KR102028423B1 - Selective catalytic reduction system for in-use vehicles - Google Patents

Abstract

The present invention relates to a selective reduction catalyst system for a driving vehicle, and more particularly, a diesel oxidation catalyst (DOC) and a urea injector in front of a diesel particulate reduction device (DPF) or a diesel particulate filter (PMC) already mounted on a vehicle. (Urea Injector), Mixer (MIXER), Selective Reduction Catalyst (SCR), Ammonia Oxidation Catalyst (AOC) or Urea Injector, Mixer (MIXER), Selective Reduction Catalyst (SCR), Ammonia Oxidation Catalyst (AOC) ) to the selective reduction catalyst (SCR) system that is configured to mount by giving, to secure the activation temperature of 200 ℃ of the selective reduction catalyst (SCR) to improve reduction rate of the nitrogen oxides (NO _X), through the minimization of heat loss Nitrogen oxide (NO _X ) by converting nitrogen oxide (NO) into nitrogen dioxide (NO ₂ ) by a diesel oxidation catalyst (DOC) in a selective reduction catalyst (SCR) system and preventing the temperature of the exhaust gas from changing rapidly. Reduction It is possible to improve the rate, to minimize the heat radiation loss of the exhaust gas temperature discharged out of the engine by using a double pipe exhaust pipe and insulation, diesel particulate reduction device (DPF) or diesel particulate filter (PMC) In the case of a vehicle without a catalyst, a simultaneous reduction device combined with a selective reduction catalyst (SCR) system and a diesel particulate reduction device (DPF) or a diesel particulate filter (PMC) ensures an activation temperature of 200 ° C. of the selective reduction catalyst (SCR). Therefore, there is an effect of improving the reduction rate of nitrogen oxides (NO _X ) through the minimization of heat dissipation losses.

Description

Selective catalytic reduction system for in-use vehicles

The present invention includes a diesel oxidation catalyst (DOC), a urea injector, a mixer (MIXER), and a selective reduction catalyst in front of a diesel particulate reduction device (DPF) or a diesel particulate filter (PMC) that is mounted on a vehicle. SCR), ammonia oxidation catalyst (AOC) or a selective reduction catalyst (SCR) system consisting of urea injector, mixer (MIXER), selective reduction catalyst (SCR), ammonia oxidation catalyst (AOC) and by giving, it is possible to improve the reduction rate of the selective reduction catalyst NOx with minimal activation to secure the temperature of the heat loss of 200 ℃ of (SCR) (NO _X), the selective reduction catalyst (SCR) diesel oxidation in the system the catalyst DOC converts nitrogen oxide (NO) into nitrogen dioxide (NO ₂ ) and prevents the temperature of exhaust gas from changing rapidly, thereby improving the efficiency of reducing nitrogen oxides (NO _X ). Exhaust pipe and insulation This can minimize the heat dissipation loss of the exhaust gas temperature discharged from the outside of the engine, and the selective reduction catalyst (SCR) system and diesel for vehicles without a diesel particulate filter (DPF) or diesel particulate filter (PMC). that the emission control device (DPF) or diesel particulate filter of nitrogen oxides (NO _X) (PMC) is to secure the activation temperature of 200 ℃ of the selective reduction catalyst (SCR) to the simultaneous reduction apparatus coupled with the minimization of heat loss The present invention relates to a selective reduction catalyst system for a vehicle that can improve a reduction ratio.

In general, hazardous emissions of diesel vehicles are composed of CO, HC, NO _X and PM. Diesel engine combustion characteristics lean air-fuel ratio, since the combustion is performed under the condition only the unburned product, emissions of CO and HC less than the gasoline engine, there is a relatively large amount of NO _X emission due to the high compression ratio diesel fuel injection characteristics particulate Material PM is produced.

In accordance with the emission regulations, the emission reduction of diesel engines has been reduced by using soot purifiers (PMC or DPF), including EGR systems and common rails, to reduce the emission of diesel engines.

However, increasingly applied in order to meet the emission regulations is enhanced after for the reduction of NO _X emission treatment apparatus is essential.

