KR101391333B1 - Device for purifying exhaust and vessel having the same - Google Patents

Abstract

The present invention relates to an exhaust gas purification device loaded on a ship. The exhaust gas purification device according to an embodiment of the present invention comprises: a catalyst part for reducing nitrogen oxide contained in exhaust gas by reacting the exhaust gas discharged from an engine with a reducing agent which is hydrocarbon; a reducing agent supply part for supplying the reducing agent to the catalyst part; an air supply part for supplying some of air compressed by a super charger for supplying the air supplied from the engine with the pressure of the exhaust gas discharged from the engine to the catalyst part; a motor part for applying rotation force to the super charger; and a control part for controlling the amount of the air supplied to the catalyst part by controlling the motor and the air supply part.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a device for purifying exhaust gas,

The present invention relates to an exhaust gas purification apparatus mounted on a ship.

As the industry develops, marine transportation using vessels is expanding. In addition, with the development of industry, concerns about environmental pollution are growing, and many environmental regulations are emerging as countermeasures.

Generally, ships for transporting logistics are propelled by an oil or gas-fueled engine, which inevitably results in exhaust gas.

Among such exhaust gases, particularly, nitrogen oxides (NOx) have a great adverse effect on the environment and are thus subject to major environmental regulations.

On the other hand, the International Maritime Organization (IMO) regulates emission of nitrogen oxides by grade as shown in Fig. 1 for environmental protection.

The emission standards for nitrogen oxides are applied differently in different regions. In particular, Tier 3 grades are applied in emission control areas specifically designated for coastal areas close to land.

In order to satisfy the exhaust gas regulations as described above, techniques for increasing the efficiency of the engine, changing the fuel to be used, and post-treatment for reducing sulfur compounds (SOx) or nitrogen oxides (NOx) in the exhaust gas have been proposed.

As described above, selective catalytic reduction (SCR) using urea water is widely used for reducing nitrogen oxides among technologies for post-treating exhaust gas among technologies.

As shown in FIG. 2, the selective catalyst reduction method using the urea water is a method in which a catalyst 40 composed of a carrier such as Al 2 O 3 or TiO 2 and an active component such as Pd, Pt, Rd or RU is mixed with the exhaust gas of the engine 10 (Urea) is sprayed as a reducing agent to the exhaust gas before the exhaust gas enters the catalyst (40), so that the nitrogen oxides are reacted in the catalyst (40) so as to be reduced to nitrogen Method.

However, in the selective catalytic reduction of nitrogen oxides using the urea water described above, the urea water used as a reducing agent must be separately stored in the vessel. Therefore, in addition to the fuel tank 20 for storing the fuel, a separate urea water storage tank 50, There is a problem in that a space is required for the number of elements.

In general, the engine of a ship is mainly composed of a diesel engine. The diesel engine uses heavy fuel oil (HFO) or marine diesel oil (MDO).

The heavy oil is relatively inexpensive as compared with light oil, and it must be heated and purified at a certain temperature or higher to be used as a fuel in ships, and more toxic substances such as nitrogen oxides and sulfur oxides tend to be discharged.

In addition, the diesel oil is relatively expensive compared to heavy oil, and the emission of harmful substances is low, but still discharges harmful substances such as nitrogen oxides and sulfur oxides.

On the other hand, engines that use natural gas as a fuel instead of heavy oil or light oil have been developed as ship engine fuel. In the case of an engine using natural gas as described above, the concentration of harmful substances such as nitrogen oxides and sulfur oxides can be drastically reduced in the exhaust gas.

However, due to the characteristics of the natural gas having a very low specific gravity and the characteristics of the marine engine having a low number of revolutions and a very large combustion chamber, some of the natural gas supplied to the combustion chamber can not be burnt and discharged as exhaust gas.

The phenomenon that such unburned fuel is discharged into exhaust gas is called slip. The main component of natural gas is methane (CH4). In the case of methane, the effect of greenhouse effect on global warming is 23 times that of carbon dioxide Given the point, slip methane is a problem that must be solved.

