Aftertreatment assembly, vehicle and vehicle control methods

Abstract

This invention discloses an aftertreatment assembly, a vehicle, and a vehicle control method, belonging to the field of vehicle technology. The aftertreatment assembly comprises a pre-stage SCR, an MOC, a DPF, a post-stage mixer, and a post-stage SCR, sequentially connected along the exhaust gas flow direction. That is, the aftertreatment assembly has two stages of SCR, thereby improving its ability to reduce nitrogen oxides and adapting to higher engine exhaust emissions, thus enhancing exhaust gas purification. Simultaneously, the ratio of platinum to palladium in the oxidation catalytic coating of the MOC is greater than 12:1, resulting in stronger oxidation capabilities for CO, NO, and HC in the exhaust gas. This not only provides more NO2 for DPF regeneration, thus improving DPF functionality, but also further enhances exhaust gas purification.

Description

Technical Field

[0001] This invention relates to the field of technology, and more particularly to an aftertreatment assembly, a vehicle, and a vehicle control method. Background Technology

[0002] With technological advancements, diesel engine exhaust emission requirements are becoming increasingly stringent. Existing exhaust aftertreatment systems consist of four units: DOC (Diesel Oxidation Catalyst), DPF (Diesel Particulate Filter), SCR (Selective Catalytic Reduction), and ASC (Ammonia Slip Catalyst). These four units remove harmful pollutants such as PM and NOx from diesel engine exhaust, resulting in clean exhaust gases while simultaneously meeting noise regulations.

[0003] The increased emission requirements for diesel engines are mainly due to stricter after-treatment emission requirements for cold starts. Furthermore, domestic emission testing cycles calculate emissions separately for cold and hot conditions. Therefore, the requirements for treating nitrogen oxides in cold conditions are more stringent, and existing exhaust after-treatment devices cannot meet these higher emission standards. Summary of the Invention

[0004] The purpose of this invention is to provide an aftertreatment assembly, a vehicle, and a vehicle control method to improve exhaust gas purification efficiency.

[0005] To achieve the above objectives, the following technical solution is provided:

[0006] The aftertreatment assembly includes a pre-stage SCR, an MOC, a DPF, a post-stage mixer, and a post-stage SCR connected sequentially along the exhaust gas flow direction. The post-stage mixer includes a first mixing inlet, a second mixing inlet, and a post-stage mixing outlet. The first mixing inlet is connected to the outlet of the DPF, the post-stage mixing outlet is connected to the inlet of the post-stage SCR, and the second mixing inlet is used to connect to a urea supply device.

[0007] The MOC includes an oxidative catalytic coating, wherein the ratio of platinum to palladium in the oxidative catalytic coating is greater than 12:1.

[0008] As a preferred embodiment of the above-mentioned post-processing assembly, the post-processing assembly further includes a pre-stage housing, wherein the pre-stage SCR, the MOC, and the DPF are all disposed within the pre-stage housing.

[0009] As a preferred embodiment of the above-mentioned post-processing assembly, the post-processing assembly further includes a post-stage housing and a connecting housing disposed between the pre-stage housing and the post-stage housing. The post-stage SCR is disposed within the post-stage housing. The post-stage mixer is disposed within the connecting housing. The connecting housing and the post-stage housing are both located on the same side of the connecting housing to form a U-shaped assembly housing.

[0010] As a preferred technical solution for the above-mentioned post-processing assembly, the pre-stage housing, the connecting housing, and the post-stage housing are separately arranged and fixedly connected; or, the pre-stage housing, the connecting housing, and the post-stage housing are integrally formed.

[0011] As a preferred embodiment of the above-mentioned after-treatment assembly, the after-treatment assembly further includes a mounting component, the mounting component including a support structure, the support structure including:

[0012] The first support part is a tubular structure;

[0013] The second support portion is fixedly disposed on the first support portion, and the second support portion is fixedly connected to the front housing and the rear housing respectively.

