Diagnostic method, device and vehicle for a scr dual injection urea apparatus

Abstract

The application provides a diagnosis method, device and vehicle for an SCR double-injection urea equipment, which comprises the following steps: in the case that the change rate of the pressure value of the pumping equipment is less than a first preset value, closing two nozzles, adjusting the pressure value of the pumping equipment, and obtaining the change rate of the pressure value in the adjustment process to obtain a first change rate; in the case that the first change rate is not located in a first predetermined range, determining that a flow structure has a fault; in the case that the flow structure has no fault and the change rate of the pressure value is less than a second preset value, opening a target nozzle to spray urea, the target nozzle being one of the two nozzles; obtaining the change rate of the pressure value in the process of spraying urea by the target nozzle to obtain a second change rate; and determining whether the target nozzle has a fault according to the second change rate, and in the case that the second change rate is not located in a second predetermined range, determining that the target nozzle has a fault. The application solves the problem of difficult and timely discovery of the fault of the SCR double-injection urea equipment.

Description

Technical Field

[0001] This application relates to the field of vehicle fault diagnosis, and more specifically, to a diagnostic method, apparatus, computer-readable storage medium, and vehicle for an SCR dual-injection urea device. Background Technology

[0002] SCR (Selectively Catalytic Reduction) systems can reduce NOx emissions, and dual SCR systems can further improve NOx conversion efficiency, which is beneficial for engines to improve their original NOx levels and reduce fuel consumption. Dual SCR systems require a dual-injection urea system, which controls the duty cycle of nozzles 1 and 2 to drive the nozzles to periodically inject urea into the exhaust tailpipe, thus controlling emissions. Currently, dual-injection urea systems suffer from blockage or leakage problems, affecting the exhaust gas purification function of the SCR system.

[0003] Therefore, how to detect the working status of SCR dual-injection urea equipment and promptly identify blockages or leaks in the SCR dual-injection urea equipment is a problem that urgently needs to be solved in the existing technology. Summary of the Invention

[0004] The main objective of this application is to provide a diagnostic method, apparatus, computer-readable storage medium, and vehicle for SCR dual-injection urea equipment, so as to at least solve the problem of difficulty in timely detection of SCR dual-injection urea equipment faults in the prior art.

[0005] To achieve the above objectives, according to one aspect of this application, a diagnostic method for an SCR dual-injection urea device is provided. The SCR dual-injection urea device includes a urea storage device, a flow structure, and two nozzles. The flow structure includes a pumping device, a one-way return structure, a pumping pipeline, and a return pipeline. A first end of the pumping device is connected to the urea storage device via the pumping pipeline and the return pipeline, respectively. The one-way return structure is located on the return pipeline. When fluid in the return pipeline flows from the pumping device to the urea storage device, the one-way return structure is activated. A second end of the pumping device is connected to the two nozzles. The method includes a shut-off step: when the rate of change of the pressure value of the pumping device is less than a first preset value, closing the two nozzles; adjusting the pressure value of the pumping device; and acquiring the change in the pressure value during the adjustment process. The process involves several steps: a first rate of change is obtained; a first determination step is taken, based on the first rate of change, to determine whether the flow structure has malfunctioned; if the first rate of change is not within a first predetermined range, the flow structure is determined to have malfunctioned; if the first rate of change is within the first predetermined range, the flow structure is determined not to have malfunctioned; a first activation step is taken, if the flow structure has not malfunctioned and the rate of change of the pressure value is less than a second preset value, to activate the target nozzle to spray the urea, wherein the target nozzle is one of two nozzles; an acquisition step is taken, to acquire the rate of change of the pressure value during the spraying of the urea by the target nozzle, to obtain a second rate of change; a second determination step is taken, based on the second rate of change, to determine whether the target nozzle has malfunctioned; if the second rate of change is not within a second predetermined range, the target nozzle is determined to have malfunctioned.

[0006] Optionally, adjusting the pressure value of the pumping device and obtaining the rate of change of the pressure value during the adjustment process to obtain a first rate of change includes: obtaining the pressure value when both nozzles are closed to obtain a first pressure; reducing the duty cycle of the pumping device to a preset duty cycle to adjust the pressure value; determining that the adjustment is complete when the rate of change of the adjusted pressure value is less than a third preset value, and obtaining the pressure value corresponding to the completed adjustment to obtain a second pressure; and determining the ratio of the difference between the first pressure and the second pressure to the first interval duration as the first rate of change based on the first pressure, the second pressure, and a first interval duration, wherein the first interval duration is the acquisition interval duration between the first pressure and the second pressure.

[0007] Optionally, before opening the target nozzle to spray the urea, the method further includes: a control step, controlling the duty cycle of the pumping equipment to an initial duty cycle; a second opening step, opening the two nozzles and controlling the duty cycle of the two nozzles according to the required urea injection volume, so that the two nozzles spray the urea according to the required urea injection volume; and a third determining step, determining whether the rate of change of the pressure value is less than the second preset value.

[0008] Optionally, opening the target nozzle to spray the urea includes: keeping the target nozzle open while controlling the duty cycle of the pumping equipment to remain constant, and closing the other nozzle besides the target nozzle. The acquisition step includes: acquiring the pressure value when the target nozzle is open to obtain a third pressure, and continuing to acquire multiple pressure values ​​to obtain multiple fourth initial pressures; if the rate of change of the fourth initial pressure is less than a fourth preset value, determining the fourth initial pressure whose rate of change is less than the fourth preset value as the fourth pressure; and determining the ratio of the difference between the third pressure and the fourth pressure to the second interval time as the second rate of change based on the third pressure, the fourth pressure, and the second interval time, where the second interval time is the acquisition interval time between the third pressure and the fourth pressure.

[0009] Optionally, after the second determining step, the method further includes: a third opening step, determining that the other of the two nozzles is the target nozzle; and a looping step, cyclically executing the control step, the second opening step, the third determining step, the first opening step, the acquisition step, and the second determining step once to determine whether the target nozzle has malfunctioned.

[0010] Optionally, one nozzle is used to inject urea into the pre-stage SCR unit, and the other nozzle is used to inject urea into the post-stage SCR unit. The pre-stage and post-stage SCR units are connected and spaced apart along a distance from the turbine outlet. Before the shut-off step, the method further includes: acquiring the temperature of the pre-stage SCR unit, the temperature of the post-stage SCR unit, the cumulative urea injection quantity of the two nozzles, the exhaust gas flow rate of the engine, the pressure value, and the average conversion efficiency of the pre-stage and post-stage SCR units; and controlling the pumping device when the dual-injection urea SCR unit meets the detection conditions. The duty cycle of the equipment is the initial duty cycle, wherein the detection conditions include at least the following: the temperature of the pre-stage SCR equipment is within a predetermined temperature range, the temperature of the post-stage SCR equipment is within the predetermined temperature range, the cumulative urea injection volume is greater than a fifth preset value, the exhaust gas flow rate is within a third predetermined range, the pressure value is within a fourth predetermined range, and the average conversion efficiency is greater than a sixth predetermined value; the two nozzles are opened, and the duty cycle of the two nozzles is controlled according to the required urea injection volume, so that the two nozzles inject urea according to the required urea injection volume; it is determined whether the rate of change of the pressure value is less than the first preset value.

[0011] Optionally, in the event of a failure in the flow structure, the method further includes: generating first fault information characterizing the failure of the flow structure and sending the first fault information to a terminal; and in the event that the target nozzle has failed, the method further includes: disabling the target nozzle from injecting urea; generating second fault information characterizing the failure of the target nozzle and sending the second fault information to the terminal.

[0012] According to another aspect of this application, a diagnostic device for an SCR dual-injection urea device is provided. The SCR dual-injection urea device includes a urea storage device, a flow structure, and two nozzles. The flow structure includes a pumping device, a one-way return structure, a pumping pipeline, and a return pipeline. A first end of the pumping device is connected to the urea storage device through the pumping pipeline and the return pipeline, respectively. The one-way return structure is located on the return pipeline. When fluid in the return pipeline flows from the pumping device to the urea storage device, the one-way return structure is activated. A second end of the pumping device is connected to the two nozzles. The device includes: a shut-off unit for a shut-off step, which closes the two nozzles when the rate of change of the pressure value of the pumping device is less than a first preset value, adjusts the pressure value of the pumping device, and obtains the rate of change of the pressure value during the adjustment process to obtain a first rate of change; and a first determination unit for... In the first determining step, based on the first rate of change, it is determined whether the flow structure has malfunctioned. If the first rate of change is not within a first predetermined range, it is determined that the flow structure has malfunctioned; if the first rate of change is within the first predetermined range, it is determined that the flow structure has not malfunctioned. A first opening unit is used in the first opening step to open the target nozzle to spray urea when the flow structure has not malfunctioned and the rate of change of the pressure value is less than a second preset value. The target nozzle is one of two nozzles. A first acquiring unit is used in the acquiring step to acquire the rate of change of the pressure value during the spraying of urea by the target nozzle, obtaining a second rate of change. A second determining unit is used in the second determining step to determine whether the target nozzle has malfunctioned based on the second rate of change. If the second rate of change is not within a second predetermined range, it is determined that the target nozzle has malfunctioned.

[0013] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform any of the methods described.

[0014] According to another aspect of this application, a vehicle is provided, comprising: an SCR dual-injection urea device, including a urea storage device, a flow structure, and two nozzles, the flow structure including a pumping device, a one-way return structure, a pumping line, and a return line, a first end of the pumping device being connected to the urea storage device via the pumping line and the return line respectively, the one-way return structure being located on the return line, the one-way return structure being activated when fluid in the return line flows from the pumping device to the urea storage device, and a second end of the pumping device being connected to the two nozzles; one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any one of the methods described.

