KR101393031B1 - Purifier for exhaust gas and controling method thereof - Google Patents

Abstract

The present invention relates to an exhaust gas purification apparatus and a control method thereof, and more particularly, to an exhaust gas purification apparatus and a control method thereof capable of stably controlling a flame for raising the temperature of exhaust gas in a flow field in which flow rate fluctuation of exhaust gas is significant ≪ / RTI >
The present invention relates to an internal combustion engine comprising a reduction material supply unit for supplying a reduction material for reacting with a foreign matter contained in exhaust gas of an internal combustion engine to extract a foreign substance, an air supply unit for supplying air to be mixed with the reduction material supplied from the reduction material supply unit, A burner for heating the exhaust gas and burning foreign matter filtered by the post-processing unit, an engine speed sensor for measuring the number of revolutions per minute of the internal combustion engine, And a control unit for determining an injection amount of the reduction material supply unit and the air supply unit according to a signal received from the engine speed detection sensor and the sensing unit.

Description

TECHNICAL FIELD [0001] The present invention relates to a purifier for purifying exhaust gas,

The present invention relates to an exhaust gas purification apparatus and a control method thereof, and more particularly, to an exhaust gas purification apparatus and a control method thereof capable of stably controlling a flame for raising the temperature of exhaust gas in a flow field in which flow rate fluctuation of exhaust gas is significant ≪ / RTI >

The reduction of pollutants emitted from automobiles is one of the major research and development goals of the automobile industry around the world in accordance with recently enforced environmental regulations.

HC, CO, and soot in automobile exhaust gas are comparatively easy to reduce by the improvement of combustion and post-treatment, but the reduction technology of nitrogen oxide suffers from development due to adverse effect on combustion and fuel consumption.

Generally, a diesel engine uses a compression ignition and diffusion combustion mechanism irrespective of the amount of fuel supplied, and even when the fuel and air mixture is lean, the fuel can be burned, resulting in high fuel economy.

This diesel engine has advantages such as high efficiency in low load operation compared with gasoline engine, high fuel economy, lean burning, low HC (Hydro Carbon) and low CO emission. However, in the diffusive combustion process, (PM, Particulate Matter) and NOx (NOx) are emitted in a high region.

Direct injection diesel engines generate large amounts of nitrogen oxides (NOx) under high temperature combustion conditions and generate particulate matter (PM) in relatively fuel-rich areas.

In the case of a direct-injection diesel engine that directly injects fuel into the combustion chamber, the common rail fuel injection system and the electronically controlled fuel injector are used to control the high-pressure injection and injection timing, the injection amount, the injection frequency, .

In addition, in the case of direct injection diesel engines, the common rail fuel injection system improves intake and exhaust system and combustion chamber design to improve the output by improving fuel atomization and fuel and air mixing and air utilization, There is a possibility that pollutant emissions such as PM and NOx can be reduced.

As a method for purifying the exhaust gas by raising the temperature of the flow field in the flow field where the oxygen concentration is low and the flow rate fluctuates considerably, such as the exhaust gas of the diesel engine vehicle or the internal combustion engine for generator as described above, the liquid fuel is atomized and injected, A burner device for maintaining combustion is provided.

BACKGROUND ART [0002] The background art of the present invention is disclosed in Korean Patent Laid-Open Publication No. 10-2010-0000542 (entitled "Nitrogen Oxide Reduction System Using Synthetic Gas and Its Control Method", published on January 6, 2010).

There is a problem that it is difficult to accurately determine the injection amount of the fuel and air injected to provide the flame, so that it is difficult to reduce the time required to raise the temperature of the exhaust gas to the target temperature and the amount of fuel and air injected.

Therefore, there is a need for improvement.

An object of the present invention is to provide an exhaust gas purifying apparatus and a control method thereof capable of reducing the time required for raising the temperature of the exhaust gas in the flow field where the flow rate fluctuation of the exhaust gas is significant and the amount of injection of fuel and air. have.

The present invention relates to a reduction material supply unit for supplying a reduction material for extracting a foreign substance by reacting with a foreign matter contained in exhaust gas of an internal combustion engine; An air supply unit for supplying air to be mixed with the reducing material supplied from the reduction material supply unit; A post-treatment unit for filtering foreign matter contained in the exhaust gas; A burner for heating the exhaust gas and burning the foreign matters filtered by the post-processing unit; An engine speed detecting sensor for measuring the number of revolutions per minute of the internal combustion engine; A sensing unit for measuring a temperature or a pressure of the exhaust gas before and after the burner and the post-treatment unit; And a control unit for determining an injection amount of the reduction material supply unit and the air supply unit according to a signal received from the engine speed detection sensor and the sensing unit.

