CN207554223U - A kind of high-low pressure egr system - Google Patents

Abstract

This application discloses a kind of high-low pressure egr systems, including engine, cooler for recycled exhaust gas, booster, high pressure EGR tube road, low pressure EGR pipeline, high pressure EGR valve and low pressure EGR valve, the both ends on high pressure EGR tube road connect respectively with before the turbine of air outlet pipe and after the compressor of air inlet pipe；Cooler for recycled exhaust gas is set to high pressure EGR tube road；High pressure EGR valve is set to high pressure EGR tube road, and the import of high pressure EGR valve and the outlet of cooler for recycled exhaust gas connect；The import of low pressure EGR pipeline is connected between high pressure EGR valve and cooler for recycled exhaust gas, before the outlet of low pressure EGR pipeline is connected to the compressor of air inlet pipe；Low pressure EGR valve is connected to low pressure EGR tube road.High pressure EGR tube road and low pressure EGR pipeline share a cooler for recycled exhaust gas, switch high pressure EGR cycles and low pressure EGR loop according to different engine operating conditions by high pressure EGR valve and low pressure EGR valve, reduce cost.And low pressure EGR system can be arranged in engine side, there is no the influences of vehicle pipeline arrangement, facilitate the arrangement of low pressure EGR system.

Description

A high and low pressure EGR system

technical field

The utility model relates to the technical field of engine exhaust gas recirculation, in particular to a high and low pressure EGR system.

Background technique

The existing main technologies that can effectively reduce the nitrogen oxides of internal combustion engines are SCR and EGR technologies, and the EGR technology is to introduce the exhaust gas from the internal combustion engine into the engine to participate in combustion again, so as to reduce the oxygen concentration and combustion temperature, thereby reducing nitrogen oxides generation.

Existing EGR technologies are mainly divided into high-pressure EGR technology and low-pressure EGR technology. High-pressure EGR technology takes exhaust gas from the front of the turbocharger turbine of the engine, and the exhaust gas returns to the engine intake pipe through the EGR cooler, EGR valve and other components, and is mixed with fresh intake air. ;Low-pressure EGR technology takes exhaust gas from the engine turbocharger turbine, generally after after-treatment, and the exhaust gas passes through the EGR cooler, EGR valve and other components and returns to the engine compressor to mix with fresh intake air.

Usually a vehicle is separately equipped with a high-pressure EGR system and a low-pressure EGR system. However, the two EGR systems operate for different engine operating conditions. resulting in higher costs. And because low-pressure EGR needs to introduce exhaust gas after the post-treatment of the turbocharger turbine, the pipeline layout is affected by the layout of the engine and the whole vehicle, so it is difficult to realize, and the low-pressure EGR technology pipeline is long, resulting in engine transient response time It is difficult to meet the increasingly stringent emission regulations.

To sum up, how to solve the problems of high cost of the existing EGR system and difficult arrangement of the low-pressure EGR system has become an urgent problem to be solved by those skilled in the art.

Utility model content

In view of this, the purpose of the utility model is to provide a high and low pressure EGR system, so as to reduce the cost and facilitate the arrangement of the low pressure EGR system.

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

A high and low pressure EGR system, comprising an engine, an EGR cooler and a supercharger, the turbine of the supercharger is arranged in the outlet pipe of the engine, and the compressor of the supercharger is arranged in the inlet of the engine in the trachea;

It also includes a high-pressure EGR pipeline, a low-pressure EGR pipeline, a high-pressure EGR valve and a low-pressure EGR valve, and the two ends of the high-pressure EGR pipeline communicate with the front of the turbine of the outlet pipe and the rear of the compressor of the intake pipe respectively;

The EGR cooler is arranged on the high-pressure EGR pipeline;

The high-pressure EGR valve is arranged on the high-pressure EGR pipeline, and the inlet of the high-pressure EGR valve is connected to the outlet of the EGR cooler;

The inlet of the low-pressure EGR pipeline is connected between the high-pressure EGR valve and the EGR cooler, and the outlet of the low-pressure EGR pipeline is connected before the compressor of the intake pipe;

The low-pressure EGR valve is connected to the low-pressure EGR pipeline.

Preferably, the above-mentioned high-low pressure EGR system further includes a particulate trapping device arranged on the high-pressure EGR pipeline or the low-pressure EGR pipeline and before the inlet of the compressor.

Preferably, in the above-mentioned high-low pressure EGR system, the particulate trapping device is arranged on the high-pressure EGR pipeline, and the outlet of the particulate trapping device is connected to the inlet of the EGR cooler.

