Post-treatment technical route and treatment method of Europe 7 diesel engine

Abstract

The invention discloses a post-treatment technical route and a treatment method of an Europe seven diesel engine. The post-treatment technical route comprises a heating unit, a diesel oxidation catalyst, a selective catalytic reduction filter, a selective catalytic reduction device and an ammonia slip catalyst. The heating unit is arranged at the front end of the diesel engine exhaust system and is in typical data connection with an electronic control unit of the whole vehicle; the diesel oxidation catalyst is arranged at the downstream of the heating unit; the selective catalytic reduction filter is arranged at the downstream of the diesel oxidation catalyst; and the selective catalytic reduction device and the ammonia slip catalytic converter are arranged at the downstream of the selective catalytic reduction filter. According to the post-processing technical route and the processing method of the Euro 7 diesel engine, the components of the post-processing system are reconfigured, the system arrangement is simplified, the system complexity is reduced, the system compactness is improved, emission can be effectively controlled, and the requirements of the Euro 7 emission standard are met.

Description

Technical Field

[0001] The present invention relates to the field of engine design and manufacturing, and in particular to a post-processing technical route and a processing method for a Euro VII diesel engine. Background Art

[0002] With the gradual implementation of Euro VII emission standards, diesel engine aftertreatment systems need to respond to stricter emission requirements. Traditional diesel engine aftertreatment systems usually include DOC, DPF, and SCR systems, but with the improvement of emission standards, a single aftertreatment technology is often difficult to meet the requirements of the new standards. Therefore, an integrated aftertreatment technology route is needed to comprehensively improve the emission control effect.

[0003] Existing Euro VII diesel engine aftertreatment systems usually adopt a configuration of heating unit + SCR + DOC + DPF + SCR + ASC. Although this configuration can meet the requirements of emission control, its system layout is complex, occupies a large space, and increases the overall complexity of the system. Especially in various stages of emission control, it is difficult for various components to work together, which may affect the overall efficiency and reliability of the system.

[0004] To meet this challenge, the present invention proposes an optimized technical route, which simplifies the system layout, reduces the system complexity, improves the system compactness, and ensures that emissions can be effectively controlled to meet the requirements of the Euro VII emission standards by reconfiguring the components of the after-treatment system.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a post-treatment technology route for Euro VII diesel engines, which simplifies the system layout, reduces system complexity, improves system compactness, and ensures that emissions can be effectively controlled to meet the requirements of the Euro VII emission standards by reconfiguring the components of the post-treatment system.

[0007] Another object of the present invention is to provide a processing method for the post-processing technical route of a Euro VII diesel engine.

[0008] To achieve the above-mentioned purpose, the present invention provides a post-treatment technology route for a Euro VII diesel engine, comprising a heating unit, a diesel oxidation catalyst, a selective catalytic reduction filter, a selective catalytic reduction device and an ammonia slip catalyst; the heating unit is arranged at the front end of the diesel engine exhaust system, and the heating unit is typically connected to the electronic control unit of the whole vehicle; the diesel oxidation catalyst is arranged at the downstream of the heating unit; the selective catalytic reduction filter is arranged at the downstream of the diesel oxidation catalyst; the selective catalytic reduction device and the ammonia slip catalyst are arranged at the downstream of the selective catalytic reduction filter.

[0009] In a preferred embodiment, the post-treatment technology route of the Euro VII diesel engine also includes a urea injection device, a first injection port of which is arranged at the intake end of the selective catalytic reduction filter, and a second injection port is arranged at the intake end of the selective catalytic reduction device and the ammonia slip catalyst, and the urea injection device is electrically connected to the electronic control unit of the vehicle.

[0010] In a preferred embodiment, the post-treatment technology route of the Euro VII diesel engine also includes a first nitrogen oxide sensor, a second nitrogen oxide sensor and a third nitrogen oxide sensor; the first nitrogen oxide sensor is arranged at the outlet end of the selective catalytic reduction filter; the second nitrogen oxide sensor is arranged at the outlet end of the selective catalytic reduction device and the ammonia slip catalyst; the third nitrogen oxide sensor is arranged at the intake end of the heating unit; wherein the first nitrogen oxide sensor, the second nitrogen oxide sensor and the third nitrogen oxide sensor are all connected to the typical data of the electronic control unit.

