Method, device and vehicle for analyzing abnormal urea consumption

Abstract

The present invention provides a method, device, and vehicle for analyzing abnormal urea consumption, belonging to the technical field of diesel engine aftertreatment. The method comprises: determining a thermal energy window based on a preset energy and a 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 cumulative heat of the multiple 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 within the thermal energy window; 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 using the absolute value of the ratio of the first product and the second product as an exhaust temperature coefficient. When the exhaust temperature coefficient is less than the preset exhaust temperature coefficient, determining that the cause of abnormal urea consumption is abnormal exhaust temperature. The present invention uses the thermal energy window as a calculation unit to analyze abnormal urea consumption and considers the influence of exhaust temperature on the ammonia nitrogen ratio, thereby improving the accuracy of the analysis results.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engine aftertreatment, 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 a major atmospheric pollutant. Currently, the mainstream method for reducing NOx in diesel engine exhaust is selective catalytic reduction (SCR). This involves injecting urea into the tailpipe. Urea hydrolyzes at a certain temperature to form ammonia, which reacts with NOx to produce pollution-free water and nitrogen. Therefore, the amount of urea injected into the tailpipe directly affects the final NOx emissions from diesel engine exhaust. China VI emission regulations have strict requirements for monitoring urea consumption.

[0003] Currently, there are two methods for determining urea consumption: 1) deriving the volume of urea consumed by multiplying the change in the urea tank level by the tank's bottom area; and 2) deriving the volume of urea consumed by cumulatively summing the actual urea injection volume from the urea nozzles. While these two methods can determine urea deviation based on the urea consumption volume and the calculated urea demand, they cannot pinpoint the cause of abnormal urea consumption.

[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 to solve the technical problem 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:

[0007] Determine a thermal energy window based on a preset energy and a 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 cumulative heat of the multiple operating points is equal to the preset energy;

[0008] Determining a target ammonia nitrogen ratio, a measured ammonia nitrogen ratio, a target window exhaust temperature, and a measured window exhaust temperature for the thermal energy window;

[0009] 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.

[0010] In one possible implementation, determining the target ammonia-nitrogen ratio and the measured ammonia-nitrogen ratio in the thermal energy window includes:

[0011] 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;

[0012] determining a total target source NOx mass flow rate in the thermal energy window based on the target source NOx mass flow rate;

[0013] determining a total measured source NOx mass flow rate in the thermal energy window based on the measured source NOx mass flow rate;

[0014] determining a total urea injection amount in the thermal energy window based on the urea injection amount;

[0015] The ratio of the total urea injection amount to the total measured original engine 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 engine NOx mass flow rate is used as the target ammonia nitrogen ratio.

[0016] In one possible implementation, determining the target source engine NOx mass flow rate and the measured source engine NOx mass flow rate at each operating point includes:

[0017] Obtaining the exhaust gas flow rate and the target original engine NOx volume fraction and the measured original engine NOx volume fraction at each operating point;

[0018] The target source NOx mass flow rate is determined based on the target source NOx volume fraction and the exhaust gas flow rate, and the measured source NOx mass flow rate is determined based on the measured source NOx volume fraction and the exhaust gas flow rate.

[0019] In one possible implementation, the target ammonia nitrogen ratio is:

[0020]

[0021]

[0022] The measured ammonia nitrogen ratio is:

[0023]

[0024]

[0025] Where, 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 engine NOx mass flow rate at each operating point; The target original engine NOx volume ratio; The measured NOx volume percentage of the original engine; is the exhaust gas flow rate.

[0026] In one possible implementation, determining the target window exhaust temperature and the measured window exhaust temperature includes:

[0027] Determining 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;

[0028] 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.

[0029] In a possible implementation, the method further includes:

[0030] Determining the power at each of the operating points;

[0031] 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;

[0032] determining a stock engine NOx specific emission deviation based on the target stock engine NOx window emission and the measured stock engine NOx window emission;

[0033] When the original engine NOx emission specific deviation is greater than a threshold deviation, it is determined that the abnormal urea consumption is caused by the original engine NOx deviating from a design value.

[0034] In a possible implementation, determining the power at each operating point includes:

[0035] The rotational speed and torque at each operating point are obtained, and the power is determined based on the rotational speed and the torque.

