Diagnosis Method, Device, Equipment and Storage Medium for Urea Nozzle Blockage

Abstract

The present application relates to a diagnostic method, device, equipment and storage medium for urea nozzle blockage in the field of tail gas treatment technology. The diagnostic method includes: stopping the urea injection of the urea nozzle, stabilizing the urea pump to a set pump pressure, and fixing the urea pump to a set rotational speed; opening the urea nozzle at a set opening degree, consuming a set volume of urea, collecting the pump pressure at the opening moment and the closing moment of the urea nozzle, and calculating the average injection flow rate of the urea nozzle according to the change in the pump pressure of the urea pump; calculating the average injection flow rate once for each consumption of the set volume of urea to obtain a sequence of the average injection flow rates; calculating the average flow rate of the urea nozzle according to the sequence of the average injection flow rates; comparing the average flow rate of the urea nozzle with a pre-established flow reference value of the urea nozzle to determine the degree of blockage of the urea nozzle. The diagnostic method of the present application can improve the robustness of fault diagnosis, reduce the diagnostic cycle of urea nozzle blockage, and improve the diagnostic accuracy of urea nozzle blockage.

Description

Technical Field

[0001] The present application relates to the technical field of exhaust gas treatment, and in particular to a method, device, equipment and storage medium for diagnosing urea nozzle blockage. Background Art

[0002] Urea nozzles are widely used in diesel engines. During long-term operation of vehicles, nozzles will be clogged due to factors such as impurities, crystallization, and rust, resulting in less urea injection. Corrosion and other factors will cause the nozzle hole to become larger, resulting in more urea injection. At present, urea consumption deviation is diagnosed by the deviation between the nozzle metering consumption and the urea liquid level sensor metering consumption. Due to the influence of urea liquid level sensor accuracy, urea tank shape, and liquid level sensor float stagnation, it is easy to make false alarms. In addition, this method has a long diagnosis cycle. After a false alarm, it is difficult to cure. The torque is limited for 10 hours and the speed is limited for 20 hours, which seriously affects the customer experience. Summary of the invention

[0003] In view of the problems existing in the background technology, the present application provides a method for diagnosing urea nozzle blockage, which can improve the robustness of fault diagnosis, reduce the diagnosis cycle of urea nozzle blockage, and improve the diagnosis accuracy of urea nozzle blockage.

[0004] According to a first aspect of the present invention, a method for diagnosing urea nozzle blockage is provided, comprising:

[0005] The urea nozzle stops spraying urea, stabilizes the urea pump to a set pump pressure, and fixes the urea pump to a set speed;

[0006] The urea nozzle is opened at a set opening degree, consumes a set volume of urea, collects the pump pressure at the time when the urea nozzle is opened, and the pump pressure at the time when the urea nozzle is closed, and calculates the average injection flow rate of the urea nozzle according to the change of the pump pressure of the urea pump;

[0007] Each time a set volume of urea is consumed, the average injection flow rate is calculated once, and a sequence of the average injection flow rates is obtained;

[0008] Calculating a flow rate mean of the urea nozzle according to the sequence of the average injection flow rates;

[0009] The flow rate mean value of the urea nozzle is compared with a pre-established flow rate reference value of the urea nozzle to determine the blockage degree of the urea nozzle.

[0010] In some embodiments of the present invention, the calculation of the average injection flow rate of the urea nozzle includes: the average injection flow rate Q dos =Q su -Q back , where Q su The average flow rate of the urea pump, Q backis the average flow rate of the urea pump reflux hole;

[0011] When the urea pump runs at a set speed and stabilizes the pump pressure to the set pump pressure and the urea nozzle does not spray, the average supply flow of the urea pump is balanced with the average flow of the reflux hole, that is, Q su With Q back Equal, calculate the system constant C b ;

[0012] Average injection flow rate Q dos =C b *(P1)^ 1 / 2 -C b *[(P1+P2) / 2]^ 1 / 2 ; Where P1 is the pump pressure at the start of injection, and P2 is the pump pressure at the end of injection.