[0014] As a preferred technical solution of the above-mentioned aftertreatment assembly, the aftertreatment assembly further includes a pre-mixer, which includes a mixing inlet one, a mixing inlet two, and a pre-mixing outlet. The pre-mixing outlet is connected to the inlet of the pre-SCR. The mixing inlet one is used to introduce exhaust gas, and the mixing inlet two is used to connect to a urea supply device.

[0015] As a preferred embodiment of the above-mentioned aftertreatment assembly, the mixing inlet is equipped with a pre-spray component, which is used to communicate with the urea supply device; and / or

[0016] The second mixing inlet is equipped with a post-stage spray element, which is used to communicate with the urea supply device.

[0017] As a preferred technical solution for the above-mentioned aftertreatment assembly, the length of the rear-stage SCR is greater than the length of the front-stage SCR along the exhaust gas flow direction.

[0018] To achieve the above objectives, a vehicle is also provided, including an engine and an aftertreatment assembly as described in any of the preceding claims, wherein the pre-stage SCR is connected to the exhaust port of the engine.

[0019] To achieve the above objectives, a vehicle control method is also provided for a vehicle as described above; the vehicle control method includes the following steps:

[0020] When the DPF is regenerated based on the pressure difference across it, the fuel injection quantity of the in-cylinder after-injection device of the engine is determined based on the temperature difference across the MOC, the pressure difference across the DPF, and the exhaust gas flow rate into the aftertreatment assembly.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The aftertreatment assembly, vehicle, and vehicle control method of the present invention include an aftertreatment assembly comprising a pre-stage SCR, an MOC, a DPF, a post-stage mixer, and a post-stage SCR connected sequentially along the exhaust gas flow direction. That is, the aftertreatment assembly is equipped with two stages of SCR, thereby improving the aftertreatment assembly's ability to reduce nitrogen oxides and can adapt to higher engine exhaust emissions, improving exhaust gas purification effect. At the same time, the ratio of platinum to palladium in the oxidation catalytic coating of the MOC is greater than 12:1, which has a stronger oxidation ability for CO (carbon monoxide), NO (nitric oxide), and HC (hydrocarbons) in the exhaust gas. This not only provides more NO2 (nitrogen dioxide) for DPF regeneration, thereby improving the functionality of the DPF, but also further improves the exhaust gas purification effect. Attached Figure Description

[0023] Figure 1 This is a first structural schematic diagram of the post-processing assembly in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the second structure of the post-processing assembly in an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the third structure of the post-processing assembly in an embodiment of the present invention;

[0026] Figure 4 This is a cross-sectional view of the post-processing assembly in an embodiment of the present invention.

[0027] Figure label:

[0028] 1. Pre-mixer; 11. Mixing inlet one; 12. Mixing inlet two; 13. Pre-mixing outlet; 2. Pre-SCR; 3. MOC; 4. DPF; 5. Post-mixer; 51. First mixing inlet; 52. Second mixing inlet; 53. Post-mixing outlet; 6. Post-SCR; 71. Pre-spray component; 72. Post-spray component; 81. Post-housing housing; 82. Connecting housing; 9. Mounting component; 91. First support; 92. Second support; 93. Mounting part. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] 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.

[0032] In the description of this invention, it should be noted that the terms "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. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0033] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] 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.

[0035] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0036] like Figures 1-3 As shown, this embodiment provides an aftertreatment assembly, including a pre-stage SCR2, MOC3, DPF4, a post-stage mixer 5, and a post-stage SCR6 connected sequentially along the exhaust gas flow direction. The post-stage mixer 5 includes a first mixing inlet 51, a second mixing inlet 52, and a post-stage mixing outlet 53. The first mixing inlet 51 is connected to the outlet of DPF4, and the post-stage mixing outlet 53 is connected to the inlet of the post-stage SCR6. The second mixing inlet 52 is used to connect to a urea supply device. The MOC3 includes an oxidation catalytic coating, and the ratio of the content of platinum to palladium in the oxidation catalytic coating is greater than 12:1.

