption analysis method in the embodiment of the present invention, based on the abnormal urea consumption analysis method, the embodiment of the present invention also provides an abnormal urea consumption analysis device, such as Figure 6 As shown, the urea abnormal consumption analysis device 600 includes: A thermal energy window determination unit 601 is used to determine a thermal energy window based on a preset energy and a current operating point; the thermal energy window includes a plurality of operating points, the end operating point of the thermal energy window is the current operating point, and the accumulated heat of the plurality of operating points is equal to the preset energy; Ammonia nitrogen ratio and window exhaust temperature determination unit 602, used to determine a target ammonia nitrogen ratio, a measured ammonia nitrogen ratio, a target window exhaust temperature and a measured window exhaust temperature of the thermal energy window; The abnormal urea consumption analysis unit 603 is used to determine a first product of a target ammonia nitrogen ratio and a target window exhaust temperature and a second product of a measured ammonia nitrogen ratio and a measured window exhaust temperature, and use the absolute value of the ratio of the first product to the second product as an exhaust temperature coefficient. When the exhaust temperature coefficient is less than a preset exhaust temperature coefficient, it is determined that the cause of the abnormal urea consumption is abnormal exhaust temperature.

[0067] It should be noted that the abnormal urea consumption analysis device 600 provided in the above embodiment can implement the technical solution described in the above embodiment of the abnormal urea consumption analysis method. The specific implementation principles or specific implementation details of the above modules or units can refer to the corresponding contents in the above embodiment of the abnormal urea consumption analysis method, which will not be described one by one here.

[0068] like Figure 7 As shown, the present invention also provides a vehicle 700. The vehicle 700 includes a processor 701, a memory 702 and a display 703. Figure 7 Only some of the components of vehicle 700 are shown, but it should be understood that implementation of all of the components shown is not a requirement, and more or fewer components may alternatively be implemented.

[0069] In some embodiments, the processor 701 may be a central processing unit (CPU), a microprocessor or other data processing chip, and is used to run program codes or process data stored in the memory 702, such as the abnormal urea consumption analysis method of the present invention.

[0070] In some embodiments of the present invention, the processor 701 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processor 701 may be local or remote. In some embodiments, the processor 701 may be implemented in a cloud platform. In one embodiment, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination thereof.

[0071] In some embodiments, the memory 702 may be an internal storage unit of the vehicle 700 , such as a hard disk or a memory of the vehicle 700 .

[0072] Furthermore, the memory 702 may include both an internal storage unit of the vehicle 700 and an external storage device. The memory 702 is used to store application software installed in the vehicle 700 and various data.

[0073] In some embodiments, the display 703 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 703 is used to display information of the vehicle 700 and to display a visual user interface. The components 701-703 of the vehicle 700 communicate with each other via a system bus.

[0074] In some embodiments of the present invention, when the processor 701 executes the urea abnormal consumption analysis program in the memory 702, the following steps may be implemented: The thermal energy window is determined based on the preset energy and the current operating point; the thermal energy window includes multiple operating points, the end operating point of the thermal energy window is the current operating point, and the accumulated heat of the multiple operating points is equal to the preset energy; Determine the target ammonia nitrogen ratio, the measured ammonia nitrogen ratio, the target window exhaust temperature and the measured window exhaust temperature of the thermal energy window; Determine the first product of the target ammonia nitrogen ratio and the target window exhaust temperature and the second product of the measured ammonia nitrogen ratio and the measured window exhaust temperature, and use the absolute value of the ratio of the first product to the second product as the exhaust temperature coefficient. When the exhaust temperature coefficient is less than the preset exhaust temperature coefficient, it is determined that the cause of the abnormal urea consumption is abnormal exhaust temperature.

[0075] It should be understood that: when the processor 701 executes the abnormal urea consumption analysis program in the memory 702, in addition to the above functions, other functions can also be implemented. For details, please refer to the description of the corresponding method embodiment above.

[0076] Furthermore, the embodiment of the present invention does not specifically limit the type of the vehicle 700 mentioned, and the vehicle 700 may be a passenger car or a commercial vehicle.

[0077] Accordingly, an embodiment of the present invention further provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the programs or instructions are executed by a processor, the steps or functions in the abnormal urea consumption analysis method provided in the above-mentioned method embodiments can be implemented.

[0078] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0079] The above is a detailed introduction to the abnormal urea consumption analysis method, device and vehicle provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for analyzing abnormal urea consumption, characterized in that: include: Determine the thermal energy window based on the preset energy and the current operating point; The thermal energy window includes a plurality of operating points, the end operating point of the thermal energy window is the current operating point, and the accumulated heat of the plurality of operating points is equal to the preset energy; Determining a target ammonia nitrogen ratio, a measured ammonia nitrogen ratio, a target window exhaust temperature, and a measured window exhaust temperature of the thermal energy window; Determine a first product of the target ammonia nitrogen ratio and the target window exhaust temperature and a second product of the measured ammonia nitrogen ratio and the measured window exhaust temperature, and use the absolute value of the ratio of the first product to the second product as an exhaust temperature coefficient. When the exhaust temperature coefficient is less than a preset exhaust temperature coefficient, determine that the cause of abnormal urea consumption is abnormal exhaust temperature.

