Dpf regeneration control method and apparatus

Abstract

The application discloses a DPF regeneration control method and device, comprising the following steps: obtaining engine speed, fuel injection quantity and fuel injection pressure; determining the maximum limited fuel injection quantity of post-injection 1 according to the engine speed and fuel injection quantity by inquiring a first inquiry table, wherein the first inquiry table stores engine speed, fuel injection quantity and corresponding maximum limited fuel injection quantity of post-injection 1; determining the post-injection 1 segmentation times according to the maximum limited fuel injection quantity of post-injection 1 and the fuel injection pressure by inquiring a second inquiry table, wherein the second inquiry table records the maximum limited fuel injection quantity of post-injection 1, fuel injection pressure and corresponding post-injection 1 segmentation times; and calculating the single post-injection 1 fuel injection quantity according to the maximum limited fuel injection quantity of post-injection 1 and the post-injection 1 segmentation times. The method of the application divides the post-injection 1 fuel injection quantity, which not only ensures that the DPF regeneration temperature meets the requirements, but also reduces the diesel engine oil dilution rate.

Description

Technical Field

[0001] This invention belongs to the field of DPF regeneration control technology, and specifically relates to a DPF regeneration control method and apparatus. Background Technology

[0002] China VI commercial vehicle diesel engine systems all use diesel particulate filters (DPFs) to treat particulate emissions from engine exhaust. When the DPF becomes saturated with particulate matter, it needs to be regenerated periodically to burn off carbon. During DPF regeneration, post-injection fuel (FIN1) is required to ensure the DPF reaches the target regeneration temperature. However, excessive FIN1 injection can easily lead to incompletely burned diesel fuel mixing with the engine oil, resulting in high oil dilution. This leads to shorter oil change intervals, increasing vehicle operating costs for users, and in severe cases, can cause engine damage due to poor lubrication caused by excessive oil dilution.

[0003] In existing DPF regeneration methods, the amount of fuel injected after the engine is calculated based on the upstream temperature of the DPF and the target required temperature. This can easily lead to a situation where the amount of fuel injected after the engine is small under low load, but the amount of fuel injected after the engine is too large. When the amount of fuel injected after the engine is too large in a single operation, it can easily cause incomplete combustion of diesel fuel and dilute the engine oil. However, if the amount of fuel injected after the engine is too small, it can easily cause the DPF regeneration temperature to be too low, resulting in the DPF failing to regenerate properly. Summary of the Invention

[0004] To address the problems of low DPF regeneration temperature or incomplete diesel engine oil dilution in existing methods, this invention provides a DPF regeneration control method and apparatus.

[0005] The objective of this invention is achieved through the following technical solution: The first aspect of this invention discloses a DPF regeneration control method, comprising the following steps: Obtain engine speed, fuel injection quantity, and fuel injection pressure; The maximum limited fuel quantity of the rear injection 1 is determined by querying the first lookup table based on the engine speed and fuel injection quantity. The first lookup table stores the engine speed, fuel injection quantity and the corresponding maximum limited fuel quantity of the rear injection 1. The number of times the rear injection 1 is divided is determined by querying a second lookup table based on the maximum limited fuel quantity of the rear injection 1 and the fuel injection pressure. The second lookup table records the maximum limited fuel quantity of the rear injection 1, the fuel injection pressure and the corresponding number of times the rear injection 1 is divided. The amount of oil in a single post-spray 1 is calculated based on the maximum limited amount of oil in post-spray 1 and the number of times post-spray 1 is divided.

[0006] The second aspect of the present invention discloses a DPF regeneration control device, comprising a memory and a controller connected in sequence, wherein the memory stores a computer program, and the controller is used to read the computer program and execute a DPF regeneration control method described in the first aspect.

