Dpf regeneration control method, storage medium, aftertreatment system, and vehicle

Abstract

The application belongs to the technical field of vehicle aftertreatment, and discloses a DPF regeneration control method, a storage medium, an aftertreatment system and a vehicle. The DPF regeneration control method comprises the following steps: S100, a parking regeneration process is started, and the DPF enters a parking regeneration Dry stage; S200, in the parking regeneration Dry stage, a difference ΔT between a DOC upstream temperature T1 and a DPF upstream temperature T2 is calculated, ΔT=T2-T1; and S300, a fuel injection amount correction value q required by the DPF in a parking regeneration Rgn stage is obtained by using ΔT. The DPF regeneration control method can improve the accuracy of the control of the injection amount of the fuel post-injection in the parking regeneration process, avoid the problems of the over-high DPF temperature and the over-temperature of the aftertreatment system caused by the large fuel leakage amount, and thus ensure the smooth progress of the parking regeneration process.

Description

Technical Field

[0001] This invention relates to the field of vehicle aftertreatment technology, and in particular to a DPF regeneration control method, a storage medium, an aftertreatment system, and a vehicle. Background Technology

[0002] The engine aftertreatment system uses a DPF (Diesel Particulate Filter) to adsorb particulate matter such as soot, particulates, hydrocarbons, nitrogen oxides and sulfur. When these particulate matter reach a certain level in the DPF, they need to be removed through a regeneration process to ensure that the DPF can be used normally.

[0003] Parking regeneration is a common method in the regeneration process. The parking regeneration process generally includes the following stages: the Dry stage, where fuel is ignited by the burner at the tail end of the DPF to burn off particulate matter, generating carbon dioxide which is then emitted. The Rgn stage, where fuel is injected into the DOC (Diesel Oxidation Catalyst) via remote injection. The oxidation reaction releases heat, raising the temperature of the DPF downstream of the DOC, thereby burning off particulate matter.

[0004] In existing aftertreatment systems, at the start of the parking regeneration Rgn stage, excessive fuel leakage into the DOC (Dead Oxide Collection) may occur. This excess fuel oxidizes and releases heat in the DOC, significantly raising the temperature upstream of the DPF (Diesel Particulate Filter). This temperature difference persists into the parking regeneration Rgn stage, potentially leading to excessively high DPF temperatures and overheating of the aftertreatment system. In such cases, to protect the aftertreatment system, the parking regeneration process is forcibly terminated, preventing completion. Failure of the parking regeneration function means that carbon deposits and other particulate matter in the DPF cannot be removed in time, causing DPF overload and severely impacting vehicle power and fuel consumption. Simultaneously, excessively high temperatures in the aftertreatment system pose reliability risks, reduce service life, and affect operational safety.

[0005] Therefore, there is an urgent need for a DPF regeneration control method, storage medium, post-processing system, and vehicle to solve the above problems. Summary of the Invention

[0006] According to one aspect of the present invention, the objective is to provide a DPF regeneration control method that can improve the accuracy of controlling the amount of fuel injection during parking regeneration, avoid excessively high DPF temperature and overheating of the aftertreatment system due to large fuel leakage, and thus ensure the smooth progress of the parking regeneration process.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] The DPF regeneration control method, wherein the aftertreatment system includes a DOC and a DPF sequentially disposed at the rear end of the engine, the DPF regeneration control method comprising:

[0009] Step S100: The parking regeneration process is started, and the DPF enters the parking regeneration Dry stage;

[0010] Step S200: During the parking regeneration Dry stage, calculate the difference ΔT between the upstream temperature T1 of DOC and the upstream temperature T2 of DPF, where ΔT = T2 - T1;

[0011] S300. Using ΔT, the fuel injection quantity correction value q of DPF in the parking regeneration Rgn stage is obtained, and the actual fuel injection quantity W in the parking regeneration Rgn stage is calculated. 实 W 实 =W 预设 -q;

[0012] Among them W 预设 This is the preset fuel injection quantity during the parking regeneration Rgn stage without considering ΔT;

[0013] Step S400: The parking regeneration process enters the parking regeneration Rgn stage, according to the actual fuel injection quantity W. 实 Inject fuel into the DOC.