Further, the post-treatment unit of the present invention includes an oxidation catalyst unit for reacting foreign substances contained in the exhaust gas passing through the burner to extract foreign matter, and a filter unit for filtering the foreign substances contained in the exhaust gas passing through the oxidation catalyst unit .

The sensing unit may further include: a first temperature sensor for measuring a temperature of the exhaust gas passing through the inlet of the burner; A second temperature sensor for measuring the temperature of the exhaust gas passing through the inlet of the oxidation catalyst portion; A third temperature sensor for measuring the temperature of the exhaust gas passing through the outlet of the oxidation catalyst unit; A fourth temperature sensor for measuring the temperature of the exhaust gas passing through the outlet of the filter unit; And a pressure sensor for measuring an outlet pressure of the oxidation catalyst unit.

Further, the present invention provides a method for controlling an internal combustion engine, comprising the steps of: (a) checking the signal of the exhaust gas purifier when the internal combustion engine is started, (b) diagnosing the state of the exhaust gas according to a signal transmitted from the exhaust gas purifier and outputting diagnosis contents; (c) determining whether the state of the exhaust gas purifier is included in the driving condition; (d) if the state of the exhaust gas purifying apparatus is included in the driving condition, driving the burner with a reducing agent injection amount corresponding to an engine speed and a burner inlet temperature of the exhaust gas purifying apparatus with reference to an ignition map; (e) when the burner is driven, determining a reduction agent injection amount according to an engine speed and the burner inlet temperature with reference to a target map; (f) injecting the reducing agent at a predetermined amount or less of the determined amount of the reducing agent injection when the amount of the reducing agent injected is determined; (g) adjusting the reducing agent injection amount according to the stepwise increasing and decreasing strategy such that the outlet temperature of the burner reaches the target temperature; (h) determining whether the engine speed and the burner inlet temperature have been changed when the amount of the reducing agent is adjusted stepwise; (i) determining whether the outlet temperature of the burner has reached a target temperature if the engine speed and the burner inlet temperature have not been changed; (j) determining whether the burner exit temperature reaches a target temperature and whether or not the burner's drive completion condition is satisfied.

(K) if the driving completion condition of the burner is not satisfied in the step (j), the difference between the amount of reduction in the target map due to the engine speed and the temperature of the burner and the latest amount of reduction agent injection Determining whether the value is equal to or greater than a set value; And (l) if the difference between the engine speed and the burn-down injection amount of the target map due to the burner inlet temperature and the latest reduction agent injection amount is equal to or greater than the set value, replacing the latest amount of reduction agent injection with the reduced injection amount of the target map .

In the step (f), if the difference between the amount of the reduced amount of the target map and the amount of the latest amount of the reduced agent is less than the set value in the step (k) of the present invention, do.

Further, when the step (l) of the present invention is completed, the step (e) is performed.

The exhaust gas purifying apparatus and the control method thereof according to the present invention can effectively reduce the nitrogen oxide contained in the exhaust gas by raising the temperature of the reducing agent so as to promote the reaction between the reducing agent and the exhaust gas, There is an advantage in that it can reduce the time required for the operation.

The exhaust gas purifying apparatus and the control method thereof according to the present invention are characterized in that the time required for the exhaust gas purifying process and the amount of injected fuel and air Can be reduced.

In addition, since the exhaust gas purifying apparatus and the control method thereof according to the present invention are burned in a state where the reducing material and the air serving as the fuel of the flame are formed in the holding block including the porous material, the flame is blown or turned off due to the flow rate of the exhaust gas Can be prevented.

In addition, since the flame is not blown or turned off by the holding block, the exhaust gas purifying apparatus and the control method thereof according to the present invention can reduce the time required for raising the temperature of the exhaust gas to the target temperature and the amount of the reducing material, And the efficiency of the control method is improved.