In recent years, a dual fuel engine capable of using all of the heavy oil, diesel, and natural gas as described above has been developed, and an exhaust gas purifying apparatus capable of treating both of nitrogen oxides as well as slip methane There is a growing need.

Korean Patent Publication No. 10-2012-0056476

In order to solve the above problems, it is an object of the present invention to provide an exhaust gas purifying apparatus capable of efficiently treating both nitrogen oxides and slip methane.

Further, the present application is to provide a ship that emits cleaner exhaust gas by mounting a dual fuel engine using heavy oil, light oil or natural gas as fuel.

The problems of the present application are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided an exhaust gas purifying catalyst comprising a catalytic unit for reacting an exhaust gas discharged from an engine with a reducing agent to reduce nitrogen oxides in the exhaust gas, using hydrocarbon as a reducing agent, An air supply unit configured to supply a part of the compressed air to the catalyst unit in a supercharger for compressing the air supplied to the engine by the pressure of the exhaust gas discharged from the engine, And a control unit for controlling the motor unit and the air supply unit to control the amount of air supplied to the catalyst unit.

The reducing agent supply unit may be configured to use natural gas stored in the natural gas storage tank as a reducing agent.

The reducing agent supply unit may include a reducing agent supply pipe that guides the natural gas stored in the natural gas storage tank to the catalyst unit and a pumping unit that guides the natural gas inside the reducing agent supply pipe to the catalyst unit side.

The air supply unit includes an air supply pipe branched at one point in the path of the compressed air in the supercharger toward the engine and extending to the catalyst unit to guide compressed air from the supercharger to the catalyst unit, And an air supply control valve installed to control the flow rate of the air flowing through the air supply pipe.

And a heater for heating the air supplied from the air supply unit to the catalyst unit to a temperature at which the reduction reaction of the catalyst unit occurs.

The turbocharger is installed on a path through which the exhaust gas of the engine flows and is rotated by the pressure of the exhaust gas. The supercharger is installed on a path through which the air to be drawn into the engine flows. The supercharger is rotated by the rotational force of the turbine, A compressor for compressing air and a shaft for transmitting the rotational force of the turbine to the compressor, and the motor may be configured to add a rotational force to a shaft rotated by the rotational force of the turbine so as to increase the air compression amount of the compressor .

Wherein the catalyst portion includes a mixer in which the exhaust gas discharged from the engine is mixed with the reducing agent and a catalyst in which a reduction reaction of nitrogen oxides occurs in the exhaust gas mixed with the reducing agent in the mixer, And the air supply unit may be configured to supply air to the mixer.

Further comprising an exhaust sensor for measuring the concentration of nitrogen oxides in the exhaust gas discharged from the engine, wherein the control unit controls the motor unit and the exhaust unit so that the discharged exhaust gas satisfies the exhaust gas regulations of the area in which the engine is currently located. To control the air supply unit.

According to the exhaust gas purifying apparatus of the present application and the vessel having the same, the following effects can be obtained.

First, since natural gas is used as the fuel of the engine, the concentration of harmful substances such as nitrogen oxides in the exhaust gas can be drastically reduced.

Second, when the engine is applied to an LNG carrier, the natural gas stored in the vessel can be used as fuel, so that a separate fuel tank is not required or the size of the fuel tank can be reduced, thereby enlarging the size of the natural gas storage tank .

Third, natural gas pre-stored in the ship can be used as a reducing agent to be supplied to a catalyst for reducing harmful substances such as nitrogen oxides in the exhaust gas, so that a separate urea storage tank is not needed, And the convenience of operation can be improved since there is no need to purchase the number of elements separately.

Fourth, since natural gas (methane) slipped in the engine can be used as a reducing agent, it is possible to simultaneously treat the slip methane and the nitrogen oxide in the exhaust gas.

Fifth, by supplying fresh air rich in oxygen to a catalyst for reducing harmful substances such as nitrogen oxides in the exhaust gas, it is possible to more effectively reduce the concentration of harmful substances in the exhaust gas by inducing the reduction reaction to be actively performed have.

