DPF regeneration control method and device

Abstract

The invention discloses a DPF regeneration control method and device. The method comprises the following steps that the engine rotating speed, the fuel injection quantity and the fuel injection pressure are obtained; according to the engine rotating speed and the fuel injection quantity, the maximum limit fuel quantity of the post-injection 1 is determined by inquiring a first inquiry table, and the engine rotating speed, the fuel injection quantity and the corresponding maximum limit fuel quantity of the post-injection 1 are stored in the first inquiry table; according to the maximum limit oil quantity of the post-injection 1 and the fuel injection pressure, the number of times of post-injection 1 segmentation is determined by querying a second query table, and the maximum limit oil quantity of the post-injection 1, the fuel injection pressure and the corresponding number of times of post-injection 1 segmentation are recorded in the second query table; and according to the maximum limit oil quantity of the post-injection 1 and the number of times of post-injection 1 segmentation, the single-time post-injection 1 oil quantity is obtained through calculation. By the adoption of the method, the post-injection 1 oil quantity is divided, it is guaranteed that the DPF regeneration temperature meets the requirement, and meanwhile the diesel engine oil dilution rate of the diesel engine is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of DPF regeneration control, and in particular relates to a DPF regeneration control method and device. Background Art

[0002] The diesel engine systems of China VI commercial vehicles all use a Diesel Particulate Filter (DPF) to handle the engine's exhaust particulate emissions. When the DPF is saturated with particulate matter, the DPF needs to be regenerated and carbonized regularly. During the DPF regeneration process, post-injection 1 is required to ensure that the DPF can reach the target regeneration temperature. However, when too much post-injection 1 oil is injected, incompletely burned diesel is likely to mix into the engine oil, ultimately resulting in a high oil dilution rate, resulting in a short mileage interval between engine oil changes, and increased vehicle usage costs for users. In severe cases, the engine may be damaged due to poor lubrication due to excessive engine oil dilution.

[0003] In the existing DPF regeneration method, the post-injection oil volume is calculated based on the DPF upstream temperature and the target required temperature. It is easy to encounter the problem that under light load, the engine injection volume is small but the post-injection oil volume is too large. When the single post-injection oil volume is too large, it is easy to cause incomplete combustion of diesel and dilution of the engine oil; but too small a post-injection oil volume can easily cause the DPF regeneration temperature to be too low, resulting in the problem that the DPF cannot regenerate normally. Summary of the Invention

[0004] In order to solve the problems of low DPF regeneration temperature or incomplete dilution of diesel engine oil in existing methods, the present invention provides a DPF regeneration control method and device.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A first aspect of the present invention discloses a DPF regeneration control method, comprising the following steps:

[0007] Obtain engine speed, fuel injection amount and fuel injection pressure;

[0008] determining a maximum limit fuel quantity of post-injection 1 by querying a first query table according to the engine speed and the fuel injection quantity, wherein the first query table stores the engine speed, the fuel injection quantity and the corresponding maximum limit fuel quantity of post-injection 1;

[0009] determining the number of splits of post-injection 1 by querying a second lookup table according to the maximum limit of post-injection 1 fuel quantity and the fuel injection pressure, wherein the second lookup table records the maximum limit of post-injection 1 fuel quantity, the fuel injection pressure, and the corresponding number of splits of post-injection 1;

[0010] The fuel quantity of a single post-injection 1 is calculated according to the maximum limit fuel quantity of the post-injection 1 and the number of split times of the post-injection 1.

[0011] A second aspect of the present invention discloses a DPF regeneration control device, comprising a memory and a controller that are communicatively 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.

[0012] The third aspect of the present 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.

[0013] The data acquisition unit is used to obtain engine speed, fuel injection amount and fuel injection pressure;

[0014] The first lookup unit is configured to determine the maximum limit fuel quantity of post-injection 1 by querying a first lookup table according to the engine speed and the fuel injection quantity, wherein the first lookup table stores the engine speed, the fuel injection quantity and the corresponding maximum limit fuel quantity of post-injection 1;

[0015] The second lookup unit is configured to determine the number of splits of post-injection 1 by looking up a second lookup table according to the maximum limit of post-injection 1 fuel quantity and the fuel injection pressure, wherein the second lookup table records the maximum limit of post-injection 1 fuel quantity, the fuel injection pressure, and the corresponding number of splits of post-injection 1;

[0016] The calculation unit is used to calculate the fuel quantity of a single post-injection 1 according to the maximum limit fuel quantity of the post-injection 1 and the number of split times of the post-injection 1.

