KR20190010942A - Exhaust gas recirculation system for engine - Google Patents

Abstract

An exhaust gas recirculation system for an engine comprises: an air suction line connected to an engine to supply sucked air; an air discharge line connected to the engine to discharge a part of exhaust gas discharged from the engine to the outside; a turbo charger having a turbine installed at the air discharge line and a compressor installed at the air suction line; a post-treatment apparatus installed at the air discharge line on the downstream of the turbine so as to post-treat the exhaust gas; a low-pressure EGR apparatus which is provided to recirculate a part of the exhaust gas discharged through the post-treatment apparatus from the downstream of the post-treatment apparatus to the engine; and an exhaust gas bypass apparatus connected to the engine, and provided to allow another part of the exhaust gas discharged from the engine to be supplied through a bypass line to the post-treatment apparatus without going via the turbine.

Description

[0001] EXHAUST GAS RECIRCULATION SYSTEM FOR ENGINE [0002]

The present invention relates to an exhaust gas recirculation system of an engine. More particularly, the present invention relates to an exhaust gas recirculation system for an engine provided with a dual EGR device.

An exhaust gas recirculation (EGR) apparatus, an exhaust gas post-treatment apparatus, or the like can be used to cope with exhaust emission regulation of a diesel engine.

As the exhaust gas recirculation device, there are a high pressure exhaust gas recirculation (HP-EGR) and a low pressure exhaust gas recirculation (LP-EGR). A dual EGR (Dual EGR) device using both high-pressure-EGR and low-pressure-EGR may be employed to apply a large-capacity EGR while reducing pumping loss. Meanwhile, in order to increase the efficiency of the exhaust gas after-treatment apparatus, it is important to raise the temperature of the front end of the after-treatment system.

Conventional turbo matching of dual EGR has been applied to wasted gate turbocharger (WGT) and variable capacity turbocharger (VGT) specifications to apply large capacity EGR. Such turbochargers are more expensive than fixed geometry turbochargers (FGTs), and therefore, the price of the turbochargers deteriorates due to the increase in the price.

An object of the present invention is to provide an exhaust gas recirculation system for an engine that can apply a large amount of EGR while reducing the pumping loss and can increase the efficiency of the exhaust gas post-treatment apparatus.

According to an exemplary embodiment of the present invention, there is provided an exhaust gas recirculation system for an internal combustion engine including an intake line connected to an engine to supply intake air, a portion of exhaust gas exhausted from the engine, A turbocharger having a turbine installed in the exhaust line and a compressor installed in the intake line, a post-treatment device installed in the exhaust line on the downstream side of the turbine and for post-treating the exhaust gas, Pressure EGR device for recirculating a part of the exhaust gas discharged from the downstream side of the treatment device through the post-treatment device to the engine, and a low-pressure EGR device connected to the engine for discharging another part of the exhaust gas discharged from the engine to the outside , A bypass line connected to the exhaust line between the downstream side of the turbine and the downstream side of the post-treatment device And an exhaust gas bypass device for supplying another portion of the exhaust gas to the post-treatment apparatus via the bypass line without passing through the turbine.

In the exemplary embodiments, the engine includes a first exhaust manifold in which exhaust gas discharged from at least one first cylinder is discharged and combined, and a second exhaust manifold in which exhaust gas discharged from at least one second cylinder is discharged A second exhaust manifold, the exhaust line connected to the first exhaust manifold, and the bypass line connected to the second exhaust manifold.

In exemplary embodiments, the exhaust gas bypass device may include a connection line connecting the bypass line to the exhaust line on the upstream side of the turbine.

In an exemplary embodiment, the exhaust gas bypass device includes an exhaust backpressure control valve installed in the connection line, for controlling an amount of the exhaust gas branched from the bypass line and merged into the exhaust line, And a bypass valve installed in the bypass line for controlling an amount of the exhaust gas supplied to the post-treatment apparatus.

