A method, apparatus, and electronic device for fault detection in an SCR system
By using multiple methods, including urea tank level sensor, urea nozzle and nitrogen oxide sensor, to calculate the urea consumption mass in the SCR system, the problem of false alarms caused by signal measurement deviation was solved, and the accurate location and efficient troubleshooting of faulty parts were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WEICHAI POWER CO LTD
- Filing Date
- 2023-09-26
- Publication Date
- 2026-05-26
Smart Images
Figure CN117189325B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of diesel engine aftertreatment technology, and in particular to a method and device for detecting faults in an SCR system, as well as electronic equipment. Background Technology
[0002] Currently, in Selective Catalytic Reduction (SCR) systems, each component can only be diagnosed based on feedback signals from that component. When there is a deviation in signal measurement, false alarms are likely to occur. For example, if the urea tank level sensor is stuck, the sensor may display a low level, even though the actual urea tank level is not low. This type of false alarm occurs frequently in the current SCR system fault detection process, resulting in low accuracy of fault diagnosis. Summary of the Invention
[0003] The purpose of this application is to provide a fault detection method, device, and electronic equipment for SCR systems. This addresses the problem of false alarms easily occurring when signal measurement deviations occur in existing SCR systems.
[0004] In a first aspect, embodiments of this application provide a fault detection method for an SCR system, the method comprising:
[0005] The volume of urea consumed within a preset time period is determined based on the urea tank level sensor.
[0006] Based on the consumed volume and the preset density value of urea, the first mass of urea consumed within the preset time period is determined;
[0007] The second mass of urea consumed is determined based on the amount of urea injected by the urea nozzle during the preset time period.
[0008] The third consumption mass of urea is determined based on the upstream and downstream nitrogen oxide consumption monitored by the nitrogen oxide sensor during the preset time period.
[0009] Determine whether there is a faulty consumed mass among the first consumed mass, the second consumed mass, and the third consumed mass;
[0010] If the first consumed mass is the fault consumed mass, it is determined that the urea tank level sensor is faulty; if the second consumed mass or the third consumed mass is the fault consumed mass, it is determined that the urea nozzle is faulty.
[0011] In some possible embodiments, determining the first mass of urea consumed within the preset time period based on the consumed volume and a preset density value of urea includes:
[0012] The first mass of urea consumed within the preset time period is obtained by multiplying the consumed volume by the preset density value.
[0013] In some possible embodiments, determining the third consumption mass of urea based on the upstream and downstream nitrogen oxide consumption monitored by the nitrogen oxide sensor within the preset time period includes:
[0014] Based on the preset mapping relationship between nitrogen oxide volume and ammonia nitrogen ratio, the ammonia nitrogen ratio corresponding to the current nitrogen oxide volume is determined;
[0015] Determine the current engine intake air volume and aftertreatment conversion efficiency;
[0016] The third urea consumption mass is determined by multiplying the nitrogen oxide consumption by the ammonia-nitrogen ratio, the engine intake air volume, and the aftertreatment conversion efficiency.
[0017] In some possible embodiments, determining whether a faulty consumption mass exists among the first, second, and third consumption masses includes:
[0018] If, among the first consumed mass, the second consumed mass, and the third consumed mass, the deviation between any two consumed masses is less than or equal to a first preset deviation, and the deviation between the target consumed mass (excluding the two consumed masses) and any one of the two consumed masses is greater than or equal to a second preset deviation, then the target consumed mass is determined to be a faulty consumed mass.
[0019] In some possible embodiments, determining that the urea nozzle has malfunctioned if the second or third consumed mass is a faulty consumed mass includes:
[0020] If the deviation between the first consumed mass and the third consumed mass is less than the first preset deviation, and the deviation between the first consumed mass and the second consumed mass is greater than the second preset deviation, it is determined that the urea nozzle is blocked.
[0021] If the deviation between the first consumed mass and the third consumed mass is less than the first preset deviation, and the deviation between the second consumed mass and the first consumed mass is greater than the second preset deviation, it is determined that the urea nozzle injection volume is too large.