[0015] By applying the technical solution of this application, the pressure change of the pumping equipment is detected by closing both nozzles to determine whether there is a fault in the flow structure of the SCR dual-injection urea equipment. When no fault is found, one nozzle is opened, and the pressure change of the pumping equipment is used to detect whether the nozzle is faulty. This realizes the automatic detection of faults in the SCR dual-injection urea equipment, which can promptly detect faults in the SCR dual-injection urea equipment. When a fault occurs, it can be located whether the fault is in the flow structure or the nozzle, which facilitates subsequent fault handling and maintenance. This effectively solves the problem of difficulty in timely detection of faults in the SCR dual-injection urea equipment. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 A hardware structure block diagram of a mobile terminal for performing a diagnostic method for an SCR dual-injection urea device is shown in an embodiment of this application.

[0018] Figure 2 A schematic diagram of the structure of an SCR dual-injection urea device according to an embodiment of this application is shown;

[0019] Figure 3 A schematic flowchart of a diagnostic method for an SCR dual-injection urea device according to an embodiment of this application is shown.

[0020] Figure 4 A schematic diagram showing the pressure value of a diagnostic pumping device changing over time according to an embodiment of this application is shown.

[0021] Figure 5A schematic diagram of a dual SCR system according to an embodiment of this application is shown;

[0022] Figure 6 A schematic flowchart of a diagnostic method for another SCR dual-injection urea device provided according to an embodiment of this application is shown;

[0023] Figure 7 A schematic diagram showing the pressure value of another pumping device provided according to an embodiment of this application varies over time;

[0024] Figure 8 A structural block diagram of a diagnostic device for an SCR dual-injection urea equipment provided according to an embodiment of this application is shown.

[0025] The above figures include the following reference numerals:

[0026] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device; 300. Urea storage device; 301. Nozzle; 302. Pumping device; 303. Unidirectional reflux structure; 304. Pumping pipeline; 305. Return pipeline; 306. Pump motor; 307. Pump pressure chamber; 308. Pressure sensor; 400. First mixer; 401. Pre-stage SCR device; 402. DOC; 403. DPF; 404. Second mixer; 405. Post-stage SCR device; 406. ASC; 407. First temperature sensor; 408. Second temperature sensor; 409. Third temperature sensor; 410. First NOx sensor; 411. Second NOx sensor. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0029] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] As described in the background section, there is a problem in the prior art that it is difficult to detect faults in SCR dual-injection urea equipment in a timely manner. In order to solve the above-mentioned technical problems, the embodiments of this application provide a diagnostic method, apparatus, computer-readable storage medium and vehicle for SCR dual-injection urea equipment.

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0032] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a diagnostic method of an SCR dual-injection urea device according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal. For example, the mobile terminal may also include components that are larger than... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0033] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the diagnostic method of the SCR dual-injection urea device in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the method described. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of such networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0034] This embodiment provides a diagnostic method for an SCR dual-injection urea device that runs on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0035] Figure 2 This is a structural schematic diagram of an SCR dual-injection urea device according to an embodiment of this application, as shown below. Figure 2As shown, the SCR dual-injection urea equipment includes a urea storage device 300, a flow structure, and two nozzles 301. The flow structure includes a pumping device 302, a one-way return structure 303, a pumping pipeline 304, and a return pipeline 305. The first end of the pumping device 302 is connected to the urea storage device 300 through the pumping pipeline 304 and the return pipeline 305, respectively. The one-way return structure 303 is located on the return pipeline 305. When the fluid in the return pipeline 305 flows from the pumping device 302 to the urea storage device 300, the one-way return structure is open. When the fluid in the return pipeline 305 flows from the urea storage device 300 to the pumping device 302, the one-way return structure is closed. The second end of the pumping device 302 is connected to the two nozzles 301.

[0036] Figure 3 This is a flowchart of a diagnostic method for an SCR dual-injection urea device according to an embodiment of this application. Figure 3 As shown, the method includes the following steps:

[0037] Step S201, Closing Step: When the rate of change of the pressure value of the pumping equipment is less than a first preset value, close the two nozzles, adjust the pressure value of the pumping equipment, and obtain the rate of change of the pressure value during the adjustment process to obtain the first rate of change;

[0038] Specifically, if the rate of change of the pressure value in the pumping equipment is less than the first preset value, it indicates that the pressure value in the pumping equipment is basically stable. Those skilled in the art can flexibly set the specific value of the first preset value according to actual needs; this application does not impose specific limitations in this regard.

[0039] Step S202, first determining step: determine whether the flow structure has failed based on the first rate of change; if the first rate of change is not within a first predetermined range, determine that the flow structure has failed; if the first rate of change is within the first predetermined range, determine that the flow structure has not failed.

[0040] Specifically, the faults include leakage faults and blockage faults. That is, if at least one of the pumping equipment, the one-way return structure, the pumping pipeline, and the return pipeline experiences a leakage fault or a blockage fault, the first rate of change is not within the first predetermined range. Generally, such as Figure 4As shown, in the case of a leakage failure in the flow structure, the first rate of change corresponds to the maximum value of the first predetermined range; in the case of a blockage failure in the flow structure, the first rate of change corresponds to the minimum value of the first predetermined range. Those skilled in the art can set the boundary values ​​of the first predetermined range based on empirical values, or they can determine, through multiple experiments, the critical pressure value in the pumping equipment that satisfies the condition that the flow structure does not fail, as the boundary value of the first predetermined range.

[0041] Step S203, first opening step: when the flow structure has not failed and the rate of change of the pressure value is less than the second preset value, the target nozzle is opened to spray the urea, and the target nozzle is one of the two nozzles;

[0042] Specifically, when the rate of change of the pressure value is less than the second preset value, it indicates that the pressure value in the pumping equipment is basically stable. Those skilled in the art can flexibly set the specific value of the second preset value according to actual needs; this application does not impose specific limitations in this regard.

[0043] Step S204, the acquisition step, acquires the rate of change of the pressure value during the process of the target nozzle injecting the urea, and obtains the second rate of change;

[0044] Step S205, second determination step: determine whether the target nozzle has malfunctioned based on the second rate of change; if the second rate of change is not within a second predetermined range, determine that the target nozzle has malfunctioned.

[0045] Specifically, the faults include leakage faults and blockage faults. That is, when the target nozzle experiences a leakage fault or a blockage fault, the second rate of change is not within the second predetermined range. Generally, when the target nozzle experiences a leakage fault, the second rate of change is greater than the maximum value of the second predetermined range; when the target nozzle experiences a blockage fault, the second rate of change is less than the minimum value of the second predetermined range. Those skilled in the art can set the boundary values ​​of the second predetermined range based on empirical values, or they can determine, through multiple experiments, the critical pressure value in the pumping equipment that satisfies the condition that the nozzle does not experience a fault as the boundary value of the second predetermined range.

[0046] In the above embodiment, when the pressure value of the pumping equipment is stable, firstly, two nozzles are controlled to be closed, the pressure value of the pumping equipment is adjusted, and a first rate of change of pressure value during the adjustment process is obtained; then, based on the magnitude of the first rate of change, it is determined whether the flow structure including the pumping equipment, the one-way return structure, the pumping pipeline, and the return pipeline has malfunctioned; then, if the flow structure has not malfunctioned and the pressure value is stable, one nozzle is opened for urea injection; then, a second rate of change of pressure value of the opened nozzle during urea injection is obtained; finally, based on the second rate of change, it is determined whether the opened nozzle has malfunctioned. Compared to the difficulty in timely detection of SCR dual-injection urea equipment faults in existing technologies, this application determines whether there is a fault in the flow structure of the SCR dual-injection urea equipment by closing both nozzles and detecting pressure changes in the pumping equipment. When no fault is found, one nozzle is opened, and the pressure changes in the pumping equipment are used to detect whether the nozzle is faulty. This achieves automatic detection of faults in the SCR dual-injection urea equipment, enabling timely detection of faults. Furthermore, when a fault occurs, it can be located whether the fault lies in the flow structure or the nozzle, facilitating subsequent fault handling and maintenance. This effectively solves the problem of difficulty in timely detection of SCR dual-injection urea equipment faults.

[0047] Furthermore, in the event of a malfunction in the flow structure, the method further includes: terminating the diagnostic process. Since, when a nozzle test is performed in the event of a malfunction in the flow structure, it is impossible to determine whether the malfunction is caused by the flow structure or the nozzle based on the test results, the diagnostic process is discontinued until the malfunction in the flow structure is resolved before resuming testing.

[0048] It should be noted that, compared to the approach of first testing the nozzle and then testing the flow structure, if a fault is determined when testing the nozzle, it is impossible to determine whether the fault is caused by the nozzle itself or by the flow structure. If a fault is determined when testing the flow structure later, it is also impossible to determine whether the nozzle is faulty. However, the approach described in this application can first determine whether the flow structure is faulty. This test result is not affected by whether the nozzle is faulty. If the flow structure is ruled out as faulty, the nozzle can then be tested. This approach can pinpoint the fault location once the fault is determined.

