An engine exhaust after-treatment device

Abstract

The present invention discloses an engine exhaust after-treatment device, which relates to waste gas treatment and solves the technical problem that when the engine is in a small load condition, the temperature of the waste gas after the turbocharger is difficult to meet the temperature requirement for the treatment of carbon particles by the diesel particulate filter. The device includes an exhaust gas recirculation system, a turbocharger, a diesel particulate filter, a bypass pipeline and a bypass valve; the input end of the exhaust gas recirculation system is connected to the exhaust pipe, and the exhaust gas output end of the turbocharger is connected to the input end of the diesel particulate filter through a connecting pipeline; one end of the bypass pipeline and the exhaust gas input end of the turbocharger are connected to the exhaust pipe through an exhaust gas diversion structure, and the other end of the bypass pipeline is connected to the connecting pipeline between the exhaust gas output end of the turbocharger and the input end of the diesel particulate filter; the bypass valve is installed on the bypass pipeline. The present invention improves the treatment capacity and treatment effect of the diesel particulate filter on carbon particles in the waste gas.

Description

Technical Field

[0001] The present invention relates to waste gas treatment, and more specifically, to an engine exhaust after-treatment device. Background Art

[0002] A supercharger is installed on the exhaust pipe of a turbocharged engine. When the engine operates in a small load area, the exhaust temperature in front of the supercharger (i.e., the exhaust temperature in front of the turbine) is relatively low. After these exhaust gases pass through the supercharger, since the exhaust gases do work on the supercharger, the exhaust gas temperature at the outlet of the supercharger (i.e., the exhaust gas temperature after the turbine) is even lower. In addition, existing engines basically come with a post-processor, which is mainly used to purify exhaust gases and solid carbon in the exhaust gases so that the emissions of the engine meet environmental protection requirements. The post-processor contains a DPF (Diesel Particulate Filter), which is used to filter out solid carbon in the exhaust gases and burn it to convert it into carbon dioxide. However, when carbon accumulates in the DPF, the required exhaust temperature needs to reach above 300 °C to burn the carbon cleanly. However, from the perspective of the current engine exhaust structure, when the engine operates at a small load, it will cause the temperature after the turbine to be difficult to reach the requirement of the temperature for carbon cleaning. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an engine exhaust after-treatment device in view of the deficiencies of the prior art, which improves the processing ability of the diesel particulate filter for carbon particles in the exhaust gas.

[0004] An engine exhaust after-treatment device described in the present invention includes an exhaust gas recirculation system, a supercharger, and a diesel particulate filter; the input end of the exhaust gas recirculation system is communicated with the exhaust pipe, and the exhaust gas output end of the supercharger is communicated with the input end of the diesel particulate filter through a connecting pipeline; it also includes a bypass pipeline and a bypass valve; one end of the bypass pipeline and the exhaust gas input end of the supercharger are communicated with the exhaust pipe through an exhaust gas diversion structure, and the other end of the bypass pipeline is connected to the connecting pipeline between the exhaust gas output end of the supercharger and the input end of the diesel particulate filter; the bypass valve is installed on the bypass pipeline, and the bypass valve is electrically connected to the ECU.

[0005] The exhaust gas diversion structure is mainly composed of a connecting pipe section, a first sub-pipe section, and a second sub-pipe section; one end of the connecting pipe section is fixedly connected to the exhaust pipe, the other end of the connecting pipe section is fixedly connected to one end of the first sub-pipe section, and the axis of the connecting pipe section coincides with the axis of the first sub-pipe section; the other end of the first sub-pipe section is connected to the bypass pipeline; one end of the second sub-pipe section is fixedly connected to the connection end of the connecting pipe section and the first sub-pipe section, and a communication cavity is formed at the connection of the connecting pipe section, the first sub-pipe section, and the second sub-pipe section; the other end of the second sub-pipe section is connected to the exhaust gas input end of the supercharger in a line connection.

[0006] The second sub-pipe section is arranged obliquely on one side of the connecting pipe section.

[0007] The included angle between the second sub-pipe section and the connecting pipe section is 30°-45°.

[0008] A slanted block is arranged in a middle position of the communicating cavity and is tilted toward an axial center direction of the sub-pipe section.