[0037] The aftertreatment assembly of this embodiment includes a pre-stage SCR2, MOC3, DPF4, a post-stage mixer 5, and a post-stage SCR6 connected sequentially along the exhaust gas flow direction. That is, the aftertreatment assembly is equipped with two stages of SCR, thereby improving the aftertreatment assembly's ability to reduce nitrogen oxides and can adapt to higher engine exhaust emissions, improving exhaust gas purification effect. At the same time, the ratio of platinum to palladium in the oxidation catalytic coating of MOC3 is greater than 12:1, which has a stronger oxidation ability for CO (carbon monoxide), NO (nitric oxide), and HC (hydrocarbons) in the exhaust gas. It can not only provide more NO2 (nitrogen dioxide) for DPF4 regeneration, thereby improving the functionality of DPF4, but also further improve the exhaust gas purification effect.

[0038] Understandably, in the field of exhaust gas treatment, MOC (Methane Oxidation Catalyst) uses noble metals (such as platinum and palladium) in its oxidation catalytic coating to oxidize CO (carbon monoxide), NO (nitric oxide), HC (hydrocarbons), and methane (CH4) in exhaust gas into CO2 (carbon dioxide), NO2 (nitrogen dioxide), and H2O. In other words, MOC combines the functions of DOC and ASC. It should be noted that the structure and working principle of MOC are existing technologies. This embodiment limits the content of platinum and palladium in the oxidation catalytic coating of MOC3, thereby improving the oxidation capacity of MOC3 for CO (carbon monoxide), NO (nitric oxide), and HC (hydrocarbons) in exhaust gas.

[0039] Optionally, the aftertreatment assembly also includes a pre-mixer 1, which includes a mixing inlet 11, a mixing inlet 12, and a pre-mixing outlet 13. The pre-mixing outlet 13 is connected to the inlet of the pre-SCR2. The mixing inlet 11 is used to introduce exhaust gas, and the mixing inlet 12 is connected to the urea supply device. Thus, the exhaust gas is mixed with ammonia (NH3) formed by the hydrolysis of urea solution through the pre-mixer 1, thereby improving the mixing uniformity and mixing efficiency of the exhaust gas and ammonia, which is beneficial to improving the NOx conversion rate of the pre-SCR2.

[0040] Optionally, a pre-spray component 71 is provided inside the mixing inlet 12, which is connected to the urea supply device. Spraying the urea solution into the pre-mixer 1 through the pre-spray component 71 improves the hydrolysis efficiency of the urea solution in the pre-mixer 1, and consequently improves the NOx conversion rate of the pre-SCR2. This embodiment does not limit the installation position of the pre-spray component 71.

[0041] Optionally, such as Figure 4 As shown, a downstream spray element 72 is provided inside the second mixing inlet 52, which is connected to the urea supply device. Spraying the urea solution into the downstream mixer 5 through the downstream spray element 72 helps improve the hydrolysis efficiency of the urea solution in the downstream mixer 5, and thus improves the NOx conversion rate of the downstream SCR6. This embodiment does not limit the installation position of the downstream spray element 72.

[0042] For example, the pre-spray component 71 is a nozzle. The post-spray component 72 is a nozzle. This embodiment does not limit the type and model of the nozzle.

[0043] Optionally, along the exhaust gas flow direction, the length of the subsequent SCR6 is greater than the length of the preceding SCR2, which can prolong the time for the exhaust gas to pass through the subsequent SCR6, thereby improving the NOx conversion rate of the subsequent SCR6 and thus enhancing the exhaust gas purification effect.

[0044] Optionally, the aftertreatment assembly also includes a pre-stage housing (not shown in the figure), in which the pre-stage SCR2, MOC3, and DPF4 are all housed. In other words, the pre-stage SCR2, MOC3, and DPF4 are all integrated into the pre-stage housing, eliminating the need for a separate housing for the pre-stage SCR2, which helps reduce the weight and cost of the aftertreatment assembly.