[0049] In one alternative approach, adjusting the pressure value of the pumping equipment and obtaining the rate of change of the pressure value during the adjustment process to obtain a first rate of change includes:

[0050] Step S2011: Obtain the pressure value when both nozzles are closed to obtain the first pressure;

[0051] Step S2012: Reduce the duty cycle of the pumping equipment to a preset duty cycle to adjust the pressure value;

[0052] Step S2013: If the rate of change of the adjusted pressure value is less than the third preset value, determine that the adjustment is complete, and obtain the pressure value corresponding to the condition that the adjustment is complete, to obtain the second pressure;

[0053] Specifically, if the rate of change of the adjusted pressure value is less than a preset value, it indicates that the pressure value in the pumping equipment is basically stable.

[0054] Step S2014: Based on the first pressure, the second pressure, and the first interval duration, determine the ratio of the difference between the first pressure and the second pressure to the first interval duration as the first rate of change, where the first interval duration is the acquisition interval duration between the first pressure and the second pressure.

[0055] In the embodiment described above, the pressure value is obtained with both nozzles closed to obtain the first pressure. Then, the duty cycle of the pumping equipment is reduced to reduce the pressure in the pumping equipment. When the pressure value is stable, the current pressure value is obtained to obtain the second pressure. The first rate of change is obtained by comparing the rate of change of the second pressure with the first pressure. The first rate of change can be obtained relatively simply and easily.

[0056] In addition to the methods described above, adjusting the pressure value of the pumping equipment and obtaining the rate of change of the pressure value during the adjustment process to obtain a first rate of change may further include: reducing the duty cycle of the pumping equipment to a preset duty cycle to adjust the pressure value; acquiring the pressure value in the pumping equipment after the pressure value is adjusted in real time, obtaining multiple pressure values ​​and the acquisition time corresponding to the pressure values; stopping the acquisition of the pressure value when the rate of change of the adjusted pressure value is less than a third preset value; calculating the pressure change rate corresponding to each pair of adjacent acquisition times based on the acquired multiple pressure values ​​and the corresponding acquisition times, and calculating the average of the multiple pressure change rates to obtain the first rate of change. This allows for a more accurate determination of the first rate of change.

[0057] Optionally, before activating the target nozzle to inject urea, the method further includes: a control step, controlling the duty cycle of the pumping equipment to an initial duty cycle; a second activation step, activating both nozzles and controlling the duty cycle of the two nozzles according to the required urea injection volume, so that the two nozzles inject urea according to the required urea injection volume; and a third determination step, determining whether the rate of change of the pressure value is less than a second preset value. In this embodiment, in the absence of a malfunction in the flow structure, the control step, the second activation step, and the third determination step are used to perform normal urea injection control on the SCR dual-injection urea equipment, so that the pressure value in the pumping equipment tends to stabilize, providing a suitable environment for subsequent diagnostic stages.

[0058] Specifically, opening the target nozzle to spray the urea includes: keeping the target nozzle open while maintaining the duty cycle of the pumping equipment constant, and closing the other nozzle besides the target nozzle. That is, maintaining the duty cycle of the pumping equipment at the duty cycle value corresponding to a pressure change rate less than a second preset value, and then detecting the nozzle.

[0059] To further simplify the acquisition of the second rate of change, in some alternative embodiments of this application, the acquisition step includes: acquiring the pressure value when the target nozzle is open to obtain a third pressure, and continuing to acquire multiple pressure values ​​to obtain multiple fourth initial pressures; if the rate of change of the fourth initial pressure is less than a fourth preset value, it indicates that the pressure value has stabilized, and the fourth initial pressure with a rate of change less than the fourth preset value is determined as the fourth pressure; based on the third pressure, the fourth pressure, and the second interval duration, the ratio of the difference between the third pressure and the fourth pressure to the second interval duration is determined as the second rate of change, where the second interval duration is the acquisition interval duration between the third pressure and the fourth pressure.

[0060] Of course, besides the method described above, those skilled in the art can also use other methods to obtain the second rate of change. In some other embodiments, the acquisition step may further include: acquiring the pressure value in the pumping device and the acquisition time corresponding to the pressure value in real time; stopping the acquisition of the pressure value when the acquired rate of change of the pressure value is less than a fourth preset value; calculating the pressure rate of change corresponding to each pair of adjacent acquisition times based on the acquired multiple pressure values ​​and the corresponding acquisition times, and calculating the average of the multiple pressure rate of change to obtain the second rate of change. This can obtain the second rate of change more accurately.

[0061] According to some other exemplary solutions of this application, after the second determining step, the method further includes: a third opening step, determining that the other of the two nozzles is the target nozzle; and a looping step, cyclically executing the control step, the second opening step, the third determining step, the first opening step, the acquisition step, and the second determining step once to determine whether the target nozzle has malfunctioned. After checking whether one of the nozzles is malfunctioning, through the above embodiment, the normal operation of the SCR dual-injection urea equipment is restored first, and then the other nozzle is tested to detect whether the other nozzle is malfunctioning, thereby achieving timely detection of SCR dual-injection urea equipment malfunctions and further facilitating subsequent fault handling and maintenance work.

[0062] In another alternative embodiment, such as Figure 5 As shown, one nozzle 301 is used to inject urea into the pre-stage SCR unit 401, and another nozzle 301 is used to inject urea into the post-stage SCR unit 405. The pre-stage SCR unit 401 and the post-stage SCR unit 405 are connected and spaced apart along a distance from the turbine outlet. Prior to the shut-off step, the method further includes:

[0063] Step S206: Obtain the temperature of the pre-stage SCR device, the temperature of the post-stage SCR device, the cumulative urea injection volume of the two nozzles, the exhaust gas flow rate of the engine, the pressure value, and the average conversion efficiency of the pre-stage SCR device and the post-stage SCR device.

[0064] Specifically, the cumulative urea injection quantity is the cumulative injection quantity recorded by the ECU after each ECU power-on; the average conversion efficiency is the average of the conversion efficiency of the pre-stage SCR device and the conversion efficiency of the post-stage SCR device. The conversion efficiency of the pre-stage SCR device can be obtained by detecting the NOx concentration after treatment by the pre-stage SCR device using a first NOx sensor located after the pre-stage SCR device, and dividing the NOx concentration by the original NOx concentration in the engine exhaust; the conversion efficiency of the post-stage SCR device can be obtained by detecting the NOx concentration after treatment by the post-stage SCR device using a second NOx sensor located after the post-stage SCR device, and dividing the NOx concentration by the NOx concentration detected by the first NOx sensor.

[0065] Step S207: When the SCR dual-injection urea equipment meets the detection conditions, control the duty cycle of the pumping equipment to the initial duty cycle, wherein the detection conditions include at least the following: the temperature of the pre-stage SCR equipment is within a predetermined temperature range, the temperature of the post-stage SCR equipment is within the predetermined temperature range, the cumulative urea injection volume is greater than a fifth preset value, the exhaust gas flow rate is within a third predetermined range, the pressure value is within a fourth predetermined range, and the average conversion efficiency is greater than a sixth predetermined value.

[0066] Specifically, the detection conditions may include all or only some of the conditions, and those skilled in the art can flexibly set them according to actual conditions. In this application, the detection conditions include the temperature of the pre-stage SCR equipment being within a predetermined temperature range, the temperature of the post-stage SCR equipment being within the predetermined temperature range, the cumulative urea injection volume being greater than a fifth preset value, the exhaust gas flow rate being within a third predetermined range, the pressure value being within a fourth predetermined range, and the average conversion efficiency being greater than a sixth predetermined value. That is to say, the diagnostic stage only begins when all the conditions are met.

[0067] Step S208: Open the two nozzles and control the duty cycle of the two nozzles according to the required urea injection volume, so that the two nozzles inject urea according to the required urea injection volume;

[0068] Step S209: Determine whether the rate of change of the pressure value is less than the first preset value.

[0069] In the embodiments described in this application, before fault diagnosis, it is first detected whether the vehicle meets at least some of the detection conditions. If it is determined that the vehicle meets at least some of the detection conditions, it indicates that the SCR dual-injection urea equipment may be faulty. At this time, normal urea injection control is performed on the SCR dual-injection urea equipment to stabilize the pressure value in the pumping equipment and provide a suitable environment for the subsequent diagnosis stage.

[0070] In practical applications, if the SCR dual-injection urea equipment does not meet the detection conditions, the system continues to determine whether the SCR dual-injection urea equipment meets the detection conditions until the SCR dual-injection urea equipment meets the detection conditions.

[0071] Specifically, in the event of a malfunction in the flow structure, the method further includes: generating first fault information characterizing the malfunction of the flow structure and sending the first fault information to a terminal; and in the event that the target nozzle has malfunctioned, the method further includes: disabling the target nozzle from injecting urea; generating second fault information characterizing the malfunction of the target nozzle and sending the second fault information to the terminal. In this embodiment, by generating the first fault information and the second fault information and sending them to the terminal, relevant personnel can promptly understand the malfunction status of the SCR dual-injection urea equipment through the terminal, further facilitating timely response and handling of malfunctions.

[0072] Furthermore, when nozzle 1 fails, nozzle 1 is disabled while nozzle 2 remains operational; when nozzle 2 fails, nozzle 2 is disabled while nozzle 1 remains operational.

[0073] In the event of a malfunction in the flow structure, the method further includes issuing a first alarm signal; in the event of a malfunction in the target nozzle, the method further includes issuing a second alarm signal.

[0074] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the diagnostic method of the SCR dual-injection urea device of this application will be described in detail below with reference to specific embodiments.