[0009] The connecting pipe section, sub-pipe section one and sub-pipe section two are an integrated structure.

[0010] The bypass pipeline is arranged obliquely on one side of the connecting pipeline.

[0011] The angle between the bypass pipeline and the connecting pipeline is 120°-150°.

[0012] Beneficial Effects

[0013] The advantages of the present invention are:

[0014] 1. Through the setting of bypass valve and bypass pipeline, when the engine is running at low load, the exhaust gas can be directly discharged into the diesel particulate filter without passing through the supercharger by opening the bypass valve. This avoids the problem of exhaust gas temperature drop caused by exhaust gas passing through the supercharger, ensures the temperature of exhaust gas under low load conditions, and improves the diesel particulate filter's ability to handle carbon particles in exhaust gas.

[0015] 2. An exhaust gas diversion structure is set at the connection between the bypass pipe and the exhaust pipe. The exhaust gas diversion structure can effectively reduce the amount of exhaust gas entering the supercharger when the bypass pipe is connected, thereby improving the treatment effect of the diesel particulate filter on carbon particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the engine intake and exhaust system of the present invention;

[0017] Figure 2 It is a schematic diagram of the cross-sectional structure of the exhaust gas drainage structure of the present invention.

[0018] Among them: 1-exhaust gas recirculation system, 2-supercharger, 3-diesel particulate filter, 4-exhaust pipe, 5-connecting pipeline, 6-bypass pipeline, 7-bypass valve, 8-exhaust gas diversion structure, 9-connecting pipe section, 10-sub-pipe section 1, 11-sub-pipe section 2, 12-connecting cavity, 13-inclined block, 14-engine, 15-intake throttle valve, 16-intercooler, 17-intake pipe. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the embodiments, but it does not constitute any limitation to the present invention. Any limited number of modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0020] Refer to Figure 1 - Figure 2 Figure 1 - Figure 2 , an engine exhaust after-treatment device of the present invention includes an exhaust gas recirculation system 1, a supercharger 2, a diesel particulate filter 3, a bypass pipeline 6 and a bypass valve 7. The input end of the exhaust gas recirculation system 1 is connected to the exhaust pipe 4, and its output end is connected to the intake pipe 17. One end of the bypass pipeline 6 and the exhaust gas input end of the supercharger 2 are connected to the exhaust pipe 4 through an exhaust gas diversion structure 8. The exhaust gas output end of the supercharger 2 and the input end of the diesel particulate filter 3 are connected through a connecting pipeline 5. The other end of the bypass pipeline 6 is connected to the connecting pipeline 5 between the exhaust gas output end of the supercharger 2 and the input end of the diesel particulate filter 3. The bypass valve 7 is installed on the bypass pipeline 6, and the bypass valve 7 is electrically connected to the ECU.

[0021]

[0021] When the ECU monitors that the engine 14 is operating at a low load, such as when the engine 14 speed is lower than a preset value or the throttle pedal opening is zero and other working conditions, the ECU will send a control signal to open the bypass valve 7, so that the bypass pipeline 6 bridging the supercharger 2 is in a conducting state. That is, the exhaust gas in the exhaust pipe 4 can be directly discharged into the connecting pipeline 5 through the bypass pipeline 6 and then transmitted to the diesel particulate filter 3 without passing through the supercharger 2. Such a setting avoids the problem of the exhaust gas temperature dropping due to the exhaust gas passing through the supercharger 2, ensures the exhaust gas temperature of the engine 14 under low load conditions, and improves the processing ability of the diesel particulate filter 3 for carbon particles in the exhaust gas.

[0022]

[0022] Considering that there is no corresponding valve provided in the exhaust pipe 4 connected to the supercharger 2 in the traditional engine 14 exhaust after-treatment device; and in order to ensure the reliability of the exhaust system, no corresponding valve can be set. Therefore, even when the added bypass pipeline 6 is conducting, there is still some exhaust gas entering the supercharger 2. This situation will also lead to the problem of reduced processing effect of the diesel particulate filter 3 on carbon particles. For this reason, an exhaust gas diversion structure 8 is provided in this embodiment. Through the guiding effect of the exhaust gas diversion structure 8 on the exhaust gas, the amount of exhaust gas entering the supercharger 2 when the bypass pipeline 6 is conducting is reduced.

