Analysis method and device for abnormal urea consumption, and vehicle

Abstract

The present invention relates to the technical field of diesel engine aftertreatment, and provides an analysis method and device for abnormal urea consumption, and a vehicle. The method comprises: determining a thermal energy window on the basis of preset energy and a current operating point, wherein the thermal energy window comprises a plurality of operating points, the terminal operating point of the thermal energy window is the current operating point, and cumulative 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 gas temperature, and a measured window exhaust gas temperature of the thermal energy window; and determining a first product of the target ammonia-nitrogen ratio and the target window exhaust gas temperature and a second product of the measured ammonia-nitrogen ratio and the measured window exhaust gas temperature, using the absolute value of the ratio of the first product to the second product as an exhaust gas temperature coefficient, and when the exhaust gas temperature coefficient is less than a preset exhaust gas temperature coefficient, determining that the cause of abnormal urea consumption is an exhaust gas temperature abnormality. In the present invention, abnormal urea consumption is analyzed by using a thermal energy window as a computing unit, and the effect of the exhaust gas temperature on the ammonia-nitrogen ratio is considered, thereby improving the accuracy of analysis results.

Description

A method, apparatus and vehicle for analyzing abnormal urea consumption Technical Field

[0001] This invention relates to the field of diesel engine aftertreatment technology, specifically to a method, apparatus, and vehicle for analyzing abnormal urea consumption. Background Technology

[0002] NOx emitted from diesel engine exhaust is one of the most significant air pollutants. Currently, the mainstream method for reducing NOx in diesel engine exhaust is Selective Catalytic Reduction (SCR). This method involves injecting urea into the exhaust tailpipe. Since urea hydrolyzes to form ammonia at certain temperatures, the ammonia reacts with NOx to produce harmless water and nitrogen. Therefore, the amount of urea injected into the exhaust tailpipe directly affects the final NOx emissions from the diesel engine. The China VI emission standards impose strict requirements on the monitoring of urea consumption.

[0003] Currently, there are two methods for determining urea consumption: 1) calculating the volume of urea consumed by multiplying the change in urea tank level by the bottom area of ​​the urea tank; 2) calculating the volume of urea consumed by summing the actual urea injection volume from the urea nozzle. While both methods can determine urea deviation based on the urea consumption volume and the obtained 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, so as to analyze the cause of abnormal urea consumption and provide a reference for subsequent maintenance. Summary of the Invention

[0005] In view of this, it is necessary to provide a method, apparatus and vehicle for analyzing abnormal urea consumption, so as to solve the technical problem that the existing technology cannot analyze the causes of abnormal urea consumption.

[0006] On the one hand, in order to solve the above-mentioned technical problems, the present invention provides a method for analyzing abnormal urea consumption, comprising:

[0007] A thermal energy window is determined based on a preset energy level and the current operating point. The thermal energy window includes multiple operating points, and the current operating point is the endpoint of the thermal energy window. The cumulative heat of the multiple operating points is equal to the preset energy level.

[0008] 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.

[0009] 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 are determined, and the absolute value of the ratio of the first product and the second product is used as the exhaust temperature coefficient. When the exhaust temperature coefficient is less than the preset exhaust temperature coefficient, the cause of abnormal urea consumption is determined to be abnormal exhaust temperature.

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

[0011] Obtain the urea injection rate at each of the aforementioned operating points, and determine the target original NOx mass flow rate and the measured original NOx mass flow rate at each of the aforementioned operating points;

[0012] The total target original NOx mass flow rate of the thermal energy window is determined based on the target original NOx mass flow rate.

[0013] The total measured original NOx mass flow rate of the thermal energy window is determined based on the measured original NOx mass flow rate.

[0014] The total urea injection rate of the thermal energy window is determined based on the urea injection rate.

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

[0016] In one possible implementation, determining the target original NOx mass flow rate and the measured original NOx mass flow rate at each of the said operating points includes:

[0017] Obtain the exhaust gas flow rate and the target NOx volume percentage and the measured NOx volume percentage of the original machine at each of the aforementioned operating conditions;

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

[0019] In one possible implementation, the target ammonia nitrogen ratio is: m1 = 0.001587 * V1 * m fqll

[0020] The measured ammonia nitrogen ratio is: m2 = 0.001587 * V2 * m fqll

[0021] In the formula, β1 is the target ammonia-nitrogen ratio; m3(k) is the urea injection rate at the k-th operating point; m1(k) is the target original NOx mass flow rate at the k-th operating point; i and j are the starting and ending operating point numbers of the thermal energy window, respectively; β2 is the measured ammonia-nitrogen ratio; m2(k) is the measured original NOx mass flow rate at the k-th operating point; V1 is the target original NOx volume percentage; V2 is the measured original NOx volume percentage; m fqll This refers to the exhaust gas flow rate.

