KR102359737B1 - Integrated exhaust gas aftertreatment unit - Google Patents

Abstract

According to an embodiment of the present invention, an integrated exhaust gas post-processing device is provided. The integrated exhaust gas post-processing device comprises: a housing having an inlet, where exhaust gas is introduced, and an outlet where the exhaust gas is discharged; a plurality of diesel particulate filters disposed inside the housing to remove a particulate substance contained in the exhaust gas; a bypass passage defined between the diesel particulate filters and allowing the exhaust gas introduced through the inlet to bypass to the outlet; a bypass valve disposed in an inlet end of the bypass passage to control the exhaust gas introduced to the bypass passage; an injection nozzle disposed in the bypass passage to inject urea; and a selective reduction catalyst disposed inside the housing and purify the exhaust gas passing the bypass passage.

Description

Integrated exhaust gas aftertreatment unit

The present invention relates to an integrated exhaust gas after-treatment device in which a diesel oxidation catalyst device, a diesel particulate filter and a selective reduction catalyst can be integrally disposed in one housing.

Exhaust gas discharged from combustion of an internal combustion engine contains various harmful components such as nitrogen oxides (NOx), carbon dioxide, and ash, and devices and methods for removing these harmful components have been devised. In particular, in a vehicle or ship equipped with a diesel engine, exhaust gas post-treatment such as a diesel particulate filter (DPF), a diesel oxidation catalyst device (Diesel Oxidation Catalyst: DOC) and a selective reduction catalyst (SCR) The device is being used to remove particulate matter and the like.

However, when all of the diesel oxidation catalyst device, the diesel particulate filter and the selective reduction catalyst are required, a design problem may occur in a small vehicle or a small vessel having a space limitation. In particular, in the case of a selective reduction catalyst, a space for mixing exhaust gas and urea is essential, and it is difficult for all of the diesel oxidation catalyst device, the diesel particulate filter and the selective reduction catalyst to be applied to small ships or vehicles.

It is an object of the present invention to provide an integrated exhaust gas post-treatment device in which a diesel oxidation catalyst device, a diesel particulate filter, and a selective reduction catalyst can be integrally disposed in a single housing.

It is an object of the present invention to provide an integrated exhaust gas post-treatment device in which a selective reduction catalyst can be efficiently operated without a separate space in which exhaust gas and urea can be mixed.

An integrated exhaust gas after-treatment device according to an embodiment of the present invention is provided. The integrated exhaust gas aftertreatment device includes a housing in which an inlet through which exhaust gas is introduced and an outlet through which exhaust gas is discharged, a plurality of diesel particulate filters disposed in the housing to remove particulate matter included in the exhaust gas, and the diesel particulate filter a bypass valve which is defined between , It is disposed in the bypass passage, the injection nozzle for injecting urea, and disposed in the housing may include a selective reduction catalyst for purifying the exhaust gas that has passed through the bypass passage.

In one example, the diesel particulate filter and the selective reduction catalyst are disposed along a direction from the inlet to the outlet.

In one example, a mixer for mixing the injected urea with the exhaust gas is disposed at the outlet end of the bypass passage.

In one example, the injection nozzle is disposed adjacent to the inlet end among the inlet end and the outlet end of the bypass passage, and the bypass passage serves as a length of a pipe required for hydrolysis of exhaust gas and urea. carry out

In one example, the housing may include a first region between the bypass valve and the inlet, a second region in which the diesel particulate filter and the diesel particulate filter are disposed, a third region in which the mixer is disposed, and the selective reduction catalyst is divided into a fourth area in which the

According to an example, a mixing chamber providing a space for mixing exhaust gas and urea is disposed between the mixer and the selective reduction catalyst, and vibration is applied to the outer wall of the mixing chamber or the outer wall of the housing in which the mixing chamber is defined. A soot blower is disposed.