[0013] In some embodiments of the present invention, the calculation of the flow mean of the urea nozzle includes:

[0014] The sequence of the average injection flow rate is divided into n first sequences, and the n first sequences are respectively obtained in n driving cycles;

[0015] In each driving cycle, each time a set volume of urea is consumed, the injection average flow rate is calculated once, and after m times, a first sequence is obtained, and a first mean value of the first sequence is calculated;

[0016] A second mean of the n first mean values ​​is calculated, where the second mean value is a flow mean of the urea nozzle.

[0017] In some embodiments of the present invention, when the flow mean of the urea nozzle is less than 0.5 times the flow reference value of the urea nozzle, it is judged that the urea nozzle is seriously clogged and a fault of insufficient consumption is reported; when the flow mean of the urea nozzle is greater than 1.5 times the flow reference value of the urea nozzle, it is judged that the urea nozzle is seriously corroded and a fault of excessive consumption is reported; otherwise, it is judged that the urea nozzle is normal.

[0018] In some embodiments of the present invention, establishing the flow reference value of the urea nozzle includes:

[0019] If the operation time of the urea nozzle is within the factory preset time period, the first obtained flow average value is stored as the flow reference value of the urea nozzle.

[0020] In some embodiments of the present invention, if the urea consumption deviation satisfies the release condition, the flow mean of the urea nozzle is calculated to determine the blockage degree of the urea nozzle, otherwise the urea nozzle is sprayed according to the normal process to treat the exhaust gas.

[0021] According to a second aspect of the present invention, a urea nozzle blockage diagnosis device is provided, comprising:

[0022] The first control module is used to control the urea nozzle to stop spraying urea, stabilize the urea pump to a set pump pressure, and fix the urea pump to a set speed;

[0023] A second control module is used to control the urea nozzle to open at a set opening degree and close after consuming a set volume of urea;

[0024] A collection module is used to collect the pump pressure when the urea nozzle is turned on and the pump pressure when it is turned off;

[0025] A determination module calculates an average injection flow rate of the urea nozzle according to a change in the pump pressure of the urea pump, obtains an injection average flow rate sequence, and then calculates a flow rate mean of the urea nozzle according to the injection average flow rate sequence;

[0026] The comparison module is used to compare the flow rate mean value of the urea nozzle with a pre-established flow rate reference value of the urea nozzle to determine the blockage degree of the urea nozzle.

[0027] In some embodiments of the present invention, the diagnostic device further comprises:

[0028] The storage module is used for storing the first flow average value of the urea nozzle as the flow reference value of the urea nozzle if the operation time of the urea nozzle is within a factory preset time period.

[0029] According to a third aspect of the present invention, there is provided a diagnostic device for urea nozzle blockage, comprising: at least one processor and a memory;

[0030] The memory stores computer-executable instructions;

[0031] The at least one processor executes the computer-executable instructions stored in the memory, so that the at least one processor performs the above-mentioned diagnosis method.

[0032] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when a processor executes the computer-executable instructions, the above-mentioned diagnostic method is implemented.

[0033] The embodiment of the present application provides a method for diagnosing urea nozzle blockage, which calculates the flow rate of the urea nozzle by using the pump pressure of a urea pump. In the new vehicle stage, for the urea injection system, the flow rate average of a normal urea nozzle is actively tested and calculated, and stored. The urea consumption deviation limit is set according to the flow rate of the normal nozzle, which can improve the adaptability of the consumption deviation strategy to different urea pumps, pipeline lengths and arrangements, and improve the robustness of fault diagnosis. When evaluating the nozzle flow rate, the pump pressure is actively stabilized, the urea pump speed is fixed, the influence of urea pump pressure fluctuation on the result is reduced, and the average method is performed for multiple evaluations to improve the accuracy of the evaluated flow rate. Compared with diagnosing urea consumption deviation through a liquid level sensor, the diagnosis cycle of the present invention is shorter, and even each driving cycle can be diagnosed, and the diagnosis accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0035] Figure 1 A schematic diagram of a urea injection system provided by the present invention.

[0036] Figure 2 The present invention provides a flowchart of a method for diagnosing urea nozzle blockage according to an embodiment of the present invention.

[0037] Figure 3 A schematic diagram of a urea nozzle blockage diagnosis device provided by the present invention.