Preferably, in the above-mentioned high-low pressure EGR system, the particulate trap is a DPF wall-flow particulate trap or a metal semi-flow particulate trap.

Preferably, the above-mentioned high-low pressure EGR system further includes an intercooler arranged after the compressor of the intake pipe.

Compared with the prior art, the beneficial effects of the utility model are:

In the high-low pressure EGR system provided by the utility model, the high-pressure EGR pipeline and the low-pressure EGR pipeline are connected, and the on-off is controlled by the high-pressure EGR valve and the low-pressure EGR valve respectively. When the high-pressure EGR valve is opened and the low-pressure EGR valve is closed, the exhaust gas enters the high-pressure EGR pipeline from the front of the turbine in the outlet pipe, passes through the EGR cooler and high-pressure EGR valve, and then enters the engine from the rear of the compressor in the intake pipe to realize the high-pressure EGR system. Function: When the low-pressure EGR valve is opened and the high-pressure EGR valve is closed, the exhaust gas enters the high-pressure EGR pipeline from the turbine in the outlet pipe, enters the low-pressure EGR pipeline after passing through the EGR cooler, and passes through the low-pressure EGR valve. It enters the intake pipe before the engine, and enters the engine after passing through the compressor to realize the function of the low-pressure EGR system. It can be seen that the high-pressure EGR pipeline and the low-pressure EGR pipeline share one EGR cooler, and the high-pressure EGR cycle and the low-pressure EGR cycle are switched according to different engine operating conditions through the high-pressure EGR valve and the low-pressure EGR valve, which reduces the cost. Moreover, the low-pressure EGR system takes air directly from the front of the turbine in the outlet pipe, and takes air from the front of the compressor in the intake pipe, which can be arranged on the engine side without the influence of the pipeline layout of the whole vehicle, which is convenient for the layout of the low-pressure EGR system.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description It is only an embodiment of the utility model, and those skilled in the art can also obtain other drawings according to the provided drawings without creative work.

Fig. 1 is the structural representation of a kind of high and low pressure EGR system that the utility model embodiment provides;

Fig. 2 is the structural representation of another kind of high and low pressure EGR system that the utility model embodiment provides;

Fig. 3 is a structural schematic diagram of another high and low pressure EGR system provided by the embodiment of the present utility model.

Among them, 1 is a supercharger, 101 is a turbine, 102 is a compressor, 2 is an air outlet pipe, 3 is an engine, 4 is a high-pressure EGR pipeline, 5 is an EGR cooler, 6 is a high-pressure EGR valve, and 7 is a low-pressure EGR pipe Road, 8 is a low-pressure EGR valve, 9 is an intake pipe, and 10 is a particle trapping device.

Detailed ways

The core of the utility model is to provide a high and low pressure EGR system, which reduces the cost and facilitates the arrangement of the low pressure EGR system.

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Please refer to Figures 1-3, the embodiment of the utility model provides a high and low pressure EGR system, including an engine 3, an EGR cooler 5, a supercharger 1, a high pressure EGR pipeline 4, a high pressure EGR valve 6, a low pressure EGR pipeline 7 and low pressure EGR valve 8.

Wherein, the supercharger 1 includes a coaxially rotating turbine 101 and a compressor 102, the turbine 101 is arranged in the outlet pipe 2 of the engine 3, and the compressor 102 of the supercharger 1 is arranged in the intake pipe 9 of the engine 3;

Both ends of the high-pressure EGR pipeline 4 communicate with the front of the turbine of the outlet pipe 2 and the rear of the compressor of the intake pipe 9 respectively, and the EGR cooler 5 is arranged on the high-pressure EGR pipeline 4;

The high-pressure EGR valve 6 is arranged on the high-pressure EGR pipeline 4, and the inlet of the high-pressure EGR valve 6 is connected with the outlet of the EGR cooler 5;

The inlet of the low-pressure EGR pipeline 7 is connected between the high-pressure EGR valve 6 and the EGR cooler 5, the outlet of the low-pressure EGR pipeline 7 is connected before the compressor of the intake pipe 9, and the low-pressure EGR valve 8 is connected to the low-pressure EGR pipeline 7 .

The working principle and working process of the high and low pressure EGR system are as follows:

When the engine 3 is in a transient state, the high-pressure EGR valve 6 is opened, the low-pressure EGR valve 8 is closed, and the exhaust gas enters the high-pressure EGR pipeline 4 from the turbine of the outlet pipe 2, and after passing through the EGR cooler 5 and the high-pressure EGR valve 6, it is discharged from The compressor of the intake pipe 9 enters the engine 3 to realize the function of the high-pressure EGR system; when the engine is in a steady state, the low-pressure EGR valve is opened, the high-pressure EGR valve 6 is closed, and the exhaust gas enters the high-pressure EGR pipe from the turbine of the outlet pipe 2 Road 4, after passing through the EGR cooler 5, enters the low-pressure EGR pipeline 7, passes through the low-pressure EGR valve 8, enters the intake pipe 9 from the front of the compressor of the intake pipe 9, enters the engine 3 after passing through the compressor 102, and realizes the low-pressure EGR system function.

