CN111927656A

CN111927656A - Exhaust gas recirculation system with asymmetric flow

Info

Publication number: CN111927656A
Application number: CN202011020328.1A
Authority: CN
Inventors: 战强; 牟海峰
Original assignee: Shandong Xinde Make Turbocharger Co ltd
Current assignee: Shandong Xinde Make Turbocharger Co ltd
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2020-11-13

Abstract

The invention discloses an exhaust gas recirculation system with asymmetric flow, which comprises a symmetric turbocharger, wherein the symmetric turbocharger comprises a turbine and a gas compressor, the turbine is provided with two flow channels, the two flow channels are respectively a first flow channel and a second flow channel, the second flow channel of the turbine is communicated with a first exhaust manifold, the first flow channel of the turbine is communicated with a second exhaust manifold, the other ends of the first exhaust manifold and the second exhaust manifold are respectively communicated with a certain number of exhaust manifolds corresponding to an engine, and an EGR pipeline is arranged between the first exhaust manifold and an air inlet end of the engine; adopt EGR valve and EGR pipeline to let in engine exhaust's partly waste gas once more in the engine, realize enough high reducible NOx of EGR rate and discharge, reduce economic nature's deterioration to a certain extent, and make conveniently, production installation cost is low, improves the result of use greatly.

Description

Exhaust gas recirculation system with asymmetric flow

Technical Field

The invention relates to an exhaust gas recirculation system, in particular to an exhaust gas recirculation system which is simple in structure and capable of effectively improving the EGR rate and has asymmetric flow, and belongs to the technical field of engines.

Background

Exhaust gas recirculation systems (EGR systems) are one of the effective means for engines to reduce NOx emissions; the EGR system leads part of exhaust gas discharged by the engine to an air inlet pipe of the engine, so that part of the exhaust gas of the engine is mixed with fresh air and enters an air inlet of the engine, the exhaust gas is reintroduced into the cylinder to participate in combustion, the oxygen concentration and the highest combustion temperature in the cylinder can be reduced, and the effect of reducing NOx is achieved.

In order to ensure the EGR rate, the prior art generally adopts an exhaust throttle valve or an asymmetric supercharger to ensure that exhaust gas has certain pressure to enter an air inlet pipe to be mixed with fresh air, wherein the asymmetric supercharger has a certain effect on reducing oil consumption when obtaining the same EGR level, and the specific structure of the asymmetric supercharger is that the asymmetric supercharger is provided with two flow channels, the cross sections of the two flow channels are not designed according to the ratio of 1:1, but are divided into two flow channels with one large flow channel and one small flow channel, and one part of exhaust ports of all cylinders of an engine is communicated with a first flow channel, and the other part of exhaust ports is communicated with a second flow channel.

As patent numbers: 201510334163.8, discloses a control device and a control method for an asymmetric flow passage turbocharger, the turbocharger comprises a first flow passage and a second flow passage which are communicated with an exhaust port of an engine, an EGR valve of the engine is communicated with a first exhaust pipeline between the first flow passage and the exhaust port, the control device comprises: the electronic control air release valve is provided with an inlet and an outlet, the inlet is communicated with the first air release pipeline, and the outlet can be communicated to the outside; a pressure detecting element for detecting an intake pressure of the first flow passage; and the controller controls the opening and closing of the electronic control air release valve according to the air inlet pressure of the first flow channel.

The asymmetric runner turbocharger can be used for ensuring the EGR rate, the deterioration of economy is reduced to a certain extent while the asymmetric turbocharger can obtain a sufficiently high EGR rate, but the asymmetric turbocharger is difficult to manufacture, the requirements on processing precision and consistency are high, and the cost of mass production is high.

The use of an exhaust throttle valve would significantly increase the fuel consumption of the engine, effective for achieving a sufficiently high EGR rate, but would be too economically inefficient.

Disclosure of Invention

The invention aims to provide an exhaust gas recirculation system with asymmetric flow, which is simple in structure and can effectively improve the EGR rate.