[0022] Secondly, embodiments of this application provide an SCR system fault detection device, the device comprising:
[0023] The module for determining the first consumed mass is used to determine the volume of urea consumed within a preset time period based on the urea tank level sensor; and to determine the first consumed mass of urea within the preset time period based on the consumed volume and a preset density value of urea.
[0024] The second consumption mass determination module is used to determine the second consumption mass of urea based on the amount of urea injected by the urea nozzle during the preset time period.
[0025] The third consumption quality determination module is used to determine the third consumption quality of urea based on the upstream and downstream nitrogen oxide consumption monitored by the nitrogen oxide sensor within the preset time period.
[0026] The fault determination module is used to determine whether there is a faulty consumption mass among the first consumption mass, the second consumption mass, and the third consumption mass; if the first consumption mass is a faulty consumption mass, it is determined that the urea tank level sensor is faulty; if the second consumption mass or the third consumption mass is a faulty consumption mass, it is determined that the urea nozzle is faulty.
[0027] Thirdly, embodiments of this application provide an electronic device, including at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the SCR system fault detection method provided in the first aspect above.
[0028] Fourthly, embodiments of this application provide a computer storage medium storing a computer program for causing a computer to execute the SCR system fault detection method provided in the first aspect.
[0029] This application aims to address the problem of false alarms caused by signal measurement deviations in SCR systems. This embodiment improves the accuracy of SCR system fault self-diagnosis, accurately locates faulty components, and facilitates troubleshooting and repair.
[0030] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description
[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0032] Figure 1 This is a flowchart illustrating a fault detection method for an SCR system according to an embodiment of this application;
[0033] Figure 2 This is a schematic diagram of the structure of an SCR system fault detection device according to an embodiment of this application;
[0034] Figure 3 This is a schematic diagram of an electronic device structure according to an embodiment of this application. Detailed Implementation
[0035] The technical solutions in the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.
[0036] In the description of the embodiments of this application, unless otherwise stated, the term "multiple" refers to two or more, and other quantifiers are similarly understood. The preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application. Furthermore, the embodiments and features in the embodiments of this application can be combined with each other without conflict.
[0037] To further illustrate the technical solutions provided in the embodiments of this application, a detailed description is provided below in conjunction with the accompanying drawings and specific implementation methods. Although the embodiments of this application provide method operation steps as shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on conventional or non-inventive effort. For steps that do not logically have a necessary causal relationship, the execution order of these steps is not limited to the execution order provided in the embodiments of this application. In actual processing or when the control device executes the method, it may be executed sequentially or in parallel according to the method shown in the embodiments or drawings.
[0038] Given that signal measurement deviations in SCR systems of related technologies can easily lead to false alarms, this application proposes an SCR system fault detection method, apparatus, and electronic equipment. These methods and equipment can improve the accuracy of SCR system fault self-diagnosis, accurately locate faulty components, and facilitate troubleshooting and repair.
[0039] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.
[0040] The following describes in detail, with reference to the accompanying drawings, a fault detection method for an SCR system in an embodiment of this application.
[0041] See Figure 1 This application provides a schematic flowchart of an SCR system fault detection method according to an embodiment, including:
[0042] Step 101: Determine the volume of urea consumed within a preset time period based on the urea tank level sensor.
[0043] Specifically, the urea tank level sensor can monitor the urea level in the urea tank in real time. By monitoring the urea tank level sensor within a preset time period, the volume of urea consumed within that preset time period can be determined.
[0044] Step 102: Based on the consumed volume and the preset density value of urea, determine the first mass of urea consumed within the preset time period.
[0045] Specifically, the density of 32.5% standard concentration urea is a fixed value ρ (i.e., a preset density value). As an optional implementation, based on the consumed volume and the preset density value of urea, the first mass of urea consumed within the preset time period is determined, including: obtaining the first mass of urea consumed within the preset time period by multiplying the consumed volume by the preset density value. Specifically, for example: at time T1, the urea tank level sensor detects a urea volume of V1; at time T2, the urea tank level sensor detects a urea volume of V2; the preset time period is from T1 to T2; and the urea consumption volume V during the time period from T1 to T2 is monitored. cns =V1-V2, the density of standard concentration urea 32.5% is a fixed value ρ, from which the mass of urea consumed during the preset time period T1 to T2 is obtained as the first consumed mass m. 1＝ V cns* ρ.