[0017] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0018] By adopting the method of the present invention, the amount of post-injection oil is divided, which not only ensures that the DPF regeneration temperature meets the requirements but also reduces the dilution rate of the diesel engine oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 Flowchart of the method of the present invention. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0023] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0025] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is typically placed when in use, or are the orientations or positional relationships commonly understood by those skilled in the art. These terms are intended only to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0027] In order to minimize the oil dilution rate of the diesel engine while taking into account the regeneration temperature of the DPF, the first aspect of the present invention discloses a DPF regeneration control method. The method is executed by a device, such as a vehicle control unit ECU or other intelligent control unit. Specifically, Figure 1 As shown, the method includes steps S1 to S4.

[0028] Step S1: Obtain engine speed, fuel injection amount, and fuel injection pressure.

[0029] The parameters in this step are collected by various sensors on the engine.

[0030] Step S2: determining the maximum limit fuel quantity of post-injection 1 by querying a first query table according to the engine speed and the fuel injection quantity, wherein the first query table stores the engine speed, the fuel injection quantity and the corresponding maximum limit fuel quantity of post-injection 1.

[0031] The maximum fuel quantity limit for post-injection 1 is determined by the engine speed and injection quantity, and the corresponding relationship can be obtained through bench testing. Due to the wide range of engine speed and injection quantity, 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, the engine speed in the first lookup table is (1000 + 200 N1) rpm and the injection quantity is Ni mg / hub. 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.

[0032] Table 1

[0033]

[0034] Data not in the first lookup table is calculated based on the data in 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 amount is greater than Ni and less than N(i+1), the maximum fuel limit for rear injection 1 is determined by querying the first lookup table based on the engine speed and fuel injection amount as:

[0035] L11=(1-(V-Ni) / 200)*L1+(VN(i+1)) / 200*L2

[0036] L12=(1-(V-Ni) / 200)*L3+(VN(i+1)) / 200*L4

[0037] L=(1-(YL-Ni)*(N(i+1-Ni)))*L11+(YL-Ni)*(N(i+1-Ni))*L12,

[0038] Where V is the engine speed, YL is the injection amount, L1 is the maximum limit fuel amount of post injection 1 corresponding to the injection amount of Ni mg / hub and the engine speed of 1000+200N1 rpm, L2 is the maximum limit fuel amount of post injection 1 corresponding to the injection amount of Ni mg / hub and the engine speed of 1000+200(N1+1) rpm, L3 is the maximum limit fuel amount of post injection 1 corresponding to the injection amount of N(i+1) mg / hub and the engine speed of 1000+200N1 rpm, L4 is the maximum limit fuel amount of post injection 1 corresponding to the injection amount of N(i+1) mg / hub and the engine speed of 1000+200(N1+1) rpm, and F is the maximum limit fuel amount of post injection 1 when the engine speed is greater than 1000+200N1 rpm and less than or equal to 1000+200(N1+1) rpm and / or the injection amount is greater than Ni and less than N(i+1).

[0039] Step S3: determining the number of splits of post-injection 1 by querying a second lookup table according to the maximum limit of post-injection 1 fuel quantity and the fuel injection pressure, wherein the second lookup table records the maximum limit of post-injection 1 fuel quantity, the fuel injection pressure, and the corresponding number of splits of post-injection 1.

[0040] The maximum fuel quantity limit of injection 1, fuel injection pressure and number of splits of post-injection 1 are obtained through bench tests.

[0041] Specifically, the second query table is shown in Table 2.

[0042] Table 2

[0043]

[0044] When the maximum limit of post-injection 1 oil volume is less than or equal to 2.4 mg, the number of splits of post-injection 1 is 1, that is, no splitting is performed, to ensure accurate oil injection and guarantee the DPF regeneration temperature.

[0045] When the fuel injection pressure is greater than or equal to 6, the number of splits of post-injection 1 is 3, which effectively reduces the oil dilution rate.

[0046] Step S4: Calculate the fuel volume of a single post-injection 1 according to the maximum fuel volume limit of post-injection 1 and the number of split times of post-injection 1.

[0047] That is, the fuel volume of a single post-injection 1 = the maximum limit fuel volume of post-injection 1 / the number of post-injection 1 splits.

[0048] The present invention limits and divides the amount of post-injection oil of the engine by the above method, which can ensure that the regeneration temperature of the engine DPF meets the requirements while keeping the engine oil dilution rate at a low level.

[0049] A second aspect of the present invention discloses a DPF regeneration control device, comprising a memory and a controller that are communicatively connected in sequence. The memory stores a computer program, and the controller is configured to read the computer program and 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-input first-output (FIFO), and / or first-input last-output (FILO) memory; and the controller may include, but is not limited to, a microcontroller of the STM32F105 series. Furthermore, the computer device may include, but is not limited to, a power supply unit, a display screen, and other necessary components. Specifically, the DPF regeneration control device may be a vehicle's control unit (ECU).

