CN210858872U

CN210858872U - Engine aftertreatment system

Info

Publication number: CN210858872U
Application number: CN201921663343.0U
Authority: CN
Inventors: 安邦; 王意宝; 张晓丽; 伏金龙; 张蒿; 庞鑫
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2020-06-26
Anticipated expiration: 2029-09-30

Abstract

The utility model discloses an engine aftertreatment system, which comprises a DOC, a first DPF and an SCR which are sequentially connected with an exhaust pipe along the exhaust direction, and is characterized by also comprising a bypass pipe, wherein the bypass pipe is connected with the first DPF in parallel, a second DPF is arranged on the bypass pipe, and the first DPF and the second DPF have different filtering effects; the first DPF and the second DPF do not operate simultaneously. The utility model discloses an engine aftertreatment system can guarantee that exhaust gas's particulate matter content is up to standard, can effectively reduce the exhaust backpressure of engine again, improves the efficiency of engine.

Description

Engine aftertreatment system

Technical Field

The utility model relates to a vehicle advances exhaust technical field, in particular to engine aftertreatment system.

Background

An engine aftertreatment system is a system for treating exhaust gas of an engine, which is installed in an engine exhaust system to reduce the amount of pollutants discharged from the exhaust gas through a catalytic oxidation reaction.

The engine aftertreatment system comprises a DOC, a DPF and an SCR which are communicated. The existing engine post-treatment system is provided with a DPF (diesel particulate filter), and the DPF is mainly used for filtering PM and PN (positive noise) in exhaust gas. In order to ensure the filtering effect on the tail gas, the DPF with a better filtering effect is generally used, so that the exhaust back pressure of the engine is large, namely the exhaust resistance is large, and the performance of the engine is influenced due to unsmooth exhaust. If the DPF with a poor filtering effect is used, the filtering effect of particulate matters in the tail gas cannot be ensured under some working conditions.

Therefore, how to provide an engine aftertreatment system, which enables the exhaust back pressure of the engine to be small and ensures the filtering effect of particulate matters in the exhaust gas, becomes a technical problem to be solved urgently by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides an engine aftertreatment system makes engine exhaust backpressure little, guarantees the filter effect of particulate matter in the tail gas simultaneously.

In order to achieve the above object, the utility model provides a following technical scheme:

an engine aftertreatment system comprises a DOC, a first DPF, an SCR and a bypass pipe, wherein the DOC, the first DPF and the SCR are sequentially connected to an exhaust pipe along an exhaust direction, the bypass pipe is connected with the first DPF in parallel, a second DPF is arranged on the bypass pipe, and the first DPF and the second DPF have different filtering effects; the first DPF and the second DPF do not operate simultaneously.

Preferably, a first valve is arranged at the front end of the first DPF, a second valve is arranged at the front end of the second DPF, and when one of the first valve and the second valve is opened, the other valve is closed.

Preferably, still include the particulate matter sensor that is used for detecting exhaust pipe internal exhaust particulate matter content, the particulate matter sensor sets up the position of the DOC front end of exhaust pipe, a particulate matter sensor communication connection controller.

Preferably, the first valve and the second valve are both electrically controlled valves, and both the first valve and the second valve are electrically connected with the controller.

Preferably, the controller is electrically connected to an indicating device.

Preferably, the indicating device is an indicator light.

Preferably, the controller is an ECU of the engine.

According to the above technical scheme, the utility model provides an engine aftertreatment system sets up the different DPF of two filter effects through parallelly connected, lets the good DPF of filter effect filter when former exhaust tail gas particulate matter content is high, lets tail gas filter through the relatively poor DPF of filter effect when former exhaust tail gas particulate matter content is low, can guarantee like this that exhaust tail gas's particulate matter content is up to standard, can effectively reduce the exhaust backpressure of engine again, improves the efficiency of engine.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic view of a connection structure of an engine aftertreatment system according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a control system of an engine aftertreatment system according to an embodiment of the present invention.