[0046] Step 103: Determine the second mass of urea consumed based on the amount of urea injected by the urea nozzle within a preset time period.
[0047] Specifically, the controller has a preset fixed value for the urea injection volume of the urea nozzle within a preset time period. This urea injection volume is the actual amount of urea injected by the urea nozzle within that preset time period. For example, within the time period T1 to T2, the actual injection volume at each time point is calculated, and then the actual injection volumes at each time point are accumulated. The calculated urea injection volume for the time period T1 to T2, which is the second consumed mass, is denoted as m2. 2＝ ∑dm Udc , where dm Udc This indicates the actual urea injection volume at each time point within a preset time period.
[0048] Step 104: Based on the upstream and downstream nitrogen oxide consumption monitored by the nitrogen oxide sensor during the preset time period, determine the third consumption mass of urea.
[0049] As an optional implementation, the third consumption mass of urea is determined based on the upstream and downstream nitrogen oxide consumption monitored by the nitrogen oxide sensor within the preset time period, including: determining the ammonia nitrogen ratio corresponding to the current nitrogen oxide volume based on a preset mapping relationship between nitrogen oxide volume and ammonia nitrogen ratio; determining the current engine intake air volume and after-treatment conversion efficiency; and determining the third consumption mass of urea by multiplying the nitrogen oxide consumption by the ammonia nitrogen ratio, the engine intake air volume, and the after-treatment conversion efficiency.
[0050] Specifically, the nitrogen oxide sensor can monitor the volume change of upstream and downstream nitrogen oxides within a preset time period, and the third mass of urea consumed (m3) within the preset time period from T1 to T2.
[0051] m3=(NOx us -NOx Ds )*ANR*dmEG*Fac eff ; of which NOx us The volume of nitrogen oxides and NOx in the upstream nitrogen oxides within a preset time period. Ds The downstream nitrogen oxides volume is the nitrogen oxide volume within a preset time period, ANR is the ammonia-to-nitrogen ratio corresponding to the current nitrogen oxide volume, dmEG is the current engine intake air volume, and Fac is the nitrogen oxide volume. eff This is the post-processing conversion efficiency. The third consumption mass is calculated using the above formula.
[0052] Step 105: Determine whether there is a faulty consumed mass among the first consumed mass, the second consumed mass, and the third consumed mass.
[0053] Specifically, in steps 101-104 above, the mass of urea consumed is calculated in three different ways. This application uses a pairwise comparison method among the three methods to perform fault detection.
[0054] As an optional implementation, determining whether there is a faulty consumed mass among the first consumed mass, the second consumed mass, and the third consumed mass includes:
[0055] If, among the first consumed mass, the second consumed mass, and the third consumed mass, the deviation between any two consumed masses is less than or equal to a first preset deviation, and the deviation between the target consumed mass (excluding the two consumed masses) and any one of the two consumed masses is greater than or equal to a second preset deviation, then the target consumed mass is determined to be a faulty consumed mass.
[0056] The logic for determining faults in this application, based on three methods of calculating urea consumption, is as follows: when the urea consumption calculated by any one method deviates from the urea consumption calculated by the other two methods by a second preset deviation (denoted as m)... set2 Furthermore, the urea mass calculated by the other two methods is basically equal (the deviation is denoted as m). set1 If the condition is met, then the component is considered to have a malfunction.
[0057] Specifically, a small first preset deviation and a relatively large second preset deviation are set. When comparing pairs of consumables, if the deviation between the two consumables is less than or equal to the first preset deviation, it proves that the deviation between the two consumables is small and both consumables are normal. Furthermore, if the deviation of a third consumable from either of the two consumables is greater than or equal to the second preset deviation, it proves that the third consumable (i.e., the target consumable) deviates too much from the other two normal consumables, meaning that the third consumable is faulty.
[0058] Step 106: If the first consumed mass is the faulty consumed mass, it is determined that the urea tank level sensor is faulty; if the second or third consumed mass is the faulty consumed mass, it is determined that the urea nozzle is faulty.
[0059] As an optional implementation, if the deviation between the first consumed mass and the third consumed mass is less than the first preset deviation, and the deviation between the first consumed mass and the second consumed mass is greater than the second preset deviation, it is determined that the urea nozzle is blocked.