[0022] In one possible implementation, determining the target window exhaust temperature and the measured window exhaust temperature includes:

[0023] Determine the target exhaust temperature and the measured exhaust temperature at multiple operating points;

[0024] The average value of the target exhaust temperature at the multiple operating points is taken as the target window exhaust temperature, and the measured exhaust temperature at the multiple operating points is taken as the measured window exhaust temperature.

[0025] In one possible implementation, the method further includes:

[0026] Determine the power at each of the aforementioned operating points;

[0027] The target NOx window emission amount is determined based on the power and the target NOx mass flow rate of the original machine, and the measured NOx window emission amount of the original machine is determined based on the power and the measured NOx mass flow rate of the original machine;

[0028] The NOx emission ratio deviation of the original engine is determined based on the target original engine NOx window emission and the measured original engine NOx window emission;

[0029] When the original NOx emission deviation is greater than the threshold deviation, the cause of abnormal urea consumption is determined to be that the original NOx emission deviates from the design value.

[0030] In one possible implementation, determining the power at each of the operating points includes:

[0031] The rotational speed and torque at each of the aforementioned operating points are obtained, and the power is determined based on the rotational speed and the torque.

[0032] In one possible implementation, the original NOx emission deviation is:

[0033] In the formula, σ represents the original NOx emission deviation; y k The measured NOx window emission of the original engine; || represents the absolute value symbol; Y k The target NOx mass flow rate; P t (k) represents power; n t(k) represents the rotational speed; T t (k) represents torque.

[0034] On the other hand, the present invention also provides a device for analyzing abnormal urea consumption, comprising:

[0035] A thermal energy window determination unit is used 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 endpoint 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.

[0036] The ammonia nitrogen ratio and window exhaust temperature determination unit is used to 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.

[0037] The urea abnormal consumption analysis unit is used to 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. The absolute value of the ratio of the first product and the second product is used as the exhaust temperature coefficient. When the exhaust temperature coefficient is less than the preset exhaust temperature coefficient, the cause of the abnormal urea consumption is determined to be abnormal exhaust temperature.

[0038] On the other hand, the present invention also provides a vehicle including a memory and a processor, wherein,

[0039] The memory is used to store programs;

[0040] The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the urea abnormal consumption analysis method described in any of the above possible implementations.

[0041] The beneficial effects of this invention are as follows: The urea abnormal consumption analysis method provided by this invention first determines the thermal energy window and uses the thermal energy window as the calculation unit to analyze urea abnormal 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, and thus improves the accuracy and stability of the urea abnormal consumption analysis results. Furthermore, this invention uses both the ammonia nitrogen ratio and the window exhaust temperature as relevant factors of the exhaust temperature coefficient, considering 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 based on the exhaust temperature coefficient to analyze the causes of urea abnormal consumption. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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 effort.

[0043] Figure 1 is a schematic flowchart of an embodiment of the urea abnormal consumption analysis method provided by the present invention;

[0044] Figure 2 is a schematic flowchart of an embodiment of determining the target ammonia nitrogen ratio and the measured ammonia nitrogen ratio in step S102 of Figure 1 of the present invention.

[0045] Figure 3 is a schematic flowchart of an embodiment of determining the target original NOx mass flow rate and the measured original NOx mass flow rate in step S201 of Figure 2 of the present invention.

[0046] Figure 4 is a schematic flowchart of an embodiment of determining the target window exhaust temperature and the measured window exhaust temperature in step S102 of Figure 1 of the present invention.

[0047] Figure 5 is a schematic diagram of an embodiment of the present invention for determining whether abnormal urea consumption is caused by the original NOx deviation from the design value;

[0048] Figure 6 is a schematic diagram of an embodiment of the urea abnormal consumption analysis device provided by the present invention;

[0049] Figure 7 is a schematic diagram of an embodiment of the vehicle provided by the present invention. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0051] It should be understood that the illustrative drawings are not drawn to scale. The flowcharts used in this invention illustrate operations implemented according to some embodiments of the invention. It should be understood that the operations in the flowcharts may be implemented out of order, and steps without logical contextual relationships may be reversed or performed simultaneously. Furthermore, those skilled in the art, guided by the content of this invention, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor systems and / or microcontroller systems.

