KR101398569B1 - Application and control method of aftertreatment system for vehicle of engine to reduce ammonia slip with aoc having changable exhaust gas path - Google Patents

Abstract

The present invention relates to a catalyst purification device for the engine of a vehicle capable of purifying ammonia slip using an ammonia oxidation catalyst (AOC) according to the structure of an exhaust gas path and a control method thereof. More specifically, the present invention can oxidize the ammonia slip used not to be oxidized to a catalyst or an SCR catalyst by purifying the ammonia slip of exhaust gas caused from an engine for a vehicle, which is operated by each of fuel for a spark ignition engine and liquid ammonia fuel or mixing them, using an AOC catalyst device according to the set conditions of a vehicle and the exhaust gas, and can emit the lower amount of NOX caused when ammonia is oxidized than the emission standard of harmful ingredients of the exhaust gas because the minimum amount of the NOX is emitted to the outside by purifying the NOX using a second catalyst device; thereby preventing environmental contamination. Also, the present invention can minimize the amount of the ammonia emitted to the atmosphere since the activation hours of the catalyst is reduced by positioning an AOC catalyst close to the engine with a primary catalyst, and can extend the life of the catalyst since the catalyst is protected by changing the path if there is a possibility that the AOC catalyst is damaged by the high temperature of the exhaust gas.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst purifying apparatus for an engine of a vehicle that purifies an ammonia slip using an AOC catalyst according to the structure of an exhaust gas flow path, }

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for purifying ammonia slip using an ammonia oxidation catalyst (AOC) catalyst according to the structure of an exhaust gas flow path, and more particularly, Or the ammonia slip of the exhaust gas generated in the vehicle engine used by mixing the ammonia liquid fuel with each of the other fuels is purified by using the AOC catalytic device according to the set conditions of the vehicle and the exhaust gas, The NOx generated during oxidation of the ammonia is purified by the second catalytic device to minimize the exhaust of NOx to the outside, which is lower than the exhaust gas harmful component emission standard value, And it is possible to prevent the AOC catalyst The amount of ammonia discharged into the atmosphere is minimized by shortening the activation time of the catalyst and when the exhaust gas temperature is high and there is a possibility of damaging the AOC catalyst, the catalyst is protected by changing the flow path, And more particularly, to a catalyst purifying apparatus and method for an engine of a vehicle that purifies ammonia slip using an AOC catalyst according to the structure of an exhaust gas flow path.

The engine after-treatment apparatus of a general spark-ignition engine is discharged after the exhaust gas generated during the operation of the engine is exhausted after the first catalytic treatment and the second catalytic treatment before the exhaust gas is exhausted to the outside.

Here, the catalyst has a catalytic temperature of 250 ° C or higher so that the exhaust gas reducing capability is properly exhibited. Therefore, it is the catalyst device that is installed closest to the engine so that the unburned gas generated at the start including the cold start can be cleaned quickly.

And, the secondary catalyst is a catalyst device installed for treating the exhaust gas which is not purified by the primary catalyst. Finally, a silencer is installed at the rear end of the secondary catalytic device to reduce exhaust noise.

An elemental SCR system for reducing NOx in the exhaust gas discharged from a general engine has been developed. This urea SCR system uses a SCR catalyst that converts NOX to nitrogen (N2) and water (H2O) by a chemical reaction between ammonia (NH3) and NOX generated by the hydrolysis of urea water.

Here, the SCR catalyst is provided in the exhaust gas passage between the engine and the muffler. Further, an injection valve for injecting the oxidation catalyst and the urea water into the exhaust gas is provided on the upstream side of the SCR catalyst. The oxidation catalyst oxidizes hydrocarbons (HC) and carbon monoxide (CO) in the exhaust gas to water (H2O) and carbon dioxide (CO2) and also promotes oxidation of nitrogen oxides (NO) to nitrogen dioxide (NO2).

A diesel particulate filter (DPF) for reducing particulate matter (PM) such as carbon in the exhaust gas is also provided in the exhaust gas passage between the engine and the muffler. The exhaust gas purifying apparatus including the urea SCR system and the DPF has many components provided between the engine and the muffler and also requires a large space for installing such components in the vehicle. Therefore, the urea SCR system must be small in size and also achieve NO x reduction efficiently in terms of urea consumption.