[0075] This embodiment relates to a specific diagnostic method for an SCR dual-injection urea device, wherein the two nozzles of the SCR dual-injection urea device are nozzle 1 and nozzle 2, as follows: Figure 6 As shown, the method includes the following steps:

[0076] Step S1: Determine whether the detection conditions are met. The detection conditions include the following:

[0077] The temperature of the pre-stage SCR device is within a predetermined temperature range, the temperature of the post-stage SCR device is within the predetermined temperature range, the cumulative urea injection volume is greater than a fifth preset value, the exhaust gas flow rate is within a third predetermined range, the pressure value is within a fourth predetermined range, and the average conversion efficiency is greater than a sixth predetermined value.

[0078] Step S2: If the diagnostic conditions are met, perform flow structure diagnosis. If a fault is detected in the flow structure, exit the diagnosis and report a flow structure fault. The flow structure diagnosis process is as follows:

[0079] First, enter the normal control phase: adjust the duty cycle of the pumping equipment to stabilize the pressure of the pumping equipment at the set value, and control the duty cycle of nozzle 1 and nozzle 2 respectively according to the required urea injection volume.

[0080] Next, proceed to the flow structure diagnosis stage: After the pressure stabilizes, reduce the duty cycle of the pumping equipment and maintain the reduced duty cycle at a fixed level. Close nozzles 1 and 2, and monitor the pressure change of the pumping equipment until the pressure stabilizes; calculate the average rate of change of pressure during the pressure change process, such as... Figure 7 As shown, if the pressure changes too quickly or too slowly, it is considered that there is a fault in the flow structure of the SCR dual-injection urea equipment, and no further testing will be conducted.

[0081] Step S3: When the flow structure is fault-free, perform a diagnostic test on the injection capability of nozzle 1. The specific diagnostic process for nozzle 1 is as follows:

[0082] First, enter the normal control phase: restore normal control, adjust the duty cycle of the pumping equipment to stabilize the pressure of the pumping equipment at the set value, and control the duty cycle of nozzle 1 and nozzle 2 respectively according to the required urea injection volume.

[0083] Next, proceed to the nozzle 1 diagnostic stage: After the pressure stabilizes, maintain a fixed pump duty cycle to ensure pressure stability. Open nozzle 1 for a period of time while simultaneously closing nozzle 2, monitoring pressure changes in the pumping equipment until the pressure stabilizes. Calculate the average rate of change during the pressure change process, such as... Figure 7 As shown, if the pressure changes too quickly or too slowly, it is considered that nozzle 1 is clogged or leaking.

[0084] Step S4: After the injection capability diagnosis of nozzle 1 is completed, the injection capability diagnosis of nozzle 2 is performed. The specific diagnosis process for nozzle 2 is as follows:

[0085] First, enter the normal control phase: restore normal control, adjust the duty cycle of the pumping equipment to stabilize the pressure of the pumping equipment at the set value, and control the duty cycle of nozzle 1 and nozzle 2 respectively according to the required urea injection volume.

[0086] Next, proceed to the nozzle 2 diagnostic stage: After the pressure stabilizes, maintain a fixed pump duty cycle to ensure pressure stability. Open nozzle 2 for a period of time while simultaneously closing nozzle 1, monitoring pressure changes in the pumping equipment until the pressure stabilizes. Calculate the average rate of change during the pressure change process, such as... Figure 7 As shown, if the pressure changes too quickly or too slowly, nozzle 2 is considered to be faulty, blocked, or leaking.

[0087] Step S5: After the injection capability diagnosis of nozzle 2 is completed, trigger the corresponding fault and nozzle action according to the diagnosis result. Specifically, when fault 1 occurs, nozzle 1 is disabled; when fault 2 occurs, nozzle 2 is disabled; when either fault 1 or fault 2 occurs, a nozzle fault is reported.

[0088] In the aforementioned embodiment, by closing the nozzle, the pressure change of the flow structure of the SCR dual-injection urea equipment is detected, and blockages and leaks in the pumping equipment and pipelines are eliminated. Then, the nozzles 1 and 2 are alternately opened and closed to detect faults in the two nozzles and their pipelines respectively, which can accurately and timely detect injection abnormalities.

[0089] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0090] This application also provides a diagnostic device for an SCR dual-injection urea equipment. It should be noted that the diagnostic device for the SCR dual-injection urea equipment in this application can be used to execute the diagnostic method for the SCR dual-injection urea equipment provided in this application. This device is used to implement the embodiments and preferred embodiments described herein; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0091] The diagnostic device for the SCR dual-injection urea equipment provided in the embodiments of this application is described below.

[0092] Figure 2 This is a structural schematic diagram of an SCR dual-injection urea device according to an embodiment of this application, as shown below. Figure 2 As shown, the SCR dual-injection urea equipment includes a urea storage device 300, a flow structure, and two nozzles 301. The flow structure includes a pumping device 302, a one-way return structure 303, a pumping pipeline 304, and a return pipeline 305. The first end of the pumping device 302 is connected to the urea storage device 300 through the pumping pipeline 304 and the return pipeline 305, respectively. The one-way return structure 303 is located on the return pipeline 305. When the fluid in the return pipeline 305 flows from the pumping device 302 to the urea storage device 300, the one-way return structure is open. When the fluid in the return pipeline 305 flows from the urea storage device 300 to the pumping device 302, the one-way return structure is closed. The second end of the pumping device 302 is connected to the two nozzles 301.

[0093] Figure 8 This is a schematic diagram of the diagnostic device of an SCR dual-injection urea equipment according to an embodiment of this application. Figure 8 As shown, the device includes:

[0094] The shut-off unit 10 is used for the shut-off step. When the rate of change of the pressure value of the pumping equipment is less than a first preset value, the two nozzles are shut off, the pressure value of the pumping equipment is adjusted, and the rate of change of the pressure value during the adjustment process is obtained to obtain the first rate of change.

[0095] Specifically, if the rate of change of the pressure value in the pumping equipment is less than the first preset value, it indicates that the pressure value in the pumping equipment is basically stable. Those skilled in the art can flexibly set the specific value of the first preset value according to actual needs; this application does not impose specific limitations in this regard.

[0096] The first determining unit 20 is used for a first determining step, determining whether the circulation structure has failed based on the first rate of change; if the first rate of change is not within a first predetermined range, determining that the circulation structure has failed; if the first rate of change is within the first predetermined range, determining that the circulation structure has not failed.

[0097] Specifically, the faults include leakage faults and blockage faults. That is, if at least one of the pumping equipment, the one-way return structure, the pumping pipeline, and the return pipeline experiences a leakage fault or a blockage fault, the first rate of change is not within the first predetermined range. Generally, such as Figure 4 As shown, in the case of a leakage failure in the flow structure, the first rate of change corresponds to the maximum value of the first predetermined range; in the case of a blockage failure in the flow structure, the first rate of change corresponds to the minimum value of the first predetermined range. Those skilled in the art can set the boundary values ​​of the first predetermined range based on empirical values, or they can determine, through multiple experiments, the critical pressure value in the pumping equipment that satisfies the condition that the flow structure does not fail, as the boundary value of the first predetermined range.

[0098] The first opening unit 30 is used in the first opening step to open the target nozzle to spray the urea when the flow structure is not faulty and the rate of change of the pressure value is less than the second preset value. The target nozzle is one of the two nozzles.

[0099] Specifically, when the rate of change of the pressure value is less than the second preset value, it indicates that the pressure value in the pumping equipment is basically stable. Those skilled in the art can flexibly set the specific value of the second preset value according to actual needs; this application does not impose specific limitations in this regard.

[0100] The first acquisition unit 40 is used for the acquisition step, acquiring the rate of change of the pressure value during the process of the target nozzle injecting the urea, and obtaining a second rate of change;

[0101] The second determining unit 50 is used in the second determining step to determine whether the target nozzle has malfunctioned based on the second rate of change, and to determine that the target nozzle has malfunctioned if the second rate of change is not within a second predetermined range.

[0102] Specifically, the faults include leakage faults and blockage faults. That is, when the target nozzle experiences a leakage fault or a blockage fault, the second rate of change is not within the second predetermined range. Generally, when the target nozzle experiences a leakage fault, the second rate of change is greater than the maximum value of the second predetermined range; when the target nozzle experiences a blockage fault, the second rate of change is less than the minimum value of the second predetermined range. Those skilled in the art can set the boundary values ​​of the second predetermined range based on empirical values, or they can determine, through multiple experiments, the critical pressure value in the pumping equipment that satisfies the condition that the nozzle does not experience a fault as the boundary value of the second predetermined range.

[0103] In this embodiment, when the pressure value of the pumping equipment is stable, the two nozzles are closed by the shut-off unit to adjust the pressure value of the pumping equipment and obtain a first rate of change of pressure value during the adjustment process; the first determination unit determines whether the flow structure, including the pumping equipment, the unidirectional return structure, the pumping pipeline, and the return pipeline, has malfunctioned based on the magnitude of the first rate of change; the first opening unit opens one nozzle for urea injection when the flow structure has not malfunctioned and the pressure value is stable; the first acquisition unit obtains a second rate of change of pressure value of the opened nozzle during urea injection; and the second determination unit determines whether the opened nozzle has malfunctioned based on the second rate of change. Compared to the difficulty in timely detection of SCR dual-injection urea equipment faults in existing technologies, this application determines whether there is a fault in the flow structure of the SCR dual-injection urea equipment by closing both nozzles and detecting pressure changes in the pumping equipment. When no fault is found, one nozzle is opened, and the pressure changes in the pumping equipment are used to detect whether the nozzle is faulty. This achieves automatic detection of faults in the SCR dual-injection urea equipment, enabling timely detection of faults. Furthermore, when a fault occurs, it can be located whether the fault lies in the flow structure or the nozzle, facilitating subsequent fault handling and maintenance. This effectively solves the problem of difficulty in timely detection of SCR dual-injection urea equipment faults.