[0052] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0053] This invention provides a method, apparatus, and vehicle for analyzing abnormal urea consumption, which will be described below.

[0054] This invention provides a method for analyzing abnormal urea consumption, as shown in Figure 1. The method includes:

[0055] S101. Determine the thermal energy window based on the preset energy and the current operating point; the thermal energy window includes multiple operating points, the endpoint of the thermal energy window is the current operating point, and the cumulative heat of multiple operating points is equal to the preset energy.

[0056] S102. Determine the target ammonia-nitrogen ratio, measured ammonia-nitrogen ratio, target window exhaust temperature, and measured window exhaust temperature for the thermal energy window.

[0057] S103. 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. Use the absolute value of the ratio of the first product and the second product as the exhaust temperature coefficient. When the exhaust temperature coefficient is less than the preset exhaust temperature coefficient, determine that the cause of abnormal urea consumption is abnormal exhaust temperature.

[0058] The specific process of determining the thermal energy window in step S101 is as follows: calculate the heat at the current operating point, accumulate the heat of the previous operating points from the current operating point, and when the accumulated heat is greater than or equal to the preset energy, take the first operating point as the starting point of the thermal energy window and the current operating point as the ending point of the thermal energy window.

[0059] Specifically, the formula for calculating the heat at each operating point is: Q=C*m*(T-T0)

[0060] In the formula, Q is the heat at each operating point; C is the specific heat capacity of air, which can be obtained from a table based on the measured exhaust temperature; m is the exhaust mass; T is the exhaust temperature; and T0 is the air temperature.

[0061] The ammonia nitrogen ratio refers to the ratio of urea to NOx, abbreviated as ANR.

[0062] In a specific embodiment of the present invention, the exhaust temperature coefficient is:

[0063] In the formula, α is the exhaust temperature coefficient; T1 is the target window exhaust temperature; β1 is the target ammonia nitrogen ratio; T2 is the measured window exhaust temperature; β2 is the measured ammonia nitrogen ratio; and || is the absolute value symbol.

[0064] Specifically, the preset exhaust temperature coefficient is 0.8.

[0065] 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 specific value mentioned above.

[0066] It should be noted that when the abnormal urea consumption is caused by exhaust temperature, it is necessary to check whether the insulation of the engine exhaust pipe and aftertreatment is abnormal.

[0067] Compared with existing technologies, the urea abnormal consumption analysis method provided in this invention first determines the thermal energy window and uses the thermal energy window as the calculation unit to analyze urea abnormal consumption. Compared with analyzing a single operating point, this avoids the influence of a single extreme operating condition on the analysis results, improving the accuracy of the target ammonia nitrogen ratio, the measured ammonia nitrogen ratio, the target window exhaust temperature, and the measured window exhaust temperature. This, in turn, improves the accuracy and stability of the urea abnormal consumption analysis results. Furthermore, this invention uses both the ammonia nitrogen ratio and the window exhaust temperature as relevant factors for the exhaust temperature coefficient, considering the influence of exhaust temperature on the ammonia nitrogen ratio. This improves the representativeness of the calculated exhaust temperature coefficient, thereby improving the accuracy of the analysis results based on the exhaust temperature coefficient to analyze the causes of urea abnormal consumption.

[0068] In some embodiments of the present invention, as shown in FIG2, the determination of the target ammonia nitrogen ratio and the measured ammonia nitrogen ratio in step S102 includes:

[0069] S201. Obtain the urea injection rate at each operating point and determine the target original NOx mass flow rate and the measured original NOx mass flow rate at each operating point.

[0070] S202. Determine the total target original NOx mass flow rate of the thermal energy window based on the target original NOx mass flow rate.

[0071] S203. Determine the total measured original NOx mass flow rate of the heat energy window based on the measured original NOx mass flow rate.

[0072] S204. Determine the total urea injection rate for the thermal energy window based on the urea injection rate.

[0073] S205. The ratio of the total urea injection rate to the total measured original NOx mass flow rate is taken as the measured ammonia nitrogen ratio, and the ratio of the total urea injection rate to the total target original NOx mass flow rate is taken as the target ammonia nitrogen ratio.