A platinum-containing preliminary catalyst having a function of filtering PM in the exhaust gas, an SCR catalyst provided on the downstream side of the platinum-containing preliminary catalyst, and a first feeder provided on the upstream side of the platinum-containing preliminary catalyst to supply ammonia or urea And a second supply device provided between the apparatus and the platinum-containing preliminary catalyst and the SCR catalyst for supplying ammonia or urea. The platinum-containing pre-catalyst functions as a reduction catalyst at a temperature of less than about 250 ° C and also as an oxidation catalyst at a temperature of at least about 250 ° C. The SCR catalyst is activated as a reducing catalyst at a temperature above about 250 < 0 > C.

When the temperature of the exhaust gas is at T1 between 220 ° C and 270 ° C, ammonia or urea is fed from the first feeder, and ammonia generated by the hydrolysis of the urea in the ammonia or platinum containing pre- NOx is reduced. If the temperature of the exhaust gas exceeds T1, ammonia or urea is fed from the second feeder, and then the ammonia generated in the SCR catalyst by the hydrolysis of ammonia or urea reduces the NOx in the exhaust gas. Oxidation of ammonia in the platinum-containing pre-catalyst is prevented by feeding ammonia or urea in the second feed unit. Therefore, the exhaust gas purifying apparatus efficiently uses the supplied ammonia or urea to reduce NOx.

In this case, the catalyst exhibits a proper performance at a temperature higher than a predetermined temperature. Therefore, in the case of a catalyst of a gasoline vehicle, the catalyst is installed close to the engine so that the catalyst temperature can rise quickly. And excessive fuel injection.

However, when the element is supplied from the first supply device or the second supply device in the exhaust gas purifier, the supplied element is supplied upstream of the platinum-containing preliminary catalyst or the SCR catalyst before reaching the platinum- Should be long enough to ensure that the element is sufficiently long to be hydrolyzed to ammonia. The distance between the first feed device and the platinum-containing pre-catalyst and the distance between the second feed device and the SCR catalyst must be sufficiently long, respectively, for the hydrolysis of the elements. Therefore, there is a problem in that the device has to be increased in its length and it is also difficult to make the device small.

Korean Patent Publication No. 10-2011-0025133 Korean Patent Publication No. 10-2012-0042778 Korean Patent Publication No. 10-0642701

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art,

The ammonia slip of the exhaust gas generated from the engine of the vehicle used for the spark ignition engine or the post-treatment catalyst or the ammonia liquid fuel is mixed with the other fuel or mixed with the other fuel, The ammonia slip which is not oxidized by the conventional catalyst or the SCR catalyst is oxidized and the NOx generated while the ammonia is oxidized is purified by the second catalytic device to minimize the exhaust of NOx to the outside, Which is lower than the component discharge reference value, and which purifies the ammonia slip using the AOC catalyst according to the structure of the exhaust gas flow path that can prevent environmental pollution.

In addition, by positioning the AOC catalyst close to the engine as the first catalyst, the amount of ammonia discharged into the atmosphere is reduced by shortening the catalyst activation time, and when the exhaust gas temperature is high and there is a possibility of damaging the AOC catalyst, The present invention also provides a catalyst purifying apparatus and method for an engine of a vehicle that purifies ammonia slip using an AOC catalyst according to a structure of an exhaust gas flow path that maintains a catalyst's life for a long time by protecting the catalyst.

In order to accomplish the above object, the present invention provides an ammonia (NH₃) slip purifier for exhaust gas generated from an engine for a vehicle, which is used in combination with gasoline and ammonia liquid fuel,

A first catalyst device for purifying the exhaust gas generated in the vehicle engine;

(AOC) oxidizing the ammonia slip in the exhaust gas purified in the first catalytic converter by the AOC oxidation catalyst, the exhaust gas purifier being connected to the first catalytic converter by an exhaust gas transfer pipe connected to the exhaust port of the first catalytic converter, A catalytic device;

And a second catalytic device for purifying the exhaust gas purified in the catalytic device. The catalytic purifying catalyst for an engine of a vehicle purifying ammonia slip using an AOC catalyst according to the structure of an exhaust gas flow path ≪ / RTI >

