KR100799306B1 - Nitrogen oxide reduction system of engine - Google Patents

Abstract

The present invention relates to a system for reducing nitrogen oxides (NOx) in the exhaust gas of a vehicle equipped with natural gas, LPG and heavy hydrocarbon (HHC) fuel, and a diesel engine, and more particularly, nitrogen oxide in exhaust gas. Engine nitrogen that reduces nitrogen oxides (NOx) by increasing the efficiency of exhaust gas recirculation (EGR) used for the purpose of reducing (NOx) by supplying hydrogen or syngas containing hydrogen to the engine An oxide (NOx) reduction system.

The present invention is used in a system in which an exhaust gas recirculation device (EGR) is used, and a nitrogen oxide (NOx) reduction system of a diesel engine according to the present invention,

It is to reduce nitrogen oxides (NOx) by supplying hydrogen or a synthesis gas containing hydrogen to an engine combusting the fuel supplied from the fuel tank and the exhaust gas supplied from the exhaust gas recirculation apparatus.

Description

NOx Reduction System of Engines

1 is a schematic view showing an embodiment of a nitrogen oxide reduction system of the present invention engine,

Figure 2 is a schematic diagram showing another embodiment of the nitrogen oxide reduction system of the present invention engine,

Figure 3 is a schematic diagram showing another embodiment of the nitrogen oxide reduction system of the present invention engine,

Figure 4 is a schematic diagram showing another embodiment of the nitrogen oxide reduction system of the present invention engine,

Figure 5 is a schematic diagram showing another embodiment of the nitrogen oxide reduction system of the present invention engine,

6 is a cross-sectional view showing an embodiment of a plasma reactor used in the nitrogen oxide reduction system of the present invention engine,

7 is a cross-sectional view showing another embodiment of the plasma reactor used in the nitrogen oxide reduction system of the present invention engine,

8 is a partial detailed view of the main part of FIG. 6 and FIG.

[Explanation of symbols on the main parts of the drawings]

1: fuel tank 2: engine

3: exhaust gas recirculation apparatus 4: exhaust pipe

5: plasma reactor 6: WGS reactor

The present invention relates to a system for reducing nitrogen oxides (NOx) in the exhaust gas of a vehicle equipped with natural gas, LPG and heavy hydrocarbon (HHC) fuel, and a diesel engine, and more particularly, nitrogen oxide in exhaust gas. Engine nitrogen that reduces nitrogen oxides (NOx) by increasing the efficiency of exhaust gas recirculation (EGR) used for the purpose of reducing (NOx) by supplying hydrogen or syngas containing hydrogen to the engine An oxide (NOx) reduction system.

Due to the development of industry, environmental pollution is getting serious day by day, and to reduce environmental pollution, mankind regulates the generation of environmental pollution.

According to the present invention, there are airplanes and automobiles in a device that gives mankind mobility, and hydrocarbon-based fuels such as gasoline and diesel are usually used in automobiles, and hydrogen autonomous vehicles and hybrid vehicles are being developed by regulations on environmental pollution.

The vehicle using the hydrocarbon-based fuel emits exhaust gas components that seriously damage mankind according to the fuel used, and in particular, diesel vehicles emit a large amount of particulate matter (PM) and nitrogen oxides (NOx). The regulation of is getting serious day by day, various techniques have been proposed in the past to overcome this.

In general, particulate matter (PM) in the exhaust gas is provided with a DPF regeneration device in the exhaust pipe from which exhaust gas is discharged to reduce particulate matter (PM) by regenerating particulate matter (PM),

NOx is reduced by using exhaust gas recirculation (EGR) that recovers a part of the exhaust gas discharged through the exhaust pipe and supplies it to the engine and reduces the generation of NOx. Reduce

Conventionally, in order to reduce the generation of nitrogen oxides (NOx) to reduce the generation of nitrogen oxides (NOx) by supplying a large amount of exhaust gas to the engine by using an exhaust gas recirculation (EGR: Exhaust gas recirculation), but because of this CO and unburned hydrocarbons increased in the gas, and the output of the engine was lowered.