Sixth, it is possible to minimize the occurrence of additional costs by using supercharger installed in ship to supply high concentration of oxygen to the catalyst.

Seventhly, since a motor for adding a rotational force to the turbocharger rotated by the exhaust gas is provided to prevent a decrease in the air supply amount supplied to the engine, which may be caused by supplying a part of the intake air compressed by the turbocharger to the catalyst, The air supply amount can be prevented from being lowered, and the fuel consumption loss of the engine can be minimized.

The effects of the present application are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

The foregoing summary, as well as the detailed description of the embodiments of the present application set forth below, may be better understood when read in conjunction with the appended drawings. Embodiments are shown in the figures for purposes of illustrating the present application. It should be understood, however, that this application is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a table showing an example of regulation of nitrogen oxide emission in the International Maritime Organization;
FIG. 2 is a schematic view of an exhaust gas treatment apparatus of a selective catalyst reduction method using urea water applied to a ship; FIG.
3 is a cross-sectional view schematically showing a state in which an exhaust gas purifying apparatus using hydrocarbons according to the present application is applied to a ship;
FIG. 4 is a view schematically showing a configuration of an embodiment of the exhaust gas purifying apparatus of FIG. 3;
FIG. 5 is a graph showing a change in reduction effect according to a change in the concentration of oxygen contained in the exhaust gas; FIG. And,
6 is a flowchart showing a method of controlling the operation of the turbocharger and the air supply unit by the control unit of the present embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In describing the present embodiment, the same designations and the same reference numerals are used for the same components, and further description thereof will be omitted.

3, the exhaust gas purifying apparatus 100 of the present embodiment is applied to the ship 200 as an example. However, the exhaust gas purifying apparatus of the present invention is not necessarily limited to this, and may be applied to any engine to which the exhaust gas is discharged.

The vessel 200 may be an LNG carrier carrying liquefied natural gas (LNG).

The LNG carrier 200 includes a plurality of natural gas storage tanks 210 for storing liquefied natural gas and an engine 230 for propelling the ship 200.

An exhaust pipe 234 for exhausting the exhaust gas generated from the engine 230 may be installed on the stack 240 of the ship.

Meanwhile, in the present embodiment, the engine 230 may be a dual fuel engine capable of using natural gas as fuel as well as heavy oil or diesel fuel, which are conventional fuels.

The dual fuel engine 230 may be equipped with heavy oil or diesel fuel as fuel and may use natural gas stored in the natural gas storage tank 210 of the ship as fuel if necessary.

That is, since the natural gas stored in the natural gas storage tank 210 of the ship 200 can be used as fuel, the storage amount of the heavy oil or the light oil can be reduced. In the transportation of the liquefied natural gas, Boiling off gas (BOG) generated by vaporization of liquefied natural gas can be utilized as fuel and the concentration of harmful substances such as nitrogen oxides in the exhaust gas can be lowered.

Of course, the engine to which the present invention is applied is not necessarily limited to the dual fuel engine, and can be applied to an engine using conventional heavy oil or light oil as fuel or an engine using only natural gas as fuel.

Meanwhile, exhaust gas is inevitably generated in the engine 230, and the generated exhaust gas can be discharged to the outside through the stack 240 on the exhaust pipe 234.

A supercharger 250 may be installed on the ship 200.

The turbocharger 250 is a component for compressing the air sucked into the engine 230 by the pressure of the exhaust gas discharged from the engine 230.

Since the turbocharger 250 compresses the air sucked into the engine 230, a larger amount of air and fuel can be supplied to the combustion chamber of the engine 230, which is a limited space, so that the output of the engine 230 can be improved have.

The turbocharger 250 may include a turbine 252, a compressor 254, and an axis 256, as shown in FIG.

The turbine 252 is installed on the exhaust pipe 234 through which the exhaust gas of the engine 230 flows, and is rotated by the pressure of the exhaust gas. The compressor 254 is installed on a suction path 232 that is a path through which the air sucked into the engine 230 flows and is rotated by the rotational force of the turbine 252, .