The present invention also provides a control method for a catalyst purifying apparatus for an engine of a vehicle which purifies ammonia slip using an AOC catalyst according to the structure of an exhaust gas flow path,

A step (S100) of first purifying the exhaust gas generated in the engine in the first catalytic device;

A step (S200) of selectively controlling a transport path of an exhaust gas to be delivered to the AOC catalytic device according to a set condition of the vehicle and exhaust gas to oxidize the ammonia slip in the exhaust gas in the AOC catalytic device after the exhaust gas primary purification, ;

In the step S200 of selectively adjusting the transport path of the exhaust gas, at the time of initial startup of the vehicle or when the temperature of the exhaust gas is in the set range, the first solenoid valve is ON, the second solenoid valve is OFF, The valve is OFF, the fourth solenoid valve is OFF, and the exhaust gas is delivered to the AOC catalytic device through the first bypass pipe (S300);

The first solenoid valve is turned OFF and the second solenoid valve is turned ON when the temperature of the exhaust gas is high or higher than the set range in step S200 of selectively controlling the exhaust gas transport path, , The third solenoid valve is ON, the fourth solenoid valve is OFF, and the exhaust gas is delivered to the AOC catalytic device through the second bypass pipe (S400);

(S500) oxidizing ammonia slip in the exhaust gas transferred through the step (S300) or the step (S400) in the AOC catalytic device;

And a step (S600) of exhausting the oxidized exhaust gas from the AOC catalytic device to the outside through a silencer after being secondarily purified by the second catalytic device. To a control method of a catalyst purifying apparatus for an engine of a vehicle which purifies ammonia slip by using the catalyst.

As described above, according to the structure of the exhaust gas flow path of the present invention, the catalyst purifying apparatus and control method for an engine for purifying the ammonia slip using the AOC catalyst can reduce the number of urea water used for the spark ignition engine or the post- Or an ammonia slurry of an exhaust gas generated from an engine for a vehicle which is used by mixing an ammonia liquid fuel with each other or with other fuels is purified by using an AOC catalyst device according to the setting conditions of a vehicle and an exhaust gas, Oxidizing ammonia slip which is not oxidized and purifying NOx generated by oxidation of the ammonia by the second catalytic device to minimize the exhaust of NOx to the outside so as to be lower than the exhaust gas harmful component emission standard value, It is effective.

In addition, by positioning the AOC catalyst close to the engine as the first catalyst, the amount of ammonia discharged into the atmosphere is reduced by shortening the catalyst activation time, and when the exhaust gas temperature is high and there is a possibility of damaging the AOC catalyst, Thereby protecting the catalyst and thereby maintaining the life of the catalyst for a long period of time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a catalyst purifying apparatus for an engine of a vehicle purifying an ammonia slip using an AOC catalyst according to the structure of an exhaust gas flow path according to an embodiment of the present invention,
Fig. 2 is a schematic view showing the start or normal operation of Fig. 1,
FIG. 3 is a schematic view showing the exhaust gas at high load or high temperature in FIG. 1,
4 is a flowchart showing a control method of a catalyst purifying apparatus for an engine of a vehicle purifying an ammonia slip using an AOC catalyst according to the structure of an exhaust gas flow path according to an embodiment of the present invention.

The present invention has the following features in order to achieve the above object.

The present invention relates to an ammonia (NH₃) slip purifier for exhaust gas generated in an engine for a vehicle which is used by mixing gasoline and ammonia liquid fuel,

A first catalyst device for purifying the exhaust gas generated in the vehicle engine;

(AOC) oxidizing the ammonia slip in the exhaust gas purified in the first catalytic converter by the AOC oxidation catalyst, the exhaust gas purifier being connected to the first catalytic converter by an exhaust gas transfer pipe connected to the exhaust port of the first catalytic converter, A catalytic device;

And a second catalytic device for secondarily purifying the exhaust gas purified in the catalytic device.