[0007] A third aspect of this invention discloses a DPF regeneration control device, comprising a data acquisition unit, a first search unit, a second search unit, and a calculation unit connected in sequence by signals. The data acquisition unit is used to acquire engine speed, fuel injection quantity, and fuel injection pressure. The first lookup unit is used to determine the maximum limited fuel quantity of the rear injection 1 by querying the first lookup table based on the engine speed and fuel injection quantity. The first lookup table stores the engine speed, fuel injection quantity and the corresponding maximum limited fuel quantity of the rear injection 1. The second lookup unit is used to determine the number of times the post-injection 1 is divided by querying a second lookup table based on the maximum limited fuel quantity of post-injection 1 and the fuel injection pressure. The second lookup table records the maximum limited fuel quantity of post-injection 1, the fuel injection pressure and the corresponding number of times the post-injection 1 is divided. The calculation unit is used to calculate the amount of fuel for a single injection of post-injection 1 based on the maximum limited amount of fuel for post-injection 1 and the number of times post-injection 1 is divided.

[0008] Compared with the prior art, the present invention has at least the following advantages and beneficial effects: The method of the present invention divides the amount of post-injection oil, which not only ensures that the DPF regeneration temperature meets the requirements, but also reduces the oil dilution rate of the diesel engine. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. 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 effort.

[0010] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0012] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0013] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0014] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0015] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0016] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0017] To minimize the oil dilution rate of diesel engines while considering the DPF regeneration temperature, the first aspect of this invention discloses a DPF regeneration control method. This method is executed by a device, such as a vehicle control unit (ECU) or other intelligent control unit. Specifically, as shown... Figure 1 As shown, the method includes steps S1 to S4.

[0018] Step S1: Obtain engine speed, fuel injection quantity, and fuel injection pressure.

[0019] The parameters in this step are collected by various sensors on the engine.

[0020] Step S2: Determine the maximum limited fuel quantity of the rear injection 1 by querying the first lookup table based on the engine speed and fuel injection quantity. The first lookup table stores the engine speed, fuel injection quantity and the corresponding maximum limited fuel quantity of the rear injection 1.

[0021] The maximum fuel quantity of the post-injection 1 is determined by the engine speed and the fuel injection quantity, and the corresponding relationship can be obtained by bench testing. Since the engine speed and fuel injection quantity range are large, in order to reduce the number of bench tests and the amount of data stored, the first lookup table can only store partial data, as shown in Table 1. In the first lookup table, the engine speed is (1000+200N1) rpm and the fuel injection quantity is Ni mg / hub, where N1 is a natural number greater than or equal to 0 and less than or equal to 11, i=1,2,...,5, and N1, N2, N3, N4, and N5 are 0, 5, 10, 20, and 30, respectively.

[0022] Table 1 Data not found in the first lookup table is calculated based on data from the first lookup table. Specifically, when the engine speed is greater than 1000+200N1 rpm and less than or equal to 1000+200(N1+1) rpm and / or the fuel injection quantity is greater than Ni and less than N(i+1), the maximum fuel injection quantity for the second injection is determined by consulting the first lookup table based on the engine speed and fuel injection quantity. L11=(1-(V-Ni) / 200)*L1+(VN(i+1)) / 200*L2 L12=(1-(V-Ni) / 200)*L3+(VN(i+1)) / 200*L4 L=(1-(YL-Ni)*(N(i+1)-Ni))* L11+(YL-Ni)*(N(i+1)-Ni)* L12, In the formula, V is the engine speed, YL is the fuel injection quantity, L1 is the maximum limited fuel injection quantity for the first injection at an engine speed of 1000+200N1 rpm with a fuel injection quantity of Ni mg / hub, L2 is the maximum limited fuel injection quantity for the first injection at an engine speed of 1000+200(N1+1) rpm with a fuel injection quantity of Ni mg / hub, L3 is the maximum limited fuel injection quantity for the first injection at an engine speed of 1000+200N1 rpm with a fuel injection quantity of N(i+1) mg / hub, L4 is the maximum limited fuel injection quantity for the first injection at an engine speed of 1000+200(N1+1) rpm with a fuel injection quantity of N(i+1) mg / hub, and F is the maximum limited fuel injection quantity for the first injection at an engine speed greater than 1000+200N1 rpm. The maximum limited fuel quantity for post-injection is rpm and less than or equal to 1000+200(N1+1) rpm and / or the fuel injection quantity is greater than Ni and less than N(i+1).