In exemplary embodiments, the exhaust gas recirculation system of the engine may include an exhaust gas recirculation system connected to the outlets of the first exhaust manifold and the second exhaust manifold, for discharging exhaust gas from the first and second exhaust manifolds, Further comprising a branching unit to which the gas is merged, and the exhaust lines and the inlets of the bypass line may be respectively connected to the branching unit.

In an exemplary embodiment, the exhaust gas recirculation system of the engine further includes a high-pressure EGR device, wherein the high-pressure EGR device includes a high-pressure EGR line connecting the exhaust line and the intake line on the upstream side of the turbine, Pressure EGR valve installed in the high-pressure EGR line and regulating the amount of the recirculated exhaust gas.

In the exemplary embodiments, the high pressure EGR line may connect the intake line on the upstream side of the exhaust line and the intercooler installed downstream of the compressor.

In an exemplary embodiment, the low-pressure EGR apparatus includes a low-pressure EGR line connecting the exhaust line and the intake line on the downstream side of the post-processing apparatus, and a low-pressure EGR line provided on the low- An exhaust gas recirculation system for an engine including a low pressure EGR valve.

In exemplary embodiments, the exhaust gas recirculation system of the engine may further include an intercooler that cools the intake air that has passed through the compressor.

In an exemplary embodiment, the exhaust gas recirculation system of the engine further includes a high-pressure EGR device, wherein the high-pressure EGR device includes a high-pressure EGR line connecting the bypass line and the intake line, And a high-pressure EGR valve installed to regulate the amount of the recirculated exhaust gas.

In an exemplary embodiment, the exhaust gas bypass device may include a connection line connecting the bypass line and the exhaust line on an upstream side of the turbine, a branch line installed in the connection line, branched from the bypass line, And a bypass valve installed in the exhaust line and controlling an amount of the exhaust gas supplied to the post-treatment apparatus, wherein the bypass valve controls the amount of the exhaust gas to be introduced into the high-pressure EGR line May be connected to the bypass line on the upstream side of the connection line.

According to exemplary embodiments, a part of the exhaust gas discharged from the engine is supplied to the after-treatment device via the exhaust line via the turbine of the turbocharger, and another part of the exhaust gas discharged from the engine is supplied to the bypass line To the post-treatment apparatus without passing through the turbine.

The high-temperature exhaust gas is directly supplied to the post-treatment apparatus without passing through the turbine, so that the post-treatment efficiency can be improved. Also, even if a relatively inexpensive fixed geometry turbocharger (FGT) equipped with an exhaust back pressure control valve and a bypass valve is used, desired performance can be secured.

Further, by supplying the post-combustion exhaust gas of high temperature and high pressure through the bypass line to the post-treatment apparatus, a large-capacity low-pressure-EGR can be applied. Accordingly, since the intake throttle valve is not used, the pumping loss can be minimized, and the intake throttle valve can also be removed.

Moreover, since it is possible to supply HP-EGR and LP-EGR by more than 50%, low-temperature combustion can be realized, and it is possible to match with a smaller capacity turbocharger to satisfy both desired EGR flow rate and engine output range, The dynamic characteristics can be improved.

However, the effects of the present invention are not limited to the above-mentioned effects, and may be variously expanded without departing from the spirit and scope of the present invention.

1 is a block diagram illustrating an exhaust gas recirculation system for an engine in accordance with exemplary embodiments.
2 is a block diagram illustrating an exhaust gas recirculation system for an engine in accordance with exemplary embodiments.
3 is a block diagram illustrating an exhaust gas recirculation system for an engine according to exemplary embodiments.
4 is a block diagram illustrating an exhaust gas recirculation system for an engine in accordance with exemplary embodiments.
5 is a block diagram illustrating an exhaust gas recirculation system for an engine in accordance with exemplary embodiments.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the drawings of the present invention, the dimensions of the structures are enlarged to illustrate the present invention in order to clarify the present invention.