1 is a configuration diagram illustrating an exhaust gas purifying apparatus according to an embodiment of the present invention.
2 is an exploded perspective view illustrating a mixing section of an exhaust gas purifying apparatus according to an embodiment of the present invention.
3 is an exploded perspective view showing a burner of an exhaust gas purifying apparatus according to an embodiment of the present invention.
4 is a cross-sectional view showing a burner of an exhaust gas purifying apparatus according to an embodiment of the present invention.
5 is a perspective view showing a holding block of an exhaust gas purifying apparatus according to an embodiment of the present invention.
6 is a block diagram illustrating an apparatus for purifying exhaust gas according to an embodiment of the present invention.
7 is a flowchart showing a control method of an exhaust gas purifying apparatus according to an embodiment of the present invention.
8 is a front cutaway perspective view showing a burner of an exhaust gas purifying apparatus according to another embodiment of the present invention.
9 is a rear cutaway perspective view showing a burner of an exhaust gas purifying apparatus according to another embodiment of the present invention.
10 is a sectional view showing a burner of an exhaust gas purifying apparatus according to another embodiment of the present invention.
11 is a perspective view showing a holding block of an exhaust gas purifying apparatus according to another embodiment of the present invention.

Hereinafter, an embodiment of an exhaust gas purifying apparatus according to the present invention will be described with reference to the accompanying drawings.

In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are terms defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator.

Therefore, definitions of these terms should be made based on the contents throughout this specification.

1 is a configuration diagram illustrating an exhaust gas purifying apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the apparatus for purifying exhaust gas according to an embodiment of the present invention includes a reduction providing unit 75 for supplying a reducing agent for reacting with a foreign substance contained in exhaust gas to extract a foreign substance, 75 and the air supplied from the air supply unit 72 to be mixed with the exhaust gas so as to be mixed with the exhaust gas. A burner 50 for burning the foreign matter filtered by the post-processing unit 31, and a burner 50 for burning the foreign matter, which is supplied to the burner 50, And a preheating unit 58 for preheating a mixture of air and air and supplying it to the burner 50.

Fuel injected into the fuel tank 12 is supplied to the internal combustion engine 10 by the operation of the fuel injection pump 14 when the internal combustion engine 10 installed in the vehicle or the generator is started and the operation of the internal combustion engine 10 Is discharged to the side of the exhaust pipe (30).

Further, the fuel supplied from the fuel tank 12 is supplied to the mixing portion 80 through the reduction providing portion 75.

Here, the internal combustion engine 10 is exemplified by a diesel engine installed in the vehicle, and the fuel supplied from the fuel tank 12 of the internal combustion engine 10 is used as a reducing agent.

The reducing agent and the air supplied by the operation of the reduction providing part 75 and the air supplying part 72 are mixed in the mixing part 80 and the fuel of the air and the diluted liquid is evaporated while passing through the preheating part 58 Is supplied to the burner (50).

Therefore, the liquid low-temperature reducing agent can be prevented from being heated by the preheating portion 58 and the burner 50 from being cooled, so that the flame generated in the burner 50 is prevented from being turned off or blown by the fuel injection, . ≪ / RTI >

The reduction providing portion 75 is provided with a first fuel pump 75a for supplying the reducing agent supplied from the fuel tank 12 to the mixing portion 80 and a reducing agent supplied from the fuel tank 12 to the mixing portion 80 and a second fuel pump 75b connected in parallel with the first fuel pump 75a.

The first fuel pump 75a and the second fuel pump 75b are connected in parallel to each other so that when the first fuel pump 75a and the second fuel pump 75b are simultaneously driven, Is increased.

Therefore, whether or not the first fuel pump 75a and the second fuel pump 75b are driven is determined by the injection amount of the reducing agent determined by the control unit 100 (see FIG. 6).

The air supply unit 72 includes a first air pump 72a that supplies air to the mixing unit 80 to be mixed with the reducing agent supplied from the reduction providing unit 75, And a second air pump 72b for supplying and mixing air.

The air supplied from the first air pump 72a is mixed with the reducing agent in the mixing portion 80 and the air supplied from the second air pump 72b is mixed with the mixer in the burner 50. [

In order to prevent this, it is necessary to control the flow rate between the first air pump 72a and the second air pump 72b in order to prevent particulate matter from forming due to unstable evaporation or pyrolysis during evaporation or pyrolysis of the liquid. A valve 78 is provided.

Therefore, it is possible to control the flow rate of the air supplied to the mixing section 80 to bypass the air to the burner 50, or to control the flow rate of the air supplied to the burner 50 to bypass the mixing section 80.

2 is an exploded perspective view illustrating a mixing section of an exhaust gas purifying apparatus according to an embodiment of the present invention.