1 illustrates an exhaust system of a conventional diesel engine vehicle, and particulate matter is purified while exhaust gas discharged during operation of the engine E passes through the diesel particulate filter (PMC) 200.

On the other hand, in the conventional case, when the selective reduction catalyst (SCR) device is mounted in a vehicle equipped with the particulate matter filter (PMC), the selective reduction catalyst (SCR) device is mounted on the rear end of the particulate matter filter (PMC).

However, in this case, the heat radiation loss of the exhaust gas occurs while the exhaust gas is moved from the exhaust manifold to the selective reduction catalyst (SCR).

In addition, there is a drawback that the selective reduction catalyst (SCR) does not reach the activation temperature in most driving regions during driving, and thus it is necessary to improve the performance of reducing the nitrogen oxide (NO _X ) of the selective reduction catalyst (SCR) device. .

In addition, when a selective chuck reduction catalyst (SCR) device is installed in a vehicle, ECUs such as post injection (EG) and exhaust gas recirculation valve (EGR Valve) control cannot be changed. Therefore, there is a problem that it is difficult to secure the activation temperature of the selective reduction catalyst because the distance between the engine and the selective reduction catalyst (SCR) system is far.

Therefore, diesel oxidation catalyst (DOC), urea injector, mixer (MIXER), selective reduction catalyst (SCR) in front of the diesel particulate reduction device (DPF) or diesel particulate filter (PMC) that is mounted on the vehicle. ), Ammonia oxidation catalyst (AOC) or a selective reduction catalyst (SCR) system consisting of urea injector, mixer (MIXER), selective reduction catalyst (SCR), ammonia oxidation catalyst (AOC) It is possible to improve the reduction rate of NO _x by minimizing the heat dissipation loss by securing the activation temperature of 200 ° C of the selective reduction catalyst (SCR), and the diesel oxidation catalyst (DOC) in the selective reduction catalyst (SCR) system. By converting nitrogen oxide (NO) into nitrogen dioxide (NO ₂ ) and preventing the temperature of the exhaust gas from changing rapidly, it is possible to improve the efficiency of reducing nitrogen oxides (NO _X ). use with The development of a borrowing station selective reduction catalyst system capable of minimizing the heat loss of the exhaust gas discharged from the temperature at which the spirit is a situation which is highly required.

KR 10-2009-0080360 (August 28, 2009)

Therefore, the present invention has been conceived to solve the above problems, a diesel oxidation catalyst (DOC), a urea injector (DPC) or a diesel particulate filter (PMC) in front of a vehicle that is already mounted on a vehicle Urea Injector, Mixer (MIXER), Selective Reduction Catalyst (SCR), Ammonia Oxidation Catalyst (AOC) or Urea Injector, Mixer (MIXER), Selective Reduction Catalyst (SCR), Ammonia Oxidation Catalyst (AOC) selective reduction catalyst (SCR) by giving to mount the system, the nitrogen to secure the activation temperature of 200 ℃ of the selective reduction catalyst (SCR) through the minimization of heat losses oxide which consists to improve reduction rate of (NO _X) It is an object of the present invention to provide a selective reduction catalyst system for a traveling vehicle.

Another object of the present invention is to convert nitrogen oxide (NO) to nitrogen dioxide (NO ₂ ) by a diesel oxidation catalyst (DOC) in a selective reduction catalyst (SCR) system and to prevent the temperature of the exhaust gas from changing drastically. The present invention provides a selective reduction catalyst system for a vehicle that can improve the reduction efficiency of NO _X ).

Another object of the present invention is to provide a selective reduction catalyst system for a traveling vehicle which can minimize the heat radiation loss of the exhaust gas temperature discharged out of the engine by using a double pipe exhaust pipe and insulation.

Another object of the present invention is a selective reduction catalyst (SCR) system and diesel particulate reduction device (DPF) or diesel particulate filter (PMC) in a vehicle without a diesel particulate reduction device (DPF) or diesel particulate filter (PMC). Is a simultaneous reduction device combined with a selective reduction catalyst (SCR) to ensure the activation temperature of 200 ℃ to provide a selective reduction catalyst system for driving vehicles that can improve the reduction rate of nitrogen oxides (NO _X ) through minimizing heat dissipation loss It is.

