Leakage diagnosis method and device of DPF regeneration injection system, vehicle and medium

Abstract

The invention provides a leakage diagnosis method and device of a DPF regeneration injection system, a vehicle and a medium, and belongs to the technical field of tail gas after-treatment.The DPF regeneration injection system is used for injecting fuel oil to a tail gas after-treatment system, and the tail gas after-treatment system comprises an oxidation type catalyst and a diesel particulate filter which are sequentially connected; the method comprises the following steps: acquiring a first inlet temperature of an oxidation catalyst and a second inlet temperature of a diesel particulate filter; whether the temperature difference between the first inlet temperature and the second inlet temperature is larger than a temperature difference threshold value or not is judged; and if yes, leakage diagnosis is conducted on the DPF regeneration injection system. According to the invention, the diagnosis frequency of leakage diagnosis is reduced, fuel oil waste and fuel oil adhesion accumulation in the tail gas after-treatment system are avoided, and the safety of the tail gas after-treatment system is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of exhaust gas post-processing, and in particular to a leakage diagnosis method, a device, a vehicle and a medium of a DPF regeneration injection system. Background Art

[0002] In order to solve the particulate pollution problem caused by diesel engine exhaust emissions, the diesel particulate filter (DPF) is currently the most effective device for reducing diesel engine soot particle emissions. However, as the working time increases, the soot particles accumulated inside the DPF will increase, which will not only affect the particle capture effect, but also cause incomplete fuel combustion in the diesel engine. In this case, a DPF regeneration injection system is proposed. The DPF regeneration injection system injects fuel into the DPF and burns it to increase the internal temperature of the DPF, thereby oxidizing and burning the particulate matter accumulated inside, thereby eliminating the soot particles accumulated inside the DPF to achieve active regeneration of the DPF. If the fuel pipeline of the DPF regeneration injection system leaks, the fuel will quickly atomize when it encounters high temperature, and produce flammable and explosive gases within a certain range, which is very likely to cause danger and even burn the vehicle.

[0003] In order to avoid safety accidents, the DPF regeneration injection system needs to be leak tested. The detection method in the prior art is: each time the vehicle is powered on, the fuel is introduced into the cavity where the pressure sensor is located, and the DPF regeneration injection system is judged to be leaking by detecting whether the oil pressure is within a reasonable range. This method has the following technical problems: 1. Every time the self-test is powered on, fuel waste will be caused; 2. After the diagnosis is completed, the fuel in the cavity is directly discharged to the exhaust gas after-treatment system. If the exhaust temperature is low at this time, it will cause adhesion to the oxidation catalyst (Diesel Oxidation Catalyst, DOC). If the fuel continues to accumulate and is not removed in time, a large amount of heat will be released during the regeneration process, causing damage to the exhaust gas after-treatment system.

[0004] Therefore, there is an urgent need to provide a leakage diagnosis method, device, vehicle and medium for a DPF regeneration injection system, which can be used to reduce fuel waste while achieving leakage diagnosis, alleviate fuel adhesion accumulation, and ensure the safety of the exhaust after-treatment system. Summary of the invention

[0005] In view of this, it is necessary to provide a leakage diagnosis method, device, vehicle and medium for a DPF regeneration injection system to solve the technical problems in the prior art that fuel needs to be introduced into the cavity where the pressure sensor is located, resulting in fuel waste, and the fuel is easily adhered and accumulated on the DOC, resulting in poor safety of the exhaust after-treatment system.

[0006] On the one hand, in order to solve the above technical problems, the present invention provides a leakage diagnosis method of a DPF regeneration injection system, the DPF regeneration injection system is used to inject fuel into an exhaust gas after-treatment system, and the exhaust gas after-treatment system includes an oxidation catalyst and a diesel particulate filter connected in sequence; the method includes: Acquiring a first inlet temperature of the oxidation catalyst and a second inlet temperature of the diesel particulate filter; determining whether a temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold; If so, a leak diagnosis is performed on the DPF regeneration injection system.