In order to solve the technical problems, the invention provides the following technical scheme:

the utility model provides an exhaust gas recirculation system of asymmetric flow, including the symmetry turbo charger, the symmetry turbo charger includes turbine and compressor, the turbine has two runners, these two runners are first runner and second runner respectively, the intercommunication has first exhaust manifold on the second runner of turbine, the intercommunication has second exhaust manifold on the first runner of turbine, the other end of first exhaust manifold and second exhaust manifold is linked together with the corresponding certain quantity's of engine exhaust manifold respectively, be provided with the EGR pipeline between the first exhaust manifold and the inlet end of engine.

The following is a further optimization of the above technical solution of the present invention:

the number of engine exhaust manifolds to which the first exhaust manifold communicates is greater than the number of engine exhaust manifolds to which the second exhaust manifold communicates.

Further optimization: the air quantity of the first exhaust manifold is larger than that of the second exhaust manifold, and the back pressure generated in the first exhaust manifold is larger than that generated in the second exhaust manifold.

Further optimization: one end of the EGR pipeline is communicated with the first exhaust manifold, and the other end of the EGR pipeline is communicated with the engine intake manifold.

Further optimization: a part of exhaust gas in the first exhaust manifold enters an engine intake manifold through an EGR pipeline to be mixed with fresh air, and then is introduced into the engine.

Further optimization: the EGR pipeline is provided with an EGR valve in series, and the EGR valve is used for adjusting different EGR rates by controlling EGR amount.

Further optimization: one end of the engine air inlet main pipe is communicated with the air outlet end of the air compressor, and the other end of the engine air inlet main pipe is communicated with an air inlet manifold of the engine.

Further optimization: the air inlet end of the air compressor is communicated with the external atmosphere, and the air compressor is used for sucking external fresh air and carrying out air inlet on the engine through an air inlet main pipe of the engine.

When the exhaust gas recirculation device is used, exhaust gas discharged by the working of an engine is guided by the first exhaust manifold and the second exhaust manifold respectively and then enters the turbine through the second flow channel and the first flow channel, the exhaust gas entering the turbine can drive the turbine to rotate, the turbine rotates to drive the compressor to rotate so as to intake air for the engine, and the exhaust gas entering the turbine is discharged through the air outlet of the turbine.

And the air quantity of the waste gas in the first exhaust manifold is greater than the air quantity of the waste gas in the two exhaust manifolds, so that the generated back pressures are different, the back pressure in the first exhaust manifold is greater than the back pressures in the two exhaust manifolds, and then a part of the waste gas in the first exhaust manifold enters the EGR pipeline.

By adopting the technical scheme, the invention has the advantages of ingenious design and reasonable structure, and realizes the effect of an asymmetric runner turbocharger and higher EGR rate by adopting the symmetric runner turbocharger; and adopt EGR valve and EGR pipeline to let in engine exhaust's partly waste gas once more in the engine, realize enough high EGR rate and can obviously reduce NOx and discharge to can satisfy when enough high EGR rate, reduce economic nature's deterioration to a certain extent, and make conveniently, production installation cost is low, improves the result of use greatly.

The invention is further illustrated with reference to the following figures and examples.

Drawings

FIG. 1 is a schematic view of the overall structure of embodiment 1 of the present invention;

FIG. 2 is a schematic view of the overall structure of embodiment 2 of the present invention;

fig. 3 is a schematic view of the overall structure of embodiment 3 of the present invention.

In the figure: 1-an engine intake manifold; 2-a first cylinder; 3-a second cylinder body; 4-a third cylinder; 5-a fourth cylinder; 6-a fifth cylinder body; 7-a sixth cylinder; 8-an EGR valve; 9-a first exhaust manifold; 10-a second exhaust manifold; 11-a turbine; 111-a first flow channel; 112-a second flow channel; 12-a compressor; 13-an engine; 14-EGR line.

Detailed Description

Example 1: as shown in fig. 1, an exhaust gas recirculation system with asymmetric flow rate includes a symmetric turbocharger, where the symmetric turbocharger includes a turbine 11 and a compressor 12, the turbine 11 has two flow channels, which are a first flow channel 111 and a second flow channel 112, the second flow channel 112 of the turbine 11 is communicated with a first exhaust manifold 9, the first flow channel 111 of the turbine 11 is communicated with a second exhaust manifold 10, the other ends of the first exhaust manifold 9 and the second exhaust manifold 10 are respectively communicated with a certain number of exhaust manifolds corresponding to an engine 13, and an EGR pipeline 14 is disposed between an exhaust end and an intake end of the engine 13.