[0038] Figure 4 A schematic diagram of the hardware structure of a urea nozzle blockage diagnostic device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0040] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0041] In the description of the present application, it should be understood that the terms "first", "second", etc. are only for descriptive purposes and cannot be construed as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances. In addition, in the description of the present application, unless otherwise specified, "a plurality of" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0042] The following will describe the diagnostic method, device, equipment and storage medium for urea nozzle clogging provided by the embodiments of the present application with reference to the accompanying drawings.

[0043] The embodiments of the present application disclose a diagnostic method for urea nozzle clogging. Figure 1 It is a schematic diagram of the urea injection system provided by the present invention. As Figure 1 shown, the urea injection system 100 includes a urea tank 101, a urea pump 102, a urea pressure pipe 103 and a urea nozzle 104; among them, the urea pump 102 is responsible for supplying urea solution to the urea nozzle 104, and the motor is responsible for driving the urea pump 102 to transport the urea solution from the urea tank 101 to the urea pressure pipe 103. A part of the urea solution is used for injection, and the other part returns to the urea tank 101 through the return hole.

[0044] The specific working process of the urea injection system is divided into three stages: pressure building, injection and reverse suction.

[0045] Pressure building: After the vehicle runs, when the exhaust gas temperature reaches 180°C, the urea injection system starts to operate to build pressure. When the pressure reaches 9 bar, the urea pump 102 stops rotating, and the urea nozzle 104 opens for a trial injection once to perform a fault diagnosis on the mechanical jamming of the urea nozzle 104; then, the pressure fluctuation range is monitored for a period of time to determine whether there is a leak in the pipeline. If there is a leak resulting in pressure building failure, the urea injection system will stop operating.

[0046] Injection: When the exhaust gas temperature is higher than a certain value, the urea nozzle 104 starts to inject urea solution, and the opening degree and opening duration of the urea nozzle 104 are controlled by the ECU according to the engine working conditions.

[0047] Reverse suction: After the engine is turned off, the steering valve of the urea injection system opens to reverse suction the residual urea solution in the pipeline to the urea tank 101 to prevent the urea from freezing and bursting the pipeline and the urea pump 102 in winter.

[0048] As Figure 1 shown, Q dos is the average injection flow rate of the urea nozzle 104, Q backis the average flow rate of the urea pump return hole, Q su is the average supply flow rate of the urea pump, P p is the urea pump pressure

[0049] Q dos = Q su - Q back (1)

[0050] As shown in formula (1), the injection flow rate of the urea nozzle 104 is equal to the reduced return flow rate. When the urea pump 102 operates at a set speed N and stabilizes the pump pressure to the set pump pressure P0 and the urea nozzle 104 does not inject, the average supply flow rate Q of the urea pump 102 su is balanced with the average flow rate Q of the return hole, that is, Q back is equal to Q su and Q back is equal. The system constant C can be calculated b ; thus, it can be obtained that

[0051] Q dos = C b *(P1) ^1 / 2 - C b *((P1 + P2) / 2) ^1 / 2 (2)

[0052] In the formula, P1 is the pump pressure at the start of injection, and P2 is the pump pressure at the end of injection. The average injection flow rate of the urea nozzle 104 can be calculated based on the change in the pump pressure when the urea nozzle 104 is opened and closed

[0053] The execution subject of the diagnostic method in this embodiment can be an electronic control unit ECU. This diagnostic method mainly completes by obtaining the flow rate mean value of the average injection flow rate of the urea nozzle 104. This diagnostic method divides the flow rate mean value of the urea nozzle 104 into a flow rate reference value Q sys and a flow rate mean value Q for diagnosis act , the calculation methods of the flow rate reference value Q sys and the flow rate mean value Q for diagnosis act are the same, only different in the time sequence of acquisition. Among them, the flow rate reference value Q sys is obtained prior to all flow rate mean values Q for diagnosis act . The corresponding flow rate mean value Q for diagnosis act is compared with the flow rate reference value Q sys to determine the current blockage degree of the urea nozzle 104

[0054] Figure 2 is the flowchart of the diagnostic method for urea nozzle blockage provided by the embodiment of the present invention. As Figure 2 shown, the diagnostic method in this embodiment includes the following steps