In one example, a cone-shaped inner wall whose cross-sectional area is widened in the direction from the outlet end of the bypass passage toward the selective reduction catalyst is disposed in the mixing chamber.

In one example, the apparatus further includes a controller for controlling the bypass valve and the injection nozzle, wherein the controller controls the injection nozzle to inject urea when the bypass valve is closed more than a preset level.

In one example, the diesel particulate filters are disposed on both sides of the bypass passage, and a plurality of diesel oxidation catalyst devices (DOCs) are provided on the outer shell of each of the diesel particulate filters.

According to an example, an exhaust gas passage is defined between the diesel oxidation catalyst devices and the housing, and when the bypass valve is closed, the exhaust gas is the outer shell of the diesel oxidation catalyst device based on the bypass passage of the housing. The exhaust gas flows to the diesel oxidation catalyst device through the exhaust gas passages defined in , and the exhaust gas that has passed through the diesel oxidation catalyst device passes through the diesel particulate filter and flows into the bypass passage.

In one example, the bypass passage, the two diesel oxidation catalyst devices and the two diesel particulate filters are disposed between the two exhaust gas passages defined in the housing, and Exhaust gas flows through the diesel oxidation catalyst device to the diesel particulate filter.

In one example, the device further includes a plate disposed on one side of the bypass passage, the diesel oxidation catalyst devices, and the diesel particulate filters, wherein the plate is disposed to face one side of the housing where the inlet is defined. The exhaust gas introduced through the inlet is prevented from flowing into one side of the diesel oxidation catalyst devices and the diesel particulate filters.

In one example, the plate is provided with barrier ribs for controlling a flow path of the exhaust gas, and each of the barrier ribs extends from the plate toward the inlet.

In one example, when the bypass valve is opened, the exhaust gas flows toward the selective reduction catalyst through the bypass passage.

According to an embodiment of the present invention, the selective reduction catalyst may be disposed in the housing integrally with the diesel oxidation catalyst devices and the diesel particulate filters. In addition, since the bypass passage in the integrated exhaust gas post-treatment device may serve as a space in which exhaust gas and urea are mixed, a separate space in which exhaust gas and urea are mixed may not be required. Accordingly, miniaturization of the exhaust gas post-treatment device for purifying exhaust gas can be realized.

1 is a perspective view showing an integrated exhaust gas aftertreatment device according to an embodiment of the present invention.
2 is a cross-sectional view showing a closed state of the bypass valve of the integrated exhaust gas after-treatment device according to the embodiment of the present invention.
3 is a cross-sectional view illustrating an open state of the bypass valve of the integrated exhaust gas after-treatment device according to an embodiment of the present invention.
4 is a view for explaining a control method of the bypass valve and the injection nozzle according to an embodiment of the present invention.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only this embodiment serves to complete the disclosure of the present invention, and to obtain common knowledge in the technical field to which the present invention pertains. It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Terms such as "...unit", "...unit", "...module", etc. described in the specification mean a unit that processes at least one function or operation, which is hardware or software or hardware and software. It can be implemented as a combination.

In addition, the reason that the names of the components are divided into the first, the second, etc. in the present specification is to distinguish the names of the components in the same relationship, and the order is not necessarily limited in the following description.

The detailed description is illustrative of the invention. In addition, the above description shows and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. That is, changes or modifications are possible within the scope of the concept of the invention disclosed herein, the scope equivalent to the described disclosure, and/or within the scope of skill or knowledge in the art. The described embodiment describes the best state for implementing the technical idea of the present invention, and various changes required in specific application fields and uses of the present invention are possible. Accordingly, the detailed description of the present invention is not intended to limit the present invention to the disclosed embodiments. Also, the appended claims should be construed to include other embodiments.

1 is a perspective view showing an integrated exhaust gas aftertreatment device according to an embodiment of the present invention.