[0104] Furthermore, the device also includes a termination unit for ending the diagnostic process in the event of a malfunction in the flow structure. Since, when a malfunction occurs in the flow structure, subsequent nozzle testing cannot determine whether the malfunction is caused by the flow structure or the nozzle, diagnostics are discontinued until the malfunction in the flow structure is resolved before resuming testing.

[0105] It should be noted that, compared to the approach of first testing the nozzle and then testing the flow structure, if a fault is determined when testing the nozzle, it is impossible to determine whether the fault is caused by the nozzle itself or by the flow structure. If a fault is determined when testing the flow structure later, it is also impossible to determine whether the nozzle is faulty. However, the approach described in this application can first determine whether the flow structure is faulty. This test result is not affected by whether the nozzle is faulty. If the flow structure is ruled out as faulty, the nozzle can then be tested. This approach can pinpoint the fault location once the fault is determined.

[0106] In one alternative embodiment, the shut-off unit includes:

[0107] The first acquisition module is used to acquire the pressure value when both nozzles are closed, and obtain the first pressure;

[0108] A reduction module is used to reduce the duty cycle of the pumping equipment to a preset duty cycle in order to adjust the pressure value;

[0109] The first determining module is used to determine that the adjustment is complete when the rate of change of the adjusted pressure value is less than a third preset value, and to obtain the pressure value corresponding to the condition that the adjustment is complete, thereby obtaining the second pressure.

[0110] Specifically, if the rate of change of the adjusted pressure value is less than a preset value, it indicates that the pressure value in the pumping equipment is basically stable.

[0111] The second determining module is used to determine, based on the first pressure, the second pressure, and the first interval duration, the ratio of the difference between the first pressure and the second pressure to the first interval duration as the first rate of change, wherein the first interval duration is the acquisition interval duration between the first pressure and the second pressure.

[0112] In the embodiment described above, the pressure value is obtained with both nozzles closed to obtain the first pressure. Then, the duty cycle of the pumping equipment is reduced to reduce the pressure in the pumping equipment. When the pressure value is stable, the current pressure value is obtained to obtain the second pressure. The first rate of change is obtained by comparing the rate of change of the second pressure with the first pressure. The first rate of change can be obtained relatively simply and easily.

[0113] In addition to the methods described above, adjusting the pressure value of the pumping equipment and obtaining the rate of change of the pressure value during the adjustment process to obtain a first rate of change may further include: reducing the duty cycle of the pumping equipment to a preset duty cycle to adjust the pressure value; acquiring the pressure value in the pumping equipment after the pressure value is adjusted in real time, obtaining multiple pressure values ​​and the acquisition time corresponding to the pressure values; stopping the acquisition of the pressure value when the rate of change of the adjusted pressure value is less than a third preset value; calculating the pressure change rate corresponding to each pair of adjacent acquisition times based on the acquired multiple pressure values ​​and the corresponding acquisition times, and calculating the average of the multiple pressure change rates to obtain the first rate of change. This allows for a more accurate determination of the first rate of change.

[0114] Optionally, the device further includes: a first control unit, used to control the duty cycle of the pumping equipment to an initial duty cycle before opening the target nozzle to inject urea; a second opening unit, used in the second opening step to open the two nozzles and control the duty cycle of the two nozzles according to the required urea injection volume, so that the two nozzles inject urea according to the required urea injection volume; and a third determining unit, used in the third determining step to determine whether the rate of change of the pressure value is less than the second preset value. In this embodiment, when the flow structure is not faulty, the control step, the second opening step, and the third determining step are used to perform normal urea injection control on the SCR dual-injection urea equipment, so that the pressure value in the pumping equipment tends to stabilize, providing a suitable environment for the subsequent diagnostic stage.

[0115] Specifically, the first opening unit includes a holding module, used to keep the target nozzle open and close the other nozzle besides the target nozzle while keeping the duty cycle of the pumping equipment constant. That is, to keep the duty cycle of the pumping equipment at the duty cycle value corresponding to the rate of change of the pressure value being less than a second preset value, and to detect the nozzle.

[0116] To further simplify the acquisition of the second rate of change, in some alternative solutions of this application, the first acquisition unit includes: a second acquisition module, configured to acquire the pressure value when the target nozzle is open, obtain a third pressure, and continue to acquire multiple pressure values ​​to obtain multiple fourth initial pressures; a third determination module, configured to determine the fourth initial pressure with a rate of change less than the fourth preset value as the fourth pressure when the rate of change of the fourth initial pressure is less than the fourth preset value, indicating that the pressure value has stabilized; and a fourth determination unit, configured to determine the ratio of the difference between the third pressure and the fourth pressure to the second interval time as the second rate of change based on the third pressure, the fourth pressure, and the second interval time, wherein the second interval time is the acquisition interval time between the third pressure and the fourth pressure.

[0117] Of course, besides the method described above, those skilled in the art can also use other methods to obtain the second rate of change. In some other embodiments, the first acquisition unit may further include: a third acquisition module, used to acquire the pressure value in the pumping equipment and the acquisition time corresponding to the pressure value in real time; a stop module, used to stop acquiring the pressure value when the acquired rate of change of the pressure value is less than a fourth preset value; and a calculation module, used to calculate the pressure rate of change corresponding to each two adjacent acquisition times based on the acquired multiple pressure values ​​and the corresponding acquisition times, and calculate the average of the multiple pressure rate of change to obtain the second rate of change. This can obtain the second rate of change more accurately.

[0118] According to some other exemplary embodiments of this application, the device further includes: a third opening unit, configured to execute a third opening step after the second determining step, to determine that the other of the two nozzles is the target nozzle; and a looping unit, configured to loop the control step, the second opening step, the third determining step, the first opening step, the acquisition step, and the second determining step once to determine whether the target nozzle has malfunctioned. After checking whether one of the nozzles is malfunctioning, through the above embodiment, the normal operation of the SCR dual-injection urea equipment is restored first, and then the other nozzle is tested to detect whether the other nozzle is malfunctioning, thereby achieving timely detection of malfunctions in the SCR dual-injection urea equipment and further facilitating subsequent fault handling and maintenance.

[0119] In another alternative embodiment, such as Figure 5As shown, one nozzle 301 is used to inject urea into the pre-stage SCR unit 401, and another nozzle 301 is used to inject urea into the post-stage SCR unit 405. The pre-stage SCR unit 401 and the post-stage SCR unit 405 are connected and spaced apart along a distance from the turbine outlet. The device also includes:

[0120] The second acquisition unit is used to acquire, before the shutdown step, the temperature of the pre-stage SCR device, the temperature of the post-stage SCR device, the cumulative urea injection volume of the two nozzles, the exhaust gas flow rate of the engine, the pressure value, and the average conversion efficiency of the pre-stage SCR device and the post-stage SCR device.

[0121] Specifically, the cumulative urea injection quantity is the cumulative injection quantity recorded by the ECU after each ECU power-on; the average conversion efficiency is the average of the conversion efficiency of the pre-stage SCR device and the conversion efficiency of the post-stage SCR device. The conversion efficiency of the pre-stage SCR device can be obtained by detecting the NOx concentration after treatment by the pre-stage SCR device using a first NOx sensor located after the pre-stage SCR device, and dividing the NOx concentration by the original NOx concentration in the engine exhaust; the conversion efficiency of the post-stage SCR device can be obtained by detecting the NOx concentration after treatment by the post-stage SCR device using a second NOx sensor located after the post-stage SCR device, and dividing the NOx concentration by the NOx concentration detected by the first NOx sensor.

[0122] The second control unit is used to control the duty cycle of the pumping equipment to an initial duty cycle when the SCR dual-injection urea equipment meets the detection conditions, wherein the detection conditions include at least the following: the temperature of the pre-stage SCR equipment is within a predetermined temperature range, the temperature of the post-stage SCR equipment is within the predetermined temperature range, the cumulative urea injection volume is greater than a fifth preset value, the exhaust gas flow rate is within a third predetermined range, the pressure value is within a fourth predetermined range, and the average conversion efficiency is greater than a sixth predetermined value.

[0123] Specifically, the detection conditions may include all or only some of the conditions, and those skilled in the art can flexibly set them according to actual conditions. In this application, the detection conditions include the temperature of the pre-stage SCR equipment being within a predetermined temperature range, the temperature of the post-stage SCR equipment being within the predetermined temperature range, the cumulative urea injection volume being greater than a fifth preset value, the exhaust gas flow rate being within a third predetermined range, the pressure value being within a fourth predetermined range, and the average conversion efficiency being greater than a sixth predetermined value. That is to say, the diagnostic stage only begins when all the conditions are met.

[0124] The fourth opening unit is used to open the two nozzles and control the duty cycle of the two nozzles according to the required urea injection volume, so that the two nozzles inject urea according to the required urea injection volume.

[0125] The fifth determining unit is used to determine whether the rate of change of the pressure value is less than the first preset value.

[0126] In the embodiments described in this application, before fault diagnosis, it is first detected whether the vehicle meets at least some of the detection conditions. If it is determined that the vehicle meets at least some of the detection conditions, it indicates that the SCR dual-injection urea equipment may be faulty. At this time, normal urea injection control is performed on the SCR dual-injection urea equipment to stabilize the pressure value in the pumping equipment and provide a suitable environment for the subsequent diagnosis stage.