[0045] Optionally, such as Figures 1-3 As shown, the aftertreatment assembly also includes a rear-stage housing 81 and a connecting housing 82 disposed between the front-stage housing and the rear-stage housing 81. The rear-stage SCR 6 is disposed within the rear-stage housing 81; the rear-stage mixer 5 is disposed within the connecting housing 82. The connecting housing 82 and the rear-stage housing 81 are both located on the same side of the connecting housing 82, forming a U-shaped assembly housing. In other words, the aftertreatment assembly of this embodiment is an integrated structure. It should be noted that the aftertreatment assembly of this embodiment can integrate both stages of SCRs into one assembly housing simply by optimizing the layout of the front-stage SCR 2, MOC 3, DPF 4, rear-stage mixer 5, and rear-stage SCR 6. This reduces the space occupied by the aftertreatment assembly and facilitates the overall vehicle layout. At the same time, only minor modifications are needed to the assembly housing of the existing aftertreatment assembly to form the assembly housing of this embodiment, reducing design and production costs.

[0046] Optionally, the pre-stage housing, connecting housing 82, and rear-stage housing 81 are separately configured and fixedly connected, which helps to reduce processing costs and facilitates assembly. Of course, the pre-stage housing, connecting housing 82, and rear-stage housing 81 can also be integrally formed.

[0047] Optionally, the aftertreatment assembly also includes a mounting component 9, which includes a support structure. The support structure includes a first support portion 91 and a second support portion 92. The first support portion 91 is a tubular structure. The second support portion 92 is fixedly mounted on the first support portion 91 and is fixedly connected to the front housing and the rear housing 81 respectively. Thus, the installation stability of the front housing and the rear housing 81 can be ensured by the second support portion 92, thereby improving the structural strength of the assembly housing. During vehicle assembly, the tubular first support portion 91 can be fitted onto the mounting structure of the vehicle frame to improve the installation stability of the aftertreatment assembly.

[0048] Optionally, multiple second support portions 92 are provided, and the multiple second support portions 92 are spaced apart along the axial direction of the tubular structure, which can further improve the installation stability of the front housing and the rear housing 81, as well as the structural strength of the assembly housing. Exemplarily, two second support portions 92 are provided, which has a simple structure and is easy to assemble.

[0049] Optionally, two support structures are provided, with the two support structures respectively located on both sides of the assembly housing, which can further improve the structural strength of the assembly housing and improve the installation stability of the aftertreatment assembly.

[0050] Optionally, the mounting component 9 also includes a mounting part 93, and the first support part 91 of the two support structures is fixedly connected to the mounting part 93. It can be connected to the vehicle frame through the mounting part 93 to further improve the installation stability of the aftertreatment assembly.

[0051] This embodiment also provides a vehicle including an engine and an aftertreatment assembly as described above, wherein the front-stage SCR2 is connected to the engine's exhaust port.

[0052] The vehicle in this embodiment, by applying the above-described aftertreatment assembly, has the same functions and beneficial effects as the above-described aftertreatment assembly, which will not be repeated here.

[0053] This embodiment also provides a vehicle control method for a vehicle as described above; the vehicle control method includes the following steps:

[0054] When DPF4 is regenerated based on its front and rear pressure difference, the fuel injection quantity of the engine's in-cylinder after-injection device is determined based on the front and rear temperature difference of MOC3, the front and rear pressure difference of DPF4, and the exhaust gas flow rate into the aftertreatment assembly.

[0055] It should be noted that the aftertreatment assembly in this embodiment adopts an integrated structure, which results in a shorter length of DPF4 along the exhaust gas flow direction, thus requiring frequent regeneration of DPF4.

[0056] When DPF4 regenerates based on its front and rear pressure difference, the amount of fuel injected by the engine's in-cylinder after-injection device is determined based on the front and rear temperature difference of MOC3, the front and rear pressure difference of DPF4, and the exhaust gas flow rate into the aftertreatment assembly. This allows the temperature of DPF4 to rise rapidly to the preset regeneration temperature (the preset regeneration temperature can be determined through experience or repeated tests, and is not limited here), ensuring the efficiency and effectiveness of DPF4 regeneration, and thus ensuring that the functionality of DPF4 can meet higher exhaust emission requirements.