[0023] Specifically, the exhaust gas diversion structure 8 is mainly composed of a connecting pipe section 9, a first sub-pipe section 10 and a second sub-pipe section 11. Among them, the connecting pipe section 9, the first sub-pipe section 10 and the second sub-pipe section 11 are of an integral structure, so that the overall strength of the exhaust gas diversion structure 8 is high.

[0024] One end of the connecting pipe segment 9 is fixedly connected to the exhaust pipe 4, and the other end of the connecting pipe segment 9 is fixedly connected to one end of the first sub-pipe segment 10, and the axis of the connecting pipe segment 9 coincides with the axis of the first sub-pipe segment 10. The other end of the first sub-pipe segment 10 is connected to the bypass pipeline 6. One end of the second sub-pipe segment 11 is fixedly connected to the connection end of the connecting pipe segment 9 and the first sub-pipe segment 10, and a communication cavity 12 is formed at the connection of the connecting pipe segment 9, the first sub-pipe segment 10 and the second sub-pipe segment 11. The other end of the second sub-pipe segment 11 is connected to the exhaust gas input end line of the supercharger 2.

[0025] Among them, the connecting pipe segment 9 is used to guide the transmission direction of the exhaust gas, so that the exhaust gas is transmitted in the axial direction of the connecting pipe segment 9. Since the exhaust gas has a transmission tendency consistent with the axial direction of the connecting pipe segment 9 when it is transmitted in the connecting pipe segment 9, when the bypass valve 7 is opened, most of the exhaust gas can directly enter the bypass pipeline 6 from the connecting pipe segment 9, achieving the purpose of reducing the amount of exhaust gas entering the supercharger 2 when the bypass pipeline 6 is conducted.

[0026] To further reduce the amount of exhaust gas entering the supercharger 2 when the bypass pipeline 6 is conducted, in this embodiment, the second sub-pipe segment 11 is also inclined and arranged on one side of the connecting pipe segment 9, and the included angle between the second sub-pipe segment 11 and the connecting pipe segment 9 is 30° - 45°. More preferably, it is 45°. That is, an acute angle structure is formed between the second sub-pipe segment 11 and the connecting pipe segment 9, so that the component of the exhaust gas transmission direction in the second sub-pipe segment 11 in the axial direction of the exhaust pipe 4 is opposite to the exhaust gas transmission direction in the connecting pipe segment 9, thereby playing a role in hindering the exhaust gas from entering the second sub-pipe segment 11.

[0027] Furthermore, an inclined block 13 is arranged at the middle position of the communication cavity 12 and is inclined and arranged in the axial direction of the first sub-pipe segment 10. Through the arrangement of the inclined block 13, the internal channel at the connection of the first sub-pipe segment 10 and the connecting pipe segment 9 forms a gradually changing channel inclined in the direction of the first sub-pipe segment 10. When the exhaust gas passes through the gradually changing channel, the inclined block 13 forms a squeezing flow effect on the exhaust gas, so that the exhaust gas passing through the communication cavity 12 is faster than the exhaust gas in the connecting pipe, which can better prevent the exhaust gas from diffusing into the second sub-pipe segment 11 through the communication cavity 12, thereby greatly reducing the amount of exhaust gas entering the supercharger 2 when the bypass pipeline 6 is conducted.

[0028] Through the reasonable setting of the exhaust gas diversion structure 8, that is, the connecting pipe segment 9 and the first sub-pipe segment 10 are coaxially arranged, the second sub-pipe segment 11 and the connecting pipe segment 9 are arranged in an acute angle structure, and the inclined block 13 is arranged in the communication cavity 12. When the bypass valve 7 is opened, the exhaust gas can basically be directly transmitted to the diesel particulate filter 3, achieving a better treatment effect on carbon particles. After actual testing, when the bypass valve 7 is opened, the intake air volume of the bypass pipeline 6 is more than 95% of the intake air volume of the connecting pipe segment 9, with less loss, which can meet the treatment requirements of the diesel particulate filter 3 for carbon particles.