Detailed Description

The utility model discloses an engine aftertreatment system makes engine exhaust backpressure little, guarantees the filter effect of particulate matter in the tail gas simultaneously.

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1, the utility model discloses an engine aftertreatment system, include DOC3, first DPF5 and SCR8 that connect gradually on blast pipe 2 along the exhaust direction, still include a bypass pipe, the entry end of bypass pipe and the front end of first DPF5 intercommunication, the exit end of bypass pipe and the rear end of first DPF5 intercommunication to make the bypass pipe and first DPF5 set up in parallel, be provided with second DPF7 on the bypass pipe. It is understood that the "front end" is an exhaust gas inlet end and the "rear end" is an exhaust gas outlet end.

The DPF is a particulate filter, and is installed in an exhaust system of the engine 1 to reduce the particulate matter content in the exhaust gas by filtering. The DOC is an oxidation-type catalytic converter, is installed in an exhaust system of the engine 1, and reduces emission of pollutants such as CO and THC in exhaust gas and SOF in Particulate Matter (PM) by catalytic oxidation reaction. The SCR is installed in an engine exhaust system to selectively catalytically reduce nitrogen oxides (NOx) in exhaust gas to reduce the amount of NOx emission.

Wherein the exhaust pipe 2 communicates with each cylinder exhaust port of the engine 1. The first DPF5 and the second DPF7 have different filtering effects; the first DPF5 and the second DPF7 do not operate simultaneously. When the particulate matter content among the former exhaust tail gas is high, the pipeline at DPF device place that the filter effect is good among first DPF5 and the second DPF7 is opened, and the work of the DPF device that the filter effect is good, and the pipeline at DPF device place that the filter effect is relatively poor is closed, and the DPF device that the filter effect is relatively poor does not work. When the content of particulate matters in the original exhaust tail gas is low, the pipeline where the DPF device with the poor filtering effect is located in the first DPF5 and the second DPF7 is opened, the DPF device with the poor filtering effect works, the pipeline where the DPF device with the good filtering effect is located is closed, and the DPF device with the good filtering effect does not work.

The better the DPF filtering effect, the thicker the walls of the DPF carrier, the denser the material in the walls that plays the filtering effect, so that the exhaust gas of the engine 1 is more difficult to exhaust, resulting in a high exhaust backpressure of the engine 1.

The utility model discloses an engine aftertreatment system sets up the different DPF of two filter effects through parallelly connected, lets the DPF that the filter effect is good filter when former exhaust tail gas particulate matter content is high, lets tail gas filter through the relatively poor DPF of filter effect when former exhaust tail gas particulate matter content is low, can guarantee like this that exhaust tail gas's particulate matter content is up to standard, can effectively reduce engine 1's exhaust backpressure again, improves engine 1's efficiency.

As shown in fig. 1 and 2, in order to control whether the first DPF5 and the second DPF7 are operated or not, a first valve 4 is provided at a front end of the first DPF5, a second valve 6 is provided at a front end of the second DPF7, and when one of the first valve 4 and the second valve 6 is opened, the other is closed. In a specific embodiment, the first DPF5 has better filtering effect than the second DPF7, when the content of particulate matters in the exhaust gas is high, the first valve 4 is opened, the second valve 6 is closed, and the first DPF5 filters to ensure that the exhaust gas emission reaches the standard; when the content of particulate matters in the exhaust gas is low, the first valve 4 is closed, the second valve 6 is opened, and the second DPF7 is filtered, so that the exhaust back pressure is reduced as far as possible on the premise of ensuring that the exhaust gas emission reaches the standard.

In order to facilitate detection of the content of particulate matters in the exhaust gas discharged from the exhaust pipe 2, a particulate matter sensor is further arranged, the particulate matter sensor is arranged at the front end of the DOC3 of the exhaust pipe 2, the particulate matter sensor is used for detecting the content of the particulate matters in the exhaust gas of the exhaust pipe 2, and the particulate matter sensor is in communication connection with a controller.