[0127] In practical applications, if the SCR dual-injection urea equipment does not meet the detection conditions, the system continues to determine whether the SCR dual-injection urea equipment meets the detection conditions until the SCR dual-injection urea equipment meets the detection conditions.

[0128] Specifically, the device further includes: a first generation unit, configured to generate first fault information characterizing the failure of the flow structure when a failure occurs, and send the first fault information to a terminal; the device further includes: a disabling unit, configured to disable urea injection from the target nozzle when a failure is determined to have occurred; and a second generation unit, configured to generate second fault information characterizing the failure of the target nozzle, and send the second fault information to the terminal. In this embodiment, by generating the first fault information and the second fault information and sending them to the terminal, relevant personnel can promptly understand the fault status of the SCR dual-injection urea equipment through the terminal, further facilitating timely response and handling of faults.

[0129] Furthermore, when nozzle 1 fails, nozzle 1 is disabled while nozzle 2 remains operational; when nozzle 2 fails, nozzle 2 is disabled while nozzle 1 remains operational.

[0130] The device further includes: a first issuing unit for issuing a first alarm signal in the event of a malfunction in the flow structure; the device further includes: a second issuing unit for issuing a second alarm signal in the event of a malfunction in the target nozzle.

[0131] The diagnostic device of the SCR dual-injection urea equipment includes a processor and a memory. The shutdown unit, the first determining unit, the first turning-on unit, the first acquiring unit, and the second determining unit are all stored as program units in the memory. The processor executes the program units stored in the memory to achieve the corresponding functions. All modules are located in the same processor; or, the modules are located in different processors in any combination.

[0132] The processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured, and adjusting kernel parameters can at least address the problem of timely detection of faults in SCR dual-injection urea equipment, a problem present in current technologies.

[0133] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0134] This invention provides a computer-readable storage medium including a stored program, wherein the program, when running, controls the device containing the computer-readable storage medium to perform a diagnostic method for the SCR dual-injection urea device.

[0135] Specifically, the diagnostic methods for SCR dual-injection urea equipment include:

[0136] Step S201, Closing Step: When the rate of change of the pressure value of the pumping equipment is less than a first preset value, close the two nozzles, adjust the pressure value of the pumping equipment, and obtain the rate of change of the pressure value during the adjustment process to obtain the first rate of change;

[0137] Specifically, if the rate of change of the pressure value in the pumping equipment is less than the first preset value, it indicates that the pressure value in the pumping equipment is basically stable. Those skilled in the art can flexibly set the specific value of the first preset value according to actual needs; this application does not impose specific limitations in this regard.

[0138] Step S202, first determining step: determine whether the flow structure has failed based on the first rate of change; if the first rate of change is not within a first predetermined range, determine that the flow structure has failed; if the first rate of change is within the first predetermined range, determine that the flow structure has not failed.

[0139] Specifically, the faults include leakage faults and blockage faults. That is, if at least one of the pumping equipment, the one-way return structure, the pumping pipeline, and the return pipeline experiences a leakage fault or a blockage fault, the first rate of change is not within the first predetermined range. Generally, such as Figure 4 As shown, in the case of a leakage failure in the flow structure, the first rate of change corresponds to the maximum value of the first predetermined range; in the case of a blockage failure in the flow structure, the first rate of change corresponds to the minimum value of the first predetermined range. Those skilled in the art can set the boundary values ​​of the first predetermined range based on empirical values, or they can determine, through multiple experiments, the critical pressure value in the pumping equipment that satisfies the condition that the flow structure does not fail, as the boundary value of the first predetermined range.

[0140] Step S203, first opening step: when the flow structure has not failed and the rate of change of the pressure value is less than the second preset value, the target nozzle is opened to spray the urea, and the target nozzle is one of the two nozzles;

[0141] Specifically, when the rate of change of the pressure value is less than the second preset value, it indicates that the pressure value in the pumping equipment is basically stable. Those skilled in the art can flexibly set the specific value of the second preset value according to actual needs; this application does not impose specific limitations in this regard.

[0142] Step S204, the acquisition step, acquires the rate of change of the pressure value during the process of the target nozzle injecting the urea, and obtains the second rate of change;

[0143] Step S205, second determination step: determine whether the target nozzle has malfunctioned based on the second rate of change; if the second rate of change is not within a second predetermined range, determine that the target nozzle has malfunctioned.

[0144] Specifically, the faults include leakage faults and blockage faults. That is, when the target nozzle experiences a leakage fault or a blockage fault, the second rate of change is not within the second predetermined range. Generally, when the target nozzle experiences a leakage fault, the second rate of change is greater than the maximum value of the second predetermined range; when the target nozzle experiences a blockage fault, the second rate of change is less than the minimum value of the second predetermined range. Those skilled in the art can set the boundary values ​​of the second predetermined range based on empirical values, or they can determine, through multiple experiments, the critical pressure value in the pumping equipment that satisfies the condition that the nozzle does not experience a fault as the boundary value of the second predetermined range.

[0145] Optionally, adjusting the pressure value of the pumping device and obtaining the rate of change of the pressure value during the adjustment process to obtain a first rate of change includes: obtaining the pressure value when both nozzles are closed to obtain a first pressure; reducing the duty cycle of the pumping device to a preset duty cycle to adjust the pressure value; determining that the adjustment is complete when the rate of change of the adjusted pressure value is less than a third preset value, and obtaining the pressure value corresponding to the completed adjustment to obtain a second pressure; and determining the ratio of the difference between the first pressure and the second pressure to the first interval duration as the first rate of change based on the first pressure, the second pressure, and a first interval duration, wherein the first interval duration is the acquisition interval duration between the first pressure and the second pressure.

[0146] Optionally, before opening the target nozzle to spray the urea, the method further includes: a control step, controlling the duty cycle of the pumping equipment to an initial duty cycle; a second opening step, opening the two nozzles and controlling the duty cycle of the two nozzles according to the required urea injection volume, so that the two nozzles spray the urea according to the required urea injection volume; and a third determining step, determining whether the rate of change of the pressure value is less than the second preset value.

[0147] Optionally, opening the target nozzle to spray the urea includes: keeping the target nozzle open while controlling the duty cycle of the pumping equipment to remain constant, and closing the other nozzle besides the target nozzle. The acquisition step includes: acquiring the pressure value when the target nozzle is open to obtain a third pressure, and continuing to acquire multiple pressure values ​​to obtain multiple fourth initial pressures; if the rate of change of the fourth initial pressure is less than a fourth preset value, determining the fourth initial pressure whose rate of change is less than the fourth preset value as the fourth pressure; and determining the ratio of the difference between the third pressure and the fourth pressure to the second interval time as the second rate of change based on the third pressure, the fourth pressure, and the second interval time, where the second interval time is the acquisition interval time between the third pressure and the fourth pressure.

[0148] Optionally, after the second determining step, the method further includes: a third opening step, determining that the other of the two nozzles is the target nozzle; and a looping step, cyclically executing the control step, the second opening step, the third determining step, the first opening step, the acquisition step, and the second determining step once to determine whether the target nozzle has malfunctioned.

[0149] Optionally, one nozzle is used to inject urea into the pre-stage SCR unit, and the other nozzle is used to inject urea into the post-stage SCR unit. The pre-stage and post-stage SCR units are connected and spaced apart along a distance from the turbine outlet. Before the shut-off step, the method further includes: acquiring the temperature of the pre-stage SCR unit, the temperature of the post-stage SCR unit, the cumulative urea injection quantity of the two nozzles, the exhaust gas flow rate of the engine, the pressure value, and the average conversion efficiency of the pre-stage and post-stage SCR units; and controlling the pumping device when the dual-injection urea SCR unit meets the detection conditions. The duty cycle of the equipment is the initial duty cycle, wherein the detection conditions include at least the following: the temperature of the pre-stage SCR equipment is within a predetermined temperature range, the temperature of the post-stage SCR equipment is within the predetermined temperature range, the cumulative urea injection volume is greater than a fifth preset value, the exhaust gas flow rate is within a third predetermined range, the pressure value is within a fourth predetermined range, and the average conversion efficiency is greater than a sixth predetermined value; the two nozzles are opened, and the duty cycle of the two nozzles is controlled according to the required urea injection volume, so that the two nozzles inject urea according to the required urea injection volume; it is determined whether the rate of change of the pressure value is less than the first preset value.

[0150] Optionally, in the event of a failure in the flow structure, the method further includes: generating first fault information characterizing the failure of the flow structure and sending the first fault information to a terminal; and in the event that the target nozzle has failed, the method further includes: disabling the target nozzle from injecting urea; generating second fault information characterizing the failure of the target nozzle and sending the second fault information to the terminal.

[0151] This invention provides a processor for running a program, wherein the program executes a diagnostic method for the SCR dual-injection urea device.

[0152] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps:

[0153] Step S201, Closing Step: When the rate of change of the pressure value of the pumping equipment is less than a first preset value, close the two nozzles, adjust the pressure value of the pumping equipment, and obtain the rate of change of the pressure value during the adjustment process to obtain the first rate of change;

[0154] Step S202, first determining step: determine whether the flow structure has failed based on the first rate of change; if the first rate of change is not within a first predetermined range, determine that the flow structure has failed; if the first rate of change is within the first predetermined range, determine that the flow structure has not failed.

