CN213235268U

CN213235268U - EGR system

Info

Publication number: CN213235268U
Application number: CN202021300539.6U
Authority: CN
Inventors: 刘俊龙; 李卫; 王俊莉
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2020-07-06
Filing date: 2020-07-06
Publication date: 2021-05-18
Anticipated expiration: 2030-07-06

Abstract

The utility model discloses a EGR system, including engine cylinder, intake pipe, blast pipe and turbo charger, intake pipe and blast pipe with engine cylinder intercommunication, turbo charger includes coaxial coupling's compressor and turbine, the entry of blast pipe and EGR pipeline the entry position of the intercommunication pipeline of turbine is provided with flow control valve, turbo charger sets up the one end of blast pipe. The utility model discloses a higher EGR rate has been realized to the EGR system.

Description

EGR system

Technical Field

The utility model relates to a vehicle engine technical field, in particular to efficient EGR system.

Background

EGR (Exhaust Gas Re-circulation), an abbreviation for Exhaust Gas recirculation. Exhaust gas recirculation refers to the recirculation of a portion of the exhaust gases from the engine back into the intake manifold and back into the cylinders along with fresh mixture. Since exhaust gas contains a large amount of polyatomic gas such as CO2, and gas such as CO2 cannot be combusted but absorbs a large amount of heat due to its high specific heat capacity, the maximum combustion temperature of the air-fuel mixture in the cylinder is lowered, and the amount of NOx generated is reduced.

At present, the further improvement of the EGR rate of an engine is limited by a supercharger and the economy of the engine, the EGR rate is difficult to realize in a low-speed large-torque area by matching of the supercharger, and a traditional EGR system needs a small turbine to realize a high EGR rate, so that the high-speed high-load oil consumption rate is greatly improved.

In summary, how to provide an efficient EGR system 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 a higher EGR rate has been realized to EGR system.

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

the utility model provides an EGR system, includes engine cylinder, intake pipe, blast pipe and turbo charger, intake pipe and blast pipe with engine cylinder intercommunication, turbo charger includes coaxial coupling's compressor and turbine, the entry of blast pipe and EGR pipeline the entry position of the intercommunication pipeline of turbine is provided with flow control valve, turbo charger sets up the one end of blast pipe.

Preferably, the inlet of the communication pipeline of the turbine and the inlet of the EGR pipeline are both arranged at the same end of the exhaust pipe, the inlet of the communication pipeline of the turbine and the inlet of the EGR pipeline are arranged in parallel, the inlet of the EGR pipeline is arranged at a side close to the exhaust pipe far away from the exhaust manifold, and the inlet of the communication pipeline of the turbine is arranged at a side close to the exhaust pipe close to the exhaust manifold.

Preferably, the flow control valve is rotatably connected to a partition wall at an inlet of a communication line of the turbine and an inlet of the EGR line.

Preferably, a valve plate rotating shaft of the flow control valve is connected with an output shaft end of a stepping motor, and the stepping motor controls the opening degree of the flow control valve.

Preferably, an EGR cooler and an EGR valve are arranged on the EGR pipeline, and the EGR valve is arranged close to one end of the intake pipe.

Preferably, the exhaust manifold is provided on an upper wall surface of the exhaust pipe, the inlet of the EGR line is provided near a lower wall surface of the exhaust pipe, and the inlet of the communication line of the turbine is provided near the upper wall surface of the exhaust pipe.

Preferably, the exhaust manifold is disposed obliquely to the turbocharger disposed end.

Preferably, the EGR valve and the flow control valve are both in communication with a controller.

Preferably, the controller is an ECU of the engine.

According to the above technical scheme, the utility model provides a EGR system, turbo charger arrange the one end at the blast pipe, rather than set up turbo charger's entry at the intermediate position of blast pipe, when having avoided the intermediate position to set up, the striking that exhaust gas produced at turbo charger's entrance in the exhaust manifold of different sides has avoided the collision to the resistance that the waste gas stream produced, has improved the utilization ratio of exhaust energy. A flow control valve is arranged between the exhaust pipe and the turbine, the flow control valve adjusts the amount of exhaust gas entering the EGR pipeline and the turbine through different opening degrees, the adjustment of the EGR rate is realized through the combined control of the EGR valve and the flow control valve, and the higher EGR rate is realized.

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 structural diagram of an EGR system according to an embodiment of the present invention;

fig. 2 is a schematic cross-sectional structural view of an exhaust pipe provided in an embodiment of the present invention;

FIG. 3 is a schematic diagram of the position of the valve plate of the flow control valve when a high EGR rate is required in the embodiment of the present invention;

fig. 4 is the valve plate position schematic diagram of the flow control valve in the embodiment of the present invention when the air input is high.