1 and 2, the mixing unit 80 according to the present embodiment includes a first injection unit 84 connected to the reduction providing unit 75 and a first injection unit 84 and a first air pump 72a, A main body 82 provided with a second injection part 86 through which air to be supplied is introduced; a main body 82 provided in a flow path where the first injection part 84 and the second injection part 86 are joined, And a heater 88 for supplying thermal energy to the guide portion 87. The guide portion 87 is provided with a guide portion 87 for supplying heat energy.

The main body 82 is connected to the discharge passage connected to the burner 50, the connection passage for installing the heater 88, the first injection section 84, and the second injection section 86.

The reducing agent supplied from the first injecting section 84 and the second injecting section 86 and the air are mixed while being moved toward the heating furnace side along the discharge flow path and the heat energy supplied from the heater 88 mixes the reducing agent and the air The mixer is heated and supplied to the burner (50).

The guide portion 87 includes a guide rod 87a inserted into the flow path and a guide groove portion 87b formed in a spiral shape on the guide rod 87a and rotating and moving the reducing agent and the air in a whirling manner.

The mixture of the reducing agent and air mixed in the main body 82 moves along the guide groove 87b while rotating in a whirling manner toward the burner 50 so that the reducing agent and the air can be effectively mixed.

At this time, since the temperature of the mixer is raised by the heat energy supplied from the heater 88, it is possible to prevent the malfunction that the evaporator is not evaporated sufficiently or the pyrolysis does not occur.

Therefore, the purification performance of the exhaust gas purification apparatus can be prevented from being lowered, and the amount of the reducing agent required for the purification operation can be reduced.

Particularly, when the urea water (UREA) for reducing the nitrogen oxide contained in the exhaust gas is used as the reducing agent, the reducing agent is evaporated or pyrolyzed to generate the reducing gas only if the temperature of the reducing agent is maintained at a specific temperature or higher.

In this embodiment, since the number of urea passing through the main body 82 and the thermal energy supplied from the heater 88 are supplied to the air, the mixture is evaporated or pyrolyzed to sufficiently supply the reducing gas, and the reducing gas reacts with the nitrogen oxide, .

One example of the reducing agent via by evaporation at 220 ~ 250 also forms a total hydrocarbon (THC), urea (UREA) is when isopropyl reduced chemical species by pyrolysis at 150 ~ 210 degrees Ansan (HNCO) to ammonia (NH ₃₎ Is generated.

In the mixing part 80 of the present embodiment, an injector is provided to adjust the supply amount of the reducing agent to the first injection part 84, and the evaporation or pyrolysis of the reducing agent is performed by the air supplied through the second injection part 86 .

Further, it is possible to prevent the reducing agent from remaining in the flow path of the mixing section 80 by the air introduced into the second injection section 86.

The post-processing unit 31 includes an oxidation catalyst unit 32 for reacting foreign substances contained in the exhaust gas passed through the burner 50 to extract foreign substances, And a filter unit 34 for filtering the exhaust gas.

In the oxidation catalyst part 32, hydrocarbons and carbon monoxide contained in the exhaust gas are oxidized and converted into harmless carbon dioxide and moisture, and the nitrogen oxide is purified by using the hydrocarbons contained in the catalyst component and the exhaust gas.

The filter unit 34 includes a hydrocarbon trap that adsorbs hydrocarbons contained in the exhaust gas under a low temperature of the exhaust gas and releases the adsorbed hydrocarbon under a high temperature of the exhaust gas, And a diesel particulate filter that removes particulate matter under a predetermined condition, and removes nitrogen oxides by using a catalyst component and hydrocarbons contained in the exhaust gas.

The post-processing unit 31 further includes a nitrogen oxide reduction unit (not shown) for filtering the foreign substances contained in the exhaust gas passing through the filter unit 34, so that the nitrogen contained in the foreign matter passing through the filter unit 34 The oxide can be effectively removed.

Here, the operation and effect of the oxidation catalyst part 32, the filter part 34 and the nitrogen oxide reduction part can be easily carried out by those skilled in the art who are aware of the technical constitution of the present invention, so detailed drawings and explanations will be omitted.

The preheating portion 58 includes a fuel supply pipe 58a which is formed in a coil shape to connect the reduction providing portion 75 and the mixing portion 80 and surround the burner 50. [

A mixture of a reducing agent and air supplied to the burner 50 through the mixing portion 80 by the operation of the reduction providing portion 75 is supplied to the burner 50 while rotating around the burner 50 along the fuel supply pipe 58a ) Is transferred to the mixer.