In the present invention, the terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

For the embodiments of the invention disclosed herein, specific structural and functional descriptions are set forth for the purpose of describing an embodiment of the invention only, and it is to be understood that the embodiments of the invention may be practiced in various forms, And should not be construed as limited to the embodiments described in the foregoing description.

1 is a block diagram illustrating an exhaust gas recirculation system for an engine in accordance with exemplary embodiments.

1, an exhaust gas recirculation system for an engine includes an intake line 30 for supplying intake air to the engine 10, an exhaust line 40 for exhausting a part of the exhaust gas discharged from the engine 10 to the outside, A turbocharger 60 for compressing the air supplied to the engine 10 by using a part of the exhaust gas and a turbocharger 60 for recirculating a part of the exhaust gas upstream of the turbine 62 of the turbocharger 60 to the engine 10 A post-treatment device 80 for purifying the exhaust gas downstream of the turbine 62 of the turbocharger 60, another part of the exhaust gas discharged from the engine 10, a first EGR device 70 (high-pressure EGR device) And an exhaust gas bypass device for directly supplying a part of the exhaust gas downstream of the post-treatment device 80 to the engine 10 without passing through the turbine 62 to the post- And an EGR device 90 (low pressure EGR device).

In the exemplary embodiments, the engine 10 may include a diesel engine as a drive source of a construction machine, such as an excavator. For example, the engine 10 may be an industrial large diesel engine. The engine 10 may include a plurality of cylinders 12a, 12b having combustion chambers for combusting fuel supplied from a fuel injecting apparatus (not shown).

For example, the engine 10 may include a first cylinder group and a second cylinder group. The first cylinder group may have at least one first cylinder 12a and the second cylinder group may have at least one second cylinder 12b. The first cylinder group and the second cylinder group include, but are not limited to, three cylinders, for example, the first cylinder group includes four cylinders and the second cylinder group includes two cylinders .

The engine 10 may include an intake manifold 20 connected to the first and second cylinders 12a and 12b to supply intake air. The engine 10 includes a first exhaust manifold 22a connected to the first cylinders 12a and for discharging the exhaust gas discharged from the first cylinders 12a to the outside and a second exhaust manifold 22b connected to the second cylinders 12b, And a second exhaust manifold 22b connected to the second cylinders 12b for discharging the exhaust gas discharged from the second cylinders 12b to the outside.

The intake line 30 is connected to the intake manifold 12 of the engine 10 to supply the intake air and the exhaust line 40 is connected to the first exhaust manifold 22a of the engine 10, A part of the exhaust gas discharged from the engine can be discharged to the outside.

The turbocharger 60 may include a turbine 62, a compressor 64, and a shaft 66 connecting them. The turbine 62 may be installed in the exhaust line 40 while the compressor 64 may be installed in the intake line 30. [ When the turbine 62 is driven by the flow of the exhaust gas, the turbine 62 can drive the compressor 64 via the shaft 66. The compressor 64 can compress the sucked air to increase the suction amount.

The turbocharger 30 may be a variable geometry turbocharger (VGT), a wastegate turbocharger (WGT), a fixed geometry turbocharger (FGT), or the like.

The air having passed through the compressor 64 can be supplied to the intake manifold 20 of the engine 10 through the intake line 30. [ An intercooler 32 is provided in the intake line 30 at the outlet side of the compressor 64 to cool the sucked air passing through the compressor 64 and to supply it to the intake manifold 20. The intercooler 50 lowers the temperature of the inhaled air to increase the mass of the same volume, thereby increasing the amount of oxygen. Thus, an appropriate mixture ratio of fuel and air can be implemented in the engine 10, thereby improving the combustion efficiency and improving the engine output.

The first EGR apparatus (high-pressure EGR apparatus) 70 can recycle a part of the exhaust gas to the engine 10 on the upstream side of the turbine 62. The first EGR device 70 includes a first EGR line 72 connecting the exhaust line 40 on the upstream side of the turbine 62 and the intake line 30 on the outlet side of the compressor 64, And a first EGR cooler 76 installed in the first EGR line 72 for cooling the recirculated exhaust gas. The first EGR cooler 76 is installed in the first EGR line 72 and controls the amount of the recirculated exhaust gas, .