In the selective reduction catalyst system for a driving vehicle according to a preferred embodiment of the present invention for achieving the above object, a heat sink is installed in the exhaust manifold and the exhaust pipe so as to reduce heat loss due to running wind and outside air. The exhaust gas is double piped through the exhaust manifold, and it is stable even at the high temperature of 1000 ℃ or higher, which is ceramic fiber, glass wool, rigid urethane foam, or skyviva, which is made of ceramic fiber to reduce heat radiation loss of exhaust gas. Ultra high temperature fireproof insulation is wrapped to maintain excellent quality, and when entering the exhaust pipe coated with a waterproof coating material combined with polyurea, primer, urea and oil paint on the outside of the insulation through a high temperature of 150 to 300 ℃ Carbon monoxide and hydrocarbons in the exhaust gases are It occurs and the diesel oxidation catalyst (DOC) that increases the proportion of NO ₂ in the exhaust gas; A urea injector (Urea Injector) for injecting an aqueous urea urea solution between the rear end of the diesel oxidation catalyst (DOC) and the front end of the mixer (MIXER); A mixer (MIXER) mounted at the front end of the selective reduction catalyst (SCR) so that the urea aqueous solution injected from the urea injector is vaporized with ammonia and mixed well in the selective reduction catalyst (SCR); Is mounted to the rear end portion of the mixer, urea (urea solution) for when injected into the exhaust pipe after the urea is decomposed into ammonia at a high temperature ammonia and nitrogen oxides (NO _X), the nitrogen oxides by the reaction (NO _X) is V ₂ O ₅ Metal oxide catalyst of -Al ₂ O ₃ , V ₂ O ₅ -SiO ₂ -TiO ₂ , V ₂ O ₅ -WO ₃ -TiO ₂ , Fe ₂ O ₃ -TiO ₂ , CuO-TiO ₂ or Y-type Zeolite, Mordenite A selective reduction catalyst (SCR) to be reduced by a zeolite catalyst of ZSM-5; Equipped with the selective reduction catalyst (SCR), after the urea water injected from the selective reduction catalyst (SCR) is decomposed into ammonia, the ammonia oxidation catalyst to reduce ammonia that ammonia and nitrogen oxides (NO _X ) did not react by oxidation reaction (AOC); When the exhaust gas passing through the ammonia oxidation catalyst (AOC) enters the exhaust pipe, a diesel oxidation catalyst (DOC) for reducing carbon monoxide and hydrocarbons in the exhaust gas by using a catalytic reaction through a high temperature of 150 to 300 ℃; When particulate matter (PM) is collected from the exhaust gas and an appropriate amount of particulate matter (PM) is accumulated, diesel particulate filter (PMC) or particulate matter (PMC) which regenerates and regenerates particulate matter (PM) using exhaust gas or additives is collected. Diesel particulate reduction device (DPF) for filtering PM); Characterized by including.

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As described above, the inventors' selective reduction catalyst system for a driving vehicle has the following effects.

First, the present invention provides a diesel oxidation catalyst (DOC), a urea injector, a mixer (MIXER), and a selective reduction in front of a diesel particulate filter (DPF) or a diesel particulate filter (PMC) that is mounted on a vehicle. Selective reduction catalyst (SCR) system consisting of catalyst (SCR), ammonia oxidation catalyst (AOC) or urea injector, mixer (MIXER), selective reduction catalyst (SCR), ammonia oxidation catalyst (AOC) By mounting the, it is possible to secure the activation temperature of 200 ℃ of the selective reduction catalyst (SCR) to improve the reduction rate of nitrogen oxides (NO _X ) through minimizing the heat radiation loss.

Second, the present invention converts nitrogen oxide (NO) to nitrogen dioxide (NO ₂ ) by diesel oxidation catalyst (DOC) in the selective reduction catalyst (SCR) system and prevents the temperature of the exhaust gas from changing drastically. The reduction efficiency of _X ) can be improved.