1, the integrated exhaust gas after-treatment device 1 is a diesel oxidation catalyst device (Diesel Oxidation Catalyst: DOC), a diesel particulate filter (Diesel Particle Filter: DPF), a selective reduction catalyst (Selective Catalyst Reduction: SCR) and It may include a housing 100 surrounding them. The integrated exhaust gas aftertreatment device 1 may be installed in a ship equipped with a diesel engine. However, the integrated exhaust gas after-treatment device 1 may be applied to vehicles other than ships.

The housing 100 may include an inlet 110 through which exhaust gas is introduced and an outlet 130 through which exhaust gas is discharged. The inlet 110 may be provided on one side 101 of the housing 100 , and the outlet 130 may be provided on the other side 102 opposite to one side of the housing 100 . Exhaust gas discharged from the engine (not shown) may be introduced through the inlet 110 , and the exhaust gas may be discharged to the outside of the vessel through the outlet 130 . A direction from the inlet 110 to the outlet 130 may be the first direction (x).

An inclined portion 103 connected to one side 101 of the housing 100 may be defined in the housing 100 . Two inclined portions 103 may be provided on one side 101 of the housing 100 in the second direction y orthogonal to the first direction x. The inclined portion 103 may serve to adjust the flow path and flow rate of the exhaust gas introduced into the housing 100 .

The inclined portion 103 may be provided with a window 105 . Through the window 105 , the operator can directly check the situation inside the housing 100 . The operator can visually confirm whether the bypass valve (not shown) is opened or closed, which will be described later, and that soot is excessively accumulated in the bypass valve (not shown).

The bypass valve (not shown) may be automatically controlled by a controller (not shown), or may be manually controlled by an operator. An operator may open and close the bypass valve (not shown) through the operation unit 50 provided on the housing 100 .

2 is a cross-sectional view showing a closed state of the bypass valve of the integrated exhaust gas after-treatment device according to the embodiment of the present invention.

1 and 2 , the integrated exhaust gas aftertreatment device 1 includes a diesel oxidation catalyst device 200 , a diesel particulate filter 300 , a bypass valve 400 , an injection nozzle 500 , and a mixer 600 . ) and a selective reduction catalyst 700 . That is, the diesel oxidation catalyst device 200 , the diesel particulate filter 300 and the selective reduction catalyst 700 may be arranged to be integrated into one housing 100 .

The housing 100 may include an inlet 110 through which exhaust gas is introduced and an outlet 130 through which exhaust gas is discharged. The inlet 110 and the outlet 130 may be arranged along the first direction (x). The housing 100 may be divided into a first area 100a, a second area 100b, a third area 100c, and a fourth area 100d. The first region 100a may mean a space between the bypass valve 400 and the inlet 110 . The second region 100b may mean a space in which the diesel oxidation catalyst device 200 and the diesel particulate filter 300 are disposed. The third region 100c may mean a space in which the mixer 600 is disposed. The fourth region 100d may mean a space in which the selective reduction catalyst 700 is disposed.

The first region 100a may be defined by inclined portions 103 connecting one side 101 of the housing 100 and four surfaces defining the second region 100b. For example, the number of inclined portions 103 may be four. The first region 100a and the second region 100b may be divided by the bypass valve 400 and the plate 150 on which the bypass valve 400 is disposed. In other words, the second region 100b may be a space defined by four surfaces surrounding the diesel oxidation catalyst device 200 and the diesel particulate filter 300 , and the first region 100a is the second region 100b ) and may be a space between the plate 150 and one side 101 of the housing 100 . At least one of the inclined portions 103 defining the first region 100a may be provided with a window 105 for visually checking the movement of the bypass valve 400 disposed inside the housing 100 .

A soot blower 190 may be disposed in the third region 100c. The soot blower 190 may be attached to the outer wall of the housing 100 to generate vibration in the housing 100 . The soot existing on the inner surface of the housing 100 or the inner wall 185 disposed inside the third region 100c may be blown off by the vibration generated by the soot blower 190 . The third region 100c may be referred to as a mixing chamber 180 , and the mixing chamber 180 will be described later.