[0023] Step S3: Determine the number of times the rear injection 1 is divided by querying the second lookup table based on the maximum limited fuel quantity of the rear injection 1 and the fuel injection pressure. The second lookup table records the maximum limited fuel quantity of the rear injection 1, the fuel injection pressure and the corresponding number of times the rear injection 1 is divided.

[0024] The maximum limited fuel quantity, fuel injection pressure, and number of subsequent injections were obtained through bench tests.

[0025] Specifically, the second lookup table is shown in Table 2.

[0026] Table 2 When the maximum oil quantity of post-spray 1 is less than or equal to 2.4mg, the number of times post-spray 1 is divided is 1, that is, no division is performed, to ensure accurate oil quantity injection and guarantee the DPF regeneration temperature.

[0027] When the fuel injection pressure is greater than or equal to 6, the number of subsequent injections is 3, which effectively reduces the oil dilution rate.

[0028] Step S4: Calculate the amount of oil for a single post-spray 1 based on the maximum limited amount of oil for post-spray 1 and the number of times post-spray 1 is divided.

[0029] That is, the amount of fuel injected in a single post-injection = the maximum limited amount of fuel injected in post-injection / the number of times post-injection is divided.

[0030] The present invention limits and segments the amount of post-injection oil in the engine by means of the above method, which can ensure that the regeneration temperature of the engine DPF meets the requirements while keeping the oil dilution rate of the engine at a low level.

[0031] A second aspect of this invention discloses a DPF regeneration control device, comprising a memory and a controller connected in sequence via communication. The memory stores a computer program, and the controller reads the computer program to execute the DPF regeneration control method described in the first aspect. Specifically, the memory may include, but is not limited to, random-access memory (RAM), read-only memory (ROM), flash memory, first-in-first-out (FIFO) memory, and / or first-in-last-out (FILO) memory, etc.; the controller may not be limited to using a microcontroller of the STM32F105 series. Furthermore, the computer device may also include, but is not limited to, a power supply unit, a display screen, and other necessary components. Specifically, this DPF regeneration control device can be a vehicle control unit (ECU).

[0032] A third aspect of this invention discloses a DPF regeneration control device, comprising a data acquisition unit, a first search unit, a second search unit, and a calculation unit connected in sequence by signals. The data acquisition unit is used to acquire engine speed, fuel injection quantity, and fuel injection pressure. The first lookup unit is used to determine the maximum limited fuel quantity of the rear injection 1 by querying the first lookup table based on the engine speed and fuel injection quantity. The first lookup table stores the engine speed, fuel injection quantity and the corresponding maximum limited fuel quantity of the rear injection 1. The second lookup unit is used to determine the number of times the post-injection 1 is divided by querying a second lookup table based on the maximum limited fuel quantity of post-injection 1 and the fuel injection pressure. The second lookup table records the maximum limited fuel quantity of post-injection 1, the fuel injection pressure and the corresponding number of times the post-injection 1 is divided. The calculation unit is used to calculate the amount of fuel for a single injection of post-injection 1 based on the maximum limited amount of fuel for post-injection 1 and the number of times post-injection 1 is divided.

[0033] It should be noted that the operating principle of the apparatus in the second and third aspects of the present invention is the same as that in the first aspect, and will not be described in detail here.