[0014] As a preferred embodiment of the DPF regeneration control method provided by the present invention, step S300 includes:

[0015] Step S310: Calculate the heat of temperature rise Q from DOC to DPF, Q = cmΔT; where c is the specific heat capacity of engine exhaust and m is the mass flow rate of engine exhaust.

[0016] Step S320: Calculate the fuel injection quantity correction value q, q = Q / F; where F is the calorific value of the fuel.

[0017] As a preferred embodiment of the DPF regeneration control method provided by the present invention, between step S200 and step S300, the following further steps are performed:

[0018] Step S210: Determine the relationship between ΔT and the preset temperature deviation t. If ΔT > t, proceed to step S300. Wherein, the preset temperature deviation t is the upper limit of the temperature deviation value that does not require fuel injection quantity correction during the parking regeneration Rgn stage.

[0019] As a preferred embodiment of the DPF regeneration control method provided by the present invention, in step S200, ΔT is the average value of the differences between multiple upstream temperatures T1 of DOC and multiple upstream temperatures T2 of DPF collected within a preset time before the end of the parking regeneration Dry stage.

[0020] As a preferred embodiment of the DPF regeneration control method provided by the present invention, during the parking regeneration Dry stage of the DPF, the burner located at the tail end of the DPF is controlled to ignite and burn.

[0021] According to another aspect of the present invention, an object is to provide a storage medium having a computer program stored thereon, which, when executed by a processor, causes a vehicle to implement the DPF regeneration control method as described in any of the above embodiments.

[0022] According to another aspect of the present invention, an object is to provide an aftertreatment system comprising a DOC, a DPF, and an SCR sequentially disposed at the rear end of an engine, the aftertreatment system being controllable based on the DPF regeneration control method described in any of the above-described schemes, wherein the DOC is configured to oxidize engine exhaust, the DPF is configured to capture particulate matter in the engine exhaust, and the SCR is configured to neutralize nitrogen oxides in the engine exhaust.

[0023] As a preferred embodiment of the post-processing system provided by the present invention, the post-processing system further includes a DOC temperature sensor and a DPF temperature sensor. The DOC temperature sensor is disposed at the front end of the DOC and is configured to detect the upstream temperature T1 of the DOC. The DPF temperature sensor is disposed between the DOC and the DPF and is configured to detect the upstream temperature T2 of the DPF.

[0024] According to another aspect of the invention, an object is to provide a vehicle comprising an engine, an injector, and an aftertreatment system as described in any of the above embodiments, the aftertreatment system being disposed at the rear end of the engine and configured to harmlessly treat the engine exhaust, the injector being connected to the DOC and a fuel source and capable of injecting fuel into the DOC.

[0025] As a preferred embodiment of the vehicle provided by the present invention, it further includes a control module, wherein the injector is communicatively connected to the control module, and the control module is configured to control the injector to inject fuel into the DOC based on the upstream temperature T1 of the DOC and the upstream temperature T2 of the DPF.

[0026] The beneficial effects of this invention are:

[0027] The DPF regeneration control method provided by this invention heats the DPF during the parking regeneration Dry stage, causing the particulate matter within it to burn. During the parking regeneration Dry stage, the difference ΔT between the upstream temperature T1 of the DOC and the upstream temperature T2 of the DPF is calculated to determine if there is excessive heat release from the DOC oxidation reaction due to excessive fuel leakage into the DOC. The required fuel injection quantity correction value q for the DPF during the parking regeneration Rgn stage is calculated using ΔT, taking into account the increased heat caused by excessive heat release from the DOC oxidation reaction due to excessive fuel leakage into the DOC. Then, the formula W is used... 实 =W 预设 -q, calculates the actual fuel injection quantity W during the parking regeneration Rgn stage. 实 This facilitates accurate control of the fuel injection volume during the subsequent parking regeneration Rgn stage, effectively avoiding excessive DPF temperature and overheating of the aftertreatment system due to large fuel leakage, thus ensuring the smooth progress of the parking regeneration process.

[0028] The post-processing system provided by this invention can avoid overheating during the parking regeneration process, has a long service life, and is highly safe.