The selective reduction catalyst 700 may be disposed in the fourth region 100d. An outlet 130 may be defined in the fourth region 100d. The outlet 130 may be defined on the other side 102 opposite to the one side 101 of the housing 100 .

Each of the diesel oxidation catalyst device 200 and the diesel particulate filter 300 may have a rectangular parallelepiped shape. The diesel oxidation catalyst device 200 may oxidize hydrocarbons (HC) or carbon monoxide (CO) or oxidize soluble organic factors (SOF) contained in particulate matter. The diesel particulate filter 300 may filter and collect particulate matter included in the exhaust gas. Based on the flow path of the exhaust gas, the diesel oxidation catalyst device 200 may be disposed in front of the diesel particulate filter 300 . For example, the diesel oxidation catalyst device 200 and the diesel particulate filter 300 may be disposed to overlap in a second direction (y) orthogonal to a first direction (x) from the inlet 110 to the outlet 130 . have. However, the diesel oxidation catalyst device 200 and the diesel particulate filter 300 may be arranged to overlap in a direction other than the direction perpendicular to the first direction (x).

A plurality of each of the diesel oxidation catalyst device 200 and the diesel particulate filter 300 may be disposed in the second region 100b of the housing 100 . For example, the diesel oxidation catalyst device 200 and the diesel particulate filter 300 may each be disposed two. A bypass passage 140 may be defined between the two diesel particulate filters 300 . Two diesel oxidation catalyst devices 200 may be disposed at positions opposite to the bypass passage 140 with respect to each of the two diesel particulate filters 300 . Accordingly, the diesel oxidation catalyst device 200, the diesel particulate filter 300, the bypass passage 140, the diesel particulate filter 300, and the diesel oxidation catalyst device 200 are sequentially arranged along the second direction y. can be

The bypass passage 140 may discharge the exhaust gas introduced through the inlet 110 to the mixer 600 . The length of the bypass passage 140 in the first direction (x) may be the same as the length in the first direction (x) of each of the diesel oxidation catalyst device 200 and the diesel particulate filter 300 . When exhaust gas flows into the bypass passage 140 , the exhaust gas may not flow into the diesel oxidation catalyst device 200 and the diesel particulate filter 300 . In other words, the bypass passage 140 may bypass the exhaust gas introduced through the inlet 110 to the mixer 600 .

A space between the two surfaces of the second region 100b disposed along the second direction y and the diesel oxidation catalyst devices 200 may be defined as an exhaust gas passage 160 . The exhaust gas flowing into the exhaust gas passage 160 may be blocked by a barrier wall 170 that separates the second region 100b and the third region 100c of the housing 100 . The blocking wall 170 may be in contact with one surface of each of the diesel oxidation catalyst device 200 and the diesel particulate filter 300, and the other surface of each of the diesel oxidation catalyst device 200 and the diesel particulate filter 300 is a plate 150 ) can be in contact with At this time, one surface and the other surface of each of the diesel oxidation catalyst device 200 and the diesel particulate filter 300 may be defined based on the first direction (x). Accordingly, the exhaust gas introduced into the exhaust gas passage 160 may be introduced into the diesel oxidation catalyst devices 200 .

A plate 150 may be disposed on the other surfaces of the diesel oxidation catalyst device 200 and the diesel particulate filter 300 . The other surfaces of the diesel oxidation catalyst device 200 and the diesel particulate filter 300 may mean an area adjacent to the inlet 110 and not the outlet 130 . The plate 150 may be a wall extending in the second direction (y) and the third direction (z). The third direction z may mean a direction perpendicular to the first direction x and the second direction y. The plate 150 may be disposed at the inlet end of the bypass passage 140 . The inlet end of the bypass passage 140 may refer to an area adjacent to the inlet 110 of the housing 100 . The plate 150 is disposed to face one side 101 of the housing 100 where the inlet 110 is defined, so that the exhaust gas introduced through the inlet 110 is supplied to the diesel oxidation catalyst devices 200 and diesel particulate filters. It can be prevented from flowing into the other surface of (300). Between both ends of the plate 150 in the second direction y and the housing 100 may mean an inlet end of the exhaust gas passage 160 . The diesel oxidation catalyst device 200 and the diesel particulate filter 300 may be disposed between the plate 150 and the blocking wall 170 .