[0034] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A DPF regeneration control method, characterized in that, Includes the following steps: Obtain engine speed, fuel injection quantity, and fuel injection pressure; The maximum limited fuel quantity of the rear injection 1 is determined by querying the first lookup table based on the engine speed and fuel injection quantity. The first lookup table stores the engine speed, fuel injection quantity and the corresponding maximum limited fuel quantity of the rear injection 1. The number of times the rear injection 1 is divided is determined by querying a second lookup table based on the maximum limited fuel quantity of the rear injection 1 and the fuel injection pressure. The second lookup table records the maximum limited fuel quantity of the rear injection 1, the fuel injection pressure and the corresponding number of times the rear injection 1 is divided. The amount of oil in a single post-spray 1 is calculated based on the maximum limited amount of oil in post-spray 1 and the number of times post-spray 1 is divided. The engine speed in the first lookup table is (1000+200N1) rpm, and the fuel injection quantity is Ni mg / hub, where N1 is a natural number greater than or equal to 0 and less than or equal to 11, i=1,2,...,5, and N1, N2, N3, N4, and N5 are 0, 5, 10, 20, and 30 respectively. When the engine speed is greater than 1000+200N1 rpm and less than or equal to 1000+200(N1+1) rpm and / or the fuel injection quantity is greater than Ni and less than N(i+1), the maximum fuel injection quantity for the second injection is determined by querying the first lookup table based on the engine speed and fuel injection quantity. L11=(1-(V-Ni) / 200)*L1+(VN(i+1)) / 200*L2 L12=(1-(V-Ni) / 200)*L3+(VN(i+1)) / 200*L4 L=(1-(YL-Ni)*(N(i+1)-Ni))* L11+(YL-Ni)*(N(i+1)-Ni)* L12, In the formula, V is the engine speed, YL is the fuel injection quantity, L1 is the maximum limited fuel injection quantity for the first injection at an engine speed of 1000+200N1 rpm with a fuel injection quantity of Ni mg / hub, L2 is the maximum limited fuel injection quantity for the first injection at an engine speed of 1000+200(N1+1) rpm with a fuel injection quantity of Ni mg / hub, L3 is the maximum limited fuel injection quantity for the first injection at an engine speed of 1000+200N1 rpm with a fuel injection quantity of N(i+1) mg / hub, L4 is the maximum limited fuel injection quantity for the first injection at an engine speed of 1000+200(N1+1) rpm with a fuel injection quantity of N(i+1) mg / hub, and F is the maximum limited fuel injection quantity for the first injection at an engine speed greater than 1000+200N1 rpm. The maximum limited fuel quantity for post-injection is rpm and less than or equal to 1000+200(N1+1) rpm and / or the fuel injection quantity is greater than Ni and less than N(i+1).

2. The DPF regeneration control method according to claim 1, characterized in that: The number of times the post-injection 1 is segmented is determined by querying a second lookup table based on the maximum limited fuel quantity of post-injection 1 and the fuel injection pressure. When the maximum limited amount of oil for post-spray 1 is less than or equal to 2.4 mg, the number of times post-spray 1 is divided is 1. When the fuel injection pressure is greater than or equal to 6, the number of subsequent injections is 3.

3. A DPF regeneration control device, comprising a memory and a controller connected in sequence via communication, wherein the memory stores a computer program, characterized in that: The controller is used to read the computer program and execute a DPF regeneration control method according to any one of claims 1-2.

4. A DPF regeneration control device for implementing the DPF regeneration control method according to any one of claims 1 to 2, characterized in that, It includes a data acquisition unit, a first search unit, a second search unit, and a calculation unit connected by signals in sequence. The data acquisition unit is used to acquire engine speed, fuel injection quantity, and fuel injection pressure. The first lookup unit is used to determine the maximum limited fuel quantity of the rear injection 1 by querying the first lookup table based on the engine speed and fuel injection quantity. The first lookup table stores the engine speed, fuel injection quantity and the corresponding maximum limited fuel quantity of the rear injection 1. The second lookup unit is used to determine the number of times the post-injection 1 is divided by querying a second lookup table based on the maximum limited fuel quantity of post-injection 1 and the fuel injection pressure. The second lookup table records the maximum limited fuel quantity of post-injection 1, the fuel injection pressure and the corresponding number of times the post-injection 1 is divided. The calculation unit is used to calculate the amount of fuel for a single injection of post-injection 1 based on the maximum limited amount of fuel for post-injection 1 and the number of times post-injection 1 is divided.

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