It can be seen that the high-pressure EGR pipeline 4 and the low-pressure EGR pipeline 7 share one EGR cooler 5, and the high-pressure EGR cycle and the low-pressure EGR cycle are switched according to different engine operating conditions and intake-exhaust pressure differences through the high-pressure EGR valve 6 and the low-pressure EGR valve 8 , reducing costs. Moreover, the low-pressure EGR system takes air directly from the front of the turbine of the outlet pipe 2, and takes air from the front of the compressor of the intake pipe 9, which can be arranged on the side of the engine 3, without the influence of the pipeline layout of the whole vehicle, which facilitates the layout of the low-pressure EGR system .

As shown in FIG. 2 , further, in this embodiment, the high-low pressure EGR system further includes a particulate trapping device 10 disposed on the high-pressure EGR pipeline 4 or the low-pressure EGR pipeline 7 and before the inlet of the compressor 102 . During the low-pressure EGR cycle, since the exhaust gas needs to flow through the compressor 102 of the supercharger 1, the particulate matter content in the exhaust gas should not be too high, otherwise it will easily cause the compressor 102 to fail. Therefore, in the low-pressure EGR cycle path of the high-low pressure EGR system, Moreover, a particle trap 10 is added at the position before the compressor 102, and the particle trap 10 can effectively filter the particulate matter in the exhaust gas.

Furthermore, in this embodiment, the particulate trapping device 10 is arranged on the high-pressure EGR pipeline 4 , and the outlet of the particulate trapping device 10 is connected to the inlet of the EGR cooler 5 . Since the particle trap 10 is located before the turbine 101, the temperature of the gas is consistent with the exhaust temperature of the engine 3, and before the particulate matter enters the EGR cooler 5 to cool, the carbon particles in the particulate matter are recombusted under the condition of high temperature and oxygen, and will not has been accumulated in the particle trap 10, thereby ensuring that the particle trap 10 will not be easily blocked.

As an optimization, in this embodiment, the particle trap 10 can be a DPF wall-flow particle trap commonly used in existing diesel engines, or a metal semi-flow particle trap.

As shown in FIG. 3 , in this embodiment, the high-low pressure EGR system further includes an intercooler 11 arranged after the compressor of the intake pipe 9 . During the low-pressure EGR cycle, the exhaust gas enters the engine 3 after passing through the compressor 102 and the intercooler 11 .

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

The above description of the disclosed embodiments enables those skilled in the art to realize or use the utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims (5)

1. a kind of high-low pressure egr system, including engine, cooler for recycled exhaust gas and booster, the turbine of the booster is set to In the air outlet pipe of the engine, the compressor of the booster is set in the air inlet pipe of the engine；

It is characterized in that, high pressure EGR tube road, low pressure EGR pipeline, high pressure EGR valve and low pressure EGR valve are further included, the high pressure EGR The both ends of pipeline connect respectively with before the turbine of the air outlet pipe and after the compressor of the air inlet pipe；

The cooler for recycled exhaust gas is set to the high pressure EGR tube road；

The high pressure EGR valve is set to the high pressure EGR tube road, and the import of the high pressure EGR valve and the cooler for recycled exhaust gas Outlet connection；

The import of the low pressure EGR pipeline is connected between the high pressure EGR valve and the cooler for recycled exhaust gas, the low pressure EGR tube Before the outlet on road is connected to the compressor of the air inlet pipe；

The low pressure EGR valve is connected to the low pressure EGR tube road.

2. high-low pressure egr system according to claim 1, which is characterized in that further include and be set to the high pressure EGR tube road Or low pressure EGR tube road and the granule capturing device before the import of the compressor.

3. high-low pressure egr system according to claim 2, which is characterized in that the granule capturing device is set to described High pressure EGR tube road, and the outlet of the granule capturing device is connect with the import of the cooler for recycled exhaust gas.

4. high-low pressure egr system according to claim 2, which is characterized in that the granule capturing device is DPF wall-flow types Half flow type grain catcher of grain catcher or metal.

5. high-low pressure egr system according to claim 1, which is characterized in that further include the compressor for being set to air inlet pipe Charge air cooler afterwards.