[0057] It should be noted that the methods for obtaining the temperature difference before and after MOC3, the pressure difference before and after DPF4, and the exhaust gas flow rate into the aftertreatment assembly are all existing technologies. For example, the temperature difference before and after MOC3 can be determined by detecting the gas temperatures at the inlet and outlet of MOC3 using two temperature sensors. The pressure difference before and after DPF4 is detected using a pressure differential sensor. The exhaust gas flow rate at the inlet of DPF4 is detected using a flow sensor as the exhaust gas flow rate into the aftertreatment assembly; alternatively, the exhaust gas flow rate at the mixing inlet -11 of the pre-mixer 1 can also be detected using a flow sensor as the exhaust gas flow rate into the aftertreatment assembly, and this is not limited here.

[0058] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A post-processing assembly, characterized in that, The system includes a pre-stage SCR, MOC, DPF, post-stage mixer, and post-stage SCR connected sequentially along the exhaust gas flow direction. The post-stage mixer includes a first mixing inlet, a second mixing inlet, and a post-stage mixing outlet. The first mixing inlet is connected to the outlet of the DPF, and the post-stage mixing outlet is connected to the inlet of the post-stage SCR. The first mixing inlet and the post-stage mixing outlet are located on the same side. The second mixing inlet is used to connect to a urea supply device. The aftertreatment assembly adopts an integrated structure. The after-treatment assembly also includes a pre-stage housing, in which the pre-stage SCR, the MOC, and the DPF are all housed; The MOC includes an oxidative catalytic coating, wherein the ratio of platinum to palladium in the oxidative catalytic coating is greater than 12:

1.

2. The post-processing assembly according to claim 1, characterized in that, The post-processing assembly further includes a post-stage housing and a connecting housing disposed between the pre-stage housing and the post-stage housing. The post-stage SCR is disposed within the post-stage housing. The post-stage mixer is disposed within the connecting housing. The connecting housing and the post-stage housing are both located on the same side of the connecting housing to form a U-shaped assembly housing.

3. The post-processing assembly according to claim 2, characterized in that, The front housing, the connecting housing, and the rear housing are separately configured and fixedly connected; or, the front housing, the connecting housing, and the rear housing are integrally formed.

4. The post-processing assembly according to claim 3, characterized in that, The after-treatment assembly further includes a mounting component, the mounting component including a support structure, the support structure comprising: The first support part is a tubular structure; The second support portion is fixedly disposed on the first support portion, and the second support portion is fixedly connected to the front housing and the rear housing respectively.

5. The post-processing assembly according to claim 1, characterized in that, The aftertreatment assembly also includes a pre-mixer, which includes a mixing inlet one, a mixing inlet two, and a pre-mixing outlet. The pre-mixing outlet is connected to the inlet of the pre-SCR. The mixing inlet one is used to introduce exhaust gas, and the mixing inlet two is used to connect to a urea supply device.

6. The post-processing assembly according to claim 5, characterized in that, The mixing inlet is equipped with a pre-spray unit, which is used to communicate with the urea supply device; and / or The second mixing inlet is equipped with a post-stage spray element, which is used to communicate with the urea supply device.

7. The post-processing assembly according to any one of claims 1-6, characterized in that, Along the exhaust gas flow direction, the length of the subsequent SCR is greater than the length of the preceding SCR.

8. A vehicle, characterized in that, Includes an engine and an aftertreatment assembly as described in any one of claims 1-7, wherein the pre-stage SCR is connected to the exhaust port of the engine.

9. A vehicle control method, characterized in that, For use in the vehicle as described in claim 8; the vehicle control method includes the following steps: When the DPF is regenerated based on the pressure difference across it, the fuel injection quantity of the in-cylinder after-injection device of the engine is determined based on the temperature difference across the MOC, the pressure difference across the DPF, and the exhaust gas flow rate into the aftertreatment assembly.

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