In addition, most of the technologies proposed in the related art are technologies for reducing exhaust gas by controlling an engine of a vehicle.

In order to reduce the occurrence of particulate matter (PM), the fuel supplied to the engine is controlled to burn close to lean combustion, but in this case, lean burning of the fuel supplied to the engine increases the generation of NOx. Has the disadvantage of being

In order to reduce the generation of NOx, the fuel supplied to the engine is controlled for rich combustion.However, in this case, when the fuel supplied to the engine is richly burned, CO and HC are increased. In this case, there is a disadvantage in that excessive generation of particulate matter (PM).

That is, the generation of nitrogen oxides (NOx) increases when the CO, HC, or particulate matter (PM) is to be reduced, and when the nitrogen oxides (NOx) are to be reduced, the particulate matter (PM) is increased. It is difficult to simultaneously control the engine of the particulate matter (PM) and nitrogen oxides (NOx) to reduce the same.

In addition, additional control of the engine of the vehicle to control lean, rich combustion conditions has resulted in additional problems such as reduced fuel economy and efficiency.

In order to solve the above problems, the present invention is to reduce the nitrogen oxides of the diesel engine by supplying a synthesis gas containing hydrogen or hydrogen to the engine using the exhaust gas recirculation device (EGR) to suppress the nitrogen oxides (NOx) The purpose is to present a system to

It will be described in detail with reference to the drawings presented as an embodiment to achieve the above object.

1 is a schematic view showing an embodiment of a nitrogen oxide reduction system of the engine of the present invention, Figure 2 is a schematic diagram showing another embodiment of a nitrogen oxide reduction system of the engine of the present invention, Figure 3 is a nitrogen oxide reduction system of the engine of the present invention 4 is a schematic view showing another embodiment of the present invention, Figure 4 is a schematic view showing another embodiment of the nitrogen oxide reduction system of the engine of the present invention, Figure 5 is an embodiment of a plasma reactor used in the nitrogen oxide reduction system of the engine of the present invention 6 is a cross-sectional view showing another embodiment of a plasma reactor used in the nitrogen oxide reduction system of the engine of the present invention, and FIG. 7 is a partial detailed view of the main part of FIGS.

The present invention is a nitrogen oxide (NOx) reduction system of the engine as shown in Figure 1,

A part of the exhaust gas discharged to the exhaust pipe 4 from the engine 2 that generates power by burning fuel supplied from the fuel tank 1 which is generally used is returned to the engine 2 and supplied with nitrogen oxides ( The engine 2 is supplied with hydrogen or a synthesis gas containing hydrogen to a system in which an exhaust gas recirculation device (EGR) 3 for reducing NOx) is installed.

By supplying hydrogen or a synthesis gas containing hydrogen into the engine 2 as described above, the combustion safety in the engine 2 is increased while maintaining the effect of deNOx of the exhaust gas recirculation device (EGR), and the amount of by-products such as CO and HC are generated. There is a positive effect that can reduce the risk.

The use of this method reduces the amount of NOx generated in the engine, resulting in an alternative effect that can reduce or eliminate various catalyst-based pollution reduction devices that were previously installed in exhaust pipes for deNOx.

Figure 2 shows an embodiment of a nitrogen oxide (NOx) reduction system of the engine of the present invention, the nitrogen oxide (NOx) reduction system of the engine,

A part of the exhaust gas discharged to the exhaust pipe 4 from the engine 2 that generates power by burning fuel supplied from the fuel tank 1 which is generally used is returned to the engine 2 and supplied with nitrogen oxides ( To supply the engine 2 with the product produced in the catalytic reactor which receives the fuel supplied from the fuel tank 1 in a system equipped with an exhaust gas recirculation device (EGR) 3 which reduces NOx) and causes a catalytic reaction. In one embodiment, the product produced in the catalytic reactor is hydrogen or a synthesis gas containing hydrogen.