Two partition walls 155 may be provided on the plate 150 . The partition walls 155 may control a flow path of the exhaust gas. The partition walls 155 may extend from the plate 150 toward the inlet 110 . For example, the partition walls 155 may extend to be perpendicular to the surface of the plate 150 facing the one side 101 of the housing 100 . As another example, the partition walls 155 may extend to be inclined to form an acute angle with the surface of the plate 150 facing the one side 101 of the housing 100 , and the direction in which the partition walls 155 are inclined is an inclined portion. It may be in the direction toward (103). The partition walls 155 may be provided at the same height as the plate 150 in the third direction z.

A bypass valve 400 may be disposed at an inlet end of the bypass passage 140 . The bypass valve 400 may control the exhaust gas flowing into the bypass passage 140 . The bypass valve 400 may be disposed in an opening (not shown) defined in the plate 150 , and the opening (not shown) may mean an inlet end of the bypass passage 140 . The bypass valve 400 may be of a plate type that can rotate about one axis. The bypass valve 400 may be a wall having the same height as the plate 150 in the third direction z.

When the bypass valve 400 is closed, the bypass valve 400 and the plate 150 may function as one wall. When the bypass valve 400 is opened, the opening of the plate 150 (or the inlet end of the bypass passage 140 ) may be opened. By opening and closing the bypass valve 400 , the exhaust gas may flow to the diesel oxidation catalyst devices 200 or to the bypass passage 140 .

A spray nozzle 500 for spraying urea may be disposed in the bypass passage 140 . The injection nozzle 500 is a component of the selective reduction catalyst 700 to be described later, and may spray urea. Urea is an aqueous ammonia solution and may mean mixing a urea component with water. Urea may be a substance used to purify nitrogen oxides (NOx) generated in diesel engines. When urea is injected into the bypass passage 140 through which the exhaust gas passes, nitrogen oxides may be reduced to water and nitrogen. Purifying the exhaust gas by the above method is called chemical purification, and in particular, since only nitrogen compounds are reduced, it may be called a 'selective reduction catalyst method'. For example, the injection nozzle 500 may inject urea while moving in the bypass passage 140 , and a moving means (not shown) is provided on the inner surface of the housing 100 for movement of the injection nozzle 500 . can be provided.

The bypass passage 140 may serve as a length of a pipe required for hydrolysis of exhaust gas and urea. In other words, a space in which urea and exhaust gas can be mixed is required for hydrolysis of urea, and the bypass passage 140 can provide a space in which exhaust gas and urea can be mixed. In order to maximize the role of the bypass passage 140 , the injection nozzle 500 may be disposed adjacent to the inlet end of the bypass passage 140 .

A mixer 600 for mixing the injected urea with the exhaust gas may be disposed at the outlet end of the bypass passage 140 . The mixer 600 may be connected to the outlet end of the bypass passage 140 and be disposed in the third region 100c of the housing 100 . That is, the mixer 600 may be disposed in the mixing chamber 180 . A cone-shaped inner wall 185 having a larger cross-sectional area in the direction from the outlet end of the bypass passage 140 toward the selective reduction catalyst 700 may be disposed in the mixing chamber 180 . The mixer 600 may be disposed in the interior defined by the inner wall 185 . Due to the shape of the inner wall 185 , the rate at which the exhaust gas and urea mixed by the mixer 600 are introduced into the selective reduction catalyst 700 can be slowed down.