Third, the present invention can minimize the heat radiation loss of the exhaust gas temperature discharged out of the engine by using the exhaust pipe and the heat insulating material is a double pipe.

Fourth, the present invention provides a selective reduction catalyst (SCR) system and a diesel particulate reduction device (DPF) or diesel particulate filter (PMC) in a vehicle without a diesel particulate reduction device (DPF) or diesel particulate filter (PMC). The combined simultaneous reduction device can improve the reduction rate of nitrogen oxide (NO _X ) through minimizing the heat dissipation loss by securing the activation temperature of 200 ℃ of the selective reduction catalyst (SCR).

1 is a view showing an exhaust system of a conventional diesel engine vehicle.
2 is a view showing for explaining the configuration of a selective reduction catalyst system for a driving vehicle according to an embodiment of the present invention.
3 is a view showing for explaining the configuration of a selective reduction catalyst system for a driving vehicle according to another embodiment of the present invention.

Looking at the preferred embodiment of the present invention together with the accompanying drawings as follows, when it is determined that the detailed description of the known art or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention The description will be omitted, and the following terms are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator, and the definitions thereof describe the selective reduction catalyst system for the driving vehicle of the present invention. It should be made based on the contents throughout the specification.

Hereinafter, with reference to the accompanying drawings will be described in detail a selective reduction catalyst system for a driving vehicle according to an embodiment of the present invention.

2 is a view showing the configuration of a selective reduction catalyst system for a driving vehicle according to an embodiment of the present invention, Figure 3 illustrates a configuration of a selective reduction catalyst system for a driving vehicle according to another embodiment of the present invention The figure is shown for.

Selective reduction catalyst system for the present inventors vehicle engine (E), exhaust manifold 100, exhaust pipe (exhaust pipe) 110, selective reduction catalyst system 200, diesel oxidation catalyst (DOC) 210, urea injector 220, MIXER 230, selective reduction catalyst (SCR) 240, ammonia oxidation catalyst (AOC) 250, diesel oxidation catalyst (DOC) 300, diesel particulate filter (PMC) ( 400), a diesel particulate reduction device (DPF) 410, and the like.

As shown in Figures 2 to 3, the selective reduction catalyst system for a driving vehicle of the present invention is a urea aqueous solution of urea when the exhaust gas combusted from the engine (E) enters the exhaust pipe (110) through the exhaust manifold (100) A urea injector 220 for spraying; Mixer (MIXER) mounted on the front end portion of the selective reduction catalyst (SCR) 240 so that the urea aqueous solution injected from the urea injector 220 is vaporized with ammonia and mixed well in the selective reduction catalyst (SCR) 240 ( 230; When the urea (urea solution) is injected into the exhaust pipe 110, the urea is decomposed into ammonia at a high temperature, and then ammonia and nitrogen oxides (NO _X ) react to form nitrogen oxides (NO _X). A selective reduction catalyst (SCR) 240 to reduce); Equipped with the selective reduction catalyst (SCR) 240, the urea water injected from the selective reduction catalyst (SCR) 240 is decomposed into ammonia, the ammonia and the nitrogen oxide (NO _X ) oxidation reaction ammonia was not reacted It is equipped with an ammonia oxidation catalyst (AOC) 250 to reduce the temperature, and when the exhaust gas combusted from the engine enters the exhaust pipe through the exhaust manifold, it catalyzes carbon monoxide and hydrocarbons in the exhaust gas through a high temperature of 150 to 300 ° C. A diesel oxidation catalyst (DOC) 210 which reduces the use, burns particulate matter (PM), and increases the ratio of NO _{2 in} the exhaust gas; It is provided between the rear end of the diesel oxidation catalyst (DOC) 210 and the front end of the mixer (MIXER) 230, exhaust gas passing through the ammonia oxidation catalyst (AOC) 250 is exhaust pipe 110 When it enters, the diesel oxidation catalyst (DOC) reduces carbon monoxide and hydrocarbons in the exhaust gas through a high temperature of 150 to 300 ℃ by catalytic reaction, burns particulate matter (PM), and increases the ratio of NO _{2 in} the exhaust gas. 300; Diesel particulate filter (PMC) 410 that collects particulate matter (PM) from the exhaust gas and accumulates an appropriate amount of particulate matter (PM) by re-burning and regenerating particulate matter (PM) using exhaust gas or additives. A diesel particulate filter (DPF) 400 for filtering particulate matter PM is provided.