Such catalytic reactors are generally presented in various prior art and are not described in the present invention.

By supplying the product generated by the catalytic reactor in the engine 2 as described above, while maintaining the effect of the deNOx of the exhaust gas recirculation device (EGR) to increase the combustion safety in the engine (2) to reduce the amount of by-products such as CO, HC, etc. It has a positive effect.

Using this method reduces the amount of NOx generated in the engine, and has an alternative effect of reducing or eliminating various catalyst-based pollution reduction devices that were previously installed in exhaust pipes for deNOx.

Figure 3 shows another embodiment of a nitrogen oxide (NOx) reduction system of the engine of the present invention, the nitrogen oxide (NOx) reduction system of the engine,

A part of the exhaust gas discharged to the exhaust pipe 4 from the engine 2 that generates power by burning fuel supplied from the fuel tank 1 which is generally used is returned to the engine 2 and supplied with nitrogen oxides ( The product produced in the plasma reactor (5) generating a plasma reaction by receiving the fuel supplied from the fuel tank (1) to a system in which an exhaust gas recirculation device (EGR) 3 for reducing NOx) is installed. To be supplied to.

As described above, when the product generated in the plasma reactor 5 is supplied into the engine 2, the combustion safety in the engine 2 is increased while maintaining the effect of deNOx of the exhaust gas recirculation device (EGR). There is a positive effect that can reduce the amount produced.

The use of this method reduces the amount of nitrogen oxides (NOx) generated in the engine, resulting in a replacement effect that can reduce or eliminate various catalyst-based pollution reduction devices previously installed in exhaust pipes for deNOx. .

The plasma reactor 5 is formed as shown in Figure 6,

The plasma reactor 5,

The body 10 is formed of a cylindrical reactor 11 formed with an outlet 40 so as to open upward, and a base 12 supporting the reactor 11.

An endothermic furnace 13 is formed in the reactor 11 so that the gas flowing from the inlet 50 formed at one side of the reactor 11 is preheated, and the endothermic furnace 13 heats the reactor 11. It is formed spirally on the circumference of the reactor 11 so that it can stay and absorb for a long time.

The gas flowing into the inlet 50 is usually a mixture of air or some exhaust gas supplied to the air and the exhaust pipe 4.

Inside the reactor 11, an electrode 20 to which a current is applied is supported on the base 12 and installed.

The electrode 20 has an endothermic chamber 21 formed of a space for absorbing the fuel supplied inwardly, and a nozzle 22 is formed so that the supplied preheated fuel is injected into the reactor 11. .

The nozzles 22 are formed such that a plurality of the nozzles 22 are disposed on the electrode 20 so as to be evenly sprayed on the reactor 11 or at equal intervals.

The fuel injection device 30 is installed so that the liquid fuel may be injected and supplied into the endothermic chamber 21 of the electrode 20 supported and supported by the base 12.

The fuel injection device 30 is connected to the fuel tank 1 for supplying fuel by a connection pipe, and usually uses an injector but may use a nozzle.

The gas introduced from the inlet 50 of the reactor 11 is preheated in the endothermic furnace 13 and moved to the mixing chamber 14 formed in the base 12, and the gas moved to the mixing chamber 14 is The fuel injection device 30 is injected into the endothermic chamber 21 of the electrode 20 and mixed with the preheated fuel to generate a mixed fuel.

The mixed fuel mixed in the mixing chamber 14 is introduced into the reactor 11 through the inlet hole 15.

As shown in FIG. 8, the inflow hole 15 is rotated and supplied such that a mixed fuel supplied by being inclined to the reactor 11 in a tangential direction generates a swirl shape.

One or two or more inflow holes 15 are formed, and the number of the inflow holes 15 is set according to the size of the plasma reactor 5, that is, the size of the reactor 11 and the flow rate of the reactants. Changes.