[0036] In a possible implementation, the original engine NOx emission ratio deviation is:

[0037]

[0038]

[0039]

[0040]

[0041] Where, 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 rotational speed; is the torque.

[0042] On the other hand, the present invention also provides a device for analyzing abnormal urea consumption, comprising:

[0043] 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 comprising a plurality of operating points, the end operating point of the thermal energy window being the current operating point, and the accumulated heat of the plurality of operating points being equal to the preset energy;

[0044] an ammonia nitrogen ratio and window exhaust temperature determination unit, configured 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;

[0045] 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.

[0046] In another aspect, the present invention further provides a vehicle, comprising a memory and a processor, wherein:

[0047] The memory is used to store programs;

[0048] The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps of the abnormal urea consumption analysis method described in any one of the possible implementations above.

[0049] 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 the calculation unit to analyze abnormal urea consumption. Compared with analyzing a single operating point, this avoids the influence of a single extreme operating condition on the analysis results, 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, thereby improving the accuracy and stability of the abnormal urea consumption analysis results. Furthermore, 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 results of the abnormal urea consumption based on the exhaust temperature coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] 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.

[0051] Figure 1 A schematic flow chart of an embodiment of the abnormal urea consumption analysis method provided by the present invention;

[0052] 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;

[0053] Figure 3 For the present invention Figure 2 A schematic flow chart of an embodiment of determining the target source NOx mass flow rate and the measured source NOx mass flow rate in step S201;

[0054] Figure 4 For the present invention Figure 1 A flowchart of an embodiment of determining the target window exhaust temperature and the measured window exhaust temperature in step S102;

[0055] 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;

[0056] Figure 6 A schematic structural diagram of an embodiment of the abnormal urea consumption analysis device provided by the present invention;

[0057] Figure 7 This is a schematic structural diagram of an embodiment of a vehicle provided by the present invention. DETAILED DESCRIPTION

[0058] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0059] It should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present invention illustrate operations implemented according to some embodiments of the present invention. It should be understood that the operations of the flowcharts can be implemented out of sequence, and steps that have no logical contextual relationship can be reversed in order or implemented simultaneously. In addition, those skilled in the art, guided by the content of the present invention, can add one or more other operations to the flowcharts or remove one or more operations from the flowcharts. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0060] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0061] The present invention provides a method, device and vehicle for analyzing abnormal urea consumption, which are described below respectively.

[0062] The embodiment of the present invention provides a method for analyzing abnormal urea consumption, such as Figure 1 As shown, the analysis method of abnormal urea consumption includes:

[0063] S101, determining a thermal energy window based on a preset energy and a 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 cumulative heat of the multiple operating points is equal to the preset energy;

[0064] 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;

[0065] S103. 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 the abnormal urea consumption is abnormal exhaust temperature.

[0066] 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, use 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.

[0067] Specifically, the heat calculation formula for each operating point is:

[0068] Q=C*m*(TT 0 )

[0069] Where, 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.

[0070] Among them, the ammonia nitrogen ratio refers to the ratio of urea to NOx, abbreviated as ANR.

[0071] In a specific embodiment of the present invention, the exhaust temperature coefficient is:

[0072]

[0073] Where, is the exhaust temperature coefficient; exhaust temperature for the 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.

[0074] Specifically, the preset exhaust temperature coefficient is 0.8.

[0075] 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.

[0076] 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 aftertreatment is abnormal.

[0077] Compared to the prior art, the abnormal urea consumption analysis method provided in the embodiments of the present invention first determines a thermal energy window and uses the thermal energy window as a calculation unit to analyze abnormal urea consumption. Compared to analyzing a single operating point, this method avoids the influence of a single extreme operating condition on the analysis results, 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, thereby improving the accuracy and stability of the abnormal urea consumption analysis results. Furthermore, the present invention uses both the ammonia-nitrogen ratio and the window exhaust temperature as relevant factors of the exhaust temperature coefficient, taking into account the influence of exhaust temperature on the ammonia-nitrogen ratio, improving the representativeness of the calculated exhaust temperature coefficient, and thus improving the accuracy of the analysis results of abnormal urea consumption based on the exhaust temperature coefficient.