The post-treatment apparatus 80 may be installed in the exhaust line 40 on the downstream side of the turbine 62 to post-treat the exhaust gas. For example, the post-treatment apparatus 80 may include a diesel oxidation catalyst apparatus (DOC), a selective reduction catalyst (SCR) apparatus, and the like.

The diesel oxidation catalyst device (DOC) can purify carbon monoxide, hydrocarbons, and soluble organic fractions contained in the exhaust gas. The selective reduction catalyst (SCR) apparatus can catalytically react nitrogen oxides in the exhaust gas with a reducing agent to reduce nitrogen oxides to nitrogen and water harmless to the human body.

The second EGR apparatus (low pressure EGR apparatus) 90 can recycle a part of the exhaust gas discharged from the post-treatment apparatus 80 through the post-treatment apparatus 80 to the engine 10 on the downstream side. The second EGR device 90 includes a second EGR line 92 for connecting the exhaust line 40 on the downstream side of the post-treatment device 80 and the intake line 30 on the upstream side of the compressor 64, A second EGR valve 94 installed in the second EGR line 92 for regulating the amount of the recirculated exhaust gas and a second EGR cooler 94 installed in the second EGR line 92 for cooling the recirculated exhaust gas . The second EGR line 92 can connect the exhaust line 40 on the downstream side of the post-treatment device 80 and the intake line 30 on the upstream side of the intake throttle valve 34. Therefore, the second EGR device 90 can supply a part of the exhaust gas downstream of the post-treatment device 80 to the intake line 30 on the upstream side of the intake throttle valve 34.

In the exemplary embodiments, the exhaust gas bypass device may include a bypass line 50 for supplying another portion of the exhaust gas from the engine 10 to the post-treatment device 80 . One end of the bypass line 50 is connected to the second exhaust manifold 22b of the engine 10 and the other end of the bypass line 50 is connected between the downstream side of the turbine 62 and the downstream side of the post- The exhaust line 40 of FIG. The exhaust gas discharged through the second exhaust manifold 22b is guided through the bypass line 50 to the exhaust line 40 between the downstream side of the turbine 62 and the downstream side of the post-treatment device 80 , And can be supplied directly to the post-treatment apparatus 80 without passing through the turbine 62.

The exhaust gas bypass device is installed in a connection line 51 connecting the bypass line 50 and the exhaust line 40 on the upstream side of the turbine 62 and is connected to the exhaust line 40, And a bypass valve 54 provided in the bypass line 50 for controlling the amount of the exhaust gas supplied to the post-treatment device 80 have.

Another part of the exhaust gas discharged from the engine 10 through the second exhaust manifold 22b is supplied to the turbine 62 while the exhaust backpressure control valve 52 is closed and the bypass valve 54 is opened. Processing apparatus 80 through the bypass line 50 without passing through the bypass line.

Another part of the exhaust gas discharged from the engine 10 through the second exhaust manifold 22b is supplied to the turbine 62 while the exhaust backpressure control valve 52 is opened and the bypass valve 54 is closed, Can be joined to the upstream side exhaust line 40 and supplied to the turbine 62. At this time, the exhaust gas discharged from the first exhaust manifold 22a is partially supplied to the first EGR line 72, and the remaining part thereof is combined with the exhaust gas discharged from the second exhaust manifold 22b Can be supplied from the post-turbine 62.

In the exemplary embodiments, the exhaust gas recirculation system of the engine may include an engine control unit (ECU) (not shown) for performing dual EGR control. For example, the control unit may receive signals relating to an engine rpm, an engine torque, a velocity, a throttle valve, an air amount, and the like. The control unit may receive a signal relating to the temperature of the exhaust gas supplied from the post-treatment device 80 from the temperature sensor 82 provided on the exhaust line upstream of the post-treatment device 80. [ In addition, the control unit may receive signals relating to the pressure from the pressure sensors provided at the front and rear ends of the post-processing apparatus 80.