Detailed Description

The utility model discloses a higher EGR rate has been realized to EGR system.

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 to 4, the present invention provides an EGR system, which includes an engine cylinder 1, an intake pipe 7, an exhaust pipe 2 and a turbocharger 4, wherein the intake pipe 7 and the exhaust pipe 2 are communicated with the engine cylinder 1, the turbocharger 4 includes a compressor 42 and a turbine 41 which are coaxially connected, a flow control valve 3 is disposed at an inlet of the exhaust pipe 2 and an EGR pipeline 9 and an inlet of a communication pipeline 10 of the turbine 41, and the turbocharger 4 is disposed at one end of the exhaust pipe 2.

The engine cylinder 1 is a multi-cylinder engine. An intercooler 11 is arranged on an air inlet pipeline communicated with the compressor 42. The intercooler 11 is used to reduce the temperature of the supercharged high-temperature air to reduce the heat load of the engine, increase the intake air amount, and further increase the power of the engine. Air in an air inlet pipeline communicated with the compressor 42 and tail gas in the EGR pipeline 9 both enter the air inlet pipe 7, the flow control valve 3 is arranged at the position where the exhaust pipe 2 is communicated with the communication pipeline 10 and the EGR pipeline 9 of the turbine 41, and the flow control valve 3 divides the exhaust gas entering the communication pipeline 10 and the EGR pipeline 9 of the turbine 41. The EGR line 9 is provided with an EGR cooler 5 and an EGR valve 6, and the EGR valve 6 is provided near one end of the intake pipe 7. The structure within the dashed box in fig. 1 is shown in fig. 2 after being axially cut. The direction of the arrows in fig. 1 is the exhaust gas flow direction.

The utility model discloses a EGR system, turbo charger 4 arranges the one end at blast pipe 2, rather than setting up turbo charger 4's entry at the intermediate position of blast pipe 2, the intermediate position of here is for exhaust manifold 8 arrange, the intermediate position, a plurality of exhaust manifold 8 symmetric positions on blast pipe 2 promptly, when having avoided the intermediate position to set up, the striking that exhaust gas produced in turbo charger 4's entrance in the exhaust manifold 8 of different sides, the resistance of collision to the waste gas stream production has been avoided, the utilization ratio of exhaust energy has been improved. The flow control valve 3 is arranged between the exhaust pipe 2 and the turbine 41, the flow control valve 3 adjusts the amount of exhaust gas entering the EGR pipeline 9 and the turbine 41 through different opening degrees, and the adjustment of the EGR rate is realized through the combined control of the EGR valve 6 and the flow control valve 3, so that the higher EGR rate is realized.

Specifically, as shown in fig. 1 and 2, the inlet of the communication line 10 of the turbine 41 and the inlet of the EGR line 9 are both provided at the same end of the exhaust pipe, and the inlet of the communication line 10 of the turbine 41 and the inlet of the EGR line 9 are provided in parallel. The inlet of the EGR line 9 is provided at a pipe wall position near the side of the exhaust pipe 2 remote from the exhaust manifold 8, and the inlet of the communication line 10 of the turbine 41 is provided at a pipe wall position near the side of the exhaust pipe 2 near the exhaust manifold 8. The exhaust gas discharged from each exhaust manifold 8 flows along a side wall surface of the exhaust pipe 2 away from the exhaust manifold 8 by inertia, and the inlet of the EGR line 9 is provided at a pipe wall position of the exhaust pipe 2 away from the exhaust manifold 8, so that the inertia of the exhaust gas can be sufficiently utilized to smoothly enter the EGR line 9.

Further, the flow control valve 3 is rotatably connected to a partition wall at an inlet of the communication line 10 of the turbine 41 and an inlet of the EGR line 9. The valve plate rotating shaft of the flow control valve 3 is connected with the output shaft end of the stepping motor, and the stepping motor transmits power to the valve plate rotating shaft to control the opening degree of the flow control valve 3 according to a control signal sent by the controller when working.

In a specific embodiment, as shown in fig. 2, the exhaust manifold 8 is provided on the upper wall surface of the exhaust pipe 2, i.e., the inlet of the exhaust manifold 8 is provided on the upper wall surface of the exhaust pipe 2. The inlet of the EGR line 9 is provided near the lower wall surface of the exhaust pipe 2, and the inlet of the communication line 10 of the turbine 41 is provided near the upper wall surface of the exhaust pipe 2. The gas intake position of the EGR line 9 is arranged at a position close to the lower wall surface of the outlet of the exhaust pipe 2, the inlet position of the communication line 10 of the turbine 41 is arranged at a position close to the upper wall surface of the outlet of the exhaust pipe 2, and the exhaust gas discharged from each exhaust manifold 8 flows along the lower wall surface of the exhaust pipe 2 due to the inertia and gravity, and particularly under the working condition of small exhaust flow, the exhaust gas smoothly enters the EGR line 9 by fully utilizing the inertia and gravity, so that high EGR rate is realized.