[0011] In a preferred embodiment, the post-treatment technology route of the Euro VII diesel engine also includes a fourth temperature sensor, a fifth temperature sensor, a sixth temperature sensor, a seventh temperature sensor and an eighth temperature sensor; the fourth temperature sensor is arranged at the intake end of the diesel oxidation catalyst; the fifth temperature sensor is arranged at the outlet end of the diesel oxidation catalyst; the sixth temperature sensor is arranged between the outlet end of the selective catalytic reduction filter and the second injection port of the urea injector; the seventh temperature sensor is arranged at the outlet end of the selective catalytic reduction device and the ammonia slip catalyst; the eighth temperature sensor is arranged at the intake end of the heating unit; wherein the fourth temperature sensor, the fifth temperature sensor, the sixth temperature sensor, the seventh temperature sensor and the eighth temperature sensor are all connected to the typical data of the electronic control unit.

[0012] In a preferred embodiment, the temperature increasing unit includes a burner or an electric heater.

[0013] In a preferred embodiment, the temperature increasing unit, the diesel oxidation catalyst, the selective catalytic reduction filter, the selective catalytic reduction device and the ammonia slip catalyst are arranged on a chassis.

[0014] To achieve the above another object, the present invention also provides a processing method of the post-processing technical route of Euro VII diesel engine, which adopts the post-processing technical route of Euro VII diesel engine as mentioned above for processing, and the processing method comprises: after the exhaust gas of the diesel engine is discharged, it first passes through the turbine end of the supercharger to drive the turbine to rotate, and drives the compressor to rotate to supercharge the cylinder intake air; then the exhaust gas first enters the heating device along the pipeline of the post-processing system for heating; the electronic control unit detects the nitrogen oxide content at the intake end of the heating unit through the third nitrogen oxide sensor, and detects the temperature of the intake end of the heating unit through the eighth temperature sensor, and then detects the temperature of the intake end and the outlet end of the diesel oxidation catalyst through the fourth temperature sensor and the fifth temperature sensor, so as to control the heating temperature of the heating device; the exhaust gas after heating enters the diesel oxidation catalyst, and the diesel oxidation catalyst is used to oxidize part of CO and HC into CO2 and H2O, and convert NO into NO2; then the exhaust gas enters the selective catalytic reduction filter, and the electronic control unit detects the temperature of the intake end of the selective catalytic reduction filter and the nitrogen oxide content of the outlet end through the fifth temperature sensor and the first nitrogen oxide sensor The content of nitrogen oxides is determined by the urea sensor, thereby controlling the urea injection amount of the first injection port of the urea injection device. The exhaust gas can reduce the content of nitrogen oxides through the catalytic reduction of urea in the selective catalytic reduction filter, and can also capture a part of tiny particles and improve the reduction efficiency of nitrogen oxides. Finally, the exhaust gas enters the selective catalytic reduction device and the ammonia slip catalyst. The electronic control unit detects the temperatures of the inlet and outlet ends of the selective catalytic reduction device and the ammonia slip catalyst through the sixth temperature sensor and the seventh temperature sensor, and detects the content of nitrogen oxides at the inlet and outlet ends of the selective catalytic reduction device and the ammonia slip catalyst through the first nitrogen oxide sensor and the second nitrogen oxide sensor, thereby controlling the urea injection amount of the second injection port of the urea injection device. The exhaust gas enters the selective catalytic reduction device, and by using urea as a reducing agent, the nitrogen oxides are further reduced to nitrogen and water, thereby achieving efficient removal of nitrogen oxides. Finally, the exhaust gas enters the ammonia slip catalyst, which is used to capture and convert ammonia that may be generated in the process of the selective catalytic reduction device, prevent ammonia slip, and further optimize the emission quality of the exhaust gas.