[0007] In a possible implementation manner, before determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold, the method further includes: Acquiring a first inlet temperature change gradient of the oxidation catalyst and a second inlet temperature change gradient of the diesel particulate trap; Determining whether the first inlet temperature change gradient and the second inlet temperature change gradient are both less than a gradient change threshold; Then, determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold includes: When both the first inlet temperature change gradient and the second inlet temperature change gradient are smaller than a gradient change threshold, it is determined whether a temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

[0008] In a possible implementation manner, before determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold, the method further includes: Obtaining the speed change gradient and torque change gradient of the engine; Determining whether the speed change gradient is less than a speed gradient threshold and whether the torque change gradient is less than a torque gradient threshold; Then, determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold includes: When the speed change gradient is less than a speed gradient threshold, and the torque change gradient is less than a torque gradient threshold, it is determined whether a temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

[0009] In a possible implementation manner, before determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold, the method further includes: Determining whether the first inlet temperature is greater than a combustion setting temperature; Then, determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold includes: When the first inlet temperature is greater than the combustion setting temperature, it is determined whether a temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

[0010] In a possible implementation, the DPF regeneration injection system includes an air intake circuit, an oil intake circuit, an air discharge valve arranged on the air intake circuit, a fuel cut-off valve and a diesel metering valve arranged on the oil intake circuit, and a pressure sensor connecting the fuel cut-off valve and the diesel metering valve; The leak diagnosis of the DPF regeneration injection system includes: Control the diesel metering valve and the fuel cut-off valve to close, and the air discharge valve to open, obtain a first pressure value collected by the pressure sensor, and determine whether the first pressure value is greater than a pressure threshold value, if so, determine that the diesel metering valve is leaking, if not, determine that the diesel metering valve is not leaking; Control the diesel metering valve, the fuel shut-off valve and the air discharge valve to close, obtain the second pressure value collected by the pressure sensor, and determine whether the second pressure value is greater than a pressure threshold. If so, determine that the fuel shut-off valve is leaking; if not, determine that the fuel shut-off valve is not leaking.

[0011] In a possible implementation, after the DPF regeneration injection system is leak diagnosed, the method further includes: The fuel cut-off valve and the air discharge valve are kept closed, and the diesel metering valve is opened. When the opening time of the diesel metering valve is equal to the preset time, the diesel metering valve is closed.

[0012] In a possible implementation, the DPF regeneration injection system further includes a nozzle disposed on a side of the diesel metering valve away from the fuel cut-off valve, and after the leakage diagnosis of the DPF regeneration injection system is performed, the method further includes: The diesel metering valve and the fuel cut-off valve are kept closed, the air discharge valve is opened, and the air discharge valve is controlled to intermittently purge the pipeline between the diesel metering valve and the nozzle.

[0013] On the other hand, the present invention also provides a leakage diagnosis device for a DPF regeneration injection system, the DPF regeneration injection system is used to inject fuel into an exhaust gas aftertreatment system, the exhaust gas aftertreatment system includes an oxidation catalyst and a diesel particulate filter connected in sequence; the device includes: a temperature acquisition unit, used to acquire a first inlet temperature of the oxidation catalyst and a second inlet temperature of the diesel particulate filter; a temperature difference judgment unit, used to judge whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold; The leakage diagnosis unit is used to perform leakage diagnosis on the DPF regeneration injection system when the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

[0014] In another aspect, the present invention further provides a vehicle, comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the leakage diagnosis method of the DPF regeneration injection system described in any one of the possible implementations above.

[0015] On the other hand, the present invention also provides a computer-readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps in the leakage diagnosis method of the DPF regeneration injection system described in any one of the above possible implementation methods are implemented.