When the reducing agent is heated and evaporated or thermally decomposed by the thermal energy transmitted from the burner 50, the flame can be prevented from being turned off by the low temperature reducing agent when the reducing agent is injected into the burner 50.

The preheating unit 58 and the mixing unit 80 may be installed in one exhaust gas purifying apparatus and the preheating unit 58 or the mixing unit 80 may be selectively installed in one exhaust gas purifying apparatus It will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the spirit and scope of the invention.

4 is a cross-sectional view of a burner of an exhaust gas purifying apparatus according to an embodiment of the present invention, and FIG. 5 is a cross-sectional view of the burner of the exhaust gas purifying apparatus according to the embodiment of the present invention. 1 is a perspective view showing a holding block of an exhaust gas purifying apparatus according to an embodiment of the present invention.

1 and 3 to 5, the burner 50 according to the present embodiment is provided with a housing 52 (see FIG. 1), which is installed in an exhaust pipe 30 through which exhaust gas is exhausted and in which a suction port 52a and a discharge port 52b are formed A mixing pipe 54 in which a mixture of a reducing agent and air supplied from the mixing unit 80 and air supplied from the air supply unit 72 are mixed in the housing 52, And a flame holding portion 57 for preventing the flame injected from the mixing pipe 54 from being turned off by the flow rate of the exhaust gas.

When the exhaust gas purifying operation is started, the reducing agent and air supplied from the reduction supply portion 75 and the air supply portion 72 are mixed in the mixing tube 54, and a flame is generated by the flame supplied from the igniter 55 .

At this time, the exhaust gas flows into the housing 52 through the intake port 52a, is heated to the target temperature while being in contact with the flame, and then is moved to the post-treatment unit 31 side so that foreign substances such as nitrogen oxides are removed, do.

The housing 52 has a space in which a flame is sprayed between the suction port 52a and the discharge port 52b and the suction port 52a and the discharge port 52b are spaced apart from each other.

The housing 52 is formed in a shape similar to a rectangular shape, and has a suction port 52a formed at an upper portion of one side thereof and a discharge port 52b formed at a lower portion of the other side thereof.

The exhaust gas flowing into the housing 52 through the intake port 52a generates a vortex inside the housing 52 after colliding with the upper surface of the other side of the housing 52. [

When the exhaust gas flows inside the housing 52, the flame and the exhaust gas provided in the mixing pipe 54 are brought into contact with each other, so that the temperature of the exhaust gas is raised to reach the target temperature.

In addition, since foreign matter filtered by the post-processing unit 31 is burned by the flame provided in the mixing pipe 54, foreign matter can be prevented from accumulating in the exhaust pipe 30.

The mixing pipe 54 is installed so as to be in parallel with the traveling direction of the exhaust gas flowing through the suction port 52a and is installed to face the discharge port 52b.

The flame generated in the mixing pipe 54 extends toward the discharge port 52b and becomes parallel to the traveling direction of the discharge gas supplied into the housing 52 through the inlet port so that the discharge gas does not collide with the flame frontally.

Accordingly, the exhaust gas flows into the housing 52 to prevent the flame from colliding with the front face, thereby preventing the flame from being turned off or blown.

The mixing pipe 54 is formed so that a connection hole portion 54b connected to the reduction supply portion 75 and a mounting hole portion 54a provided with the igniter 55 are connected to each other.

The mixing pipe 54 is formed in a funnel shape in which an outlet through which the flame is discharged is wider than an inlet through which air is introduced. An air supply part 72 is connected to the inlet of the mixing pipe 54, A connection hole portion 54b into which the liquid is introduced is formed.

A mounting hole portion 54a is formed on the circumferential surface of the mixing pipe 54 to provide a flame to the mixture of the reducing agent and the air to generate a flame.

The inlet of the mixing pipe 54, the connecting hole 54b and the mounting hole 54a are connected to each other through the inner space of the mixing pipe 54.

The reducing agent and the air supplied through the inlet of the mixing pipe 54 and the connecting hole portion 54b are mixed in the mixing pipe 54 and the flame Is generated.

The flame holding part 57 includes a pore tube 56 coupled to the mixing tube 54 and guiding the flame and allowing the exhaust gas to pass therethrough, a mixer 56 for mixing a reducing agent and air to be injected into the pore tube 56, And a retaining block 57a for preventing the exhaust pipe 56 from being discharged outside the perforated pipe 56.