[0155] Step S203, first opening step: when the flow structure has not failed and the rate of change of the pressure value is less than the second preset value, the target nozzle is opened to spray the urea, and the target nozzle is one of the two nozzles;

[0156] Step S204, the acquisition step, acquires the rate of change of the pressure value during the process of the target nozzle injecting the urea, and obtains the second rate of change;

[0157] Step S205, second determination step: determine whether the target nozzle has malfunctioned based on the second rate of change; if the second rate of change is not within a second predetermined range, determine that the target nozzle has malfunctioned.

[0158] The devices mentioned in this article can be servers, PCs, tablets, mobile phones, etc.

[0159] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps:

[0160] Step S201, Closing Step: When the rate of change of the pressure value of the pumping equipment is less than a first preset value, close the two nozzles, adjust the pressure value of the pumping equipment, and obtain the rate of change of the pressure value during the adjustment process to obtain the first rate of change;

[0161] Step S202, first determining step: determine whether the flow structure has failed based on the first rate of change; if the first rate of change is not within a first predetermined range, determine that the flow structure has failed; if the first rate of change is within the first predetermined range, determine that the flow structure has not failed.

[0162] Step S203, first opening step: when the flow structure has not failed and the rate of change of the pressure value is less than the second preset value, the target nozzle is opened to spray the urea, and the target nozzle is one of the two nozzles;

[0163] Step S204, the acquisition step, acquires the rate of change of the pressure value during the process of the target nozzle injecting the urea, and obtains the second rate of change;

[0164] Step S205, second determination step: determine whether the target nozzle has malfunctioned based on the second rate of change; if the second rate of change is not within a second predetermined range, determine that the target nozzle has malfunctioned.

[0165] According to another aspect of this application, a vehicle is also provided, comprising:

[0166] like Figure 2 The SCR dual-injection urea equipment shown includes a urea storage device 300, a flow structure, and two nozzles 301. The flow structure includes a pumping device 302, a one-way return structure 303, a pumping pipeline 304, and a return pipeline 305. The first end of the pumping device 302 is connected to the urea storage device 300 through the pumping pipeline 304 and the return pipeline 305, respectively. The one-way return structure 303 is located on the return pipeline 305. When the fluid in the return pipeline 305 flows from the pumping device 302 to the urea storage device 300, the one-way return structure is open. When the fluid in the return pipeline 305 flows from the urea storage device 300 to the pumping device 302, the one-way return structure is closed. The second end of the pumping device 302 is connected to the two nozzles 301.

[0167] One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include methods for performing any one of the methods described.

[0168] The vehicle described herein, by operating the method described above, closes two nozzles and detects pressure changes in the pumping equipment to determine whether there is a fault in the flow structure of the SCR dual-injection urea equipment. When no fault is found, it opens one nozzle and detects whether the nozzle is faulty based on pressure changes in the pumping equipment. This achieves automatic detection of faults in the SCR dual-injection urea equipment, enabling timely detection of faults and pinpointing whether the fault lies in the flow structure or the nozzle when it occurs. This facilitates subsequent fault handling and maintenance, effectively solving the problem of difficulty in timely detection of faults in the SCR dual-injection urea equipment.

[0169] In one alternative, such as Figure 2As shown, the pumping device 302 includes a pump motor 306 and a pump pressure chamber 307. The first end of the pump pressure chamber 307 is connected to the urea storage device 300 through the pumping pipeline 304 and the return pipeline 305, respectively. The pump motor 306 is located on the pumping pipeline 304. The SCR dual-injection urea device also includes a pressure sensor 308. The pump motor 306 draws urea from the urea storage device 300 into the pump pressure chamber 307. The pressure sensor 308 monitors the pressure value of the pumping device 302. Most of the urea in the pump pressure chamber 307 is periodically injected into the exhaust tailpipe by controlling the duty cycle of the two nozzles 301. A small portion of the urea in the pump pressure chamber 307 is returned to the urea storage device 300 through the one-way return structure 303. The one-way return structure 303 can be a one-way return valve or a one-way return orifice.

[0170] In practical applications, the vehicle also includes a dual SCR system, the structure of which is shown in the diagram below. Figure 5As shown, the system specifically includes, in sequence along the direction away from the turbine, a first mixer 400, a pre-stage SCR device 401, a DOC (Diesel Oxide Catalyst) 402, a DPF (Diesel Particulate Filter) 403, a second mixer 404, a post-stage SCR device 405, and an ASC (Ammonia Scrubber Condensate) 406. The dual SCR system also includes a first temperature sensor 407 before the pre-stage SCR device 401, a second temperature sensor 408 before the DPF 403, a third temperature sensor 409 before the second mixer 404, a first NOx sensor 410, and a second NOx sensor 411 after the ASC 406. One nozzle 301 is connected to the first mixer 400 for injecting urea into the first mixer 400, and the other nozzle 301 is connected to the second mixer 404 for injecting urea into the second mixer 404. The pre-stage SCR unit 401 performs a first catalytic reduction on the exhaust gas to reduce nitrogen oxides. DOC 402 converts NO in the exhaust gas to NO2, while simultaneously increasing the exhaust gas temperature to assist the DPF 403 and the subsequent SCR unit 405 in their normal operation. The DPF 403 captures particulate matter in the exhaust gas; when the captured particulate matter reaches a certain level, passive or active regeneration is required to restore the DPF 403's particulate matter capture capacity. The subsequent SCR unit 405 performs a second catalytic reduction on the exhaust gas to further reduce nitrogen oxides. ASC 406 oxidizes excess ammonia. The first temperature sensor 407, the second temperature sensor 408, and the third temperature sensor 409 collect the temperature value at the installation location. The first NOx sensor 410 and the second NOx sensor 411 detect the NOx concentration.

[0171] In practical applications, DOC (Dry Oxide Catalyst) is formed by coating a honeycomb ceramic carrier with a noble metal catalyst (such as Pt). The purpose is to lower the activation energy of the chemical reactions of HC, CO, and SOF in engine exhaust, allowing these substances to react with oxygen in the exhaust at a lower temperature and ultimately convert into CO2 and H2O. DOC does not require a regeneration system or control device, and is characterized by its simple structure and high reliability. It has already found some application in modern small engines.

[0172] DPF (Diffusion-Powered Filter) primarily filters and traps particulate matter in engine exhaust through diffusion, deposition, and impaction mechanisms. As exhaust flows through the filter, particulate matter is trapped within the filter element, leaving the cleaner exhaust to be released into the atmosphere. Currently, wall-flow honeycomb ceramic filters are widely used, mainly in construction machinery and city buses. They are characterized by simple operation and high filtration efficiency, but suffer from issues such as filter regeneration and sensitivity to sulfur in fuel.

[0173] The basic working principle of DPF is as follows: When engine exhaust flows through DOC, under temperature conditions of 200-600℃, CO and HC are almost entirely oxidized into CO2 and H2O, while NO is converted into NO2. After the exhaust exits DOC and enters DPF, the particulate matter is captured in the filter element, and the remaining cleaner exhaust is discharged into the atmosphere. The capture efficiency of DPF can reach over 90%.

[0174] NO2 has a strong oxidizing ability on the captured particles. The generated NO2 is used as an oxidant to remove particles from the particulate trap and generate CO2. The NO2 is then reduced to NO, thereby achieving the purpose of removing particles.

[0175] The reaction principle within the DOC is as follows:

[0176] 2NO+O2→2NO2; 2CO+O2→2CO2; 2CH+O2→CO2+H2O.

[0177] The internal reaction principle of DPF is as follows:

[0178] C + 2NO₂ → CO₂ + 2NO

[0179] There are two methods for filter regeneration: active regeneration and passive regeneration. Active regeneration refers to using external energy to raise the temperature inside the filter, causing the particulate matter to ignite and burn. When the temperature inside the filter reaches 550°C, the deposited particulate matter will oxidize and burn. If the temperature does not reach 550°C, excessive deposits will clog the filter. In this case, external energy (such as an electric heater, burner, or changes in engine operating conditions) is needed to raise the temperature inside the DPF to oxidize and burn the particulate matter. Passive regeneration refers to using fuel additives or catalysts to lower the ignition temperature of the particulate matter, allowing it to ignite and burn at normal engine exhaust temperatures. Additives (such as cerium, iron, and strontium) must be added to the fuel in a certain proportion. Too much additive has little effect, but too little will lead to delayed regeneration or an increased regeneration temperature.

[0180] The basic principle of SCR is to inject fuel or add a reducing agent into the exhaust gas, using a suitable catalyst to promote the reaction between the reducing agent and NOx, while inhibiting the non-selective oxidation reaction between the reducing agent and oxygen. Commonly used urea-SCR catalysts include V2O5 / W2O3 / TiO2 and metal oxide / zeolite. Vanadium-based catalysts have high selectivity for NOx and a wide efficient temperature window, as well as high sulfur resistance. Their disadvantages are susceptibility to poisoning by phosphorus components in lubricating oil and high-temperature failure. Zeolite catalysts have extremely strong adsorption capacity for NH3, but at low temperatures, zeolite also has a strong adsorption capacity for HC. HC adsorption affects the low-temperature performance of the catalyst. Furthermore, zeolite has poor hydrothermal stability and sulfur resistance, thus limiting its practical application and requiring the use of low-sulfur fuels.