[0016] The beneficial effects of the present invention are as follows: the leakage diagnosis method of the DPF regeneration injection system provided by the present invention, before leak diagnosis, first determines whether there is a leakage risk based on the temperature difference between the first inlet temperature of the oxidation catalyst and the second inlet temperature of the diesel particulate filter, and only performs leakage diagnosis on the DPF regeneration injection system when there is a leakage risk, and does not need to perform leakage diagnosis on the DPF regeneration injection system every time the vehicle is powered on, thereby reducing the number of leak diagnosis, thereby reducing the number of times fuel is introduced into the cavity where the pressure sensor is located, and avoiding fuel waste. In addition, due to the reduction in the number of leaks, the degree of fuel accumulation is slowed down, and the safety risk of the exhaust gas after-treatment system is avoided to a certain extent, ensuring the safety of the exhaust gas after-treatment system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of the structure of an embodiment of an exhaust gas after-treatment system; Figure 2 A schematic flow chart of an embodiment of a leakage diagnosis method for a DPF regeneration injection system provided by the present invention; Figure 3A schematic diagram of a flow chart of an embodiment of determining temperature gradient change provided by the present invention; Figure 4 A schematic diagram of a flow chart of an embodiment of judging engine operating condition changes provided by the present invention; Figure 5 A schematic diagram of the structure of an embodiment of a DPF regeneration injection system; Figure 6 For the present invention Figure 1 A schematic flow chart of an embodiment of step S103; Figure 7 A schematic structural diagram of an embodiment of a leakage diagnosis device for a DPF regeneration injection system provided by the present invention; Figure 8 A schematic structural diagram of an embodiment of a vehicle provided by the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0020] It should be understood that the schematic drawings are not drawn to scale. The flowchart used in the present invention shows the operations implemented according to some embodiments of the present invention. It should be understood that the operations of the flowchart can be implemented out of order, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present invention, can add one or more other operations to the flowchart, and can also remove one or more operations from the flowchart. Some of the block diagrams shown in the accompanying drawings are functional entities, which do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0021] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] The present invention provides a leakage diagnosis method, device, vehicle and medium for a DPF regeneration injection system, which are respectively described below.

[0023] Before presenting the specific embodiments, the exhaust gas aftertreatment system is first introduced. Figure 1 As shown, the exhaust gas aftertreatment system includes a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF) and a selective catalytic reduction (SCR) or an ammonia slip catalyst (ASC) connected in sequence.

[0024] Among them, DOC has three main functions: 1. Reduce hydrocarbon (HC) emissions: oxidize unburned HC in the exhaust gas into H2O and CO2; 2. Oxidize NO into NO2; 3. Oxidize the fuel sprayed into the exhaust pipe.

[0025] DPF is mainly used to capture particles in exhaust gas to meet the National VI emission requirements for the number of particles.

[0026] The function of SCR is: urea aqueous solution is sprayed into the exhaust pipe and hydrolyzed into NH3, which converts NO in the exhaust gas into NH3 in the SCR. x Reduced to non-toxic nitrogen N2.

[0027] The function of ASC is to eliminate excess or escaped NH3 and oxidize excess NH3 into N2, N2O, and NO x At the same time, catalyze NO x , NH3 reacts to produce nitrogen N2.

[0028] And, if Figure 1 As shown, one end of the DPF regeneration injection system is used to introduce fuel, and the other end is connected to the exhaust gas after-treatment system, which is used to inject fuel into the exhaust gas after-treatment system, and the fuel burns the carbon particles in the DPF.

[0029] The embodiment of the present invention provides a leakage diagnosis method for a DPF regeneration injection system, such as Figure 2 As shown, the leakage diagnosis method of the DPF regeneration injection system includes: S201, obtaining a first inlet temperature of an oxidation catalyst and a second inlet temperature of a diesel particulate filter; S202, determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold; S203: If yes, perform leakage diagnosis on the DPF regeneration injection system.

[0030] The first inlet temperature and the second inlet temperature are acquired in step S201 by collecting the first inlet temperature and the second inlet temperature based on temperature sensors disposed at the inlet of the oxidation catalyst and the inlet of the diesel particulate filter.

[0031] It should be noted that the accuracy of the first inlet temperature and the second inlet temperature is crucial to the subsequent judgment of leakage risk. Therefore, before executing step S201, it is necessary to ensure that the temperature sensor is fault-free.