The present invention also provides a control method for a catalyst purifying apparatus for an engine of a vehicle which purifies ammonia slip using an AOC catalyst according to the structure of an exhaust gas flow path,

A step (S100) of first purifying the exhaust gas generated in the engine in the first catalytic device;

A step (S200) of selectively controlling a transport path of an exhaust gas to be delivered to the AOC catalytic device according to a set condition of the vehicle and exhaust gas to oxidize the ammonia slip in the exhaust gas in the AOC catalytic device after the exhaust gas primary purification, ;

In the step S200 of selectively adjusting the transport path of the exhaust gas, at the time of initial startup of the vehicle or when the temperature of the exhaust gas is in the set range, the first solenoid valve is ON, the second solenoid valve is OFF, The valve is OFF, the fourth solenoid valve is OFF, and the exhaust gas is delivered to the AOC catalytic device through the first bypass pipe (S300);

The first solenoid valve is turned OFF and the second solenoid valve is turned ON when the temperature of the exhaust gas is high or higher than the set range in step S200 of selectively controlling the exhaust gas transport path, , The third solenoid valve is ON, the fourth solenoid valve is OFF, and the exhaust gas is delivered to the AOC catalytic device through the second bypass pipe (S400);

(S500) oxidizing ammonia slip in the exhaust gas transferred through the step (S300) or the step (S400) in the AOC catalytic device;

And a step (S600) in which the exhaust gas oxidized in the AOC catalytic device is secondarily purified in the second catalytic device and then discharged to the outside through a silencer.

The present invention having such characteristics can be more clearly described by the preferred embodiments thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing in detail several embodiments of the present invention with reference to the accompanying drawings, it is to be understood that the present invention is not limited to the details of construction and the arrangement of components shown in the following detailed description or illustrated in the drawings will be. The invention may be embodied and carried out in other embodiments and carried out in various ways. It should also be noted that the device or element orientation (e.g., "front," "back," "up," "down," "top," "bottom, Expressions and predicates used herein for terms such as "left," " right, "" lateral, " and the like are used merely to simplify the description of the present invention, Or that the element has to have a particular orientation. Also, terms such as " first "and" second "are used herein for the purpose of the description and the appended claims, and are not intended to indicate or imply their relative importance or purpose.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

1 is a schematic view showing a catalyst purifying apparatus for an engine of a vehicle purifying an ammonia slip using an AOC catalyst according to an exhaust gas flow path structure according to an embodiment of the present invention. FIG. 3 is a schematic view showing the exhaust gas at high load or high temperature in FIG. 1, and FIG. 4 is a schematic view showing the ammonia slip using the AOC catalyst according to the structure of the exhaust gas flow path according to an embodiment of the present invention. Fig. 3 is a flowchart showing a control method of a catalyst purifying apparatus for an engine of a purifying vehicle. Fig.

As shown in Figs. 1 to 3, a catalyst purifying apparatus for an engine of a vehicle, which purifies ammonia slip using an AOC catalyst according to the structure of an exhaust gas flow path of the present invention, uses gasoline and ammonia liquid fuel, The AOC catalytic device 20 and the second catalytic device 40. The first catalytic device 10, the AOC catalytic device 20, and the second catalytic device 40 are the devices for purifying harmful substances of the exhaust gas and ammonia (NH₃) The first catalytic device 10 and the second catalytic device 40 are connected to each other by an exhaust gas transfer pipe 70 and are connected to the outlet side of the first catalytic device 10 and the second catalytic device 40, The second solenoid valve 52 and the fourth solenoid valve 54 are respectively installed in the exhaust gas transfer pipe 70 on the suction port side of the engine.

The first catalytic device 10 and the second catalytic device 40 purify the harmful substances in the exhaust gas while the exhaust gas generated in the engine 1 passes through the catalytic device containing the conventional catalytic agent, The catalytic device 10 is located at a position closest to the engine 1 and the second catalytic device 40 is located farthest from the engine 1 to purify exhaust gas which is finally exhausted.

Here, the catalysts of the first catalytic device 10 and the second catalytic device 40 include ordinary oxidation catalysts, SCR catalysts, etc. At this time, the "SCR" means that the catalytic reaction of the reducing agent and the nitrogen oxides To selective catalytic reduction of nitrogen oxides, that is, N2O to N2. The reducing agent may be supplied via a combination of external, internal, or external and internal sources, as the hydrocarbons in the exhaust gas may function as a reducing agent. As described below, the SCR catalyst is reduced upon reaction with NOX, but need not be a reduction catalyst alone. Oxidation reaction may occur.