[0050] The third aspect of the present 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.

[0051] The data acquisition unit is used to obtain engine speed, fuel injection amount and fuel injection pressure;

[0052] The first lookup unit is configured to determine the maximum limit fuel quantity of post-injection 1 by querying a first lookup table according to the engine speed and the fuel injection quantity, wherein the first lookup table stores the engine speed, the fuel injection quantity and the corresponding maximum limit fuel quantity of post-injection 1;

[0053] The second lookup unit is configured to determine the number of splits of post-injection 1 by looking up a second lookup table according to the maximum limit of post-injection 1 fuel quantity and the fuel injection pressure, wherein the second lookup table records the maximum limit of post-injection 1 fuel quantity, the fuel injection pressure, and the corresponding number of splits of post-injection 1;

[0054] The calculation unit is used to calculate the fuel quantity of a single post-injection 1 according to the maximum limit fuel quantity of the post-injection 1 and the number of split times of the post-injection 1.

[0055] It should be noted that the operating principles of the devices of the second and third aspects of the present invention are the same as those of the first aspect and will not be described in detail here.

[0056] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A DPF regeneration control method, characterized in that: The following steps are involved: Obtain engine speed, fuel injection amount and fuel injection pressure; determining a maximum limit fuel quantity of post-injection 1 by querying a first query table according to the engine speed and the fuel injection quantity, wherein the first query table stores the engine speed, the fuel injection quantity and the corresponding maximum limit fuel quantity of post-injection 1; determining the number of splits of post-injection 1 by querying a second lookup table according to the maximum limit of post-injection 1 fuel quantity and the fuel injection pressure, wherein the second lookup table records the maximum limit of post-injection 1 fuel quantity, the fuel injection pressure, and the corresponding number of splits of post-injection 1; The fuel quantity of a single post-injection 1 is calculated according to the maximum limit fuel quantity of the post-injection 1 and the number of split times of the post-injection 1.

2. A DPF regeneration control method according to claim 1, characterized in that: The engine speed in the first query table is (1000+200N1) rpm, and the fuel injection amount 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 amount is greater than Ni and less than N(i+1), the maximum fuel amount limit of the rear injection 1 is determined by querying the first query table according to the engine speed and the fuel injection amount: 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, Where V is the engine speed, YL is the injection amount, L1 is the maximum limit of the post-injection 1 fuel amount when the injection amount is Ni mg / hub and the engine speed is 1000+200N1 rpm, L2 is the maximum limit of the post-injection 1 fuel amount when the injection amount is Ni mg / hub and the engine speed is 1000+200(N1+1) rpm, L3 is the maximum limit of the post-injection 1 fuel amount when the injection amount is N(i+1) mg / hub and the engine speed is 1000+200N1 rpm, L4 is the maximum limit of the post-injection 1 fuel amount when the injection amount is N(i+1) mg / hub and the engine speed is 1000+200(N1+1) rpm, and F is the maximum limit of the post-injection 1 fuel amount when the engine speed is greater than 1000+200N1 rpm and less than or equal to 1000+200 (N1+1) rpm and / or the injection amount is greater than Ni and less than N(i+1) maximum limit fuel quantity for post injection 1.

3. A DPF regeneration control method according to claim 1, characterized in that: The number of splits of post-injection 1 is determined by querying a second query table according to the maximum limit fuel quantity of post-injection 1 and the fuel injection pressure: When the maximum oil quantity limit of the rear spray 1 is less than or equal to 2.4 mg, the number of splits of the rear spray 1 is 1; When the fuel injection pressure is greater than or equal to 6, the number of splits of post-injection 1 is 3.

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

5. A DPF regeneration control device, characterized in that: comprising a data acquisition unit, a first search unit, a second search unit and a calculation unit which are sequentially connected by signals, The data acquisition unit is used to obtain engine speed, fuel injection amount and fuel injection pressure; The first lookup unit is configured to determine the maximum limit fuel quantity of post-injection 1 by querying a first lookup table according to the engine speed and the fuel injection quantity, wherein the first lookup table stores the engine speed, the fuel injection quantity and the corresponding maximum limit fuel quantity of post-injection 1; The second lookup unit is configured to determine the number of splits of post-injection 1 by looking up a second lookup table according to the maximum limit of post-injection 1 fuel quantity and the fuel injection pressure, wherein the second lookup table records the maximum limit of post-injection 1 fuel quantity, the fuel injection pressure, and the corresponding number of splits of post-injection 1; The calculation unit is used to calculate the fuel quantity of a single post-injection 1 according to the maximum limit fuel quantity of the post-injection 1 and the number of split times of the post-injection 1.

Images