The shaft 256 is configured to transmit the rotational force of the turbine 252 to the compressor 254. That is, the pressure of the exhaust gas is converted into rotational force by the turbine 252, and the rotational force of the turbine 252 is transmitted to the compressor 254 through the shaft 256. In the compressor 254, And is converted into a force for compressing the air.

The exhaust gas purifying apparatus 100 of this embodiment can be installed on the discharge path of the exhaust gas.

3 and 4, the exhaust gas purifying apparatus 100 according to the present embodiment includes a catalytic unit 110, a reducing agent supply unit 120, an air supply unit 130, a motor unit 150, and a controller (not shown) 160).

The catalytic unit 110 reacts with exhaust gas discharged from the engine 230 and a reducing agent to reduce harmful substances such as nitrogen oxides (NOx) in the exhaust gas. The catalytic portion 110 of the exhaust gas purifying apparatus 100 according to the present embodiment can be made to use hydrocarbon as a reducing agent instead of the conventional urea as a reducing agent.

A hydrocarbon-based reductant supplied to the catalytic unit 110 may be a hydrocarbon-containing material such as diesel fuel. In this embodiment, the natural gas storage tank 210 ) Can be used as a reducing agent.

The catalyst unit 110 may include a mixer 114 and a catalyst 112, as shown in FIG.

The mixer 114 is a component that mixes the exhaust gas discharged from the engine 230 with the reducing agent.

The catalyst 112 is a component in which the reduction reaction of the nitrogen oxide contained in the exhaust gas mixed with the reducing agent occurs in the mixer 114.

The reducing agent supply unit 120 may supply the natural gas stored in the natural gas storage tank 210 of the ship to the catalyst unit 110 as a reducing agent.

The natural gas is mainly composed of methane (CH4). When the natural gas is supplied to the catalyst as a reducing agent, it is mixed with the exhaust gas so that the following reaction occurs in the catalyst.

2NO + CH4 + O2 - > N2 + CO2 + 2H2O

That is, the nitrogen oxide (NOx) contained in the exhaust gas in the catalyst 112 reacts with the reducing agent and oxygen to be reduced to harmless nitrogen, carbon dioxide, and moisture.

The reducing agent supply unit 120 may include a reducing agent supply pipe 122, a pumping means 124, and a reducing agent supply valve 126, as shown in FIG.

The reducing agent supply pipe 122 is a component for guiding natural gas from the natural gas storage tank 210 to the catalyst unit 110. One end of the reducing agent supply pipe 122 is connected to the natural gas storage tank 210, And may be a pipe connected to the mixer 114 of the unit 110.

The pumping means 124 may include a compressor or a pump, which is a component for forming a pressure to flow the natural gas in the reducing agent supply pipe 122 toward the catalyst unit 110 side.

The reducing agent supply valve 126 is a component for controlling the supply of the reducing agent supplied to the catalyst unit 110 by opening and closing the reducing agent supply pipe 122.

The reduction efficiency of the harmful substances such as nitrogen oxides contained in the exhaust gas in the catalytic unit 110 may vary depending on the concentration of air in the exhaust gas supplied to the catalytic unit 110.

Generally, the concentration of oxygen in the atmosphere is about 20 to 21%, but the exhaust gas is a gas discharged after being burned in the engine, so the oxygen concentration is very low.

The graph of FIG. 5 is shown in Sung Su Kim et al., CLEAN TECHNOLOGY, Vol. 17, No. 3, September 2011, pp. 225-230.

As can be seen from the graph of FIG. 5, the reduction efficiency of nitrogen oxides tends to be improved as the oxygen concentration is higher in a temperature range (between 250 ° C. and 500 ° C.) where the reduction reaction of the catalyst occurs .

The catalyst may be composed of Pt and Al 2 O 3.

Accordingly, the exhaust gas purifying apparatus 100 of this embodiment can improve the reduction efficiency of nitrogen oxides in the catalytic portion 110 by supplying fresh air having a high concentration of oxygen to the catalytic portion 110.