2. The method for analyzing abnormal urea consumption according to claim 1, characterized in that: Determine the target ammonia nitrogen ratio and the measured ammonia nitrogen ratio in the thermal energy window, including: Obtaining the urea injection amount at each of the operating points, and determining the target original engine NOx mass flow rate and the measured original engine NOx mass flow rate at each of the operating points; Determining a total target source NOx mass flow rate of the thermal energy window based on the target source NOx mass flow rate; Determining a total measured original engine NOx mass flow rate in the thermal energy window based on the measured original engine NOx mass flow rate; determining a total urea injection amount in the thermal energy window based on the urea injection amount; The ratio of the total urea injection amount to the total measured original machine NOx mass flow rate is used as the measured ammonia nitrogen ratio, and the ratio of the total urea injection amount to the total target original machine NOx mass flow rate is used as the target ammonia nitrogen ratio.

3. The method for analyzing abnormal urea consumption according to claim 2, characterized in that: The determining of the target original engine NOx mass flow rate and the measured original engine NOx mass flow rate at each operating point includes: Obtaining the exhaust gas flow rate and the target original engine NOx volume percentage and the measured original engine NOx volume percentage at each operating point; The target source engine NOx mass flow is determined based on the target source engine NOx volume percentage and the exhaust gas flow rate, and the measured source engine NOx mass flow is determined based on the measured source engine NOx volume percentage and the exhaust gas flow rate.

4. The abnormal urea consumption analysis method according to claim 3, characterized in that: The target ammonia nitrogen ratio is: The measured ammonia nitrogen ratio is: In the formula, is the target ammonia nitrogen ratio; For the k Urea injection amount at each operating point; For the k Target original engine NOx mass flow rate at each operating point; i and j They are the starting point number and the ending point number of the thermal energy window respectively; is the measured ammonia nitrogen ratio; For the k The measured original machine NOx mass flow rate at each operating point; The target original engine NOx volume percentage; It is the measured NOx volume percentage of the original engine; is the exhaust gas flow rate.

5. The method for analyzing abnormal urea consumption according to claim 1, characterized in that: Determine the target window exhaust temperature and the measured window exhaust temperature, including: Determine a plurality of target exhaust temperatures at the plurality of operating points and a plurality of measured exhaust temperatures at the plurality of operating points; The average value of the target exhaust temperatures of the multiple operating points is used as the target window exhaust temperature, and the actually measured exhaust temperatures of the multiple operating points are used as the actually measured window exhaust temperature.

6. The method for analyzing abnormal urea consumption according to claim 4, characterized in that: The method further comprises: Determining the power of each of the operating points; Determining a target source engine NOx window emission based on the power and the target source engine NOx mass flow rate, and determining a measured source engine NOx window emission based on the power and the measured source engine NOx mass flow rate; Determining the original engine NOx specific emission deviation based on the target original engine NOx window emission and the measured original engine NOx window emission; When the original engine NOx emission specific deviation is greater than the threshold deviation, it is determined that the cause of the abnormal urea consumption is that the original engine NOx deviates from the design value.

7. The method for analyzing abnormal urea consumption according to claim 6, characterized in that: The determining of the power of each operating point comprises: The rotation speed and torque at each operating point are obtained, and the power is determined based on the rotation speed and the torque.

8. The method for analyzing abnormal urea consumption according to claim 7, characterized in that: The original engine NOx emission ratio deviation is: In the formula, It is the NOx emission deviation of the original engine; is the measured NOx window emission of the original engine; | | is the absolute value symbol; is the target original engine NOx mass flow rate; is power; is the rotation speed; For torque.

9. A device for analyzing abnormal urea consumption, characterized in that: include: A thermal energy window determination unit, used to determine the thermal energy window based on a preset energy and a current operating point; The thermal energy window includes a plurality of operating points, the end operating point of the thermal energy window is the current operating point, and the accumulated heat of the plurality of operating points is equal to the preset energy; An ammonia nitrogen ratio and window exhaust temperature determination unit, for determining a target ammonia nitrogen ratio, a measured ammonia nitrogen ratio, a target window exhaust temperature and a measured window exhaust temperature of the thermal energy window; The abnormal urea consumption analysis unit is used to determine a first product of the target ammonia nitrogen ratio and the target window exhaust temperature and a second product of the measured ammonia nitrogen ratio and the measured window exhaust temperature, and use the absolute value of the ratio of the first product to the second product as an exhaust temperature coefficient. When the exhaust temperature coefficient is less than a preset exhaust temperature coefficient, it is determined that the cause of the abnormal urea consumption is abnormal exhaust temperature.

10. A vehicle, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the abnormal urea consumption analysis method described in any one of claims 1 to 8 above.

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