It will be appreciated that if the EGR rate requirement is not high, the inlet of the communication line 10 of the turbine 41 is disposed near the lower wall surface of the exhaust pipe 2, which makes it possible to make full use of the exhaust energy and improve the efficiency of the turbocharger. That is, the inlet of the communication line 10 of the turbine 41 and the gas-taking position of the EGR line 9 are set according to the demand for the EGR rate, which is not limited herein.

Specifically, the exhaust manifolds 8 are each disposed obliquely to the flow control valve 3 disposed end. I.e. the outlet end of the exhaust manifold 8 is closer to the flow control valve 3 than the inlet end.

For control convenience, the EGR valve 6 and the flow control valve 3 are both communicatively connected to the controller. The controller is an ECU of the engine.

The utility model discloses a flow control valve 3 is arranged in the exit of blast pipe 2 to the EGR system, by its aperture of step motor control, waste gas partly gets into turbo charger 4 through the valve, and partly get into EGR pipeline 9. When the valve plate of the flow control valve 3 is close to the upper wall surface of the exhaust pipe 2, as shown in fig. 3, most of the exhaust gas discharged from each cylinder enters the EGR line 9 through the diversion of the valve plate, so that a high EGR rate is achieved, and even when the valve plate is at the uppermost position, the inlet of the communication line 10 of the turbine 41 is completely closed, so that the exhaust gas can be completely diverted to enter the EGR line 9, and the EGR rate of 100% is achieved. When the EGR demand is small, the valve plate of the flow control valve 3 is rotated to the position shown in fig. 4, and the exhaust gas discharged from each cylinder is guided by the valve plate to enter the turbine 41 for a large part, so that the intake pressure is increased and the efficiency of the turbocharger 4 is improved. When the EGR rate is not required at all, the valve plate of the flow control valve 3 is in the lowermost position, the EGR line 9 is completely closed, and the exhaust gas is completely introduced into the turbine 41. The combined control of the EGR valve 6 and the flow control valve 3 achieves the intake air amount and EGR rate required by the engine.

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.

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. The EGR system comprises an engine cylinder (1), an air inlet pipe (7), an exhaust pipe (2) and a turbocharger (4), wherein the air inlet pipe (7) and the exhaust pipe (2) are communicated with the engine cylinder (1), the turbocharger (4) comprises a compressor (42) and a turbine (41) which are coaxially connected, the EGR system is characterized in that the inlet of the exhaust pipe (2) and an EGR pipeline (9) is arranged at the inlet position of a communication pipeline (10) of the turbine (41) and provided with a flow control valve (3), and the turbocharger (4) is arranged at one end of the exhaust pipe (2).

2. The EGR system according to claim 1, wherein an inlet of the communication pipe (10) of the turbine (41) and an inlet of the EGR pipe (9) are both provided at the same end of the exhaust pipe (2), the inlet of the communication pipe (10) of the turbine (41) is provided in parallel with the inlet of the EGR pipe (9), and the inlet of the EGR pipe (9) is provided near a side of the exhaust pipe (2) away from an exhaust manifold (8), and the inlet of the communication pipe (10) of the turbine (41) is provided near a side of the exhaust pipe (2) close to the exhaust manifold (8).

3. EGR system according to claim 2, characterized in that the flow control valve (3) is rotatably connected to a partition wall at the inlet of the communication line (10) of the turbine (41) and at the inlet of the EGR line (9).

4. The EGR system according to claim 3, characterized in that a valve plate rotating shaft of the flow control valve (3) is connected with an output shaft end of a stepping motor, and the stepping motor controls the opening degree of the flow control valve (3).

5. The EGR system according to claim 1, wherein the EGR line (9) is provided with an EGR cooler (5) and an EGR valve (6), and the EGR valve (6) is provided near one end of the intake pipe (7).

6. The EGR system according to claim 2, wherein the exhaust manifold (8) is provided at an upper wall surface of the exhaust pipe (2), an inlet of the EGR line (9) is provided near a lower wall surface of the exhaust pipe (2), and an inlet of the communication line (10) of the turbine (41) is provided near an upper wall surface of the exhaust pipe (2).

7. The EGR system according to claim 2, wherein the exhaust manifold (8) is provided obliquely to the flow control valve (3).

8. The EGR system of claim 5, wherein the EGR valve (6) and the flow control valve (3) are each communicatively connected to a controller.

9. The EGR system of claim 8 wherein the controller is an ECU of the engine.