Referring to the functions of the technical means constituting the selective reduction catalyst system for the present invention car as follows.

In an embodiment related to a selective reduction catalyst system for a vehicle, the selective reduction catalyst system 200 includes a diesel oxidation catalyst (DOC) 210, a urea injector 220, a mixer (MIXER) 230, and an optional It includes a reduction catalyst (SCR) 240 and an ammonia oxidation catalyst (AOC) 250.

Here, the diesel oxidation catalyst (DOC) 210 is a high temperature of 150 to 300 ℃ when the exhaust gas burned from the engine (E) enters the exhaust pipe 110 through the exhaust manifold (100) It reduces carbon monoxide and hydrocarbons in exhaust gas by catalytic reaction, burns particulate matter (PM), and increases the ratio of NO ₂ in exhaust gas.

In addition, the exhaust pipe 110 is a double pipe, the exhaust pipe 110 is wrapped with a heat insulating material (not shown) to reduce the heat radiation loss of the exhaust gas.

Here, the heat insulator (not shown) is stable even at very high temperature of 1000 ℃ or more. As ultra-high temperature fire-resistant insulation that maintains excellent quality, cerac wool made of ceramic fiber is most preferred, but glass wool, rigid urethane foam, skyviva, etc. may be possible.

In addition, the waterproof coating material coated on the outside of the heat insulating material (not shown) is a combination of polyurea, primer, urea and oil paint.

In addition, by installing a heat sink (not shown) in the exhaust manifold 100 and the exhaust pipe 110 to reduce the heat dissipation loss due to running wind and outside air.

The urea injector 220 is mounted between the rear end of the diesel oxidation catalyst (DOC) 210 and the front end of the mixer (MIXER) 230 to spray the urea aqueous solution of urea.

The mixer (MIXER) 230 is the front end portion of the selective reduction catalyst (SCR) 240 so that the urea aqueous solution injected from the urea injector 220 is vaporized with ammonia and mixed well in the selective reduction catalyst (SCR) 240 It is mounted on.

The Selective Catalytic Reduction (SCR) 240 is mounted to the rear end of the mixer 230, and when urea (aqueous urea) is injected into the exhaust pipe 110, the urea is decomposed into ammonia at a high temperature. And nitrogen oxide (NO _X ) reacts to reduce the nitrogen oxide (NO _X ).

The Ammonia Oxidation Catalyst (AOC) 250 is mounted together with the selective reduction catalyst (SCR) 240 and ammonia after the urea water injected from the selective reduction catalyst (SCR) 240 is decomposed into ammonia. And nitrogen oxides (NO _X ) reduce the ammonia that has not reacted to oxidation.

In addition, in the case of another embodiment related to the selective reduction catalyst system for a vehicle, the diesel oxidation catalyst (DOC) 300, the diesel particulate filter (PMC) 410 or the diesel particulate reduction device (DPF) in the above-described embodiment It is a form that further includes (400).

The diesel oxidation catalyst (DOC) 300 is a carbon monoxide in the exhaust gas through a high temperature of 150 to 300 ℃ when the exhaust gas passing through the ammonia oxidation catalyst (AOC) 250 enters the exhaust pipe 110 This can reduce hydrocarbons by catalytic reactions, burn particulate matter (PM), and increase the proportion of NO _{2 in} the exhaust gas.

Here, the catalyst of the selective reduction catalyst (SCR) device is V ₂ O ₅ -Al ₂ O ₃ , V ₂ O ₅ -SiO ₂ -TiO ₂ , V ₂ O ₅ -WO ₃ -TiO ₂ , Fe ₂ O _3- Metal oxide catalysts such as TiO ₂ and CuO-TiO ₂ or Zeolite catalysts such as Y-type Zeolite, Mordenite and ZSM-5, but are not limited to the above catalysts.