[0029] To enable the exhaust gas to better enter the connecting pipe 5 from the bypass pipe 6, the bypass pipe 6 of this embodiment is arranged obliquely on one side of the connecting pipe 5, and the included angle between the bypass pipe 6 and the connecting pipe 5 is 120°-150°. More preferably, it is 120°. That is, an obtuse angle structure is formed between the bypass pipe 6 and the connecting pipe 5, so that the exhaust gas in the bypass pipe 6 has a component in the same axial direction as the connecting pipe 5, thereby enabling the exhaust gas to be better transmitted to the diesel particulate filter 3.

[0030] The working principle of the present invention is:

[0031] When the ECU monitors that the engine 14 is operating at a small load, the ECU will send a control signal to open the bypass valve 7, so that the bypass pipe 6 bridged on the supercharger 2 is in a conducting state. At this time, the exhaust gas in the exhaust pipe 4 can be directly discharged into the connecting pipe 5 through the bypass pipe 6, and then transmitted to the diesel particulate filter 3 without passing through the supercharger 2. This ensures the temperature of the exhaust gas under the condition of the small load of the engine 14 and improves the processing ability of the diesel particulate filter 3 for the carbon particles in the exhaust gas.

[0032] When the ECU monitors that the engine 14 is not operating at a small load, the bypass valve 7 does not act and is in a closed state, and the bypass pipe 6 is not conducting. When the exhaust gas enters the communication cavity 12, it will be transmitted from the second sub-pipe section 11 to the supercharger 2, causing the supercharger 2 to work to meet the power requirements of the vehicle for the engine 14.

[0033] The above is only the preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which will not affect the implementation effect of the present invention and the practicability of the patent.

Claims

1. An engine exhaust aftertreatment device, comprising an exhaust gas recirculation system (1), a supercharger (2) and a diesel particulate filter (3); an input end of the exhaust gas recirculation system (1) is communicated with an exhaust pipe (4), and the exhaust gas output end of the supercharger (2) and the input end of the diesel particulate filter (3) are communicated through a connecting pipeline (5); characterized in that, It also includes a bypass pipeline (6) and a bypass valve (7); one end of the bypass pipeline (6) and the exhaust gas input end of the supercharger (2) are connected to the exhaust pipe (4) through an exhaust gas diversion structure (8), and the other end of the bypass pipeline (6) is connected to a connecting pipeline (5) between the exhaust gas output end of the supercharger (2) and the input end of the diesel particulate filter (3); the bypass valve (7) is installed on the bypass pipeline (6), and the bypass valve (7) is electrically connected to the ECU; The exhaust gas diversion structure (8) is mainly composed of a connecting pipe section (9), a first sub-pipe section (10) and a second sub-pipe section (11); one end of the connecting pipe section (9) is fixedly connected to the exhaust pipe (4), the other end of the connecting pipe section (9) is fixedly connected to one end of the first sub-pipe section (10), and the axis of the connecting pipe section (9) coincides with the axis of the first sub-pipe section (10); the other end of the first sub-pipe section (10) is connected to the bypass pipeline (6); one end of the second sub-pipe section (11) is fixedly connected to the connection end of the connecting pipe section (9) and the first sub-pipe section (10), and a communication cavity (12) is formed at the connection of the connecting pipe section (9), the first sub-pipe section (10) and the second sub-pipe section (11); the other end of the second sub-pipe section (11) is connected to the exhaust gas input end of the supercharger (2) in a line connection; The second sub-pipe section (11) is arranged obliquely on one side of the connecting pipe section (9); The bypass pipeline (6) is arranged obliquely on one side of the connecting pipeline (5).

2. An engine exhaust aftertreatment device according to claim 1, characterized in that, The included angle between the second sub-pipe section (11) and the connecting pipe section (9) is 30° - 45°.

3. An engine exhaust aftertreatment device according to claim 1, characterized in that, An inclined block (13) arranged obliquely towards the axis direction of the first sub-pipe section (10) is provided at the middle position of the communication cavity (12).

4. An engine exhaust aftertreatment device according to any one of claims 2-3, characterized in that, The connecting pipe section (9), the first sub-pipe section (10) and the second sub-pipe section (11) are of an integral structure.

5. An engine exhaust aftertreatment device according to claim 1, characterized in that, The included angle between the bypass pipeline (6) and the connecting pipeline (5) is 120° - 150°.

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