[0074] In step S201, the amount of urea injected can be obtained by detecting the flow meter installed at the urea nozzle.

[0075] In some embodiments of the present invention, as shown in FIG3, the determination of the target original NOx mass flow rate and the measured original NOx mass flow rate at each operating point in step S201 includes:

[0076] S301. Obtain the exhaust gas flow rate and the target NOx volume percentage of the original machine and the measured NOx volume percentage of the original machine at each operating point.

[0077] S302. Determine the target original NOx mass flow rate based on the target original NOx volume ratio and exhaust gas flow rate, and determine the measured original NOx mass flow rate based on the measured original NOx volume ratio and exhaust gas flow rate.

[0078] In step S301, the measured NOx volume percentage of the original machine can be obtained by actual measurement using a NOx sensor.

[0079] The process of obtaining the target original engine NOx volume percentage is as follows: First, determine the current speed and current torque at the current operating point, and then interpolate the target original engine NOx volume percentage in the map table based on the current speed and current torque.

[0080] Specifically, the interpolation method is the minimum linear interpolation method.

[0081] In a specific embodiment of the present invention, the target ammonia nitrogen ratio is: m1 = 0.001587 * V1 * m fqll

[0082] The measured ammonia nitrogen ratio is: m2 = 0.001587 * V2 * m fqll

[0083] In the formula, β1 is the target ammonia-nitrogen ratio; m3(k) is the urea injection rate at the k-th operating point, in g / h; m1(k) is the target original NOx mass flow rate at the k-th operating point; i and j are the starting and ending operating point numbers of the thermal energy window, respectively; β2 is the measured ammonia-nitrogen ratio; m2(k) is the measured original NOx mass flow rate at the k-th operating point; V1 is the target original NOx volume percentage, in ppm; V2 is the measured original NOx volume percentage, in ppm; m fqll This represents the exhaust gas flow rate, expressed in kg / h.

[0084] In some embodiments of the present invention, as shown in FIG4, the determination of the target window exhaust temperature and the measured window exhaust temperature in step S102 includes:

[0085] S401. Determine the target exhaust temperature and the measured exhaust temperature at multiple operating points;

[0086] S402. The average value of the target exhaust temperature at multiple operating points is taken as the target window exhaust temperature, and the measured exhaust temperature at multiple operating points is taken as the measured window exhaust temperature.

[0087] The target exhaust temperature at each operating point can be obtained by interpolation in the MAP table based on the speed and torque at each operating point. The actual measured exhaust temperature at each operating point can be obtained from temperature sensors.

[0088] The above process can only determine whether the abnormal urea consumption is due to heat loss, which is a single cause. To further improve the comprehensiveness of the causes of abnormal urea consumption, in some embodiments of the present invention, as shown in Figure 5, the abnormal urea consumption analysis method further includes:

[0089] S501. Determine the power at each operating point;

[0090] S502. Determine the target NOx window emission amount based on power and target NOx mass flow rate of the original unit, and determine the measured NOx window emission amount of the original unit based on power and measured NOx mass flow rate of the original unit;

[0091] S503. Determine the NOx emission ratio deviation of the original engine based on the target original engine NOx window emission and the measured original engine NOx window emission;

[0092] S504. When the original NOx emission deviation is greater than the threshold deviation, the cause of abnormal urea consumption is determined to be that the original NOx deviates from the design value.

[0093] This invention determines the NOx emission deviation of the original machine based on the determined target NOx window emission and the measured NOx window emission. The deviation can be used to determine whether the abnormal urea consumption is due to the original machine's NOx deviating from the design value. If the abnormal urea consumption is due to exhaust temperature, other causes of abnormal urea consumption can be analyzed, thus improving the comprehensiveness and accuracy of the analysis of abnormal urea consumption.

[0094] It should be noted that if the abnormal urea consumption is caused by the original engine's NOx deviating from the design value, then the engine manufacturing consistency needs to be checked to ensure that the abnormal urea consumption is not caused by an engine with abnormal parameters.

[0095] In a specific embodiment of the present invention, the threshold deviation is 20%.

[0096] It should be understood that the threshold deviation can be set or calibrated according to the actual application scenario, which will not be elaborated here.

[0097] In a specific embodiment of the present invention, step S501 specifically includes:

[0098] Obtain the speed and torque at each operating point, and determine the power based on the speed and torque.