The exhaust gas purifying apparatus 100 of the present embodiment is configured such that the exhaust gas purifying apparatus 100 of the present embodiment is capable of purifying exhaust gas in the compressed air in the compressor 254 of the turbocharger 250, And an air supply unit 130 for supplying a part of the air to the catalyst unit 110.

Since the fresh air compressed by the turbocharger 250 contains more oxygen than the normal atmosphere, the nitrogen oxide reduction efficiency in the catalytic unit 110 can be further improved as compared with the air supply in the standby state.

The air supply unit 130 may include an air supply pipe 132 and an air supply control valve 134, as shown in FIG.

The air supply pipe 132 is branched at one point of the intake path 232 through which air compressed in the turbocharger 250 flows toward the engine and is extended to the catalyst unit 110, And may be configured to guide the compressed air in the compressor 254 to the catalyst unit 110. At this time, the point where the air supply pipe 132 is connected to the catalyst unit 110 may be connected to the mixer 114 of the catalyst unit 110.

The air supply control valve 134 is provided at a branch point with the air intake path 232 of the air supply pipe 132 and is connected to the air supply pipe 132 to control the flow rate of the air flowing through the air supply pipe 132. It can be made adjustable.

On the other hand, the temperature at which the above-described reduction reaction of the catalyst occurs may range from approximately 280 degrees Celsius to approximately 510 degrees Celsius.

Generally, in the case of exhaust gas discharged from the engine 230, since the combustion reaction occurs, the temperature range in which the reduction reaction of the catalyst occurs can be satisfied. However, It may be in a cooled state lower than the temperature range at which the reduction reaction of the catalyst occurs.

Therefore, a heater 140 for heating the air supplied from the air supply unit 130 to the catalytic unit 110 may be further provided.

The heater 140 is provided at a front end of the air supply pipe 132 connected to the catalytic unit 110 so that the temperature of the air passing through the air supply pipe 132 is lower than the temperature of the catalytic unit 110 The temperature can be increased.

The heater 140 may be heated by electricity or gas, or may be heated using heat of the exhaust gas passing through the catalyst unit 110.

Therefore, since the fresh compressed air rich in oxygen is heated to the temperature at which the reduction reaction of the catalyst part 110 occurs, and then supplied to the catalyst part 110, The temperature of the gas is not lowered and the efficiency of the reduction reaction of harmful substances such as nitrogen oxides contained in the exhaust gas can be increased.

Since the turbocharger 250 rotates by the exhaust pressure of the exhaust gas, the amount of air to be compressed by the compressor 254 depends on the pressure of the exhaust gas. The pressure of the exhaust gas causes the air and fuel A part of the intake air compressed by the turbocharger 250 may be supplied to the catalytic converter 110, and if the air supplied to the engine is insufficient, the output of the engine may be lowered .

Therefore, the exhaust gas purifier 100 of the present embodiment may further include a motor unit 150 for applying a rotational force to the turbocharger 250.

4, the motor unit 150 is coupled to a shaft 256 of the turbocharger 250 to apply a rotational force to the shaft 256 rotated by the pressure of the exhaust gas, so that the compressor 254 So that the air can be further compressed by an insufficient amount of air.

The motor unit 150 may be coupled to the shaft 256 by gears or the like to transmit power. Although not shown in the figure, the motor unit 150 may further include a power interrupter mechanism such as a clutch to operate the motor unit 150 The engagement with the shaft 256 can be released.

The control unit 160 controls the reducing agent supplying unit 120 and the air supplying unit 130 and the motor unit 150 to control the reducing agent and the amount of air supplied to the catalyst unit 110.

An exhaust sensor 170 for measuring the concentration of harmful substances such as nitrogen oxides (NOx) in the exhaust gas may be further provided at a point where the exhaust gas is discharged from the engine 230.

A position measuring unit 260, such as a GPS navigation device, for measuring the current position of the ship on the ship's steering wheel can be provided.

In addition, an ECU 236 for monitoring and controlling the operating state of the engine 230, such as the rotational speed of the engine 230, may be provided.