[0055] 1) Determine whether the calculation of the flow rate reference value of the urea nozzle is completed

[0056] When the flow rate reference value Q of the urea nozzle 104 sys If the calculation is not completed and the running time of the urea nozzle 104 is within the factory preset time period, specifically, it can be understood as the normal running state stage of a new vehicle or the starting running state stage after replacing the urea pump 102, urea pressure pipe 103, and urea nozzle 104 later. Moreover, it is required that the SCR efficiency is normal and there is no ammonia leakage in this stage. At this time, the state of the urea nozzle 104 is considered normal, and the flow rate mean value of the urea nozzle 104 in the normal state is calculated, that is, the above-mentioned flow rate reference value Q sys , which is also the first flow rate mean value obtained for the urea nozzle 104, and then the obtained flow rate reference value Qsys is stored.

[0057] 2) Obtain the flow rate reference value of the urea nozzle

[0058] When the flow rate reference value Q of the urea nozzle 104 sys If the calculation is not completed and its state meets the acquisition standard of the flow rate reference value Q sys , start to obtain the flow rate reference value Q of the urea nozzle 104 sys .

[0059] First, obtain the sequence of the injection average flow rate of the urea nozzle 104; the sequence of the injection average flow rate is divided into n' first sequences, and the n' first sequences are obtained in n' driving cycles respectively, where n'≥1.

[0060] Specifically, in each driving cycle, m' injection average flow rates of the urea nozzle 104 are obtained respectively. The m' injection average flow rates of the urea nozzle 104 are the first sequences. Among them, m' is greater than 1, and the calculation of the m' injection average flow rates of the urea nozzle 104 respectively includes the following processes:

[0061] First, stop injecting urea from the urea nozzle 104, stabilize the pump pressure of the urea pump 102 to the set pump pressure P0, and fix the rotation speed of the urea pump 102 to the set rotation speed N; then open the urea nozzle 104 with the set opening a, consume the set volume V of urea, collect the pump pressure P'1 at the opening moment of the urea nozzle 104 and the pump pressure P'2 at the closing moment, and from the system constant C obtained in advance above b , according to formula (2), calculate the injection average flow rate of the urea nozzle 104, and obtain the injection average flow rate Q' at the opening a of the urea nozzle 104 dos ; repeat the above process until the first sequence of a driving cycle is obtained, and then calculate the first mean value of the first sequence.

[0062] Repeat the above process until the n' first mean values Q of n' driving cycles are obtaineddos1 ′, Q dos2 ′, Q dos3 ′, Q dos4 ′, …, Q dosn ′.

[0063] After that, calculate the second mean value of the n' first mean values,

[0064]

[0065] This second mean value is the flow rate reference value Q of the urea nozzle 104 sys , and store the obtained flow rate reference value Q sys .

[0066] If the calculation and storage of the flow rate reference value Q of the urea nozzle 104 sys have been completed previously, the above process of obtaining the flow rate reference value Q of the urea nozzle 104 can be skipped, sys and directly obtain the flow rate mean value Q of the urea nozzle 104 for diagnosis act , and proceed with the subsequent diagnosis process.

[0067] 3) Obtain the flow rate mean value of the urea nozzle for diagnosis

[0068] When the urea consumption deviation meets the release condition, start obtaining the flow rate mean value Q for diagnosis act .

[0069] First, obtain the sequence of the injection average flow rate of the urea nozzle 104; the sequence of the injection average flow rate is divided into n first sequences, and the n first sequences are obtained within n driving cycles respectively, where n ≥ 1.

[0070] Specifically, within each driving cycle, obtain the injection average flow rates of m urea nozzles 104 respectively. The injection average flow rates of the m urea nozzles 104 are the first sequences. Among them, m > 1, and the calculation of the injection average flow rates of the m urea nozzles 104 respectively includes the following processes:

[0071] First, stop the urea injection of the urea nozzle 104, stabilize the pump pressure of the urea pump to the set pump pressure P0, and fix the rotation speed of the urea pump to the set rotation speed N; then open the urea nozzle 104 at the set opening a, consume the set volume V of urea, collect the pump pressure P1 at the opening moment of the urea nozzle 104 and the pump pressure P2 at the closing moment, and according to the system constant C obtained in advance b , according to formula (2), calculate the injection average flow rate of the urea nozzle 104, and obtain the injection average flow rate Q at the opening a of the urea nozzle 104 dos ; repeat the above process until the first sequence of a driving cycle is obtained, and then calculate the first mean value of the first sequence.