The control unit can control the ratio of recirculating the first EGR valve 64 and the second EGR valve 74 to the engine 10 as EGR gas, that is, the EGR rate, based on the signals, it is possible to control the load percentage of the engine 10 at the rpm, that is, the engine output rate.

Further, the control unit can control the opening and closing of the exhaust back pressure control valve 52 and the bypass valve 54 based on the signals, and perform the exhaust gas bypass control. The control unit performs the exhaust gas bypass control to control the exhaust gas discharged from one or more cylinders among a plurality of cylinders, that is, a part of the exhaust gas discharged from the engine, to the turbine 62 It can be directly supplied to the post-treatment apparatus 80 without passing through.

When the temperature detected by the temperature sensor 82 becomes lower than the predetermined value, the control unit can perform the exhaust gas bypass control by closing the exhaust backpressure control valve 52 and opening the bypass valve 54 have. In the exhaust gas bypass control, another part of the exhaust gas discharged from the engine 10 through the second exhaust manifold 22b flows through the bypass line 50 without passing through the turbine 62 Can be supplied to the processing device (80). The high-temperature exhaust gas is directly supplied to the post-treatment apparatus 80 without passing through the turbine 62, so that the post-treatment efficiency can be improved.

Further, by supplying the post-combustion high-pressure exhaust gas through the bypass line 50 to the post-treatment apparatus 80, a large-capacity LP-EGR can be applied. Accordingly, since the intake throttle valve 34 is not used, the pumping loss can be minimized and the intake throttle valve 34 can be removed.

Further, since it is possible to supply 50% or more of high pressure EGR (70, first EGR) and low pressure EGR (90, second EGR), it is possible to realize low temperature combustion, It can be matched with a smaller capacity turbocharger and the low speed dynamic characteristic can be improved. On the other hand, even if a relatively inexpensive fixed geometry turbocharger (FGT) is used, the above-described technical effect can be secured.

2 is a block diagram illustrating an exhaust gas recirculation system for an engine in accordance with exemplary embodiments. The exhaust gas recirculation system is substantially the same as the exhaust gas recirculation system described with reference to Fig. 1, except for the configuration of adding a branch unit. Accordingly, the same constituent elements are denoted by the same reference numerals, and repetitive description of the same constituent elements is omitted.

2, in the exemplary embodiments, the exhaust gas recirculation system of the engine may further include a branch unit 24 for distributing the exhaust gas discharged from the engine 10. [

The engine 10 includes a first exhaust manifold 22a for discharging the exhaust gas discharged from the first cylinders 12a to the outside and a second exhaust manifold 22b for discharging the exhaust gas discharged from the second cylinders 12b to the outside And a second exhaust manifold 22b for the second exhaust manifold 22b.

The inlet of the branching unit 24 may be connected to the outlet of the first exhaust manifold 22a and the second exhaust manifold 22b. Therefore, the exhaust gas discharged from the first and second exhaust manifolds 22a, 22b can be merged in the branching unit 24. [

The inlet of the exhaust line 40 and the bypass line 50 may be connected to the branch unit 24, respectively. A part of the exhaust gas supplied to the branching unit 24 can be supplied to the post-processing device 80 after being supplied to the turbine 62 through the exhaust line 40, Another portion of the exhaust gas may be fed directly to the post-treatment unit 80 via the bypass line 50.

A first valve 46 is provided in the exhaust line 40 to regulate the amount of exhaust gas discharged through the exhaust line 40. A second valve 56 is provided in the bypass line 50, The amount of exhaust gas discharged through the line 50 can be adjusted. The first and second valves 46 and 56 can prevent back pressure interference between the exhaust line 40 and the bypass line 50. [ Here, the branching unit 24 may be equipped with valves that perform a similar function to at least one of the first and second valves 46, 56. At least one of the first and second valves 46, 56 may be omitted when at least one valve is incorporated in the branch unit 24.