When two or more inflow holes 15 are installed, they are arranged at equal intervals.

The shape of the electrode 20 to which the high voltage current is applied is formed in a conical shape, and a predetermined space is formed inside to form an endothermic chamber 21 for preheating the fuel supplied from the fuel injection device 30. The nozzle 22 is formed at the upper side to supply the preheated fuel into the reactor 11.

The mixed fuel rotated and supplied through the inflow hole 15 proceeds while forming a rotational flow and moves while rotating in the circumferential direction rather than being immediately moved upward in the longitudinal direction of the reaction furnace 11, thereby reducing the plasma reaction efficiency to the same volume. It can be higher.

The fuel injected from the nozzle 22 formed in the electrode 20 to which the high pressure current is applied performs a plasma reaction in the reaction section 60 to discharge the product generated by the plasma reaction to the discharge port 40.

In addition, as illustrated in FIG. 7, the fuel injection device 8 for injecting fuel may be further provided in the reaction section 60 where the plasma reaction occurs.

The fuel injection device 8 is capable of producing a large number of plasma products while minimizing the plasma reactor 5.

Usually the liquid fuel injection device 8 uses an injector or a nozzle.

When fuel is injected into the reaction section 60 of the plasma reactor 5 through the fuel injection device 8, the fuel is vaporized momentarily and converted into gaseous fuel, which is burned or partially oxidized, or becomes unburned gaseous fuel. In addition, according to the type of fuel injected from the fuel injection device 8, the composition of the unburned gas fuel may also be variously changed.

Plasma reactor 5 made as described above,

Gas introduced through the inlet port 50 (mixed gas in which air or air and exhaust gas are mixed) is preheated in the endothermic furnace 13, and the gas preheated in the endothermic furnace 13 flows into the mixing chamber 14. The mixture is mixed with the preheated fuel in the endothermic chamber 21 of the electrode 20 to form a mixed fuel and flows into the reactor 11 through the inlet hole 15.

The mixed fuel introduced through the inlet hole 15 is rotated and supplied by the shape of the inlet hole 15 so that fuel is evenly distributed in the reactor 11.

The mixed fuel introduced into the reactor 11 undergoes a plasma reaction by the high voltage applied from the electrode 20 together with the preheated fuel injected from the nozzle 22 of the electrode 20.

In a reaction section in which a plasma reaction is performed by the fuel injected from the fuel injection device 8, a product of a large amount of plasma reaction is generated, and a product of the plasma reaction is generated according to the fuel injected through the fuel injection device 8. Synthesis gas containing hydrogen can be produced. When the synthesis gas containing hydrogen is supplied to the engine 2, nitrogen oxides (NOx) can be generated while suppressing combustion instability and CO, HC, etc. in the engine caused by EGR. It is possible to reduce the occurrence.

Figure 4 shows another embodiment of a nitrogen oxide (NOx) reduction system of the engine of the present invention, the nitrogen oxide (NOx) reduction system of the engine,

A part of the exhaust gas discharged to the exhaust pipe 4 from the engine 2 that generates power by burning fuel supplied from a fuel tank 1 that is generally used is returned to the engine 2 to supply the exhaust gas. The product produced in the plasma / catalytic reactor that catalyzes the reaction from the fuel supplied from the fuel tank 1 is supplied to a system equipped with an exhaust gas recirculation unit (EGR) 3 which reduces the amount and NOx. In order to supply the engine 2, the product produced in the plasma / catalytic reactor is hydrogen or a synthesis gas containing hydrogen.

The plasma / catalytic reactor generally has been proposed as a prior art, and in the present invention, a general plasma / catalytic reactor may be used, or one having the same configuration as the plasma reactor 5 described in the above embodiment may be used. . The plasma / catalytic reactor having the same configuration as the plasma reactor 5 is a plasma catalysis instead of the plasma reaction in the plasma reactor 5.