The number of exhaust manifolds of the engine 13 communicated with the first exhaust manifold 9 is larger than that of the exhaust manifolds of the engine 13 communicated with the second exhaust manifold 10.

In embodiment 1, the number of cylinders of the engine 13 is six, and the number of cylinders is the first cylinder 2, the second cylinder 3, the third cylinder 4, the fourth cylinder 5, the fifth cylinder 6, and the sixth cylinder 7.

The other end of the first exhaust manifold 9 is communicated with the exhaust manifolds of the first cylinder body 2, the second cylinder body 3, the third cylinder body 4 and the fourth cylinder body 5 of the engine 13 in sequence, and the other end of the second exhaust manifold 10 is communicated with the exhaust manifolds of the fifth cylinder body 6 and the sixth cylinder body 7 of the engine 13 in sequence.

The design is that the engine 13 operates, and the exhaust gas discharged from the first cylinder block 2, the second cylinder block 3, the third cylinder block 4 and the fourth cylinder block 5 of the engine 13 respectively enters the first exhaust manifold 9, and then the exhaust gas enters the turbine 11 of the symmetrical turbocharger through the second flow passage 112 by being guided by the first exhaust manifold 9, and then the symmetrical turbocharger operates to discharge the exhaust gas.

And the exhaust gas discharged from the fifth cylinder 6 and the sixth cylinder 7 of the engine 13 respectively enters the second exhaust manifold 10, and then the exhaust gas enters the turbine 11 of the symmetrical turbocharger through the first flow passage 111 by being guided by the second exhaust manifold 10, and then the symmetrical turbocharger works to discharge the exhaust gas.

The cross-sectional areas of the first flow passage 111 and the second flow passage 112 are 1: 1.

With this arrangement, when the number of cylinders of the engine 13 in which the first flow passage 111 and the second flow passage 112 communicate is different, the flow rates in the first flow passage 111 and the second flow passage 112 are not equal.

When the number of cylinders of the engine 13 in which the first flow passage 111 and the second flow passage 112 communicate is the same, the flow rates in the first flow passage 111 and the second flow passage 112 are equal.

The air flow of the first exhaust manifold 9 is different from that of the second exhaust manifold 10, so that the generated backpressure is different, wherein the air flow of the first exhaust manifold 9 is large, the generated backpressure is large, the air flow of the second exhaust manifold 10 is small, and the generated backpressure is small.

The central shaft of the turbine 11 is in transmission connection with the central shaft of the compressor 12.

The air inlet end of the compressor 12 is communicated with the outside atmosphere, and the compressor 12 can be used for sucking outside fresh air during operation.

The air outlet end of the compressor 12 is communicated with an air inlet manifold of an engine 13 through an engine air inlet main pipe 1.

By the design, when exhaust gas discharged by the operation of the engine 13 is guided by the first exhaust manifold 9 and the second exhaust manifold 10, and then enters the turbine 11 through the second flow passage 112 and the first flow passage 111, the exhaust gas entering the turbine 11 can drive the turbine 11 to rotate, the turbine 11 rotates to drive the compressor 12 to rotate for air intake of the engine 13, and the exhaust gas entering the turbine 11 is discharged through the air outlet of the turbine 11.

And then can be used for driving the symmetrical turbocharger to work through the exhaust gas, the energy consumption of the symmetrical turbocharger can be greatly reduced, and the use effect is improved.

The downstream ends of the first exhaust manifold 9 and the second exhaust manifold 10 are connected to a symmetrical turbocharger, and the turbocharger can be used for quickly discharging exhaust gas, so that a good oil consumption level can be obtained.

One end of the EGR line 14 communicates with the first exhaust manifold 9, and the other end of the EGR line 14 communicates with the engine intake manifold 1.

When the engine 13 works, exhaust gas discharged from the first cylinder block 2, the second cylinder block 3, the third cylinder block 4 and the fourth cylinder block 5 of the engine 13 respectively enters the first exhaust manifold 9, and at the moment, the exhaust gas in the first exhaust manifold 9 can enter the engine intake manifold 1 through the guidance of the EGR pipeline 14.

At this time, the exhaust gas delivered into the engine intake manifold 1 by the EGR pipeline 14 is mixed with the fresh air in the engine intake manifold 1, and then introduced into the engine 13 through the engine intake manifold 1, so that the exhaust gas intake amount of the engine 13 can be increased, and the EGR rate can be improved.