3 is a block diagram illustrating an exhaust gas recirculation system for an engine according to exemplary embodiments. The exhaust gas recirculation system is substantially the same as the exhaust gas recirculation system described with reference to Fig. 1, except for the arrangement of the first EGR apparatus. Accordingly, the same constituent elements are denoted by the same reference numerals, and repetitive description of the same constituent elements is omitted.

3, the first EGR line 72 of the first EGR device 70 is connected to the exhaust line 30 on the downstream side of the intercooler 32 and is connected to the turbocharger 60 A part of the exhaust gas upstream of the turbine 62 of the engine 10 can be recirculated directly to the engine 10 without passing through the intercooler 32.

The first EGR line 72 can connect the exhaust line 40 on the upstream side of the turbine 62 and the intake line 30 on the outlet side of the intercooler 32. A part of the exhaust gas discharged from the first exhaust manifold 22a of the engine 10 is supplied to the intake manifold 20 of the engine 10 via the first EGR line 72 without passing through the intercooler 32 ). ≪ / RTI >

The first EGR valve 74 is installed in the first EGR line 72 and can regulate the amount of the recirculated exhaust gas. The first EGR cooler 76 is installed in the first EGR line 72 and can cool the recycle exhaust gas.

4 is a block diagram illustrating an exhaust gas recirculation system for an engine in accordance with exemplary embodiments. The exhaust gas recirculation system is substantially the same as the exhaust gas recirculation system described with reference to FIG. 1, except that the first EGR line is connected to a bypass line rather than an exhaust line. Accordingly, the same constituent elements are denoted by the same reference numerals, and repetitive description of the same constituent elements is omitted.

Referring to FIG. 4, in the exemplary embodiments, the first EGR line 72 of the first EGR apparatus 70 (high pressure EGR apparatus) may be connected to the bypass line 50. The total amount of the exhaust gas discharged from the engine 10 through the first exhaust manifold 22a can be supplied to the post-treatment apparatus 80 after driving the turbine 62 to the turbine 62. [ On the other hand, a part of the exhaust gas discharged from the second exhaust manifold 22b can be branched sequentially through the first EGR line 72 and the connecting line 51, and the remaining exhaust gas, which is not branched, The exhaust gas may be supplied upstream of the first exhaust manifold 80 and merged with the exhaust gas discharged from the first exhaust manifold 22a. Thus, the turbine 62 can be driven unaffected from the first EGR device 70 and can reduce the influence from the turbine 62 at the time of exhaust gas flow to the first EGR device 70 have.

5 is a block diagram illustrating an exhaust gas recirculation system for an engine in accordance with exemplary embodiments. The exhaust gas recirculation system is substantially the same as the exhaust gas recirculation system described with reference to Fig. 1, except that the connection line of the exhaust gas bypass device is connected to the exhaust line upstream of the point where the first EGR line is connected Do. Accordingly, the same constituent elements are denoted by the same reference numerals, and repetitive description of the same constituent elements is omitted.

Referring to FIG. 5, in the exemplary embodiments, the connection line 51 of the exhaust gas bypass device may be connected to the exhaust line 40 on the upstream side of the point where the first EGR line 72 is connected. Alternatively, the connection line 51 may be connected to the exhaust line 40 at the point where the first EGR line 72 is connected.

Therefore, some of the exhaust gas discharged from the engine 10 through both of the first and second exhaust manifolds 22a and 22b can be supplied to the first EGR line 72. [ As a result, the high-pressure EGR efficiency can be improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the following claims. It can be understood that it is possible.