[0032] It should be understood that if the temperature difference between the first temperature inlet and the second temperature inlet is less than or equal to the temperature difference threshold, it means that there is no leakage risk at this time, and there is no need to perform leakage diagnosis on the DPF regeneration injection system.

[0033] The principle of judging whether there is a leakage risk based on the temperature difference between the first inlet temperature and the second inlet temperature is: Figure 1 It can be seen that the DPF regeneration injection system is arranged upstream of the DOC. If a fuel leak occurs, the fuel will be oxidized in the DOC at a suitable temperature, thereby generating heat. This heat is transferred to the DPF inlet along with the exhaust gas, and the DPF inlet temperature will increase. Therefore, when the difference between the DPF inlet and the DOC inlet temperature is greater than the limit, it is determined that there is a risk of leakage. This is to achieve the purpose of reducing the number of diagnostic times while ensuring that leakage faults can be diagnosed in a timely manner.

[0034] Compared with the prior art, the leakage diagnosis method of the DPF regeneration injection system provided in the embodiment of the present invention first determines whether there is a leakage risk based on the temperature difference between the first inlet temperature of the oxidation catalyst and the second inlet temperature of the diesel particulate filter before performing leakage diagnosis. The DPF regeneration injection system will be leak diagnosed only when there is a leakage risk. It is not necessary to perform leakage diagnosis on the DPF regeneration injection system every time the vehicle is powered on, which reduces the number of leak diagnosis, thereby reducing the number of times fuel is introduced into the cavity where the pressure sensor is located, avoiding fuel waste. In addition, due to the reduction in the number of leaks, the degree of fuel accumulation is slowed down, and the safety risk of the exhaust gas after-treatment system is avoided to a certain extent, ensuring the safety of the exhaust gas after-treatment system.

[0035] Furthermore, if Figure 1 As shown, there is a DOC between the first inlet temperature and the second inlet temperature, and the DOC has a large filtering effect on the temperature. That is, when the engine exhaust temperature changes, the first inlet temperature will change first, and the change of the second inlet temperature will be delayed. In order to avoid the technical problem that the first inlet temperature and the second inlet temperature obtained by this delay phenomenon cannot accurately determine the diagnosis risk, in some embodiments of the present invention, such as Figure 3 As shown, before step S202, it also includes: S301, obtaining a first inlet temperature change gradient of an oxidation catalyst and a second inlet temperature change gradient of a diesel particulate filter; S302, determining whether the first inlet temperature change gradient and the second inlet temperature change gradient are both less than a gradient change threshold; Then step S202 is specifically as follows: When both the first inlet temperature change gradient and the second inlet temperature change gradient are smaller than the gradient change threshold, it is determined whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than the temperature difference threshold.

[0036] The embodiment of the present invention is configured to determine whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than the temperature difference threshold when both the first inlet temperature change gradient and the second inlet temperature change gradient are less than the gradient change threshold, thereby avoiding the temperature delay caused by DOC filtering affecting the accuracy of the temperature difference, eliminating the influence of the temperature delay, ensuring the accuracy of the temperature difference between the first inlet temperature and the second inlet temperature, improving the accuracy of the judgment of the filtering risk, and further reducing the number of leakage diagnosis times.

[0037] Since a large change in the engine operating conditions will also cause a large change in the engine exhaust temperature, in order to avoid this situation affecting the accuracy of the leak diagnosis timing judgment, in some embodiments of the present invention, such as Figure 4 As shown, before step S202, it also includes: S401, obtaining a speed change gradient and a torque change gradient of the engine; S402, determining whether the speed change gradient is less than a speed gradient threshold and whether the torque change gradient is less than a torque gradient threshold; Then step S202 is specifically as follows: When the speed change gradient is less than the speed gradient threshold, and the torque change gradient is less than the torque gradient threshold, it is determined whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than the temperature difference threshold.

[0038] The embodiment of the present invention ensures that the engine operating condition does not change significantly when the first inlet temperature and the second inlet temperature are obtained by judging the speed change gradient and the torque change gradient, thereby avoiding the influence of the engine operating condition on the first inlet temperature and the second inlet temperature, and further ensuring the accuracy of the judgment of the leakage diagnosis timing.