1 to 3, the AOC catalytic device 20 is disposed at a close distance H close to the first catalytic device 10 and is provided with ammonia in the exhaust gas purified in the first catalytic device 10, (NH3) slip is oxidized by the AOC oxidation catalyst. The AOC catalyst apparatus 20 is directly used at the time of normal operation in which the temperature of the exhaust gas is within the set range or at the time of initial startup. At this time, the AOC is an abbreviation of ammonia oxidation catalyst, which means an ammonia oxidation catalyst, which is a catalyst for oxidizing ammonia.

Here, the AOC catalytic device 20 is connected by a first bypass pipe 30 branched from an exhaust gas transfer pipe 70 connected to a discharge port side of the first catalytic device 10, The other side of the first bypass pipe 30 is connected to the exhaust gas transfer pipe 70 between the first catalyst device 10 and the second solenoid valve 52, Is connected to the exhaust gas transfer pipe 70 between the device 40 and the fourth solenoid valve 54 so that the exhaust gas is delivered to the AOC catalytic device 20 by interrupting the second and fourth solenoid valves 52, do. The description of the setting condition will be described in detail in the following control method.

The first bypass pipe 30 connected to the inlet side of the AOC catalytic device 20 is provided with a first solenoid valve 51 to control opening and closing according to the setting conditions of the vehicle or exhaust gas.

As shown in FIG. 1, the first bypass pipe 30 connected to the AOC catalytic device 20 is connected to the second bypass pipe 30 so that exhaust gas is delivered to the AOC catalytic device 20, The first bypass pipe 31 is connected to the first bypass pipe 30 which is located between the inlet side of the AOC catalytic device 20 and the first solenoid valve 51, And the other side of the second bypass pipe 31 is connected to an exhaust gas transfer pipe 70 between the second solenoid valve 52 and the fourth solenoid valve 54. The description of the setting condition will be described in detail in the following control method.

The second bypass pipe 31 is further provided with a third solenoid valve 53 for opening and closing the inside thereof, and is controlled to open and close in accordance with the setting conditions of the vehicle or the exhaust gas.

The first, second, third, and fourth solenoid valves 51, 52, 53, and 54 may further include a control unit 50 for controlling the opening and closing of the pipe according to the setting conditions of the vehicle or the exhaust gas, 1, the control unit 50 receives signals from the engine 1 and the temperature sensor 55 provided at the outlet side of the engine 1, and controls the first, second, third, and fourth solenoid valves 51, (51, 52, 53, 54).

Hereinafter, a control method of a catalyst purifying apparatus for an engine for purifying ammonia slip using an AOC catalyst according to the structure of the exhaust gas flow path described above will be described in detail with reference to the drawings.

As shown in FIGS. 2 to 4, a control method of a catalyst purifying apparatus for an engine of a vehicle for purifying ammonia slip using an AOC catalyst according to the structure of an exhaust gas flow path of the present invention, After the exhaust gas is first purified in the first catalytic converter 10 (S100), the ammonia slip in the exhaust gas in the AOC catalytic converter 20 is oxidized to the setting conditions of the vehicle and the exhaust gas (S200) of the exhaust gas transport route to the AOC catalytic device 20,

In the control unit 50, the first solenoid valve 51 is turned on, the second solenoid valve 52 is turned off, and the third solenoid valve 53 And the fourth solenoid valve 54 is turned off so that the exhaust gas is directly transferred to the AOC catalytic converter 20 through the first bypass pipe 30. S300 At this time, The exhaust gas pressure is a low load (low pressure) and the temperature of the exhaust gas is low. That is, when the driver starts immediately after starting, the AOC catalyst device 20 is used because the cooling water temperature can not reach 40 degrees. The set temperature of the exhaust gas ranges from 200 to 300 占 폚, and is a temperature range in which no deterioration of the AOC oxidation catalyst occurs.

When the temperature of the exhaust gas is higher than the set range, the first solenoid valve (51) is controlled by the controller (50) The second solenoid valve 52 is turned on and the third solenoid valve 53 is turned on and the fourth solenoid valve 54 is turned off so that the exhaust gas passes through the second bypass pipe 31 at a long distance (S400). At this time, in the sudden acceleration / rapid acceleration state of the vehicle, the exhaust gas pressure is high and the temperature of the exhaust gas is high, and the temperature of the exhaust gas is 400 ° C or higher. The use of the AOC catalytic device 20 is used when the cooling water temperature is 40 DEG C or more and the throttle opening is 60% or more.