[0072] Repeat the above process until n first mean values ​​Q of n driving cycles are obtained. dos1 , Q dos2 , Q dos3 , Q dos4 ,…,Q dosn .

[0073] Then calculate the second mean of the n first means,

[0074]

[0075] The second mean value is the flow mean value Q of the urea nozzle 104 used for diagnosis. act .

[0076] Obtain the average flow rate Q of the urea nozzle 104 for diagnosis act The flow rate reference value Q of the urea nozzle 104 is obtained sys The control method is the same, wherein n′ and n, m′ and m can be the same number or different numbers respectively. Specifically, the number of the first sequence and the number of driving cycles can be selected according to different stages of automobile use to ensure the accuracy of the flow mean calculation of the urea nozzle 104 and avoid excessively long diagnosis time.

[0077] If the urea consumption deviation does not meet the release condition, the urea nozzle 104 still sprays according to the normal process, and the urea injection system still performs the working process of pressure building, injection and back extraction to treat the exhaust gas.

[0078] 4) Determine the degree of blockage of the urea nozzle

[0079] When obtaining the flow rate mean value Q of the urea nozzle 104 for diagnosis act After that, the mean flow rate Q used for diagnosis act The flow rate reference value Q of the urea nozzle 104 established in advance sys According to the current requirements for the injection amount deviation, the injection amount deviation of the urea nozzle 104 exceeds 50% and an error is required. Therefore, in this embodiment, 50%*Q sys is the lower limit and 150%*Q sys As the upper limit, the mean flow value Q used for diagnosis act Make a comparison.

[0080] When used for diagnostic flow mean Q act <50%*Q sys When the urea nozzle 104 is judged to be seriously blocked, the consumption is too low and the fault is reported; when the flow mean value Q used for diagnosis act >150%*Q sys When the urea nozzle 104 is seriously corroded, the aperture of the urea nozzle 104 becomes larger, and the consumption is too high.sys <Flow mean value Q for diagnosis> act <Less than 150% * Q> sys When the clogging degree of the urea nozzle 104 is within the required range, it is determined that the urea nozzle 104 is normal.

[0081] In other embodiments, the flow mean value Q for diagnosis can also be set as needed. act Relative to the flow reference value Q sys The error reporting range is not limited to 50% * Q sys The lower limit and 150% * Q sys The upper limit.

[0082] By using the diagnostic method in this technical solution, the flow rate of the urea nozzle is calculated using the pump pressure of the urea pump. First, in the new vehicle stage, the calculation and storage of the flow reference value of the urea nozzle are completed. Then, when the urea consumption deviation meets the release condition, the flow mean value for diagnosing the urea nozzle is obtained, and the flow mean value for diagnosis is compared with the pre-established flow reference value of the urea nozzle 104 to determine the clogging degree of the urea nozzle; setting the urea consumption deviation limit according to the flow rate of the normal nozzle can improve the adaptability of the consumption deviation strategy to different urea pumps, pipeline lengths, and layouts, and improve the robustness of fault diagnosis; actively stabilizing the pump pressure, fixing the urea pump speed, reducing the influence of urea pump pressure fluctuations on the results during nozzle flow rate evaluation, and using the method of taking the mean value after multiple evaluations to improve the accuracy of the evaluated flow rate; and it can be diagnosed in each driving cycle, with a shorter diagnosis cycle and higher diagnosis accuracy compared to diagnosing the urea consumption deviation through the liquid level sensor.

[0083] The embodiment of the present application also proposes a diagnostic device for urea nozzle clogging. This diagnostic device corresponds to the above method embodiment and uses the above diagnostic method to diagnose the clogging degree of the urea nozzle 104. Figure 3 It is a schematic diagram of the diagnostic device for urea nozzle clogging provided by the present invention. As Figure 3 shown, this diagnostic device 200 includes:

[0084] The first control module 201 is used to control the urea nozzle 104 to stop spraying urea, stabilize the urea pump 102 to the set pump pressure P0, and fix the urea pump 102 to the set speed N.