[0099] In a specific embodiment of the present invention, the original NOx emission deviation is:

[0100] In the formula, σ represents the original NOx emission deviation; y k The measured NOx window emission of the original engine; || represents the absolute value symbol; Y k The target NOx mass flow rate; P t (k) represents power; n t (k) represents the rotational speed; T t (k) represents torque.

[0101] In summary, the urea abnormal consumption method provided by this invention accurately determines whether the abnormal urea consumption is caused by excessive exhaust temperature deviation by using actual exhaust temperature, actual ammonia-nitrogen ratio, target exhaust temperature, and target ammonia-nitrogen ratio. It also determines whether the abnormal urea consumption is caused by excessive NOx deviation in the original unit by using the deviation between the target original unit NOx window emission and the measured original unit NOx window emission, thus achieving analysis of the causes of abnormal urea consumption. Furthermore, this invention uses a thermal energy window as the analysis unit. Compared to 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.

[0102] To better implement the urea abnormal consumption analysis method in this embodiment of the invention, based on the urea abnormal consumption analysis method, this embodiment of the invention also provides a urea abnormal consumption analysis device, as shown in FIG6. The urea abnormal consumption analysis device 600 includes:

[0103] The thermal energy window determination unit 601 is used to determine the thermal energy window based on the preset energy and the current operating point; the thermal energy window includes multiple operating points, the end 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.

[0104] The ammonia nitrogen ratio and window exhaust temperature determination unit 602 is used to 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.

[0105] The urea abnormal consumption analysis unit 603 is used to determine the first product of the target ammonia nitrogen ratio and the target window discharge temperature, and the second product of the measured ammonia nitrogen ratio and the measured window discharge temperature. The absolute value of the ratio of the first product and the second product is used as the discharge temperature coefficient. When the discharge temperature coefficient is less than the preset discharge temperature coefficient, the cause of abnormal urea consumption is determined to be abnormal discharge temperature.

[0106] It should be noted that the urea abnormal consumption analysis device 600 provided in the above embodiments can realize the technical solutions described in the above embodiments of the urea abnormal consumption analysis method. The specific implementation principles or implementation details of each module or unit can be found in the corresponding content of the above embodiments of the urea abnormal consumption analysis method, which will not be elaborated here.

[0107] As shown in Figure 7, 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 shows some components of the vehicle 700; however, it should be understood that it is not required to implement all the components shown, and more or fewer components may be implemented alternatively.

[0108] In some embodiments, processor 701 may be a central processing unit (CPU), a microprocessor, or other data processing chip, used to run program code stored in memory 702 or process data, such as the urea abnormal consumption analysis method of the present invention.

[0109] In some embodiments of the present invention, processor 701 may be a single server or a group of servers. 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, public cloud, hybrid cloud, community cloud, distributed cloud, internal cloud, multi-cloud, etc., or any combination thereof.

[0110] In some embodiments, memory 702 may be an internal storage unit of vehicle 700, such as hard disk or memory of vehicle 700.

[0111] Furthermore, the memory 702 may include both internal storage units of the vehicle 700 and external storage devices. The memory 702 is used to store application software and various types of data installed on the vehicle 700.

[0112] In some embodiments, display 703 may 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 display a visual user interface. Components 701-703 of vehicle 700 communicate with each other via a system bus.

[0113] 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 can be implemented:

[0114] 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 point of the thermal energy window is the current operating point, and the cumulative heat of multiple operating points is equal to the preset energy.

[0115] 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.

[0116] 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. Use the absolute value of the ratio of the first product and the second product as the exhaust temperature coefficient. When the exhaust temperature coefficient is less than the preset exhaust temperature coefficient, the cause of abnormal urea consumption is determined to be abnormal exhaust temperature.

[0117] It should be understood that when the processor 701 executes the urea abnormal consumption analysis program in the memory 702, in addition to the functions mentioned above, it can also perform other functions, as can be found in the description of the corresponding method embodiments above.

[0118] Furthermore, the embodiments of the present invention do not specifically limit the type of vehicle 700 mentioned, and vehicle 700 can be a passenger car or a commercial vehicle.

[0119] Accordingly, embodiments of the present invention also provide a computer-readable storage medium for storing computer-readable programs or instructions. When the programs or instructions are executed by a processor, they can implement the steps or functions in the urea abnormal consumption analysis methods provided in the above-described method embodiments.