The perforated pipe 56 is formed in a cylindrical shape and has one end coupled to the outlet of the mixing pipe 54 and a plurality of ventilation holes 56a formed at the other end to be continuously spaced from each other.

When the flame is generated in the mixture of the reducing agent and the air injected through the outlet of the mixing tube 54 and the flame is generated, the flame extends along the inside of the perforated tube 56.

The exhaust gas flowing into the housing 52 through the suction port 52a flows into the porous pipe 56 through the ventilation hole 56a and then moves to the other side of the porous pipe 56, As shown in FIG.

When the exhaust gas passes through the perforated pipe 56, the exhaust gas is heated while being in contact with the flame, so that the temperature of the exhaust gas is raised and the reducing agent and the exhaust gas are reacted to purify and discharge foreign substances such as nitrogen oxides.

The holding block 57a includes a metal foam having a space portion formed therein so as to form a mixture of a reducing agent and air.

The metal foam is a metal porous structure formed of a mesh-like metal material to form a block, and an irregular space portion is continuously formed therein.

Therefore, when the mixture of the reducing agent and the air is introduced into the metal foam, it is formed inside the porous structure.

The mixture formed in the metal foam can be prevented from being discharged to the outside of the perforated pipe 56 due to the flow rate of the mixer or the exhaust gas, so that the flame formed on the metal foam can be prevented from being blown or turned off.

The retaining block 57a may include a metal fiber material. The retaining block 57a may be made of a metal fiber material and a porous structure in which an irregular space portion is continuously disposed therein. Thus, the same operation as that of the metal foam can be performed.

6 is a block diagram illustrating an apparatus for purifying exhaust gas according to an embodiment of the present invention.

1 and 6, the present embodiment includes an engine speed detecting sensor 107 for measuring the number of revolutions per minute of the internal combustion engine 10, an exhaust gas temperature sensor 107 for detecting the exhaust gas temperature before and after the burner 50 and the post- And a sensor for measuring the pressure according to a signal received from the sensors 101, 102, 103, 104 and 105, the engine speed sensor 107 and the sensors 101, 102, 103, 104 and 105, (75) and the air supply unit (72).

When the start of the engine is started, it is determined whether the vehicle is in a normal state according to signals transmitted from the engine speed sensor 107 and the sensors 101, 102, 103, 104 and 105. The sensors 101, 102, 103, 104, and 105 according to the temperature signal and the pressure signal.

Reference numeral 77 denotes an OBD display unit (One Board Diagnosis) 77 for diagnosing the state of the exhaust gas purifying apparatus according to the present embodiment and displaying the diagnosis contents.

A control method of the exhaust gas purifier according to an embodiment of the present invention will now be described.

7 is a flowchart showing a control method of an exhaust gas purifying apparatus according to an embodiment of the present invention.

Referring to FIGS. 1 to 7, a method of controlling an exhaust gas purifying apparatus according to an embodiment of the present invention includes the steps of (S10) detecting a normal state by checking a signal of an exhaust gas purifying apparatus when the internal combustion engine is started, and (S20) of diagnosing the state of the exhaust gas according to a signal transmitted from the exhaust gas purifier and outputting diagnostic contents (S30) of judging whether the state of the exhaust gas purifier is included in the driving condition, (S40) of driving the burner (50) with the amount of reduction agent sprayed in accordance with the engine speed and the inlet temperature of the burner (50) of the exhaust gas purifier with reference to the ignition map if the state of the exhaust gas purifier is included in the driving condition, (S50) of determining the amount of reduction agent injection according to the engine speed and the temperature of the inlet of the burner (50) by referring to the target map when the burner (50) is driven, a step (S50) of reducing the amount of reduction agent injection Article (S70) of adjusting the amount of reducing agent injection according to the stepwise increasing / decreasing strategy so that the outlet temperature of the burner (50) reaches the target temperature; and a step (S80) of judging whether the inlet temperature of the burner (50) has been changed; and a step (S90) of judging whether the outlet temperature of the burner (50) has reached the target temperature when the engine speed and the inlet temperature of the burner And a step (S100) of determining whether the condition for completion of driving the burner (50) is satisfied when the outlet temperature of the burner (50) reaches a target temperature.

When the start of the internal combustion engine 10 is started, the state of the exhaust gas purifying apparatus is diagnosed and displayed by the operation of the OBD display unit 77 of the exhaust gas purifying apparatus.