An EGR valve 8 is arranged on the EGR pipeline 14 in series, and the EGR valve 8 is used for adjusting different EGR rates by controlling the EGR amount.

The exhaust gas discharged from the first cylinder body 2, the second cylinder body 3, the third cylinder body 4 and the fourth cylinder body 5 of the engine 13 when the engine 13 works enters the first exhaust manifold 9, the exhaust gas in the first exhaust manifold 9 can enter the EGR pipeline 14, and the EGR valve 8 on the EGR pipeline 14 is used for adjusting different EGR rates by controlling the EGR amount and mixing the exhaust gas in the EGR pipeline 14 with the fresh air in the engine intake manifold 1 to complete exhaust gas recirculation.

The pressure of the exhaust gas delivered into the first exhaust manifold 9 is greater than the pressure of the exhaust gas delivered into the second exhaust manifold 10, and further, the pressure difference between the first exhaust manifold 9 and the second exhaust manifold 10 is greater, so that a greater EGR rate can be obtained in the EGR line 14.

Further, it is possible to avoid the problem of deterioration in economy such as increase in fuel consumption and increase in particulate matter emission of the engine 13 due to reduction in the intake air amount.

And the EGR pipeline 14 is used for conveying exhaust gas into the engine intake manifold 1, so that the heat management of the post-treatment can be obviously improved, and the conversion efficiency of the post-treatment is improved.

As shown in fig. 1, in use, when the engine 13 operates, exhaust gas discharged from the first cylinder 2, the second cylinder 3, the third cylinder 4, and the fourth cylinder 5 of the engine 13 respectively enters the first exhaust manifold 9, exhaust gas discharged from the fifth cylinder 6 and the sixth cylinder 7 of the engine 13 respectively enters the second exhaust manifold 10, at this time, the exhaust gas is guided by the first exhaust manifold 9 and the second exhaust manifold 10 and then enters the turbine 11 through the second flow passage 112 and the first flow passage 111, at this time, the exhaust gas entering the turbine 11 can drive the turbine 11 to rotate, the turbine 11 rotates to drive the compressor 12 to rotate for feeding air to the engine 13, and the exhaust gas entering the turbine 11 is discharged through an air outlet of the turbine 11.

And the gas volume of the exhaust gas in the first exhaust manifold 9 is greater than the gas volume of the exhaust gas in the two exhaust manifolds 10, so that the generated back pressures are different, the back pressure in the first exhaust manifold 9 is greater than the back pressure in the two exhaust manifolds 10, and then a part of the exhaust gas in the first exhaust manifold 9 enters the EGR pipeline 14, at this time, the EGR valve 8 on the EGR pipeline 14 is used for adjusting different EGR rates by controlling the EGR volume, and the exhaust gas in the EGR pipeline 14 is mixed with the fresh air in the engine intake manifold 1, so that the exhaust gas recirculation is completed.

Example 2: as shown in fig. 2, in the above embodiment 1, the number of cylinders of the engine 13 may be five, and the five cylinders are the first cylinder 2, the second cylinder 3, the third cylinder 4, the fourth cylinder 5, and the fifth cylinder 6.

The other end of the first exhaust manifold 9 is communicated with the exhaust manifolds of the first cylinder body 2, the second cylinder body 3 and the third cylinder body 4 of the engine 13 in sequence, and the other end of the second exhaust manifold 10 is communicated with the exhaust manifolds of the fourth cylinder body 5 and the fifth cylinder body 6 of the engine 13 in sequence.

As shown in fig. 2, the engine 13 is designed such that exhaust gas discharged from the first cylinder 2, the second cylinder 3, and the third cylinder 4 of the engine 13 respectively enters the first exhaust manifold 9, exhaust gas discharged from the fourth cylinder 5 and the fifth cylinder 6 respectively enters the second exhaust manifold 10, at this time, the exhaust gas is guided by the first exhaust manifold 9 and the second exhaust manifold 10 and then enters the turbine 11 through the second flow passage 112 and the first flow passage 111, at this time, the exhaust gas entering the turbine 11 can drive the turbine 11 to rotate, the turbine 11 rotates to drive the compressor 12 to rotate for air intake of the engine 13, and the exhaust gas entering the turbine 11 is discharged through an air outlet of the turbine 11.