[0120] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.), and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0121] The above provides a detailed description of the urea abnormal consumption analysis method, apparatus, and vehicle provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for analyzing abnormal urea consumption, characterized in that, include: 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 endpoint 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. 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. 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 are determined, and the absolute value of the ratio of the first product and the second product is used as the exhaust temperature coefficient. When the exhaust temperature coefficient is less than the preset exhaust temperature coefficient, the cause of abnormal urea consumption is determined to be 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 within the thermal energy window, including: Obtain the urea injection rate at each of the aforementioned operating points, and determine the target original NOx mass flow rate and the measured original NOx mass flow rate at each of the aforementioned operating points; The total target original NOx mass flow rate of the thermal energy window is determined based on the target original NOx mass flow rate. The total measured original NOx mass flow rate of the thermal energy window is determined based on the measured original NOx mass flow rate. The total urea injection rate of the thermal energy window is determined based on the urea injection rate. The ratio of the total urea injection rate 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 rate to the total target original 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, Determining the target original NOx mass flow rate and the measured original NOx mass flow rate at each of the aforementioned operating points includes: Obtain the exhaust gas flow rate and the target NOx volume percentage and the measured NOx volume percentage of the original machine at each of the aforementioned operating conditions; The target original NOx mass flow rate is determined based on the target original NOx volume percentage and the exhaust gas flow rate, and the measured original NOx mass flow rate is determined based on the measured original NOx volume percentage and the exhaust gas flow rate.

4. The method for analyzing abnormal urea consumption according to claim 3, characterized in that, The target ammonia nitrogen ratio is: m1 = 0.001587 * V1 * m fqll The measured ammonia nitrogen ratio is: m2=0.001587*V2*m fqll In the formula, β1 is the target ammonia-nitrogen ratio; m3(k) is the urea injection rate at the k-th operating point; m1(k) is the target original NOx mass flow rate at the k-th operating point; i and j are the starting and ending operating point numbers of the thermal energy window, respectively; β2 is the measured ammonia-nitrogen ratio; m2(k) is the measured original NOx mass flow rate at the k-th operating point; V1 is the target original NOx volume percentage; V2 is the measured original NOx volume percentage; m fqll This refers to 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 the target exhaust temperature and the measured exhaust temperature at multiple operating points; The average value of the target exhaust temperature at the multiple operating points is taken as the target window exhaust temperature, and the measured exhaust temperature at the multiple operating points is taken as the measured window exhaust temperature.

6. The method for analyzing abnormal urea consumption according to claim 4, characterized in that, The method further includes: Determine the power at each of the aforementioned operating points; The target NOx window emission amount is determined based on the power and the target NOx mass flow rate of the original machine, and the measured NOx window emission amount of the original machine is determined based on the power and the measured NOx mass flow rate of the original machine; The NOx emission ratio deviation of the original engine is determined based on the target original engine NOx window emission and the measured original engine NOx window emission; When the original NOx emission deviation is greater than the threshold deviation, the cause of abnormal urea consumption is determined to be that the original NOx emission deviates from the design value.

7. The method for analyzing abnormal urea consumption according to claim 6, characterized in that, Determining the power at each of the aforementioned operating points includes: The rotational speed and torque at each of the aforementioned operating points 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, characterized in that, The original NOx emission deviation is: In the formula, σ represents the original NOx emission deviation; y k The measured NOx window emission of the original engine; || represents the absolute value symbol; Y k The target NOx mass flow rate; P t (k) represents power; n t (k) represents the rotational speed; T t (k) represents torque.

9. A device for analyzing abnormal urea consumption, characterized in that, include: The thermal energy window determination unit is used to determine the thermal energy window based on the preset energy and the current operating point. The thermal energy window includes multiple operating points, the endpoint 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. The ammonia nitrogen ratio and window exhaust temperature determination unit is used to 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. The urea abnormal consumption analysis unit is used to 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. The absolute value of the ratio of the first product and the second product is used as the exhaust temperature coefficient. When the exhaust temperature coefficient is less than the preset exhaust temperature coefficient, the cause of the abnormal urea consumption is determined to be abnormal exhaust temperature.

10. A vehicle, characterized in that, Including memory and processor, among which, The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the urea abnormal consumption analysis method according to any one of claims 1 to 8.

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