At this time, in the OBD display unit 100, the temperature signal transmitted from the engine speed sensor 107, the power supply unit, the error detection signal of the igniter 55, and the temperature transmitted from the sensors 101, 102, 103, 104, Signal and pressure signal, the line pressure of the reduction providing part 75, the line pressure of the air supply part 72, and the like to check the steady state of the vehicle.

The OBD display unit 77 diagnoses whether the state of the emission gas purifier is in a normal state and displays the diagnosis contents so that the driver can confirm the signal.

When the diagnosis content of the exhaust gas purifier is displayed, it is judged whether or not the state of the exhaust gas purifier is included in the driving conditions.

The driving condition of the burner 50 is determined by a temperature signal and a pressure signal transmitted from the sensing units 101, 102, 103, 104, and 105 and the regeneration cycle of the post-processing unit 31 stored in the control unit 100, 50) is driven.

When the burner 50 is driven, the fuel injection pump 14 and the reduction providing portion 75 are driven to supply the fuel, that is, the reducing agent, to the mixing portion 80, Is driven to supply air to the mixing portion 80. [

In this case, since the first fuel pump 75a and the second fuel pump 75b are connected in parallel to each other, when the injection amount of the reducing agent required in the burner 50 is equal to or higher than the set value, the first fuel pump 75a and the second fuel pump 75b, The pump 75b is simultaneously driven.

Either the first fuel pump 75a or the second fuel pump 75b is driven when the injection amount of the reducing agent required by the burner 50 is less than the set value.

The amount of reduction agent injection is determined by the injection amount set in the ignition map stored in the control unit 100 and the burner 50 is driven by the amount of reduction agent injection set in the ignition map in accordance with the engine speed and the inlet temperature of the burner 50. [

The air supplied by the first air pump 72a is supplied to the mixing portion 80 and mixed with the reducing agent and the air supplied by the second air pump 72b is supplied to the mixing pipe 54, (80).

The reducing agent and the air passing through the mixing section 80 are supplied into the main body 82 through the first injection section 84 and the second injection section 86 respectively and are supplied into the main body 82 through the guide groove section 87b The reducing agent and the air are mixed with each other when being discharged while being rotated.

At this time, the heater 88 installed in the main body 82 supplies thermal energy to the reducing agent and the air, which are moved along the guide rod 87a and the guide groove 87b, so that the mixture of the reducing agent and the air is evaporated or thermally decomposed Thereby generating a reducing gas that reacts with the exhaust gas.

The reducing agent of the gas generated by the above-described operation is supplied into the mixing pipe 54 along the fuel supply pipe 58a.

Since the fuel supply pipe 58a is formed in a spiral shape surrounding the peripheral surface of the porous pipe 56, the mixture of the reducing agent and the air is heated and evaporated or pyrolyzed while passing through the burner 50, and then supplied to the mixing pipe 54 .

The mixer and the air are injected into the porous pipe 56 through the mixing pipe 54 and the flame is generated in the mixer by the operation of the igniter 55,

The igniter 55 may ignite either the first igniter 55a or the second igniter 55b depending on the amount of the reducing agent supplied to the mixing tube 54 and the amount of air injected.

At this time, the generated flame extends into the porous pipe 56 through the holding block 57a, and the mixture of the reducing agent and air is burned in the state of being formed in the porous block 57a.

Therefore, the mixer formed in the holding block 57a is not discharged to the outside of the perforated pipe 56 due to the flow rate of the exhaust gas flowing through the inlet port 52a of the housing 52, so that a malfunction such as flame blowing or turning off occurs prevent.

The flame is stably maintained without blowing or turning off as described above, so that the temperature of the exhaust gas passing through the burner 50 can be effectively increased.

When the burner 50 is driven, the injection amount of the reducing agent is determined by referring to the ignition map stored in the control unit 100. The number of injection amounts stored in the ignition map corresponds to the current engine speed and the inlet temperature of the burner 50 As shown in FIG.

When the burner 50 is driven in accordance with the control sequence stored in the ignition map, the amount of the reducing agent is controlled in accordance with the control sequence stored in the target map.

A variety of abrasive jetting amounts are set in the target map so as to achieve a speed signal transmitted from the engine speed detecting sensor 107 and a target temperature corresponding to the inlet temperature of the burner 50 and are set according to the engine speed and the inlet temperature of the burner 50 Any one of the amount of reducing agent injection is determined.