The control unit 160 may store exhaust gas regulation information. As shown in FIG. 1, the totalizing gas defining information may be information on a permissible amount of noxious gas discharge such as nitrogen oxide, which is allowed for each region and engine operating state.

The control unit 160 receives information on the concentration of nitrogen oxides contained in the exhaust gas from the exhaust sensor 170 and receives information about the concentration of nitrogen oxides contained in the exhaust gas from the ECU 236 of the engine 230, And receives the information on the current position of the ship 200 from the position measuring unit 260. [0050] As shown in FIG.

The control unit 160 may output a signal for controlling the pumping means 124 and the reducing agent supply valve 126 of the reducing agent supplying unit 120. The reducing agent supply valve 126 is controlled by a signal of the controller 160 to determine whether the valve is open or closed and whether the opening degree is controlled .

The control unit 160 may output a signal for controlling the air supply control valve 134 of the air supply unit 130. The air supply control valve 134 may be controlled by the controller 160 so as to control opening /

Also, the controller 160 may control the motor unit 150. The motor unit 150 may also be configured to control the operation and the operation speed as signals of the controller 160.

That is, the controller 160 can determine the emission allowable amount of the noxious gas such as nitrogen oxide at the current position as the information on the current position inputted from the position measuring unit 260 and the pre-stored exhaust gas specifying information for each region And the supply amount of the reducing agent and the air supplied to the catalyst unit 110 can be calculated as information on the concentration of harmful substances such as nitrogen oxides in the exhaust gas measured by the exhaust sensor 170.

Accordingly, the controller 160 controls the reducing agent supply valve 126 and the pumping means 124 according to the calculated amount of the reducing agent to control the amount of the reducing agent to be supplied, The control unit 134 and the motor unit 150 to control the supply of the appropriate amount of air.

Meanwhile, the control unit 160 may control the supercharger 250 and the air supply unit 130 to one of a normal mode, an air supply mode, and a dual mode.

6 is a flowchart illustrating a method of controlling the operation of the supercharger and the air supply unit by the control unit.

It is determined whether fresh air compressed in the turbocharger 250 is required to be supplied to the catalytic unit 110 at step S110 so that the air supply control valve 134 is closed, The operation may be operated in the normal mode (S120) in which the supply unit 130 is closed and the operation of the motor unit 150 is stopped.

In the normal mode S120, all of the air compressed by the turbocharger 250 is supplied to the engine 230, and the exhaust gas mixed with the reducing agent may flow into the catalyst unit 110. [

If it is determined that the fresh air compressed by the turbocharger 250 needs to be supplied to the catalyst unit 110, the amount of fresh air compressed in the turbocharger 250 by the amount required for the catalyst unit 110 It is determined whether the operation of the motor unit 150 is necessary or not (S130). If it is not necessary to operate the motor unit, The operation of the motor unit 150 is stopped and the operation of the motor unit 150 is stopped.

In the air supply mode S140, the air supply control valve 134 is opened by the controller 160 at an appropriate opening degree so that a part of the air compressed by the turbocharger 250 flows through the air supply pipe 132 And the exhaust gas mixed with the reducing agent and the fresh air may be introduced into the catalytic unit 110.

The fresh air compressed by the turbocharger 250 is required to be supplied to the catalyst unit 110 and the fresh air compressed by the turbocharger 250 is supplied to the catalyst unit 110 (S150) in which the air supply unit 130 is opened and the motor unit 150 is operated when the operation of the motor unit 150 is interrupted, . ≪ / RTI >

In the dual mode S150, the air supply control valve 134 is opened by the controller 160 at an appropriate opening degree, and the motor unit 150 is rotated at a proper speed to apply rotational force to the turbocharger 250 So that the air compression amount of the turbocharger 250 is increased, and a part of the air can be supplied to the catalyst unit 110 through the air supply pipe 132. The exhaust gas mixed with the reducing agent and fresh air may be introduced into the catalyst unit 110.