[0015] In a preferred embodiment, the post-processing technology route of the Euro VII diesel engine also includes: before the exhaust gas drives the turbine of the supercharger to rotate, a portion of the exhaust gas re-enters the cylinder through the exhaust gas recirculation device for secondary combustion to increase combustion efficiency.

[0016] In a preferred embodiment, the temperature increasing unit includes a burner or an electric heater.

[0017] In a preferred embodiment, the temperature increasing unit, the diesel oxidation catalyst, the selective catalytic reduction filter, the selective catalytic reduction device and the ammonia slip catalyst are arranged on a chassis.

[0018] Compared with the prior art, the post-treatment technical route and treatment method of the Euro VII diesel engine of the present invention have the following beneficial effects: compared with the configuration of the heating unit + SCR + DOC + DPF + SCR + ASC in the prior art, the system layout of the heating unit + DOC + SCRF + SCR + ASC of the present invention is more reasonable. By reconfiguring the positions and sequences of the components, the technical route of the present invention optimizes the system layout while ensuring the emission control effect, making the overall layout more reasonable and compact; reducing system complexity. Compared with the traditional technical route, the present solution simplifies the structure of the post-treatment system and reduces unnecessary components and connections, such as the front SCR and DPF, thereby improving the overall reliability and maintainability of the system; improving system compactness. The technical route of the present solution is more compact in overall design and occupies less space, which helps to improve the design flexibility of the vehicle and save space; maintaining efficient emission control. Although the system layout is more compact, through optimized configuration and combination, the technical route of the present solution can maintain efficient NOx, particulate matter and ammonia control effects, ensuring that emissions meet the requirements of the Euro VII standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the component arrangement of a post-processing technology route according to an embodiment of the present invention;

[0020] Figure 2 It is a schematic flow chart of a processing method according to one embodiment of the present invention.

[0021] Description of main reference numerals:

[0022] DOC-diesel oxidation catalyst, SCRF-selective catalytic reduction filter, SCR-selective catalytic reduction unit, ASC-ammonia slip catalyst, NOx1-first nitrogen oxide sensor, NOx2-second nitrogen oxide sensor, NOx3-third nitrogen oxide sensor, T4-fourth temperature sensor, T5-fifth temperature sensor, T6-sixth temperature sensor, T7-seventh temperature sensor, T8-eighth temperature sensor, EGR-exhaust gas recirculation unit, ECU-electronic control unit. DETAILED DESCRIPTION

[0023] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0024] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0025] like Figure 1 As shown, according to a preferred embodiment of the present invention, a post-treatment technology route for a Euro VII diesel engine mainly includes a heating unit, a diesel oxidation catalyst DOC, a selective catalytic reduction filter SCRF, a selective catalytic reduction device SCR and an ammonia slip catalyst ASC; the heating unit is arranged at the front end of the diesel engine exhaust system, and the heating unit is typically data connected with the electronic control unit ECU (not shown) of the whole vehicle, and the electronic control unit ECU can control the heating temperature of the heating unit; the diesel oxidation catalyst DOC is arranged at the downstream of the heating unit; the selective catalytic reduction filter SCRF is arranged at the downstream of the diesel oxidation catalyst DOC; the selective catalytic reduction device SCR and the ammonia slip catalyst ASC are arranged at the downstream of the selective catalytic reduction filter SCRF.

[0026] In some embodiments, the post-treatment technology route of the Euro VII diesel engine also includes a urea injection device, a first injection port of which is arranged at the intake end of the selective catalytic reduction filter SCRF, and a second injection port is arranged at the intake end of the selective catalytic reduction device SCR and the ammonia slip catalyst ASC, and the urea injection device is electrically connected to the electronic control unit ECU of the whole vehicle.