[0060] If the deviation between the first consumed mass and the third consumed mass is less than the first preset deviation, and the deviation between the second consumed mass and the first consumed mass is greater than the second preset deviation, it is determined that the urea nozzle injection volume is too large.
[0061] Specifically, when |m2-m3|<m set1 m2-m1>m set2 The first consumed mass is proven to be the faulty mass, at which point it is determined that the urea tank level sensor has malfunctioned.
[0062] When |m1-m3|<m set1 &(m1-m2)>m set2 The second consumed mass is proven to be faulty mass, at which point it is determined that the urea nozzle is blocked.
[0063] When |m1-m3|<m set1 &(m2-m1)>m set2 The second consumed mass is proven to be faulty mass, at which point it is determined that the urea nozzle injection volume is too large.
[0064] It should be noted that before calculating the urea consumption mass using any method, it is necessary to ensure that the nitrogen oxide sensor is working properly and that the added urea concentration is within the normal threshold range, thereby ensuring that the nitrogen oxide sensor readings are accurate and the urea concentration is qualified.
[0065] After calculating the urea consumption mass using three methods, it is necessary to determine whether the SCR conversion efficiency is within the normal range. When |m1-m2| < m set1 m2-m3>m set2 If the SCR conversion efficiency is determined to be low, then steps 105 and 106 are unnecessary.
[0066] This application calculates the urea consumption mass using different methods based on the internal sensor signals of the SCR system, and verifies the urea consumption mass calculated by different methods in pairs, thereby improving the accuracy of component fault detection and greatly reducing the probability of fault misjudgment caused by a single signal.
[0067] Example 2
[0068] Based on the same inventive concept, this application also provides an SCR system fault detection device, such as... Figure 2 As shown, the device includes:
[0069] The first consumption mass determination module 201 is used to determine the volume of urea consumed within a preset time period based on the urea tank level sensor; and to determine the first consumption mass of urea within the preset time period based on the consumption volume and the preset density value of urea.
[0070] The second consumption mass determination module 202 is used to determine the second consumption mass of urea based on the amount of urea injected by the urea nozzle during the preset time period.
[0071] The third consumption quality determination module 203 is used to determine the third consumption quality of urea based on the upstream and downstream nitrogen oxide consumption monitored by the nitrogen oxide sensor within the preset time period.
[0072] The fault determination module 204 is used to determine whether there is a faulty consumption mass among the first consumption mass, the second consumption mass, and the third consumption mass; if the first consumption mass is a faulty consumption mass, it is determined that the urea tank level sensor has failed; if the second consumption mass or the third consumption mass is a faulty consumption mass, it is determined that the urea nozzle has failed.
[0073] Optionally, the first consumed mass module 201 is specifically used for:
[0074] The first mass of urea consumed within the preset time period is obtained by multiplying the consumed volume by the preset density value.
[0075] Optionally, the third consumption quality module 203 is specifically used for:
[0076] Based on the preset mapping relationship between nitrogen oxide volume and ammonia nitrogen ratio, the ammonia nitrogen ratio corresponding to the current nitrogen oxide volume is determined;
[0077] Determine the current engine intake air volume and aftertreatment conversion efficiency;
[0078] The third urea consumption mass is determined by multiplying the nitrogen oxide consumption by the ammonia-nitrogen ratio, the engine intake air volume, and the aftertreatment conversion efficiency.
[0079] Optionally, the fault determination module 204 is specifically used to: among the first consumed mass, the second consumed mass, and the third consumed mass, if the deviation between any two consumed masses is less than or equal to a first preset deviation, and the deviation between the target consumed mass other than the two consumed masses and any one of the two consumed masses is greater than or equal to a second preset deviation, determine the target consumed mass as a faulty consumed mass.
[0080] Optionally, the fault determination module 204 is specifically used to: determine that the urea nozzle is blocked if the deviation between the first consumed mass and the third consumed mass is less than the first preset deviation, and the deviation between the first consumed mass and the second consumed mass is greater than the second preset deviation;
[0081] If the deviation between the first consumed mass and the third consumed mass is less than the first preset deviation, and the deviation between the second consumed mass and the first consumed mass is greater than the second preset deviation, it is determined that the urea nozzle injection volume is too large.