The particulate particulate catalyst (PMC) 410 captures particulate matter (PM) from the exhaust gas and when particulate matter (PM) is accumulated in an appropriate amount, the particulate matter (PM) is collected by using exhaust gas or additives. It is reburned and regenerated.

In addition, the diesel particulate filter (DPF) 400 is to filter particulate matter (PM) with a filter.

As described above, the selective reduction catalyst system for a traveling vehicle can be applied to a vehicle having a diesel engine, so the application is broad.

It will be appreciated by those skilled in the art that the present invention is not limited to the above embodiments, and that various modifications and changes can be made without departing from the spirit of the present invention.

E: Engine 100: Exhaust manifold
110: exhaust pipe (exhaust pipe) 200: selective reduction catalyst system
210: diesel oxidation catalyst (DOC) device 220: urea injector
230: Mixer 240: Selective Reduction Catalyst (SCR)
250: ammonia oxidation catalyst (AOC) 300: diesel oxidation catalyst (DOC) device
400: Diesel particulate reduction device (DPF) 410: Diesel particulate filter (PMC)

Claims (7)

In the selective reduction catalyst system for driving cars,
Heat sink is installed in exhaust manifold and exhaust pipe to reduce heat loss caused by running wind and outside air.
The exhaust gas from the engine is double piped through the exhaust manifold, and the ceramic fiber is made of ceramic fiber to reduce heat radiation loss of exhaust gas. It is stable even at the ultra high temperature, and it is wrapped with the ultra high temperature fireproof insulation which maintains excellent quality, and when it enters the exhaust pipe which is coated with the waterproof coating material combining polyurea, primer, urea and oil paint on the outside of the insulation Carbon monoxide and hydrocarbons in the exhaust gas through the high heat of the diesel oxidation catalyst (DOC) to generate a high heat due to the catalytic reaction and to increase the ratio of NO _{2 in} the exhaust gas;
A urea injector (Urea Injector) for injecting an aqueous urea urea solution between the rear end of the diesel oxidation catalyst (DOC) and the front end of the mixer (MIXER);
A mixer (MIXER) mounted at the front end of the selective reduction catalyst (SCR) so that the urea aqueous solution injected from the urea injector is vaporized with ammonia and mixed well in the selective reduction catalyst (SCR);
Is mounted to the rear end portion of the mixer, urea (urea solution) for when injected into the exhaust pipe after the urea is decomposed into ammonia at a high temperature ammonia and nitrogen oxides (NO _X), the nitrogen oxides by the reaction (NO _X) is V ₂ O ₅ Metal oxide catalyst of -Al ₂ O ₃ , V ₂ O ₅ -SiO ₂ -TiO ₂ , V ₂ O ₅ -WO ₃ -TiO ₂ , Fe ₂ O ₃ -TiO ₂ , CuO-TiO ₂ or Y-type Zeolite, Mordenite A selective reduction catalyst (SCR) to be reduced by a zeolite catalyst of ZSM-5;
Equipped with the selective reduction catalyst (SCR), after the urea water injected from the selective reduction catalyst (SCR) is decomposed into ammonia, the ammonia oxidation catalyst to reduce ammonia that ammonia and nitrogen oxides (NO _X ) did not react by oxidation reaction (AOC);
When the exhaust gas passing through the ammonia oxidation catalyst (AOC) enters the exhaust pipe, a diesel oxidation catalyst (DOC) for reducing carbon monoxide and hydrocarbons in the exhaust gas by using a catalytic reaction through a high temperature of 150 to 300 ℃;
When particulate matter (PM) is collected from the exhaust gas and an appropriate amount of particulate matter (PM) is accumulated, diesel particulate filter (PMC) or particulate matter (PMC) which regenerates and regenerates particulate matter (PM) using exhaust gas or additives is collected. Diesel particulate reduction device (DPF) for filtering PM); Selective reduction catalyst system for a vehicle, characterized in that it comprises a. delete delete delete delete delete delete

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