The selective reduction catalyst 700 may cause a catalytic reaction of the mixed exhaust gas and urea. Specifically, the selective reduction catalyst 700 may be a device for converting water (H2O) and nitrogen (N2) through a catalytic reaction between an aqueous ammonia (NH3) solution or a urea (NH2(2CO)) aqueous solution and exhaust gas. The selective reduction catalyst 700 can reduce nitrogen oxides (NOx) as well as carbon monoxide generated in large amounts from the engine. The exhaust gas purification method through the selective reduction catalyst 700 has the advantage of improving fuel efficiency and keeping the engine interior clean for a long time in that it does not additionally inject fuel or create accumulations through exhaust gas recirculation. The exhaust gas purified through the selective reduction catalyst 700 may be discharged through the outlet 130 . The diesel particulate filter 300 and the selective reduction catalyst 700 or the diesel oxidation catalyst device 200 and the selective reduction catalyst 700 are disposed along the first direction (x) from the inlet 110 to the outlet 130 can

Unlike the above-described example, the integrated exhaust gas aftertreatment device 1 may not include the diesel oxidation catalyst device 200 . That is, only the diesel particulate filter 300 and the selective reduction catalyst 700 may be disposed in the integrated exhaust gas post-treatment device 1 .

For example, when the bypass valve 400 is closed, the exhaust gas cannot flow into the bypass passage 140 . The exhaust gas may flow into the exhaust gas passage 160 , and may be introduced into the diesel oxidation catalyst device 200 through the exhaust gas passage 160 . The exhaust gas introduced into the diesel oxidation catalyst device 200 may be introduced into the bypass passage 140 only through the diesel particulate filter 300 . At this time, the flow path of the exhaust gas may be changed by the partition walls 155 . Specifically, the exhaust gas may flow along the inner surface of the housing 100 by the partition walls 155 . In the absence of the partition walls 155 , a portion of the exhaust gas may be moved along the plate 150 and may not flow into a portion of the diesel oxidation catalyst devices 200 adjacent to the plate 150 . Accordingly, there may be a problem that the filtering of exhaust gas is not performed over the entire area of the diesel oxidation catalyst devices 200 . However, the exhaust gas flowing along the inner surface of the housing 100 by the partition walls 155 may be uniformly introduced into the entire region of the diesel oxidation catalyst devices 200 . Accordingly, the efficiency of the process of filtering particulate matter included in the exhaust gas through the diesel oxidation catalyst devices 200 can be increased. The exhaust gas introduced into the exhaust gas passage may be introduced into the diesel oxidation catalyst device 200 by the blocking walls 170 disposed at the ends of the exhaust gas passages 160 . The exhaust gas may flow through the diesel oxidation catalyst device 200 to the diesel particulate filter 300 . The exhaust gas passing through the diesel particulate filter 300 may flow to the bypass passage 140 , and the exhaust gas may flow to the mixer 600 through the bypass passage 140 .

According to the embodiment of the present invention, considering the operation control of the vessel, the durability of the diesel oxidation catalyst devices 200 and the diesel particulate filters 300 , the degree of soot accumulated in the bypass valve 400 , etc. Thus, the opening and closing of the bypass valve 400 is controlled so that the path of the exhaust gas may be changed. Accordingly, the exhaust gas excessively flows into the diesel oxidation catalyst devices 200 and the diesel particulate filters 300, so that the durability of the diesel oxidation catalyst devices 200 and the diesel particulate filters 300 is prevented from being deteriorated. can In addition, when the exhaust gas continuously flows toward the diesel oxidation catalyst devices 200 and the diesel particulate filters 300 , soot may be excessively accumulated in the bypass valve 400 , the bypass valve By opening 400 , excessive accumulation of soot in the bypass valve 400 may be prevented.

According to an embodiment of the present invention, the selective reduction catalyst 700 may be disposed in the housing 100 integrally with the diesel oxidation catalyst devices 200 and the diesel particulate filters 300 . Accordingly, miniaturization of the exhaust gas post-treatment device for purifying exhaust gas can be realized.