[0027] In some embodiments, the post-treatment technology route of the Euro VII diesel engine also includes a first nitrogen oxide sensor NOx1, a second nitrogen oxide sensor NOx2 and a third nitrogen oxide sensor NOx3; the first nitrogen oxide sensor NOx1 is arranged at the outlet end of the selective catalytic reduction filter SCRF; the second nitrogen oxide sensor NOx2 is arranged at the outlet end of the selective catalytic reduction device SCR and the ammonia slip catalyst ASC; the third nitrogen oxide sensor NOx3 is arranged at the intake end of the heating unit; wherein the first nitrogen oxide sensor NOx1, the second nitrogen oxide sensor NOx2 and the third nitrogen oxide sensor NOx3 are all connected to the typical data of the electronic control unit ECU.

[0028] In some embodiments, the post-processing technology route of the Euro VII diesel engine also includes a fourth temperature sensor T4, a fifth temperature sensor T5, a sixth temperature sensor T6, a seventh temperature sensor T7 and an eighth temperature sensor T8; the fourth temperature sensor T4 is arranged at the intake end of the diesel oxidation catalyst DOC; the fifth temperature sensor T5 is arranged at the outlet end of the diesel oxidation catalyst DOC; the sixth temperature sensor T6 is arranged between the outlet end of the selective catalytic reduction filter SCRF and the second injection port of the urea injector; the seventh temperature sensor T7 is arranged at the outlet end of the selective catalytic reduction device SCR and the ammonia slip catalyst ASC; the eighth temperature sensor T8 is arranged at the intake end of the heating unit; wherein the fourth temperature sensor T4, the fifth temperature sensor T5, the sixth temperature sensor T6, the seventh temperature sensor T7 and the eighth temperature sensor T8 are all connected to the typical data of the electronic control unit ECU.

[0029] In some embodiments, the temperature increasing unit includes a burner or an electric heater. The temperature increasing unit of this embodiment adopts a burner, but the present invention is not limited thereto.

[0030] See also Figure 1 In some embodiments, the heating unit, the diesel oxidation catalyst DOC, the selective catalytic reduction filter SCRF, the selective catalytic reduction device SCR and the ammonia slip catalyst ASC are arranged on a chassis, such as Figure 1 The part encircled by the dotted frame shown belongs to the chassis layout range.

[0031] like Figure 2As shown, in order to achieve the above-mentioned another purpose, the present invention also provides a processing method of the post-processing technical route of the Euro VII diesel engine, which adopts the post-processing technical route of the Euro VII diesel engine as mentioned above for processing, and the processing method includes: after the exhaust gas of the diesel engine is discharged, it first passes through the turbine end of the supercharger to drive the turbine to rotate, and drives the compressor to rotate to boost the cylinder intake air; then the exhaust gas first enters the heating device along the pipeline of the post-processing system for heating; the electronic control unit ECU detects the nitrogen oxide (NOx) content at the intake end of the heating unit through the third nitrogen oxide sensor NOx3, and detects the intake end of the heating unit through the eighth temperature sensor T8. The temperature of the inlet end and the outlet end of the diesel oxidation catalyst DOC are detected by the fourth temperature sensor T4 and the fifth temperature sensor T5, so as to control the heating temperature of the heating device; the exhaust gas after heating enters the diesel oxidation catalyst DOC, and the diesel oxidation catalyst DOC is used to oxidize part of CO and HC into CO2 and H2O, and convert NO into NO2; then the exhaust gas enters the selective catalytic reduction filter SCRF, and the electronic control unit ECU detects the temperature of the inlet end and the nitrogen oxide sensor NOx1 of the selective catalytic reduction filter SCRF through the fifth temperature sensor T5 and the first nitrogen oxide sensor NOx1. The content of nitrogen oxides is determined by the urea injection amount of the first injection port of the urea injection device, and the exhaust gas can reduce the content of nitrogen oxides through the catalytic reduction effect of urea in the selective catalytic reduction filter SCRF, and can also capture some tiny particles and improve the reduction efficiency of nitrogen oxides; finally, the exhaust gas enters the selective catalytic reduction device SCR and the ammonia slip catalyst ASC, and the electronic control unit ECU detects the temperature of the intake end and the outlet end of the selective catalytic reduction device SCR and the ammonia slip catalyst ASC through the sixth temperature sensor T6 and the seventh temperature sensor T7, as well as the temperature of the first nitrogen oxide sensor NO x1 and the second nitrogen oxide sensor NOx2 detect the nitrogen oxide content at the inlet and outlet ends of the selective catalytic reduction device SCR and the ammonia slip catalyst ASC, thereby controlling the urea injection amount of the second injection port of the urea injection device; the exhaust gas enters the selective catalytic reduction device SCR, and by using urea as a reducing agent, the nitrogen oxides are further reduced to nitrogen and water, thereby achieving efficient removal of nitrogen oxides; and finally the exhaust gas enters the ammonia slip catalyst ASC, which is used to capture and convert ammonia that may be generated in the process of the selective catalytic reduction device SCR, to prevent ammonia slip, and further optimize the emission quality of the exhaust gas.