Here, the cooling water temperature of 40 ° C is a condition that the exhaust gas temperature passed through the first catalytic device 10 is 400 ° C or higher under the condition that the idle state is stabilized and the exhaust gas temperature at which the AOC sufficiently oxidizes ammonia has reached 400 ° C The ammonia oxidation by the AOC is sufficiently performed, so that the ammonia is directly passed to the AOC catalyst device 20 without passing through the AOC catalyst device 20. [

Also, in most gasoline vehicles, the throttle opening degree of 60% means 70% or more of the maximum output based on the engine output, and the temperature of the exhaust gas (after the first catalytic device) at that time may exceed 700 ° C. At this time, if the exhaust gas temperature exceeds 700 캜, there is a high possibility of damaging the AOC catalyst. Therefore, in order to protect the AOC oxidation catalyst of the AOC catalyst device 20 close to the first catalyst device 10, And is delivered to the AOC catalytic device 20 installed at a distance H2 higher than the installation distance H2 of the AOC catalytic device 20 in the first catalytic device 10. Because the temperature of the exhaust gas is high, The temperature is lowered to prevent the deterioration of the AOC catalyst.

After the ammonia slip in the exhaust gas is oxidized in the AOC catalytic device 20 (S500), the exhaust gas delivered to the AOC catalytic device 20 is delivered to the second catalytic device 40 2 catalyst device 40, and then discharged to the outside through the silencer 60. In step S500,

10: first catalytic device 20: AOC catalytic device
30: first bypass pipe 31: second bypass pipe
40: second catalytic device 50:
51: first solenoid valve 52: second solenoid valve
53: third solenoid valve 54: fourth solenoid valve
55: Temperature sensor 60: Silencer
70: Exhaust gas conveying pipe

Claims (11)