[0039] Furthermore, since the fuel can only burn at a certain temperature, in order to ensure that the fuel is fully burned and the heat is transferred to the DPF inlet, in some embodiments of the present invention, before step S202, the following is further included: Determining whether the first inlet temperature is greater than the combustion setting temperature; Then step S202 is specifically as follows: When the first inlet temperature is greater than the combustion setting temperature, it is determined whether a temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

[0040] Before determining the temperature difference, the embodiment of the present invention ensures that the first inlet temperature is greater than the combustion setting temperature, which can ensure that the fuel injected into the exhaust after-treatment system has been fully burned. The temperature difference is generated by the fuel combustion, which further ensures the accuracy of the judgment of the leakage diagnosis timing.

[0041] In a specific embodiment of the present invention, Figure 5 As shown, the DPF regeneration injection system includes an intake circuit, an oil intake circuit, an air discharge valve arranged on the intake circuit, a fuel shut-off valve and a diesel metering valve arranged on the oil intake circuit, and a pressure sensor connecting the fuel shut-off valve and the diesel metering valve. The intake circuit is used to introduce air, and the oil intake circuit is used to introduce fuel. The end point of the oil intake circuit is the nozzle.

[0042] It should be noted that the DPF regeneration injection system may also include other control valves, which are not described one by one here.

[0043] Based on the above DPF regeneration injection system, in some embodiments of the present invention, as Figure 6 As shown, step S103 includes: S601, control the diesel metering valve and the fuel shut-off valve to be closed, the air discharge valve to be opened, obtain the first pressure value collected by the pressure sensor, and determine whether the first pressure value is greater than the pressure threshold. If so, it is determined that the diesel metering valve is leaking; if not, it is determined that the diesel metering valve is not leaking; S602, control the diesel metering valve, the fuel shut-off valve and the air discharge valve to close, obtain the second pressure value collected by the pressure sensor, and determine whether the second pressure value is greater than the pressure threshold. If so, it is determined that the fuel shut-off valve is leaking; if not, it is determined that the fuel shut-off valve is not leaking.

[0044] It should be noted that: if it is determined that the fuel shut-off valve and / or the diesel metering valve is leaking, a fault alarm message will be generated to prompt the staff to pay attention and repair it.

[0045] The embodiment of the present invention controls the opening and closing of the diesel metering valve, the fuel shut-off valve and the air discharge valve, and can perform leakage diagnosis on the diesel metering valve and the fuel shut-off valve based on the pressure value collected by the pressure sensor. The diagnosis process is simple and the leakage diagnosis efficiency is improved.

[0046] Since during leakage diagnosis, fuel needs to be introduced into the oil chamber where the pressure sensor is located, and after the diagnosis is completed, the fuel needs to be discharged, therefore, in some embodiments of the present invention, after step S602, the leakage diagnosis method of the DPF regeneration injection system further includes: Keep the fuel shut-off valve and the air discharge valve closed, open the diesel metering valve, and when the opening time of the diesel metering valve is equal to the preset time, close the diesel metering valve.

[0047] The embodiment of the present invention achieves the purpose of discharging the fuel in the oil cavity by opening the diesel metering valve for a preset time.

[0048] Among them, the preset duration can be adaptively set according to the amount of fuel introduced, and is not specifically limited here.

[0049] like Figure 5 As shown, the DPF regeneration injection system also includes a nozzle arranged on the side of the diesel metering valve away from the fuel shut-off valve. After the diagnosis is completed, the fuel is discharged to the exhaust gas after-treatment system through the nozzle. Part of the fuel will remain on the nozzle, and the fuel is very easy to absorb carbon soot particles in the exhaust gas. If this continues for a long time, the nozzle will be blocked. In order to avoid nozzle blockage, in some embodiments of the present invention, after step S203, the leakage diagnosis method of the DPF regeneration injection system also includes: Keep the diesel metering valve and fuel shut-off valve closed, open the air discharge valve, and control the air discharge valve to intermittently purge the pipeline between the diesel metering valve and the nozzle.