[0082] Having introduced the SCR system fault detection method and apparatus according to exemplary embodiments of this application, we will now introduce an electronic device according to another exemplary embodiment of this application.
[0083] Those skilled in the art will understand that various aspects of this application can be implemented as a system, method, or program product. Therefore, various aspects of this application can be specifically implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software implementations, collectively referred to herein as a "circuit," "module," or "system."
[0084] In some possible implementations, the electronic device according to this application may include at least one processor and at least one memory. The memory stores program code that, when executed by the processor, causes the processor to perform the steps in the SCR system fault detection method according to the various exemplary embodiments of this application described above.
[0085] The following reference Figure 3 This application describes an electronic device 130 according to this embodiment, namely the SCR system fault detection device described above. Figure 3 The electronic device 130 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.
[0086] like Figure 3 As shown, the electronic device 130 is presented in the form of a general-purpose electronic device. The components of the electronic device 130 may include, but are not limited to: at least one processor 131, at least one memory 132, and a bus 133 connecting different system components (including memory 132 and processor 131).
[0087] Bus 133 represents one or more of several bus structures, including a memory bus or memory controller, peripheral bus, processor, or local bus using any of the various bus structures.
[0088] The memory 132 may include a readable medium in the form of volatile memory, such as random access memory (RAM) 1321 and / or cache memory 1322, and may further include read-only memory (ROM) 1323.
[0089] The memory 132 may also include a program / utility 1325 having a set (at least one) of program modules 1324, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.
[0090] Electronic device 130 can also communicate with one or more external devices 134 (e.g., keyboard, pointing device, etc.), and with one or more devices that enable a user to interact with electronic device 130, and / or with any device that enables electronic device 130 to communicate with one or more other electronic devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 135. Furthermore, electronic device 130 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 136. As shown, network adapter 136 communicates with other modules used in electronic device 130 via bus 133. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 130, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.
[0091] In some possible implementations, various aspects of the SCR system fault detection method provided in this application can also be implemented in the form of a program product, which includes program code. When the program product is run on a computer device, the program code is used to cause the computer device to perform the steps of the SCR system fault detection method according to the various exemplary embodiments of this application described above.
[0092] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.
[0093] The monitoring program product of the embodiments of this application may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on an electronic device. However, the program product of this application is not limited thereto. In this document, the readable storage medium may be any tangible medium that contains or stores a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.
[0094] A readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying readable program code. This propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting a program for use by or in conjunction with an instruction execution system, apparatus, or device.
[0095] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.
[0096] Program code for performing the operations of this application can be written in any combination of one or more programming languages, including object-oriented programming languages such as Java and C++, and conventional procedural programming languages such as C or similar languages. The program code can execute entirely on the user's electronic device, partially on the user's device, as a standalone software package, partially on the user's electronic device and partially on a remote electronic device, or entirely on a remote electronic device or server. In cases involving remote electronic devices, the remote electronic device can be connected to the user's electronic device via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external electronic device (e.g., via the Internet using an Internet service provider).
[0097] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.
[0098] Furthermore, although the operations of the method of this application are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.
[0099] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0100] This application is described with reference to flowchart illustrations and block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block and / or segment of the flowchart illustrations and block diagrams, as well as combinations of blocks and segments in the flowchart illustrations and block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations. Figure 1 One or more processes and boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0101] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and boxes Figure 1 The function specified in one or more boxes.
[0102] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and boxes Figure 1 The steps of the function specified in one or more boxes.