[0085] The second control module 202 is used to control the urea nozzle 104 to open with the set opening degree a and close after consuming the set volume V of urea.

[0086] The acquisition module 203 is used to acquire the pump pressure P1 at the opening moment of the urea nozzle 104 and the pump pressure P2 at the closing moment.

[0087] The determination module 204 calculates the average injection flow rate of the urea nozzle 104 according to the pump pressure change of the urea pump 102, obtains a sequence of average injection flow rates, and then calculates the average flow rate of the urea nozzle 104 based on the sequence of average injection flow rates.

[0088] The storage module 205 is configured to store the first average flow rate of the obtained urea nozzle 104 as the flow rate reference value of the urea nozzle 104 if the operating time of the urea nozzle 104 is within the preset period at the factory. Qs y s 。

[0089] The comparison module 206 is configured to compare the average flow rate Q of the urea nozzle 104 act with the pre-established and stored flow rate reference value Q of the urea nozzle 104 sys to determine the clogging degree of the urea nozzle 104.

[0090] An embodiment of the present application also proposes a diagnostic device for urea nozzle clogging. Figure 4 is a schematic hardware structure diagram of the diagnostic device for urea nozzle clogging provided in the embodiment of the present invention. As Figure 4 shown, the diagnostic device 300 for urea nozzle clogging in this embodiment includes: a processor 301 and a memory 302; where:

[0091] The memory 302 is used to store computer execution instructions.

[0092] The processor 301 is configured to execute the computer execution instructions stored in the memory to implement each step executed by the ECU in the above embodiment; specifically, reference can be made to the relevant descriptions in the foregoing method embodiments.

[0093] In a possible design, the memory 302 can be either independent or integrated with the processor 301.

[0094] When the memory 302 is independently provided, the diagnostic device for urea nozzle clogging further includes a bus 303 for connecting the memory 302 and the processor 301.

[0095] An embodiment of the present application also proposes a computer-readable storage medium, in which computer execution instructions are stored, and when the processor executes the computer execution instructions, the above-described diagnostic method for urea nozzle clogging is implemented.

[0096] In several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of devices or modules can be in electrical, mechanical or other forms.

[0097] The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0098] In addition, in each embodiment of the present invention, the functional modules can be integrated in a processing unit, or each module can exist physically alone, or two or more modules can be integrated in one unit. The units formed by the above modules can be implemented in the form of hardware or in the form of a combination of hardware and software functional units.

[0099] The integrated modules implemented in the form of software functional modules can be stored in a computer-readable storage medium. The above software functional modules are stored in a storage medium, including several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (English: processor) to execute some steps of the methods of various embodiments of the present application.

[0100] It should be understood that the above processor can be a central processing unit (Central Processing Unit, abbreviated as CPU), and can also be other general-purpose processors, digital signal processors (Digital Signal Processor, abbreviated as DSP), application specific integrated circuits (Application Specific Integrated Circuit, abbreviated as ASIC), etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in combination with the invention can be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0101] The memory may include high-speed RAM memory and may also include non-volatile storage NVM, such as at least one disk memory, and may also be a USB flash drive, a portable hard drive, a read-only memory, a magnetic disk, or an optical disc, etc.

[0102] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience in representation, the buses in the drawings of this application are not limited to only one bus or one type of bus.

[0103] The above storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, a magnetic disk, or an optical disc. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0104] An exemplary storage medium is coupled to the processor, enabling the processor to read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an Application Specific Integrated Circuits (ASIC). Of course, the processor and the storage medium can also exist as discrete components in an electronic device or a master control device.

[0105] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above method embodiments; and the foregoing storage medium includes: ROM, RAM, magnetic disks, or optical discs and other media that can store program codes.