[0029] The vehicle provided by this invention can render its engine exhaust harmless and improve the effectiveness of engine exhaust treatment. Attached Figure Description

[0030] Figure 1 This is a partial schematic diagram of the post-processing system provided in an embodiment of the present invention;

[0031] Figure 2 This is a flowchart of the DPF regeneration control method provided in the embodiments of the present invention.

[0032] In the picture:

[0033] 1. Engine; 2. Control module; 3. Fuel injector;

[0034] 10. DOC; 20. DPF; 30. SCR; 40. DOC temperature sensor; 50. DPF temperature sensor. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0036] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0039] Example 1

[0040] This embodiment provides an aftertreatment system and a vehicle. The vehicle includes an engine 1 and the aftertreatment system provided in this embodiment. The aftertreatment system is located at the rear end of the engine 1 and is configured to treat the exhaust gas of the engine 1 in a harmless manner.

[0041] Figure 1 A partial schematic diagram of the post-processing system provided in an embodiment of the present invention is shown. (Refer to...) Figure 1 The aftertreatment system includes DOC10, DPF20, and SCR30 (Selective Catalytic Reduction) units sequentially disposed at the rear end of engine 1. DOC10 is configured to oxidize engine exhaust, DPF20 is configured to capture particulate matter in the engine exhaust, and SCR30 is configured to neutralize nitrogen oxides in the engine exhaust.

[0042] Specifically, the DOC10 can oxidize carbon monoxide and hydrocarbons in engine exhaust, converting them into harmless carbon dioxide and water, and can also convert nitric oxide into nitrogen dioxide. Furthermore, the DOC10 can oxidize the fuel injected by engine 1 and increase its temperature during DPF20 regeneration, thus preparing for DPF20 regeneration.

[0043] More specifically, the DPF20 relies on alternating blockage of the inlet and outlet of the filter carrier holes to force airflow through the porous wall to capture particulate matter, thereby reducing PM2.5 and other pollutants in the exhaust gas. The vehicle also includes a fuel injector 3, which is connected to the DOC10 and a fuel source (not shown), and can inject fuel into the DOC10. When too much particulate matter is captured in the DPF20, a parking regeneration process is required. This process includes a parking regeneration LoF stage, a parking regeneration Dry stage, and a parking regeneration Rgn stage. In the LoF (Local Overdrive) stage of parking regeneration, the main method is to reduce the throttle valve opening and increase the engine speed of engine 1, thereby increasing the exhaust temperature of engine 1 and preheating DOC10 and DPF20. In the Dry stage of parking regeneration, the throttle valve opening is reduced again and the engine speed of engine 1 is further increased, thereby further increasing the exhaust temperature of engine 1 and preheating DOC10 and DPF20. In the Dry stage of parking regeneration, the burner located at the tail end of DPF20 is controlled to ignite and burn the particulate matter in DPF20. The Rgn (Regeneration After Drive) stage of parking regeneration follows the Dry stage. In the Rgn stage of parking regeneration, based on the Dry stage, fuel from the fuel source is injected into DOC10 using injector 3. The exothermic oxidation reaction occurring in DOC10 heats up DPF20, which is located downstream of DOC10, thereby burning off the particulate matter.

[0044] More specifically, the SCR30 can utilize the ammonia produced by urea hydrolysis to convert nitrogen oxides in engine exhaust into nitrogen under the action of a catalyst.

[0045] Continue to refer to Figure 1 The post-processing system also includes a DOC temperature sensor 40 and a DPF temperature sensor 50. The DOC temperature sensor 40 is located upstream of the DOC 10 and configured to detect the upstream temperature T1 of the DOC. The DPF temperature sensor 50 is located between the DOC 10 and the DPF 20 and configured to detect the upstream temperature T2 of the DPF. The DOC temperature sensor 40 and the DPF temperature sensor 50 are prior art, and their structure and principles will not be described in detail in this embodiment.

[0046] Continue to refer to Figure 1The vehicle also includes a control module 2. The fuel injector 3 is communicatively connected to the control module 2. The DOC temperature sensor 40 and the DPF temperature sensor 50 are also communicatively connected to the control module 2, capable of transmitting upstream DOC and upstream DPF temperature signals to the control module 2. The control module 2 is configured to control the fuel injector 3 to inject fuel into the DOC 10 based on the upstream DOC temperature T1 and the upstream DPF temperature T2. In this embodiment, the control module 2 may specifically be an engine ECU, which is existing technology, and its structure and principle will not be described in detail here.