According to the embodiment of the present invention, since the bypass passage 100 in the integrated exhaust gas after-treatment device 1 can serve as a space in which exhaust gas and urea are mixed, a separate space in which exhaust gas and urea are mixed Space may not be required. Accordingly, miniaturization of the exhaust gas post-treatment device for purifying exhaust gas can be realized.

3 is a cross-sectional view illustrating an open state of the bypass valve of the integrated exhaust gas after-treatment device according to an embodiment of the present invention. For brevity of description, descriptions of contents overlapping those of FIG. 2 will be omitted.

Referring to FIG. 3 , when the bypass valve 400 is in an open state, the exhaust gas introduced through the inlet 110 may flow into the bypass passage 140 . At this time, the exhaust gas communicates with the outlet 130 of the housing 100 rather than the exhaust gas passage 160 , and may be introduced into the bypass passage 140 having a relatively low flow resistance. Accordingly, the exhaust gas may flow to the mixer 600 without performing a purification process of the exhaust gas by the diesel oxidation catalyst devices 200 and the diesel particulate filters 300 . In addition, in the state in which the bypass valve 400 is opened, the amount of soot accumulated in the bypass valve 400 is greatly reduced, so that the durability of the bypass valve 400 may be improved. That is, opening and closing of the bypass valve 400 may be controlled according to the user's needs or the need for exhaust gas purification.

4 is a view for explaining a control method of the bypass valve and the injection nozzle according to an embodiment of the present invention.

3 and 4 , a controller 800 for controlling the bypass valve 400 and the injection nozzle 500 may be provided. The controller 800 may partially open the bypass valve 400 when particulate matter (particularly, soot) accumulates in the bypass valve 400 . For example, a sensor (not shown) for measuring the amount of soot accumulated in the bypass valve 400 may be disposed in the housing 100 .

The controller 800 may open the bypass valve 400 at regular intervals. At this time, the controller 800 may open the bypass valve 400 within a preset angle rather than completely opening it. For example, the preset angle may be 5 to 10 degrees, and the preset angle may mean an angle between the plate 150 and the bypass valve 400 . When the bypass valve 400 is completely closed, the bypass valve 400 and the plate 150 may be viewed as one wall.

The controller 800 may control the injection nozzle 500 according to the degree of opening of the bypass valve 400 . The controller 800 may control the injection nozzle 500 to inject urea when the bypass valve 400 is closed more than a preset level. For example, the preset level may be a preset angle of 5 degrees to 10 degrees. As another example, the controller 800 may inject urea by controlling the injection nozzle 500 regardless of the opening and closing of the bypass valve 400 . As another example, the controller 800 may inject urea by controlling the injection nozzle 500 only when the bypass valve 400 is completely closed. That the bypass valve 400 is closed may mean that the need for purification of exhaust gas has increased. Accordingly, the controller 800 may control the injection nozzle 500 to purify the exhaust gas from the selective reduction catalyst 700 to inject urea. If it is not necessary to purify the exhaust gas, the controller 800 may bypass the exhaust gas by opening the bypass valve 400 , and the controller 800 may control the injection nozzle 500 so that the urea is not injected. can be controlled.

In the above, embodiments of the present invention have been described with reference to the accompanying drawings, but those of ordinary skill in the art to which the present invention pertains can practice the present invention in other specific forms without changing its technical spirit or essential features. You will understand that there is Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (14)