[0050] The embodiment of the present invention adds a purge function to purge the fuel in the pipeline between the diesel metering valve and the nozzle, thereby avoiding fuel adhesion and reducing the risk of nozzle clogging.

[0051] In order to better implement the leakage diagnosis method of the DPF regeneration injection system in the embodiment of the present invention, based on the leakage diagnosis method of the DPF regeneration injection system, the embodiment of the present invention also provides a leakage diagnosis device of the DPF regeneration injection system, the DPF regeneration injection system is used to inject fuel into the exhaust gas after-treatment system, and the exhaust gas after-treatment system includes an oxidation catalyst and a diesel particulate filter connected in sequence; Figure 7 As shown, the leakage diagnosis device 700 of the DPF regeneration injection system includes: A temperature acquisition unit 701 is used to acquire a first inlet temperature of the oxidation catalyst and a second inlet temperature of the diesel particulate filter; A temperature difference judgment unit 702 is used to judge whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold; The leakage diagnosis unit 703 is used to perform leakage diagnosis on the DPF regeneration injection system when the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

[0052] It should be noted that the leakage diagnosis device 700 of the DPF regeneration injection system provided in the above embodiment can implement the technical solution described in the leakage diagnosis method embodiment of the above DPF regeneration injection system. The specific implementation principles or specific implementation details of the above modules or units can refer to the corresponding contents in the leakage diagnosis method embodiment of the above DPF regeneration injection system, which will not be described one by one here.

[0053] like Figure 8 As shown, the present invention also provides a vehicle 800. The vehicle 800 includes a processor 801, a memory 802 and a display 803. Figure 8 Only some of the components of vehicle 800 are shown, but it should be understood that implementation of all of the components shown is not a requirement, and more or fewer components may alternatively be implemented.

[0054] In some embodiments, the processor 801 is an electronic control unit (ECU) in the vehicle 800 , which is used to run program codes or process data stored in the memory 802 , such as the leakage diagnosis method of the DPF regeneration injection system in the present invention.

[0055] The memory 802 may be an internal storage unit of the vehicle 800 , such as a hard disk or a memory of the vehicle 800 , in some embodiments.

[0056] Furthermore, the memory 802 may include both an internal storage unit of the vehicle 800 and an external storage device. The memory 802 is used to store application software installed in the vehicle 800 and various data.

[0057] In some embodiments, the display 803 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 803 is used to display information of the vehicle 800 and to display a visual user interface. The components 801-803 of the vehicle 800 communicate with each other via a system bus.

[0058] In some embodiments of the present invention, when the processor 801 executes the leakage diagnosis program of the DPF regeneration injection system in the memory 802, the following steps may be implemented: obtaining a first inlet temperature of the oxidation catalyst and a second inlet temperature of the diesel particulate filter; Determine whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold; If yes, perform a leak diagnosis on the DPF regeneration injection system.

[0059] It should be understood that: when the processor 801 executes the leakage diagnosis program of the DPF regeneration injection system in the memory 802, in addition to the above functions, other functions can also be implemented. For details, please refer to the description of the corresponding method embodiment above.

[0060] Accordingly, an embodiment of the present invention also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, it can implement the steps or functions in the leakage diagnosis method of the DPF regeneration injection system provided in the above-mentioned method embodiments.

[0061] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0062] The leakage diagnosis method, device, vehicle and medium of a DPF regeneration injection system provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A leakage diagnosis method for a DPF regeneration injection system, characterized in that: The DPF regeneration injection system is used to inject fuel into an exhaust gas aftertreatment system, wherein the exhaust gas aftertreatment system includes an oxidation catalyst and a diesel particulate filter connected in sequence; the method includes: Acquiring a first inlet temperature of the oxidation catalyst and a second inlet temperature of the diesel particulate filter; determining whether a temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold; If so, a leak diagnosis is performed on the DPF regeneration injection system.