[0078] In some embodiments of the present invention, Figure 2 As shown, determining the target ammonia nitrogen ratio and the measured ammonia nitrogen ratio of the thermal energy window in step S102 includes:

[0079] 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;

[0080] S202, determining a total target source NOx mass flow rate in a thermal energy window based on the target source NOx mass flow rate;

[0081] 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;

[0082] S204, determining a total urea injection amount in the thermal energy window based on the urea injection amount;

[0083] S205: The ratio of the total urea injection amount to the total measured original engine 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 engine NOx mass flow rate is used as the target ammonia nitrogen ratio.

[0084] The urea injection amount in step S201 can be obtained by detecting a flow meter disposed at the urea nozzle.

[0085] In some embodiments of the present invention, Figure 3 As shown, the determination of the target original engine NOx mass flow rate and the measured original engine NOx mass flow rate at each operating point in step S201 includes:

[0086] S301, obtaining the exhaust gas flow rate and the target original engine NOx volume fraction and the measured original engine NOx volume fraction at each operating point;

[0087] S302 : Determine a target source NOx mass flow rate based on the target source NOx volume fraction and the exhaust gas flow rate, and determine a measured source NOx mass flow rate based on the measured source NOx volume fraction and the exhaust gas flow rate.

[0088] The measured original engine NOx volume percentage in step S301 can be obtained by actual measurement using a NOx sensor.

[0089] The process of obtaining the target original engine NOx volume fraction is as follows: first determine the current speed and current torque of the current operating point, and then interpolate in the map table based on the current speed and current torque to obtain the target original engine NOx volume fraction.

[0090] Specifically, the interpolation method is minimum linear interpolation.

[0091] In a specific embodiment of the present invention, the target ammonia nitrogen ratio is:

[0092]

[0093]

[0094] The measured ammonia nitrogen ratio is:

[0095]

[0096]

[0097] Where, 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; The target original engine NOx volume ratio, in ppm; The measured NOx volume percentage of the original engine, in ppm; is the exhaust gas flow rate, in kg / h.

[0098] 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:

[0099] S401, determining multiple target exhaust temperatures at multiple operating points and multiple measured exhaust temperatures at multiple operating points;

[0100] 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.

[0101] The target exhaust temperature at each operating point can be obtained by interpolating the speed and torque at each operating point in the MAP table. The actual exhaust temperature at each operating point can be obtained by collecting data from the temperature sensor.

[0102] The above process can only check whether the cause of abnormal urea consumption is exhaust temperature, 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:

[0103] S501, determining the power of each operating point;

[0104] S502, 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;

[0105] 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;

[0106] 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.

[0107] 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.

[0108] 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 that the abnormal urea consumption is caused by the abnormal engine parameters.

[0109] In a specific embodiment of the present invention, the threshold deviation is 20%.

[0110] 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.

[0111] In a specific embodiment of the present invention, step S501 is specifically as follows:

[0112] The speed and torque at each operating point are obtained, and the power is determined based on the speed and torque.

[0113] In a specific embodiment of the present invention, the original engine NOx emission deviation is:

[0114]

[0115]

[0116]

[0117]

[0118] Where, 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 rotational speed; is the torque.

[0119] In summary, the abnormal urea consumption method provided by the embodiments of the present invention accurately determines whether abnormal urea consumption is caused by excessive exhaust temperature deviation based on the actual exhaust temperature, actual ammonia-nitrogen ratio, target exhaust temperature, and target ammonia-nitrogen ratio. Furthermore, the deviation between the target source engine NOx window emissions and the measured source engine NOx window emissions determines whether the abnormal urea consumption is caused by excessive source engine NOx deviation, thus enabling analysis of the cause of abnormal urea consumption. Furthermore, the embodiments of the present invention use the thermal energy window as the analysis unit. Compared to a single operating point, the thermal energy window includes multiple operating points, further improving the accuracy, representativeness, and stability of the analysis results.

[0120] 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:

[0121] A thermal energy window determination unit 601 is configured to determine a thermal energy window based on a preset energy and a 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;

[0122] Ammonia nitrogen ratio and window exhaust temperature determination unit 602, 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;

[0123] The abnormal urea consumption analysis unit 603 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 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.