[0047] Example 2

[0048] Figure 2 A flowchart of the DPF regeneration control method provided in an embodiment of the present invention is shown. (Refer to...) Figure 2 This embodiment provides a DPF regeneration control method. The post-processing system provided in Embodiment 1 can be controlled based on the DPF regeneration control method provided in this embodiment.

[0049] Specifically, the DPF regeneration control method includes the following steps:

[0050] Step S100: The parking regeneration process is started, and DPF20 enters the parking regeneration Dry stage;

[0051] Step S200: During the parking regeneration Dry stage, calculate the difference ΔT between the upstream temperature T1 of DOC and the upstream temperature T2 of DPF, where ΔT = T2 - T1;

[0052] Step S300: Calculate the fuel injection quantity correction value q of DPF20 in the parking regeneration Rgn stage using ΔT, and calculate the actual fuel injection quantity W in the parking regeneration Rgn stage. 实 W 实 =W 预设 -q;

[0053] Among them, W 预设 This is the preset fuel injection quantity during the parking regeneration Rgn stage without considering ΔT.

[0054] Specifically, to improve the accuracy of ΔT calculation, in step S200, ΔT is the average of the differences between multiple upstream DOC temperatures T1 and multiple upstream DPF temperatures T2 collected within a preset time before the end of the parking regeneration Dry stage. In this embodiment, the preset time can be 10 seconds, that is, the average of the differences between multiple upstream DOC temperatures T1 and multiple upstream DPF temperatures T2 collected within 10 seconds before the end of the parking regeneration Dry stage.

[0055] More specifically, step S300, "using ΔT to calculate the fuel injection quantity correction value q of DPF20 in the parking regeneration Rgn stage," includes the following steps:

[0056] Step S310: Calculate the heat of temperature rise Q from DOC10 to DPF20, Q = cmΔT; where c is the specific heat capacity of engine exhaust and m is the mass flow rate of engine exhaust.

[0057] Step S320: Calculate the fuel injection quantity correction value q, q=Q / F; where F is the calorific value of the fuel, which is a constant and can be obtained from the physicochemical property table of the fuel actually used;

[0058] Preferably, considering the normal errors of the DOC temperature sensor 40 and the DPF temperature sensor 50 themselves, or the cases where the errors are negligible when ΔT is very small, the following steps are performed between steps S200 and S300:

[0059] Step S210: Determine the relationship between ΔT and the preset temperature deviation t. If ΔT > t, proceed directly to step S300. The preset temperature deviation t is the upper limit of the temperature deviation value that does not require fuel injection quantity correction during the parking regeneration Rgn stage. The preset temperature deviation t can be set based on the actual measurement errors of the DOC temperature sensor 40 and DPF temperature sensor 50, as well as the actual operating conditions of DOC10 and DPF20. Its specific value is not limited in this embodiment. If ΔT ≤ t, no correction of the fuel injection quantity correction value q is required. The injector 3 can inject fuel into DOC10 according to the preset fuel injection quantity. This preset fuel injection quantity is automatically set by the control module 2 based on the preset heat requirement for complete combustion of particulate matter in DPF20 during the parking regeneration Rgn stage. Its specific value is not limited in this embodiment.

[0060] After step S300, proceed to step S400:

[0061] Step S400: The parking regeneration process enters the parking regeneration Rgn stage, according to the actual fuel injection quantity W. 实Fuel is injected into DOC10. Following steps S100-S300, the increased heat due to excessive fuel leakage into DOC10, resulting in excessive exothermic oxidation, is taken into account. This facilitates accurate control of the fuel injection quantity in subsequent step S400. The fuel injection quantity correction value q in step S400 represents the actual amount of fuel that injector 3 needs to inject into DOC10 to achieve the required heat for the parking regeneration Rgn stage after fuel leakage. This setting effectively avoids excessively high DPF20 temperature and overheating of the aftertreatment system due to large fuel leakage, thus ensuring the smooth operation of the parking regeneration process.