a housing having an inlet through which exhaust gas is introduced and an outlet through which exhaust gas is discharged;
a plurality of diesel particulate filters disposed in the housing to remove particulate matter contained in exhaust gas (Diesel Particle Filter: DPF);
a bypass passage defined between the diesel particulate filters and bypassing the exhaust gas introduced through the inlet to the outlet;
a bypass valve disposed at the inlet end of the bypass passage to control exhaust gas flowing into the bypass passage;
a spray nozzle disposed in the bypass passage to spray urea; and
Containing a selective reduction catalyst (Selective Catalyst Reduction: SCR) disposed in the housing and purifying the exhaust gas that has passed through the bypass passage,
Integrated exhaust gas aftertreatment unit. According to claim 1,
The diesel particulate filter and the selective reduction catalyst are disposed along a direction from the inlet to the outlet,
Integrated exhaust gas aftertreatment unit. According to claim 1,
A mixer for mixing the injected urea with the exhaust gas is disposed at the outlet end of the bypass passage,
Integrated exhaust gas aftertreatment unit. 4. The method of claim 3,
The injection nozzle is disposed adjacent to the inlet end of the inlet end and the outlet end of the bypass passage,
The bypass passage serves as a length of pipe required for hydrolysis of exhaust gas and urea,
Integrated exhaust gas aftertreatment unit. 4. The method of claim 3,
The housing includes a first area between the bypass valve and the inlet, a second area in which the diesel particulate filter and the diesel particulate filter are disposed, a third area in which the mixer is disposed, and a fourth area in which the selective reduction catalyst is disposed divided into areas,
Integrated exhaust gas aftertreatment unit. 6. The method of claim 5,
A mixing chamber providing a space in which exhaust gas and urea are mixed is disposed between the mixer and the selective reduction catalyst,
A soot blower for generating vibration is disposed on the outer wall of the mixing chamber or the outer wall of the housing in which the mixing chamber is defined,
Integrated exhaust gas aftertreatment unit. 7. The method of claim 6,
In the mixing chamber, a cone-shaped inner wall whose cross-sectional area is widened in a direction from the outlet end of the bypass passage toward the selective reduction catalyst is disposed,
Integrated exhaust gas aftertreatment unit. According to claim 1,
Further comprising a controller for controlling the bypass valve and the injection nozzle,
The controller controls the injection nozzle to inject urea when the bypass valve is closed above a preset level,
Integrated exhaust gas aftertreatment unit. According to claim 1,
The diesel particulate filters are disposed on both sides of the bypass passage, and a plurality of diesel oxidation catalyst devices (Diesel Oxidation Catalyst: DOC) are provided on the outer shell of each of the diesel particulate filters,
Integrated exhaust gas aftertreatment unit. 10. The method of claim 9,
An exhaust gas passage is defined between the diesel oxidation catalyst devices and the housing,
When the bypass valve is closed, the exhaust gas flows to the diesel oxidation catalyst device through exhaust gas passages defined in the outer shell of the diesel oxidation catalyst device with respect to the bypass passage of the housing,
Exhaust gas passing through the diesel oxidation catalyst device passes through the diesel particulate filter and flows into the bypass passage,
Integrated exhaust gas aftertreatment unit. 11. The method of claim 10,
the bypass passage, the two diesel oxidation catalyst devices and the two diesel particulate filters are disposed between the two exhaust gas passages defined in the housing;
The exhaust gas introduced into the exhaust gas passage passes through the diesel oxidation catalyst device and flows to the diesel particulate filter,
Integrated exhaust gas aftertreatment unit. 10. The method of claim 9,
Further comprising a plate disposed on one side of the bypass passage, the diesel oxidation catalyst devices and the diesel particulate filters,
The plate is disposed to face one side of the housing where the inlet is defined to prevent exhaust gas introduced through the inlet from flowing into one side of the diesel oxidation catalyst devices and the diesel particulate filters,
Integrated exhaust gas aftertreatment unit. 13. The method of claim 12,
The plate is provided with barrier ribs for controlling the flow path of the exhaust gas,
Each of the partition walls extends in a direction from the plate toward the inlet,
Integrated exhaust gas aftertreatment unit. According to claim 1,
When the bypass valve is opened, the exhaust gas flows toward the selective reduction catalyst through the bypass passage,
Integrated exhaust gas aftertreatment unit.

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