When the product generated by the plasma / catalytic reactor is supplied into the engine 2 as described above, the combustion safety in the engine 2 is increased while maintaining the effect of deNOx of the exhaust gas recirculation device (EGR), thereby generating the amount of by-products such as CO and HC. There is a positive effect that can reduce the risk.

Figure 5 shows another embodiment of a nitrogen oxide (NOx) reduction system of the engine of the present invention, the nitrogen oxide (NOx) reduction system of the engine,

A part of the exhaust gas discharged to the exhaust pipe 4 from the engine 2 that generates power by burning fuel supplied from a fuel tank 1 that is generally used is returned to the engine 2 to supply the exhaust gas. The product produced in the plasma reactor (5) generating a reaction by receiving the fuel supplied from the fuel tank (1) in a system equipped with an exhaust gas recirculation device (EGR) 3 which reduces the amount and NOx. And some or all of the exhaust gas to the aqueous liquefaction (WGS) reactor,

In the aqueous gasification (WGS) reactor, a reaction occurs as shown in the following Equation 1 to remove CO of the exhaust gas, and to supply a high concentration of hydrogen to the engine 2.

CO + H20-> CO2 + H2 ------------- Equation 1

That is, the aqueous gasification (WGS) reactor removes CO in the plasma reactor product by reacting the exhaust gas containing a large amount of water with the product generated in the plasma reactor 5 to produce CO 2 and H 2, Hydrogen can be supplied to the engine 2.

It is also possible to use a catalytic reactor or a plasma / catalyst in place of the plasma reactor 5.

Since the plasma reactor 5 is described above, the description thereof is omitted, and the aqueous hydrolysis (WGS) reactor and the plasma / catalytic reactor are generally presented as prior art, and thus the construction thereof is not described in the present invention.

As described above, supplying the product generated by the plasma 5 or the plasma / catalyst reactor to the engine 2 increases the combustion safety in the engine 2 while maintaining the effect of deNOx of the exhaust gas recirculation device (EGR). A positive effect is expected to reduce the amount of by-products such as HC.

The use of such a method reduces the amount of NOx generated in the engine, resulting in an alternative effect of reducing or eliminating various catalyst-based pollution reduction devices previously installed in the exhaust pipe for deNOx.

The engine 2 may be any one of an engine using gasoline fuel, an engine using diesel fuel, an engine using LPG fuel, and an engine using natural (CNG) gas.

The nitrogen oxide (NOx) reduction system of the engine made as described above can reduce the nitrogen oxides (NOx) in the exhaust gas generated from the engine,

By supplying hydrogen or syngas containing hydrogen in the engine to reduce the amount of NOx generated in the engine, there is an alternative effect to reduce or eliminate various catalyst-based pollution reduction devices that have been installed in the exhaust pipe for deNOx. .

In addition, by using a plasma reactor as a method of supplying hydrogen or hydrogen-containing syngas to be supplied to the engine, the reactor has a startup time of several seconds, thereby rapidly responding to load variations and engine conditions, thereby improving operating conditions.

Claims (17)