[0106] As described above, it is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A diagnostic method for urea nozzle blockage, characterized in that, include: The urea nozzle stops spraying urea, stabilizes the urea pump to a set pump pressure, and fixes the urea pump to a set speed; The urea nozzle is opened at a set opening degree, consumes a set volume of urea, collects the pump pressure at the time when the urea nozzle is opened, and the pump pressure at the time when the urea nozzle is closed, and calculates the average injection flow rate of the urea nozzle according to the change of the pump pressure of the urea pump; Each time a set volume of urea is consumed, the average injection flow rate is calculated once, and a sequence of the average injection flow rates is obtained; Calculating a flow rate mean of the urea nozzle according to the sequence of the average injection flow rates; If the operation time of the urea nozzle is within the factory preset time period, storing the first obtained flow average value as the flow reference value of the urea nozzle; The flow rate mean value of the urea nozzle is compared with a pre-established flow rate reference value of the urea nozzle to determine the blockage degree of the urea nozzle.

2. The diagnostic method according to claim 1, characterized in that, The calculation of the average injection flow rate of the urea nozzle includes: Average injection flow rate Q dos = Q su - Q back , where Q su is the average supply flow rate of the urea pump, and Q back is the average flow rate of the urea pump return hole; When the urea pump runs at a set speed and stabilizes the pump pressure to the set pump pressure and the urea nozzle does not spray, the average supply flow rate of the urea pump is balanced with the average flow rate of the return hole, that is, Q su is equal to Q back to calculate the system constant C b ; The average injection flow rate Q of the urea nozzle dos = C b *(P1)^ 1 / 2 - C b *[(P1 + P2) / 2]^ 1 / 2 ; where P1 is the pump pressure at the start of injection and P2 is the pump pressure at the end of injection.

3. The diagnostic method according to claim 1 or 2, characterized in that The calculation of the flow mean of the urea nozzle includes: The sequence of the average injection flow rate is divided into n first sequences, and the n first sequences are respectively obtained in n driving cycles; In each driving cycle, each time a set volume of urea is consumed, the injection average flow rate is calculated once, and after m times, a first sequence is obtained, and a first mean value of the first sequence is calculated; A second mean of the n first mean values ​​is calculated, where the second mean value is a flow mean of the urea nozzle.

4. The diagnostic method according to claim 1, wherein When the flow mean of the urea nozzle is less than 0.5 times the flow reference value of the urea nozzle, it is judged that the urea nozzle is seriously clogged and a consumption failure is reported; when the flow mean of the urea nozzle is greater than 1.5 times the flow reference value of the urea nozzle, it is judged that the urea nozzle is seriously corroded and a consumption failure is reported; otherwise, it is judged that the urea nozzle is normal.

5. The diagnostic method according to claim 1, characterized in that, If the urea consumption deviation meets the release condition, the flow mean of the urea nozzle is calculated to determine the blockage degree of the urea nozzle; otherwise, the urea nozzle is sprayed according to a normal process to treat the exhaust gas.

6. A diagnostic device for urea nozzle clogging, which is used to perform the diagnostic method according to any one of claims 1 to 5, characterized in that, include: The first control module is used to control the urea nozzle to stop spraying urea, stabilize the urea pump to a set pump pressure, and fix the urea pump to a set speed; A second control module is used to control the urea nozzle to open at a set opening degree and close after consuming a set volume of urea; A collection module is used to collect the pump pressure when the urea nozzle is turned on and the pump pressure when it is turned off; A determination module calculates an average injection flow rate of the urea nozzle according to a change in the pump pressure of the urea pump, obtains an injection average flow rate sequence, and then calculates a flow rate mean of the urea nozzle according to the injection average flow rate sequence; A comparison module, used for comparing the flow rate mean value of the urea nozzle with a pre-established flow rate reference value of the urea nozzle to determine the blockage degree of the urea nozzle; The storage module is used for storing the first flow average value of the urea nozzle as the flow reference value of the urea nozzle if the operation time of the urea nozzle is within a factory preset time period.

7. A diagnostic device for urea nozzle blockage, characterized in that, include: at least one processor and memory; The memory stores computer-executable instructions; The at least one processor executes the computer-executable instructions stored in the memory, such that the at least one processor executes the diagnostic method according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, Computer-executable instructions are stored in the computer-readable storage medium, and when the processor executes the computer-executable instructions, the diagnostic method according to any one of claims 1-5 is implemented.

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