An ammonia (NH₃) slip purifier for an exhaust gas generated from an engine for a vehicle which is used by mixing gasoline and ammonia liquid fuel, respectively,
A first catalyst device (10) for purifying the exhaust gas generated in the vehicle engine (1) first;
The first catalytic device 10 is connected to the first catalytic device 10 by an exhaust gas transfer pipe 70 connected to an exhaust port of the first catalytic device 10 and is connected to the ammonia slip An AOC catalyst device 20 for oxidizing the exhaust gas by an AOC (Ammonia Oxidation Catalyst) oxidation catalyst;
A second catalytic device (40) for secondarily purifying the exhaust gas purified in the catalytic device (20);
Wherein the ammonia slip is purified using an AOC catalyst according to the structure of the exhaust gas flow path.
The method according to claim 1,
The first catalytic device 10 and the second catalytic device 40 are connected to each other by an exhaust gas transfer pipe 70, And a second solenoid valve (52) and a fourth solenoid valve (54) are provided in the exhaust gas transfer pipe (70) on the suction port side, respectively. The ammonia slip Catalytic purifiers for engines of purifying vehicles.
3. The method of claim 2,
The AOC catalytic device 20 is branched and connected to a separate first bypass pipe 30 in the exhaust gas transfer pipe 70 connected between the first catalytic device 10 and the second catalytic device 40 , And a first solenoid valve (51) is installed in a first bypass pipe (30) connected to the inlet side of the AOC catalytic device (20). According to the structure of the exhaust gas flow path, ammonia slip The catalyst purifying device for an engine of a vehicle.
The method of claim 3,
The first bypass pipe 30 connected to the AOC catalytic device 20 is connected to an exhaust gas transfer pipe 70 having one side between the first catalyst device 10 and the second solenoid valve 52, Is connected to the exhaust gas transfer pipe 70 between the second catalytic device 40 and the fourth solenoid valve 54 so that the exhaust gas is supplied to the AOC catalytic device 20 Wherein the ammonia slip is purified by using the AOC catalyst according to the structure of the exhaust gas flow path.
5. The method of claim 4,
The second bypass pipe 31 is connected to the first bypass pipe 30 connected to the AOC catalytic device 20 so that the exhaust gas is delivered to the AOC catalytic device 20 according to the setting conditions of the vehicle or exhaust gas Wherein the ammonia slip is purified using an AOC catalyst according to the structure of the exhaust gas flow path.
6. The method of claim 5,
One end of the second bypass pipe 31 is connected to a first bypass pipe 30 between the suction port side of the AOC catalytic device 20 and the first solenoid valve 51 and the other end is connected to a second solenoid valve A third solenoid valve 53 is provided in the second bypass pipe 31 to open and close the inside of the second bypass pipe 31. The third solenoid valve 53 is connected to the exhaust gas transfer pipe 70 between the first solenoid valve 52 and the fourth solenoid valve 54, Wherein the ammonia slip is purified using an AOC catalyst according to the structure of the exhaust gas flow path.
The method according to claim 6,
The first, second, third and fourth solenoid valves (51, 52, 53, 54) are further provided with a control unit (50) for controlling the opening and closing of the pipe in accordance with the setting conditions of the vehicle or exhaust gas An apparatus for purifying ammonia slip using an AOC catalyst according to the structure of a flow path.
A control method for a catalyst purifying apparatus for an engine of a vehicle which purifies an ammonia slip using an ammonia oxidation catalyst (AOC) catalyst according to the structure of an exhaust gas flow path,
A step (S100) of first purifying the exhaust gas generated in the engine (1) in the first catalytic device (10);
After the first purification of the exhaust gas, the AOC catalytic converter 20 selectively oxidizes the ammonia slip in the exhaust gas by selectively feeding the exhaust gas conveying path to the AOC catalytic converter 20 according to the setting conditions of the vehicle and the exhaust gas Adjusting (S200);
The first solenoid valve 51 is turned on and the second solenoid valve 52 is turned on at the initial start of the vehicle or when the temperature of the exhaust gas is in a set range in step S200, The third solenoid valve 53 is OFF, the fourth solenoid valve 54 is OFF, and the exhaust gas is delivered to the AOC catalytic device 20 through the first bypass pipe 30 (S300);
In the step S200 of selectively controlling the exhaust gas transport path, when the vehicle suddenly accelerates / abruptly accelerates or when the temperature of the exhaust gas is higher than a predetermined range, the first solenoid valve 51 is turned OFF, The exhaust gas is delivered to the AOC catalytic converter 20 through the second bypass pipe 31 by turning on the valve 52, the third solenoid valve 53, and the fourth solenoid valve 54, (S400);
The step S500 of oxidizing the ammonia slip in the AOC catalytic device 20 with the exhaust gas transferred through the step S300 or S400;
A step S600 in which the exhaust gas oxidized in the AOC catalytic device 20 is secondarily purified in the second catalytic device 40 and then discharged to the outside through the silencer 60;
Wherein the ammonia slip is purified using an AOC catalyst according to the structure of the exhaust gas flow path.
9. The method of claim 8,
In step S300, in which the exhaust gas is delivered to the AOC catalytic device 20 through the first bypass pipe,
Wherein the first bypass pipe (30) is used when the temperature of the exhaust gas is in the range of 200 to 300 DEG C, characterized in that the ammonia slip is purified using an AOC catalyst according to the structure of the exhaust gas flow path A method for controlling a catalyst purifying device for an engine.
9. The method of claim 8,
In step S400, in which the exhaust gas is delivered to the AOC catalytic converter 20 through the second bypass pipe 31,
The use of the second bypass pipe (31) is performed when the throttle opening is at least 60%, the exhaust gas temperature is at least 700 ° C, or the cooling water temperature is at least 40 ° C. According to the structure of the exhaust gas flow path, Wherein the ammonia slip is purified by using the catalyst.
11. The method of claim 10,
The exhaust gas purified in the first catalytic device 10 is transferred through the exhaust gas transfer pipe 70 to the second bypass pipe 31 and transferred to the AOC catalytic device 20, Since the distance to which the exhaust gas is transferred through the second bypass pipe 31 is longer than the distance through which the exhaust gas is delivered to the AOC catalytic device 20 through the path pipe 30, And the ammonia slip is oxidized while preventing the deterioration of the AOC catalyst, thereby purifying the ammonia slip using the AOC catalyst according to the structure of the exhaust gas flow path.

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