10: engine 12a: first cylinder
12b: second cylinder 20: intake manifold
22a: first exhaust manifold 22b: second exhaust manifold
24: branching unit 30: intake line
32: intercooler 34: intake throttle valve
40: exhaust line 46: first valve
50: waste gate line 51: connection line
52: exhaust backpressure control valve 54: waste gate valve
56: second valve 60: turbocharger
62: turbine 64: compressor
66: Axis 70: First EGR device
72: first EGR line 74: first EGR valve
76: first EGR cooler 80: post-treatment device
82: Temperature sensor 90: Second EGR device
92: second EGR line 94: second EGR valve
96: Second EGR cooler

Claims (11)

An intake line connected to the engine to supply intake air;
An exhaust line connected to the engine and discharging a part of exhaust gas discharged from the engine to the outside;
A turbocharger having a turbine installed in the exhaust line and a compressor installed in the intake line;
A post-treatment device installed on the exhaust line on the downstream side of the turbine to purify the exhaust gas;
A low pressure EGR device for recirculating a part of the exhaust gas discharged through the post-treatment device to the engine at the downstream of the post-treatment device; And
And a bypass line connected to the engine for discharging another part of the exhaust gas discharged from the engine to the outside and connected to the exhaust line between the downstream side of the turbine and the upstream side of the post- And an exhaust gas bypass device for supplying another portion of the exhaust gas to the post-treatment apparatus via the bypass line without passing through the turbine. The engine according to claim 1, wherein the engine includes a first exhaust manifold through which exhaust gas discharged from at least one first cylinder is discharged and a second exhaust manifold through which exhaust gas discharged from at least one second cylinder is discharged, Comprising a manifold,
Wherein the exhaust line is connected to the first exhaust manifold and the bypass line is connected to the second exhaust manifold. 3. The exhaust gas recycling system of claim 2, wherein the exhaust gas bypass device includes a connection line connecting the bypass line and the exhaust line on the upstream side of the turbine. 4. The exhaust gas bypass apparatus according to claim 3,
An exhaust backpressure control valve installed in the connection line for controlling an amount of the exhaust gas branched from the bypass line and merged into the exhaust line; And
And a bypass valve installed in the bypass line for controlling an amount of the exhaust gas supplied to the post-processing apparatus. 3. The exhaust gas purification apparatus according to claim 2, further comprising: a branching unit connected to the outlets of the first exhaust manifold and the second exhaust manifold to join the exhaust gas discharged from the first and second exhaust manifolds,
And the exhaust lines and the inlets of the bypass line are connected to the branch unit, respectively. 3. The EGR apparatus according to claim 2, further comprising a high-pressure EGR apparatus,
The high-pressure EGR apparatus includes:
A high-pressure EGR line connecting the exhaust line on the upstream side of the turbine and the intake line; And
And a high-pressure EGR valve installed in the high-pressure EGR line for regulating the amount of the recirculated exhaust gas. The exhaust gas recycling system of claim 6, wherein the high-pressure EGR line connects the intake line on the upstream side of the exhaust line and the intercooler installed downstream of the compressor. The EGR device according to claim 2, wherein the low-pressure EGR device
A low-pressure EGR line connecting the exhaust line and the intake line on the downstream side of the post-treatment apparatus; And
And a low-pressure EGR valve installed in the low-pressure EGR line for regulating the amount of the recirculated exhaust gas. 2. The exhaust gas recycling system of claim 1, further comprising an intercooler for cooling the intake air that has passed through the compressor. 4. The apparatus of claim 3, further comprising a high-pressure EGR device,
The high-pressure EGR apparatus includes:
A high-pressure EGR line connecting the bypass line and the intake line; And
And a high-pressure EGR valve installed in the high-pressure EGR line for regulating the amount of the recirculated exhaust gas. 11. The exhaust gas bypass apparatus according to claim 10,
A connecting line connecting the bypass line and the exhaust line on an upstream side of the turbine;
An exhaust backpressure control valve installed in the connection line for controlling an amount of the exhaust gas branched from the bypass line and merged into the exhaust line; And
Further comprising a bypass valve installed in the exhaust line for controlling an amount of the exhaust gas supplied to the post-treatment apparatus,
And the high-pressure EGR line is connected to the bypass line on the upstream side of the connection line.

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