[0062] This embodiment also provides a storage medium on which a computer program is stored. When executed by a processor, the computer program causes the vehicle to implement the DPF regeneration control method provided in this embodiment.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A DPF regeneration control method, characterized in that, The aftertreatment system includes a DOC (10) and a DPF (20) sequentially disposed at the rear end of the engine (1), wherein the DPF regeneration control method includes: S100, the parking regeneration process starts, and DPF (20) enters the parking regeneration Dry stage; S200. During the parking regeneration Dry stage, calculate the difference ΔT between the upstream temperature T1 of DOC and the upstream temperature T2 of DPF, where ΔT = T2 - T1. S300, using ΔT to calculate the fuel injection quantity correction value q of DPF (20) in the parking regeneration Rgn stage, the actual fuel injection quantity W in the parking regeneration Rgn stage is calculated. 实 W 实 =W 预设 -q; Among them, W 预设 The preset fuel injection amount in the parking regeneration Rgn stage without considering ΔT is set according to the preset heat requirement for complete combustion of particulate matter in DPF(20) in the parking regeneration Rgn stage. S400, the parking regeneration process enters the parking regeneration Rgn stage, according to the actual fuel injection quantity W. 实 Inject fuel into DOC (10).

2. The DPF regeneration control method according to claim 1, characterized in that, Step S300 includes: S310. Calculate the heat of heating Q from DOC (10) to DPF (20), Q = cmΔT; where c is the specific heat capacity of the engine exhaust and m is the mass flow rate of the engine exhaust. S320. Calculate the fuel injection quantity correction value q, q=Q / F; where F is the calorific value of the fuel.

3. The DPF regeneration control method according to claim 1, characterized in that, Between step S200 and step S300, the following also needs to be performed: S210. Determine the relationship between ΔT and the preset temperature deviation t. If ΔT > t, proceed to step S300. Wherein, the preset temperature deviation t is the upper limit of the temperature deviation value that does not require fuel injection quantity correction during the parking regeneration Rgn stage.

4. The DPF regeneration control method according to claim 1, characterized in that, In step S200, ΔT is the average value of the differences between multiple upstream temperatures T1 of DOC and multiple upstream temperatures T2 of DPF collected within a preset time before the end of the parking regeneration Dry stage.

5. The DPF regeneration control method according to any one of claims 1-4, characterized in that, During the parking regeneration Dry phase of the DPF (20), the burner located at the tail end of the DPF (20) is controlled to ignite and burn.

6. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it causes the vehicle to implement the DPF regeneration control method as described in any one of claims 1-5.

7. A post-processing system, characterized in that, The aftertreatment system includes a DOC (10), a DPF (20) and an SCR (30) sequentially disposed at the rear end of the engine (1). The aftertreatment system is controlled based on the DPF regeneration control method according to any one of claims 1-5. The DOC (10) is configured to oxidize the engine exhaust, the DPF (20) is configured to capture particulate matter in the engine exhaust, and the SCR (30) is configured to harmlessly treat nitrogen oxides in the engine exhaust.

8. The post-processing system according to claim 7, characterized in that, The post-processing system also includes a DOC temperature sensor (40) and a DPF temperature sensor (50). The DOC temperature sensor (40) is located at the front end of the DOC (10) and is configured to detect the upstream temperature T1 of the DOC. The DPF temperature sensor (50) is located between the DOC (10) and the DPF (20) and is configured to detect the upstream temperature T2 of the DPF.

9. A vehicle, characterized in that, Includes an engine (1), an injector (3), and an aftertreatment system as described in claim 7 or 8, the aftertreatment system being disposed at the rear end of the engine (1) and configured to harmlessly treat the exhaust of the engine (1), the injector (3) being connected to the DOC (10) and a fuel source and capable of injecting fuel into the DOC (10).

10. The vehicle according to claim 9, characterized in that, It also includes a control module (2), the injector (3) being communicatively connected to the control module (2), the control module (2) being configured to control the injector (3) to inject fuel into the DOC (10) according to the upstream temperature T1 of the DOC and the upstream temperature T2 of the DPF.

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