And the air quantity of the first exhaust manifold 9 is different from that of the second exhaust manifold 10, so that the generated back pressure is different, wherein the air quantity of the first exhaust manifold 9 is large, the generated back pressure is larger, and after the adjustment of the EGR valve 8, a relatively ideal EGR rate can be obtained.

Example 3: as shown in fig. 3, in the above embodiment 1, the number of cylinders of the engine 13 may be four, and the four cylinders are the first cylinder 2, the second cylinder 3, the third cylinder 4, and the fourth cylinder 5.

The other end of the first exhaust manifold 9 is communicated with the exhaust manifolds of the first cylinder body 2, the second cylinder body 3 and the third cylinder body 4 of the engine 13 in sequence, and the other end of the second exhaust manifold 10 is communicated with the exhaust manifold of the fourth cylinder body 5 of the engine 13.

As shown in fig. 3, the engine 13 is designed such that exhaust gas discharged from the first cylinder 2, the second cylinder 3, and the third cylinder 4 of the engine 13 respectively enters the first exhaust manifold 9 when the engine 13 is operated, exhaust gas discharged from the fourth cylinder 5 enters the second exhaust manifold 10, at this time, the exhaust gas is guided by the first exhaust manifold 9 and the second exhaust manifold 10 and then enters the turbine 11 through the second flow passage 112 and the first flow passage 111, at this time, the exhaust gas entering the turbine 11 can drive the turbine 11 to rotate, the turbine 11 rotates to drive the compressor 12 to rotate for supplying air to the engine 13, and the exhaust gas entering the turbine 11 is discharged through the air outlet of the turbine 11.

It will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in the embodiments described above without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims.

Claims

1. An exhaust gas recirculation system with asymmetric flow, comprising a symmetric turbocharger, wherein the symmetric turbocharger comprises a turbine (11) and a compressor (12), the turbine (11) is provided with two flow channels which are a first flow channel (111) and a second flow channel (112), and the exhaust gas recirculation system is characterized in that: a first exhaust manifold (9) is communicated with a second flow passage (112) of the turbine (11), a second exhaust manifold (10) is communicated with a first flow passage (111) of the turbine (11), the other ends of the first exhaust manifold (9) and the second exhaust manifold (10) are respectively communicated with a certain number of exhaust manifolds corresponding to the engine (13), and an EGR pipeline (14) is arranged between the exhaust end and the air inlet end of the engine (13);

the number of exhaust manifolds of the engine (13) communicated with the first exhaust manifold (9) is larger than that of the exhaust manifolds of the engine (13) communicated with the second exhaust manifold (10).

2. An asymmetric flow exhaust gas recirculation system according to claim 1, wherein: the air quantity of the first exhaust manifold (9) is larger than that of the second exhaust manifold (10), and the back pressure generated in the first exhaust manifold (9) is larger than that generated in the second exhaust manifold (10).

3. An asymmetric flow exhaust gas recirculation system according to claim 2, wherein: one end of the EGR pipeline (14) is communicated with the first exhaust manifold (9), and the other end of the EGR pipeline (14) is communicated with the engine intake manifold (1).

4. An asymmetric flow exhaust gas recirculation system according to claim 3, wherein: a part of exhaust gas in the first exhaust manifold (9) enters an engine intake manifold (1) through an EGR pipeline (14) and is mixed with fresh air, and then the mixture is introduced into an engine (13).

5. An asymmetric flow exhaust gas recirculation system according to claim 4, wherein: an EGR valve (8) is arranged on the EGR pipeline (14) in series, and the EGR valve (8) is used for adjusting different EGR rates by controlling the EGR amount.

6. An asymmetric flow exhaust gas recirculation system according to claim 5, wherein: one end of an engine air inlet main pipe (1) is communicated with an air outlet end of the air compressor (12), and the other end of the engine air inlet main pipe (1) is communicated with an air inlet manifold of the engine (13).

7. An asymmetric flow exhaust gas recirculation system according to claim 6, wherein: the air inlet end of the compressor (12) is communicated with the outside atmosphere, and the compressor (12) is used for sucking outside fresh air and carrying out air inlet on the engine (13) through the engine air inlet main pipe (1).