[0032] In some embodiments, the post-processing technology route of the Euro VII diesel engine also includes: before the exhaust gas drives the turbine of the supercharger to rotate, a portion of the exhaust gas re-enters the cylinder through the exhaust gas recirculation device for secondary combustion to increase combustion efficiency.

[0033] In summary, the post-treatment technical route and treatment method of the Euro VII diesel engine of the present invention have the following advantages: compared with the configuration of the heating unit + SCR + DOC + DPF + SCR + ASC in the prior art, the system layout of the heating unit + DOC + SCRF + SCR + ASC of the present invention is more reasonable. By reconfiguring the positions and sequences of the components, the technical route of the present invention optimizes the system layout while ensuring the emission control effect, making the overall layout more reasonable and compact; reducing system complexity. Compared with the traditional technical route, the present solution simplifies the structure of the post-treatment system and reduces unnecessary components and connections, such as the front SCR and DPF, thereby improving the overall reliability and maintainability of the system; improving system compactness. The technical route of the present solution is more compact in overall design and occupies less space, which helps to improve the design flexibility of the vehicle and save space; maintaining efficient emission control. Although the system layout is more compact, through optimized configuration and combination, the technical route of the present solution can maintain efficient NOx, particulate matter and ammonia control effects, ensuring that emissions meet the requirements of the Euro VII standard.

[0034] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A post-processing technology route for Euro VII diesel engines, characterized in that: include: A heating unit is arranged at the front end of the diesel engine exhaust system, and the heating unit is typically connected to the electronic control unit of the vehicle; A diesel oxidation catalyst, which is arranged downstream of the temperature increasing unit; a selective catalytic reduction filter disposed downstream of the diesel oxidation catalyst; as well as A selective catalytic reduction device and an ammonia slip catalyst are arranged downstream of the selective catalytic reduction filter.

2. The post-processing technology route of the Euro 7 diesel engine as claimed in claim 1, characterized in that: It also includes a urea injection device, a first injection port of which is arranged at the air intake end of the selective catalytic reduction filter, and a second injection port is arranged at the air intake ends of the selective catalytic reduction device and the ammonia slip catalyst. The urea injection device is electrically connected to the electronic control unit of the vehicle.

3. The post-processing technology route of the Euro 7 diesel engine as claimed in claim 2, characterized in that: Also includes: a first nitrogen oxide sensor disposed at an outlet end of the selective catalytic reduction filter; A second nitrogen oxide sensor, which is arranged at the outlet end of the selective catalytic reduction device and the ammonia slip catalyst; as well as a third nitrogen oxide sensor, which is disposed at the air intake end of the temperature increasing unit; The first nitrogen oxide sensor, the second nitrogen oxide sensor and the third nitrogen oxide sensor are all connected to the electronic control unit in typical data connection.

4. The post-processing technology route of the Euro 7 diesel engine as claimed in claim 2, characterized in that: Also includes: a fourth temperature sensor, which is disposed at the intake end of the diesel oxidation catalyst; a fifth temperature sensor, which is disposed at an outlet end of the diesel oxidation catalyst; a sixth temperature sensor, which is disposed between the gas outlet end of the selective catalytic reduction filter and the second injection port of the urea injector; a seventh temperature sensor, which is arranged at the outlet end of the selective catalytic reduction device and the ammonia slip catalyst; as well as an eighth temperature sensor, which is disposed at an air inlet end of the temperature increasing unit; The fourth temperature sensor, the fifth temperature sensor, the sixth temperature sensor, the seventh temperature sensor and the eighth temperature sensor are all typically data connected to the electronic control unit.