Further, in order to control the opening and closing of the valves conveniently, the first valve 4 and the second valve 6 are both electric control valves, the first valve 4 and the second valve 6 are both electrically connected with the controller, and the controller controls the opening and closing of the first valve 4 and the second valve 6 according to the detection result of the particulate matter sensor.

In a specific embodiment, the controller is electrically connected to an indicating device, and the indicating device is disposed at a position convenient for a user to view during use, which may be a position of a cab panel, and is not limited herein. The particulate matter sensor detects the particulate matter content of the original exhaust tail gas in the exhaust pipe 2, and the controller judges whether the particulate matter content of the original exhaust tail gas is in a calibration range, so that the controller controls the opening and closing of the first valve 4 and the second valve 6, and the indicating device is convenient for checking the opening and closing state of the current valve. Specifically, the indicating device is an indicating lamp.

The controller is an ECU of the engine. The first valve 4 and the second valve 6 are controlled by the ECU. The ECU is an electric control unit and is a special microcomputer controller for the engine; the ECU is used for monitoring and controlling the work of the valve, so that accurate control can be realized, a new control unit cannot be added, and the original structure does not need to be changed greatly.

The utility model discloses an engine aftertreatment system, DPF section have the DPF of two parallelly connected settings of different filter effects, and every DPF front end corresponds and sets up a control flap. The control valve is an electric control valve, and the opening of the valve can be accurately controlled by adopting the electric control valve.

As shown in fig. 2, the particulate matter sensor transmits two data of the detected PM content and the detected PN amount in the exhaust gas to the ECU, and after calculation by the ECU, the electrically controlled valve serving as an actuator is selectively opened or closed according to a control command of the ECU. In a specific embodiment, the first DPF5 has better filtering effect than the second DPF7, when the content of PM and PN exceeds a set range, the second valve 6 is closed, the first valve 4 is opened, and the whole exhaust gas is filtered through the first DPF5, and when the content of PM and PN is within the set range, the first valve 4 is closed, the second valve 6 is opened, and the whole exhaust gas is filtered through the second DPF7, so that the exhaust back pressure is reduced as much as possible on the premise of ensuring the emission to reach the standard. Aiming at engines 1 with different discharge capacities and different purposes, different DPFs can be selected for filtering according to the contents of PM and PN in the exhaust gas.

In the description of the present solution, it is to be understood that the terms "upper", "lower", "vertical", "inside", "outside", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present solution.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An engine aftertreatment system comprises a DOC (3), a first DPF (5) and an SCR (8) which are sequentially connected to an exhaust pipe along an exhaust direction, and is characterized by further comprising a bypass pipe, wherein the bypass pipe is connected with the first DPF (5) in parallel, a second DPF (7) is arranged on the bypass pipe, and the first DPF (5) and the second DPF (7) have different filtering effects; the first DPF (5) and the second DPF (7) do not operate simultaneously.

2. The engine aftertreatment system according to claim 1, characterized in that a first valve (4) is provided at the front end of the first DPF (5), a second valve (6) is provided at the front end of the second DPF (7), and one of the first valve (4) and the second valve (6) is opened while the other is closed.

3. The engine aftertreatment system of claim 2, further comprising a particulate matter sensor for detecting the particulate matter content of the exhaust gas in the exhaust pipe (2), wherein the particulate matter sensor is arranged at the front end of the DOC (3) of the exhaust pipe (2), and the particulate matter sensor is in communication connection with a controller.

4. The engine aftertreatment system of claim 3, wherein the first valve (4) and the second valve (6) are both electrically controlled valves, and the first valve (4) and the second valve (6) are both electrically connected to the controller.

5. The engine aftertreatment system of claim 3, wherein the controller is electrically connected to an indicator device.

6. The engine aftertreatment system of claim 5, wherein the indicator device is an indicator light.

7. The engine aftertreatment system of claim 3, wherein the controller is an ECU of the engine.