[0181] Sulfur oxides in copper-based SCRs form sulfates, reducing catalyst active sites, clogging pores, and decreasing the SCR's NOx conversion efficiency. Therefore, once a certain amount of sulfur oxides are captured within the SCR, desulfurization is necessary. Sulfur poisoning has two mechanisms: the formation of (NH4)SO4, etc., reducing SCR catalyst active sites and clogging pores, thereby decreasing NOx conversion efficiency; and SO2 and SO3 competing with NOx for adsorption, reducing NOx adsorption.

[0182] The reaction principles of the catalytic reduction technology in the pre-stage SCR equipment and the post-stage SCR equipment are as follows:

[0183] Urea hydrolyzes into ammonia (urea injection system): (NH2)2CO + H2O → 2NH3 + CO2;

[0184] SCR post-processing reactions (SCR catalytic converter): NO + NO2 + 2NH3 → 2N2 + 3H2O; 4NO + O2 + 4NH3 → 4N2 + 6H2O; 2NO2 + O2 + 4NH3 → 3N2 + 6H2O.

[0185] In SCR (Selective Catalytic Reduction), the actual reducing agent participating in the selective catalytic reduction reaction is ammonia (NH3). However, due to the high corrosiveness of ammonia, liquid ammonia and ammonia water present difficulties in storage and transportation, and therefore cannot be directly used in vehicle-mounted SCR systems. Currently, urea aqueous solution is generally used as the reducing agent. Furthermore, because a 32.5% urea aqueous solution has the lowest freezing point of -11℃ compared to other concentrations, it is internationally adopted as the standard reducing agent for SCR and named AdBlue.

[0186] It will be apparent to those skilled in the art that the modules or steps of the present invention can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using device-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular hardware and software combination.

[0187] 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.

[0188] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or 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, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0189] 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 / or boxes Figure 1 The function specified in one or more boxes.

[0190] 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 / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0191] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0192] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0193] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0194] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0195] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A diagnostic method for an SCR dual-injection urea equipment, the SCR dual-injection urea equipment comprising a urea storage device, a flow structure, and two nozzles, the flow structure comprising a pumping device, a one-way recirculation structure, a pumping pipeline, and a recirculation pipeline, the first end of the pumping device being connected to the urea storage device via the pumping pipeline and the recirculation pipeline respectively, the one-way recirculation structure being located on the recirculation pipeline, the one-way recirculation structure being activated when fluid in the recirculation pipeline flows from the pumping device to the urea storage device, and the second end of the pumping device being connected to the two nozzles, characterized in that... The method includes: In the closing step, if the rate of change of the pressure value of the pumping equipment is less than a first preset value, the two nozzles are closed, the pressure value of the pumping equipment is adjusted, and the rate of change of the pressure value during the adjustment process is obtained to obtain the first rate of change. The first determining step involves determining whether the circulation structure has malfunctioned based on the first rate of change. If the first rate of change is not within a first predetermined range, the circulation structure is determined to have malfunctioned. If the first rate of change is within the first predetermined range, the circulation structure is determined not to have malfunctioned. In the first activation step, if the flow structure is not faulty and the rate of change of the pressure value is less than the second preset value, the target nozzle is activated to spray the urea, wherein the target nozzle is one of the two nozzles. The acquisition step involves acquiring the rate of change of the pressure value during the process of the target nozzle injecting urea, thereby obtaining a second rate of change. The second determining step involves determining whether the target nozzle has malfunctioned based on the second rate of change. If the second rate of change is not within a second predetermined range, the target nozzle is determined to have malfunctioned.

2. The method according to claim 1, characterized in that, Adjusting the pressure value of the pumping equipment and obtaining the rate of change of the pressure value during the adjustment process to obtain a first rate of change includes: The pressure value is obtained when both nozzles are closed, to obtain the first pressure; The duty cycle of the pumping equipment is reduced to a preset duty cycle to adjust the pressure value; If the rate of change of the adjusted pressure value is less than a third preset value, the adjustment is determined to be complete, and the corresponding pressure value under the condition of complete adjustment is obtained to obtain the second pressure; Based on the first pressure, the second pressure, and the first interval duration, the ratio of the difference between the first pressure and the second pressure to the first interval duration is determined as the first rate of change, where the first interval duration is the acquisition interval duration between the first pressure and the second pressure.

3. The method according to claim 1, characterized in that, Before opening the target nozzle to spray the urea, the method further includes: The control step involves controlling the duty cycle of the pumping equipment to the initial duty cycle. The second starting step involves opening the two nozzles and controlling the duty cycle of the two nozzles according to the required urea injection volume, so that the two nozzles inject urea according to the required urea injection volume. The third determination step is to determine whether the rate of change of the pressure value is less than the second preset value.

4. The method according to claim 3, characterized in that, Opening the target nozzle to spray the urea includes: While keeping the duty cycle of the pumping equipment constant, the target nozzle remains open, and the other nozzle is closed. The acquisition steps include: The pressure value is obtained when the target nozzle is open, to obtain a third pressure, and multiple pressure values ​​are obtained to obtain multiple fourth initial pressures; If the rate of change of the fourth initial pressure is less than a fourth preset value, the fourth initial pressure whose rate of change is less than the fourth preset value is determined to be the fourth pressure. Based on the third pressure, the fourth pressure, and the second interval duration, the ratio of the difference between the third pressure and the fourth pressure to the second interval duration is determined as the second rate of change, whereby the second interval duration is the acquisition interval duration between the third pressure and the fourth pressure.

5. The method according to claim 3, characterized in that, Following the second determining step, the method further includes: The third activation step involves determining that the other of the two nozzles is the target nozzle. The looping step involves repeatedly executing the control step, the second activation step, the third determination step, the first activation step, the acquisition step, and the second determination step once to determine whether the target nozzle has malfunctioned.

6. The method according to any one of claims 1 to 5, characterized in that, One of the nozzles is used to inject the urea into a pre-stage SCR unit, and the other nozzle is used to inject the urea into a post-stage SCR unit. The pre-stage and post-stage SCR units are connected and spaced apart along a distance from the turbine outlet. Prior to the shut-down step, the method further includes: The temperature of the pre-stage SCR device, the temperature of the post-stage SCR device, the cumulative urea injection volume of the two nozzles, the exhaust gas flow rate of the engine, the pressure value, and the average conversion efficiency of the pre-stage SCR device and the post-stage SCR device are obtained. When the SCR dual-injection urea equipment meets the detection conditions, the duty cycle of the pumping equipment is controlled to the initial duty cycle. The detection conditions include at least the following: the temperature of the pre-stage SCR equipment is within a predetermined temperature range; the temperature of the post-stage SCR equipment is within the predetermined temperature range; the cumulative urea injection volume is greater than a fifth preset value; the exhaust gas flow rate is within a third predetermined range; the pressure value is within a fourth predetermined range; and the average conversion efficiency is greater than a sixth predetermined value. Open the two nozzles and control the duty cycle of the two nozzles according to the required urea injection volume, so that the two nozzles inject urea according to the required urea injection volume; Determine whether the rate of change of the pressure value is less than the first preset value.

7. The method according to any one of claims 1 to 5, characterized in that, In the event of a failure in the circulation structure, the method further includes: generating first fault information characterizing the failure of the circulation structure, and sending the first fault information to a terminal. If it is determined that the target nozzle has malfunctioned, the method further includes: disabling the target nozzle from injecting urea; generating second fault information characterizing the malfunction of the target nozzle; and sending the second fault information to the terminal.

8. A diagnostic device for an SCR dual-injection urea equipment, the SCR dual-injection urea equipment comprising a urea storage device, a flow structure, and two nozzles, the flow structure comprising a pumping device, a one-way reflux structure, a pumping pipeline, and a reflux pipeline, the first end of the pumping device being connected to the urea storage device via the pumping pipeline and the reflux pipeline respectively, the one-way reflux structure being located on the reflux pipeline, the one-way reflux structure being activated when fluid in the reflux pipeline flows from the pumping device to the urea storage device, and the second end of the pumping device being connected to the two nozzles, characterized in that... The device includes: The shut-off unit is used for the shut-off step. When the rate of change of the pressure value of the pumping equipment is less than a first preset value, the two nozzles are shut off, the pressure value of the pumping equipment is adjusted, and the rate of change of the pressure value during the adjustment process is obtained to obtain the first rate of change. The first determining unit is used in the first determining step to determine whether the circulation structure has failed based on the first rate of change; if the first rate of change is not within a first predetermined range, the circulation structure is determined to have failed; if the first rate of change is within the first predetermined range, the circulation structure is determined not to have failed. The first opening unit is used in the first opening step to open the target nozzle to spray urea when the flow structure is not faulty and the rate of change of the pressure value is less than a second preset value. The target nozzle is one of the two nozzles. The first acquisition unit is used for the acquisition step, acquiring the rate of change of the pressure value during the process of the target nozzle injecting the urea, and obtaining a second rate of change; The second determining unit is used in the second determining step to determine whether the target nozzle has malfunctioned based on the second rate of change, and to determine that the target nozzle has malfunctioned if the second rate of change is not within a second predetermined range.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 7.

10. A vehicle, characterized in that, include: The SCR dual-injection urea equipment includes a urea storage device, a flow structure, and two nozzles. The flow structure includes a pumping device, a one-way reflux structure, a pumping pipeline, and a reflux pipeline. The first end of the pumping device is connected to the urea storage device through the pumping pipeline and the reflux pipeline, respectively. The one-way reflux structure is located on the reflux pipeline. When the fluid in the reflux pipeline flows from the pumping device to the urea storage device, the one-way reflux structure is activated. The second end of the pumping device is connected to the two nozzles. One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising methods for performing any one of claims 1 to 7.

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