5. The post-processing technology route of the Euro VII diesel engine as claimed in claim 2, characterized in that: The temperature increasing unit includes a burner or an electric heater.

6. The post-processing technology route of the Euro VII diesel engine as claimed in claim 2, characterized in that: The temperature raising unit, the diesel oxidation catalyst, the selective catalytic reduction filter, the selective catalytic reduction device and the ammonia slip catalyst are arranged on a chassis.

7. A method for treating a Euro VII diesel engine using a post-treatment technology route, which is treated using the Euro VII diesel engine post-treatment technology route as described in claims 1 to 6, characterized in that: The processing method comprises: After the exhaust gas of the diesel engine is discharged, it first passes through the turbine end of the supercharger to drive the turbine to rotate, and then drives the compressor to rotate to boost the cylinder intake air; Then the exhaust gas first enters the heating device along the pipeline of the post-treatment system to be heated; The electronic control unit detects the nitrogen oxide content at the intake end of the heating unit through the third nitrogen oxide sensor, detects the temperature of the intake end of the heating unit through the eighth temperature sensor, and then detects the temperatures of the intake end and the outlet end of the diesel oxidation catalyst through the fourth temperature sensor and the fifth temperature sensor, thereby controlling the heating temperature of the heating device; The heated exhaust gas enters the diesel oxidation catalyst, which is used to oxidize part of CO and HC into CO2 and H2O, and convert NO into NO2; Then the exhaust gas enters the selective catalytic reduction filter, and the electronic control unit detects the temperature of the air inlet end and the nitrogen oxide content at the air outlet end of the selective catalytic reduction filter through the fifth temperature sensor and the first nitrogen oxide sensor, thereby controlling the urea injection amount of the first injection port of the urea injection device. The exhaust gas can reduce the nitrogen oxide content through the catalytic reduction effect of urea in the selective catalytic reduction filter, and can also capture a part of the tiny particles, thereby improving the reduction efficiency of the nitrogen oxides. Finally, the exhaust gas enters the selective catalytic reduction device and the ammonia slip catalyst, and the electronic control unit detects the temperatures of the inlet end and the outlet end of the selective catalytic reduction device and the ammonia slip catalyst through the sixth temperature sensor and the seventh temperature sensor, and detects the nitrogen oxide content at the inlet end and the outlet end of the selective catalytic reduction device and the ammonia slip catalyst through the first nitrogen oxide sensor and the second nitrogen oxide sensor, thereby controlling the urea injection amount of the second injection port of the urea injection device; The tail gas enters the selective catalytic reduction device, and by using urea as a reducing agent, the nitrogen oxides are further reduced to nitrogen and water, thereby achieving efficient removal of nitrogen oxides; and Finally, the exhaust gas enters the ammonia slip catalyst, which is used to capture and convert ammonia that may be generated in the process of the selective catalytic reduction device, prevent ammonia slip, and further optimize the emission quality of the exhaust gas.

8. The post-processing method of the Euro VII diesel engine according to claim 7, characterized in that: Also includes: Before the exhaust gas drives the turbine of the supercharger to rotate, a part of the exhaust gas re-enters the cylinder through the exhaust gas recirculation device for secondary combustion, thereby increasing the combustion efficiency.

9. The post-processing method of the Euro VII diesel engine according to claim 7, characterized in that: The temperature increasing unit includes a burner or an electric heater.

10. The post-processing method of the Euro VII diesel engine according to claim 7, characterized in that: The temperature raising unit, the diesel oxidation catalyst, the selective catalytic reduction filter, the selective catalytic reduction device and the ammonia slip catalyst are arranged on a chassis.

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