2. The leak diagnosis method of the DPF regeneration injection system according to claim 1, characterized in that: Before determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold, the method further includes: Acquiring a first inlet temperature change gradient of the oxidation catalyst and a second inlet temperature change gradient of the diesel particulate trap; Determining whether the first inlet temperature change gradient and the second inlet temperature change gradient are both less than a gradient change threshold; Then, determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold includes: When both the first inlet temperature change gradient and the second inlet temperature change gradient are smaller than a gradient change threshold, it is determined whether a temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

3. The leak diagnosis method of the DPF regeneration injection system according to claim 1, characterized in that: Before determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold, the method further includes: Obtaining the speed change gradient and torque change gradient of the engine; Determining whether the speed change gradient is less than a speed gradient threshold and whether the torque change gradient is less than a torque gradient threshold; Then, determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold includes: When the speed change gradient is less than a speed gradient threshold, and the torque change gradient is less than a torque gradient threshold, it is determined whether a temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

4. The leak diagnosis method of the DPF regeneration injection system according to claim 1, characterized in that: Before determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold, the method further includes: Determining whether the first inlet temperature is greater than a combustion setting temperature; Then, determining whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold includes: When the first inlet temperature is greater than the combustion setting temperature, it is determined whether a temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

5. The leak diagnosis method of the DPF regeneration injection system according to claim 1, characterized in that: The DPF regeneration injection system includes an air intake circuit, an oil intake circuit, an air discharge valve arranged on the air intake circuit, a fuel cut-off valve and a diesel metering valve arranged on the oil intake circuit, and a pressure sensor connecting the fuel cut-off valve and the diesel metering valve; The leak diagnosis of the DPF regeneration injection system includes: Control the diesel metering valve and the fuel cut-off valve to close, and the air discharge valve to open, obtain a first pressure value collected by the pressure sensor, and determine whether the first pressure value is greater than a pressure threshold value, if so, determine that the diesel metering valve is leaking, if not, determine that the diesel metering valve is not leaking; Control the diesel metering valve, the fuel shut-off valve and the air discharge valve to close, obtain the second pressure value collected by the pressure sensor, and determine whether the second pressure value is greater than a pressure threshold. If so, determine that the fuel shut-off valve is leaking; if not, determine that the fuel shut-off valve is not leaking.

6. The leak diagnosis method of the DPF regeneration injection system according to claim 5, characterized in that: After the leakage diagnosis of the DPF regeneration injection system is performed, the method further includes: The fuel cut-off valve and the air discharge valve are kept closed, and the diesel metering valve is opened. When the opening time of the diesel metering valve is equal to the preset time, the diesel metering valve is closed.

7. The leak diagnosis method of the DPF regeneration injection system according to claim 6, characterized in that: The DPF regeneration injection system further includes a nozzle disposed on a side of the diesel metering valve away from the fuel cut-off valve, and after the DPF regeneration injection system is leak diagnosed, the system further includes: The diesel metering valve and the fuel cut-off valve are kept closed, the air discharge valve is opened, and the air discharge valve is controlled to intermittently purge the pipeline between the diesel metering valve and the nozzle.

8. A leakage diagnosis device for a DPF regeneration injection system, characterized in that: The DPF regeneration injection system is used to inject fuel into the exhaust gas after-treatment system, wherein the exhaust gas after-treatment system includes an oxidation catalyst and a diesel particulate filter connected in sequence; the device includes: a temperature acquisition unit, used to acquire a first inlet temperature of the oxidation catalyst and a second inlet temperature of the diesel particulate filter; a temperature difference judgment unit, used to judge whether the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold; The leakage diagnosis unit is used to perform leakage diagnosis on the DPF regeneration injection system when the temperature difference between the first inlet temperature and the second inlet temperature is greater than a temperature difference threshold.

9. A vehicle, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps of the leakage diagnosis method of the DPF regeneration injection system as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program or instruction, and when the program or instruction is executed by a processor, the steps of the leakage diagnosis method of the DPF regeneration injection system described in any one of claims 1 to 7 are implemented.

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