[0124] It should be noted that the urea abnormal consumption analysis device 600 provided in the above embodiment can implement the technical solution described in the above embodiment of the urea abnormal consumption analysis method. The specific implementation principles or specific implementation details of the above modules or units can be found in the corresponding contents in the above embodiment of the urea abnormal consumption analysis method, and will not be described one by one here.

[0125] 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 implementing all of the shown components is not a requirement, and more or fewer components may alternatively be implemented.

[0126] In some embodiments, the processor 701 may be a central processing unit (CPU), a microprocessor, or other data processing chip, configured to execute program codes or process data stored in the memory 702 , such as the abnormal urea consumption analysis method of the present invention.

[0127] In some embodiments of the present invention, processor 701 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, processor 701 may be local or remote. In some embodiments, processor 701 may be implemented on 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, multiple clouds, or any combination thereof.

[0128] In some embodiments, the memory 702 may be an internal storage unit of the vehicle 700 , such as a hard drive or memory of the vehicle 700 .

[0129] 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.

[0130] In some embodiments, display 703 can be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 703 is used to display information about vehicle 700 and to present a visual user interface. Components 701-703 of vehicle 700 communicate with each other via a system bus.

[0131] In some embodiments of the present invention, when the processor 701 executes the abnormal urea consumption analysis program in the memory 702, the following steps may be implemented:

[0132] A thermal energy window is determined based on a preset energy and a 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;

[0133] Determine the target ammonia nitrogen ratio, the measured ammonia nitrogen ratio, the target window exhaust temperature, and the measured window exhaust temperature for the thermal energy window;

[0134] 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.

[0135] 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, it can also implement other functions. For details, please refer to the description of the corresponding method embodiment above.

[0136] Furthermore, the embodiment of the present invention does not specifically limit the type of the vehicle 700 mentioned, and the vehicle 700 can be a passenger car or a commercial vehicle.

[0137] 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 program or instructions are executed by a processor, the steps or functions of the abnormal urea consumption analysis method provided in the above-mentioned method embodiments can be implemented.

[0138] Those skilled in the art will appreciate that all or part of the process flow of the above-described method embodiment can be implemented by instructing related hardware (such as a processor, controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0139] 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 herein 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 ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting 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 for 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, it is determined that the cause of the abnormal urea consumption is abnormal exhaust temperature.

2. The method for analyzing abnormal urea consumption according to claim 1, wherein: 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 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; determining a total target source NOx mass flow rate in the thermal energy window based on the target source NOx mass flow rate; determining a total measured source NOx mass flow rate in the thermal energy window based on the measured source 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 engine 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 engine NOx mass flow rate is used as the target ammonia nitrogen ratio.

3. The method for analyzing abnormal urea consumption according to claim 2, wherein: Determining 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 fraction and the measured original engine NOx volume fraction at each operating point; The target source NOx mass flow rate is determined based on the target source NOx volume fraction and the exhaust gas flow rate, and the measured source NOx mass flow rate is determined based on the measured source NOx volume fraction and the exhaust gas flow rate.

4. The method for analyzing abnormal urea consumption according to claim 3, wherein: The target ammonia nitrogen ratio is: The measured ammonia nitrogen ratio is: Where, 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 engine NOx mass flow rate at each operating point; The target original engine NOx volume ratio; 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, wherein: Determine the target window exhaust temperature and the measured window exhaust temperature, including: Determining 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, wherein: The method further comprises: Determining the power at 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 a stock engine NOx specific emission deviation based on the target stock engine NOx window emission and the measured stock engine NOx window emission; When the original engine NOx emission specific deviation is greater than a threshold deviation, it is determined that the abnormal urea consumption is caused by the original engine NOx deviating from a design value.

7. The method for analyzing abnormal urea consumption according to claim 6, wherein: Determining the power of each operating point includes: The rotational speed and torque at each operating point are obtained, and the power is determined based on the rotational speed and the torque.

8. The method for analyzing abnormal urea consumption according to claim 7, wherein: The original engine NOx emission ratio deviation is: Where, 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 rotational speed; is the torque.

9. A urea abnormal consumption analysis device, characterized in that: include: 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, configured 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 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 configured to execute the program stored in the memory to implement the steps of the abnormal urea consumption analysis method according to any one of claims 1 to 8.

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