Meanwhile, since the natural gas slip in the engine 230 and discharged together with the exhaust gas is also hydrocarbon-based, which is a main component of CH4, it acts as a reducing agent through the catalyst unit 110 together with the exhaust gas, It is possible to reduce harmful substances such as nitrogen oxides and the like and to use the slipped natural gas to be treated as a reducing agent.

The engine 230 is a diesel engine that uses diesel or heavy oil as a fuel, or a diesel engine that uses both diesel and heavy oil and natural gas as fuels Fueled engine used as a dual-fuel engine.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or scope of the invention as defined in the appended claims. . Therefore, the above-described embodiments are to be considered as illustrative rather than restrictive, and thus the present application is not limited to the above description, but may be modified within the scope of the appended claims and equivalents thereof.

100: Exhaust gas purifying apparatus 110:
112: catalyst 114: mixer
120: Reducing agent supply unit 122: Reducing agent supply pipe
124: compressor 126: reducing agent supply valve
130: air supply part 132: air supply pipe
134: air supply regulating valve 140: heater section
150: motor unit 160:
170: exhaust sensor 200: ship
210: natural gas storage tank 220: fuel tank
230: engine 232: intake path
234: Exhaust pipe 236: ECU
240: stack 250: supercharger
252: Turbine 254: Compressor
256: Axis 260: Position measuring unit

Claims (8)

A catalytic unit which reacts exhaust gas discharged from an engine with a reducing agent to reduce nitrogen oxides in the exhaust gas, and uses hydrocarbon as a reducing agent;
A reducing agent supply unit supplying the reducing agent to the catalyst unit;
An air supply unit for supplying a part of the compressed air to the catalyst unit in a supercharger for compressing the air supplied to the engine by the pressure of the exhaust gas discharged from the engine;
A motor unit that applies a rotational force to the turbocharger to further compress air by the air supplied to the catalyst unit from the air compressed by the turbocharger; And
And a control unit controlling the motor unit and the air supply unit to control the amount of air supplied to the catalyst unit,
The supercharger includes:
A turbine provided on a path through which the exhaust gas of the engine flows and rotated by the pressure of the exhaust gas;
A compressor installed on a path through which air sucked into the engine flows and compressing air sucked into the engine by rotation of the turbine;
And a shaft for transmitting the rotational force of the turbine to the compressor,
Wherein the motor unit is configured to add a rotational force to a shaft rotated by a rotational force of the turbine so as to increase an air compression amount of the compressor. The method according to claim 1,
The reducing agent supply unit,
An exhaust gas purifier using natural gas stored in a natural gas storage tank as a reducing agent. 3. The method of claim 2,
The reducing agent supply unit,
A reducing agent supply pipe for guiding the natural gas stored in the natural gas storage tank to the catalyst section;
And pumping means for guiding the natural gas inside the reducing agent supply pipe to the catalyst portion side. The method according to claim 1,
The air-
An air supply pipe branched at a certain point in the path of the compressed air in the turbocharger toward the engine and extending to the catalyst portion and guiding the compressed air from the turbocharger to the catalyst portion;
And an air supply control valve installed in the air supply pipe and being adjustable in opening degree to control a flow rate of air flowing in the air supply pipe. 5. The method of claim 4,
And a heater for heating the air supplied from the air supply unit to the catalyst unit to a temperature at which the reduction reaction of the catalyst unit occurs. delete 6. The method according to any one of claims 1 to 5,
Wherein the catalyst portion comprises:
A mixer for mixing the exhaust gas discharged from the engine and the reducing agent; And
And a catalyst in which a reduction reaction of nitrogen oxides occurs in the exhaust gas mixed with the reducing agent in the mixer,
Wherein the reducing agent supply unit supplies the reducing agent to the mixer, and the air supply unit supplies air to the mixer . 6. The method according to any one of claims 1 to 5,
Further comprising an exhaust sensor for measuring the concentration of nitrogen oxides in the exhaust gas discharged from the engine,
Wherein,
And controls the motor unit and the air supply unit such that the discharged exhaust gas satisfies the exhaust gas regulation in the region where the engine is located.

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