In a nitrogen oxide (NOx) reduction system of an engine using an exhaust gas recirculation device, By installing a catalytic reactor, the product produced in the catalytic reactor is supplied to the engine 2 which burns the fuel supplied from the fuel tank 1 and the exhaust gas supplied from the exhaust gas recirculation apparatus 3, thereby providing nitrogen oxides (NOx). NOx reduction system of the engine, characterized in that to reduce. In a nitrogen oxide (NOx) reduction system of an engine using an exhaust gas recirculation device, Plasma reactor 5 is installed in the engine 2 to combust the product produced in the plasma reactor 5 from the fuel tank 1 and the exhaust gas supplied from the exhaust gas recirculation apparatus 3. A nitrogen oxide (NOx) reduction system for an engine, characterized in that by supplying to reduce nitrogen oxides (NOx). In a nitrogen oxide (NOx) reduction system of an engine using an exhaust gas recirculation device, Plasma / catalyst reactors are installed to supply the products produced in the plasma / catalyst reactors to the engine 2 which burns the fuel supplied from the fuel tank 1 and the exhaust gas supplied from the exhaust gas recirculation apparatus 3. A nitrogen oxide (NOx) reduction system of an engine, characterized by reducing nitrogen oxides (NOx). The method according to any one of claims 1 to 3, Nitrogen oxide (NOx) reduction system of the engine, characterized in that it further comprises an aqueous reactor (6) to supply a high concentration of hydrogen to the engine (2). The method of claim 4, wherein The aqueous hydrolysis reactor 6 reacts the exhaust gas with the product generated from the reactor CO + H20-> CO2 + H2 The nitrogen oxide (NOx) reduction system of the engine, characterized in that to reduce the CO and increase the hydrogen concentration by using the moisture contained in the exhaust gas. The method according to any one of claims 1 to 3, The engine (2) is a nitrogen oxide (NOx) reduction system of the engine, characterized in that the engine using a diesel fuel. The method according to any one of claims 1 to 3, The engine (2) is a nitrogen oxide (NOx) reduction system of the engine, characterized in that the engine using gasoline fuel. The method according to any one of claims 1 to 3, The engine (2) is a nitrogen oxide (NOx) reduction system of the engine, characterized in that the engine using LPG fuel. The method according to any one of claims 1 to 3, The engine (2) is a nitrogen oxide (NOx) reduction system of the engine, characterized in that the engine using natural gas (CNG) fuel. The method of claim 2, The plasma reactor 5, A body (10) formed with a discharge port (40) formed at an upper side, a cylindrical reactor (11) having an inlet (50) formed therein, and a base (12) supporting the reactor (11); An electrode 20 having an endothermic chamber 21 and a nozzle 22 provided inside the reactor 11; Nitrogen oxide (NOx) reduction system of the engine, characterized in that it comprises a fuel injection device (30) installed in the base (12) is formed to inject and supply liquid fuel into the endothermic chamber (21) of the electrode (20). The method of claim 3, The plasma / catalyst reactor, A body (10) formed with a discharge port (40) formed at an upper side, a cylindrical reactor (11) having an inlet (50) formed therein, and a base (12) supporting the reactor (11); An electrode 20 having an endothermic chamber 21 and a nozzle 22 provided inside the reactor 11; Nitrogen oxide (NOx) reduction system of the engine, characterized in that it comprises a fuel injection device (30) installed in the base (12) is formed to inject and supply liquid fuel into the endothermic chamber (21) of the electrode (20). The method according to claim 10 or 11, wherein The gas flowing into the inlet (50) is nitrogen oxide (NOx) reduction system of the engine, characterized in that the air containing exhaust gas. The method according to claim 10 or 11, wherein An endothermic furnace (13) is formed in the reactor (11) so that the gas flowing into the inlet (50) is preheated. The method of claim 13, The endothermic furnace 13 formed in the reactor 11 is formed in a spiral around the circumference of the reactor 11 so as to absorb the heat of the reactor 11 NOx reduction system of the engine . The method according to claim 10 or 11, wherein In the base 12, a mixing chamber 14 is formed to mix the gas introduced from the inlet 50 of the reactor 11 and the fuel preheated in the endothermic chamber 21 of the electrode 20. The nitrogen oxide (NOx) reduction system of the engine, characterized in that the inlet hole (15) is formed so that the mixed fuel mixed in the mixing chamber (14) flows into the reactor (11). The method of claim 15, The inlet hole (15) is a nitrogen oxide (NOx) reduction system of the engine, characterized in that the fuel is mixed to be supplied to the reactor (11) is formed to rotate. The method according to claim 10 or 11, wherein Nitrogen oxide (NOx) reduction system of the engine, characterized in that the fuel injection device (8) is further provided to supply fuel to the reaction section (60) of the reactor (11).

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