[0103] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
[0104] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
Claims
1. A fault detection method for an SCR system, characterized in that, The method includes: The volume of urea consumed within a preset time period is determined based on the urea tank level sensor. Based on the consumed volume and the preset density value of urea, the first mass of urea consumed within the preset time period is determined; The second mass of urea consumed is determined based on the amount of urea injected by the urea nozzle during the preset time period. The third consumption mass of urea is determined based on the upstream and downstream nitrogen oxide consumption monitored by the nitrogen oxide sensor during the preset time period. If the deviation between the first consumed mass and the second consumed mass is less than the first preset deviation, and the deviation between the second consumed mass and the third consumed mass is greater than the second preset deviation, it is determined that the SCR conversion efficiency is low, wherein the second preset deviation is greater than the first preset deviation. If the SCR conversion efficiency is within the normal range, determine whether there is a faulty consumption mass among the first consumption mass, the second consumption mass, and the third consumption mass; If the first consumed mass is the fault consumed mass, it is determined that the urea tank level sensor is faulty; if the second consumed mass or the third consumed mass is the fault consumed mass, it is determined that the urea nozzle is faulty. Determining whether there is a faulty consumption mass among the first consumption mass, the second consumption mass, and the third consumption mass includes: If the deviation between any two of the first, second, and third consumption masses is less than or equal to a first preset deviation, and the deviation between the target consumption mass other than the two consumption masses and any one of the two consumption masses is greater than or equal to a second preset deviation, then the target consumption mass is determined to be a faulty consumption mass. If the second consumed mass or the third consumed mass is a faulty consumed mass, determining that the urea nozzle has malfunctioned includes: If the deviation between the first consumed mass and the third consumed mass is less than the first preset deviation, and the deviation between the first consumed mass and the second consumed mass is greater than the second preset deviation, it is determined that the urea nozzle is blocked. If the deviation between the first consumed mass and the third consumed mass is less than the first preset deviation, and the deviation between the second consumed mass and the first consumed mass is greater than the second preset deviation, it is determined that the urea nozzle injection volume is too large.
2. The method according to claim 1, characterized in that, Determining the first mass of urea consumed within the preset time period based on the consumed volume and a preset density value of urea includes: The first mass of urea consumed within the preset time period is obtained by multiplying the consumed volume by the preset density value.
3. The method according to claim 1, characterized in that, The determination of the third consumption mass of urea based on the upstream and downstream nitrogen oxide consumption monitored by the nitrogen oxide sensor within the preset time period includes: Based on the preset mapping relationship between nitrogen oxide volume and ammonia nitrogen ratio, the ammonia nitrogen ratio corresponding to the current nitrogen oxide volume is determined; Determine the current engine intake air volume and aftertreatment conversion efficiency; The third urea consumption mass is determined by multiplying the nitrogen oxide consumption by the ammonia-nitrogen ratio, the engine intake air volume, and the aftertreatment conversion efficiency.
4. A fault detection device for an SCR system, characterized in that, The apparatus for performing the method according to any one of claims 1-3, the apparatus comprising: The module for determining the first consumed mass is used to determine the volume of urea consumed within a preset time period based on the urea tank level sensor; and to determine the first consumed mass of urea within the preset time period based on the consumed volume and a preset density value of urea. The second consumption mass determination module is used to determine the second consumption mass of urea based on the amount of urea injected by the urea nozzle during the preset time period. The third consumption quality determination module is used to determine the third consumption quality of urea based on the upstream and downstream nitrogen oxide consumption monitored by the nitrogen oxide sensor within the preset time period. The fault determination module is used to determine whether there is a faulty consumption mass among the first consumption mass, the second consumption mass, and the third consumption mass; if the first consumption mass is a faulty consumption mass, it is determined that the urea tank level sensor is faulty; if the second consumption mass or the third consumption mass is a faulty consumption mass, it is determined that the urea nozzle is faulty.
5. The apparatus according to claim 4, characterized in that, The module for determining the first consumed mass is specifically used for: The first mass of urea consumed within the preset time period is obtained by multiplying the consumed volume by the preset density value.
6. The apparatus according to claim 4, characterized in that, The module for determining the third consumed mass is specifically used for: Based on the preset mapping relationship between nitrogen oxide volume and ammonia nitrogen ratio, the ammonia nitrogen ratio corresponding to the current nitrogen oxide volume is determined; Determine the current engine intake air volume and aftertreatment conversion efficiency; The third urea consumption mass is determined by multiplying the nitrogen oxide consumption by the ammonia-nitrogen ratio, the engine intake air volume, and the aftertreatment conversion efficiency.
7. An electronic device, characterized in that, The method includes at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method as described in any one of claims 1-3.
8. A computer storage medium, characterized in that, The computer storage medium stores a computer program that enables the computer to perform the method as described in any one of claims 1-3.