Therefore, when the burner 50 is driven, the reduction supply part 75 and the air supply part 72 are driven to raise the exhaust gas to the target temperature so as to achieve the amount of the low-pressure spray set in the target map.

When the burner 50 is driven and a flame is generated, it is determined whether the temperature of the exhaust gas is increased to the target temperature. When the exhaust gas reaches the set temperature corresponding to 90% of the target temperature which is lower than the target temperature, PID control method.

PID control means control by P (Proportional), I (Integral, Integral) and D (Derivative, Derivative).

If the difference between the temperature of the exhaust gas and the target temperature is large, it is possible to increase the heating rate by increasing the injection rate. When the temperature of the exhaust gas is heated close to the target temperature, To a target temperature.

In the present embodiment, assuming that the target temperature is 100 degrees, the burner 50 is driven by the amount of the reducing agent determined based on the data of the target map, the temperature of the exhaust gas is raised to 90 degrees, The exhaust gas is raised to 100 degrees.

Therefore, the temperature of the exhaust gas can be raised to the target temperature in a relatively short time so that the temperature of the exhaust gas does not exceed the target temperature.

Since the amount of the foreign matter to be filtered by the filter unit 34 is determined according to the temperature of the exhaust gas, whether or not the target temperature is reached is determined by the temperature of the outlet of the oxidation catalyst unit 32, It is determined whether or not the temperature of the exhaust gas measured by the sensor 103 reaches the target temperature.

It is determined whether or not the engine speed and the inlet temperature of the burner 50 have been changed before the temperature of the exhaust gas is determined to reach the target temperature. Therefore, when the engine speed and the load change during the burner operation, .

The temperature of the exhaust gas at the inlet of the burner 50 sensed by the first temperature sensor 101, the temperature of the exhaust gas at the outlet of the burner 50 sensed by the second temperature sensor 102, The temperature of the exhaust gas at the outlet of the oxidation catalyst part 32 sensed by the first temperature sensor 104, the temperature of the exhaust gas at the outlet of the filter part 34 sensed by the fourth temperature sensor 104, The pressure at the outlet of the burner 32 is used as data for determining whether the burner 50 is driven.

When the temperature of the exhaust gas reaches the target temperature by the above operation, the engine speed sensor 107, the first temperature sensor 101, the second temperature sensor 102, the third temperature sensor 103 ), The fourth temperature sensor 104, and the pressure sensor 105, and determines whether the condition for driving the burner 50 is satisfied.

If it is not included in the driving completion condition of the burner 50, the burner 50 is stopped, and after the flame is exhausted, it is determined whether the exhaust gas purifier is in a normal state (S10) .

It is determined whether or not the temperature of the exhaust gas has reached the target temperature and the driving time of the burner 50 has exceeded the set time so that the driving completion condition of the burner 50 is satisfied The driving of the exhaust gas purifier is terminated.

Of course, the driving completion condition of the burner 50 can be variously changed, and it can be detected by the engine speed sensor 107 and the sensing units 101, 102, 103, 104, and 105 Lt; RTI ID = 0.0 > and / or < / RTI >

In the present embodiment, if the driving completion condition of the burner 50 is not satisfied in the step S100 of judging whether or not the driving completion condition of the burner 50 is satisfied, the target map by the engine speed and the inlet temperature of the burner 50 (S110) of judging whether or not the difference between the amount of reduction in the amount of fuel sprayed by the burner 50 If the difference is equal to or greater than the set value, replacing the latest reduced agent injection amount with the reduced injection amount of the target map (S120).

After the temperature of the exhaust gas reaches the target temperature and the driving completion condition of the burner 50 is satisfied, the control unit 100 advances the operation of comparing the amount of the low-sensitive agent stored in the target map with the amount of the latest amount of the low-sensitive agent.

At this time, when the difference between the amount of the reduced agent injection stored in the target map and the amount of the latest reduced agent injection is equal to or greater than the set value, the amount of the reduced agent injection stored in the target map is replaced with the latest amount of the reduced agent injection.

Accordingly, it is possible to store, in the target map, the actual amount of reduction agent injection required to raise the exhaust gas to the target temperature according to the engine speed and the inlet temperature of the burner 50, The burner is driven until it is satisfied.

If the difference between the amount of the reduced agent injection stored in the target map and the amount of the latest reduced agent injection is less than the set value, the process proceeds to step S60 in which the reducing agent is injected at a value lower than the set value of the reduced agent injection amount stored in the target map.

Therefore, the burner 50 is driven by the amount of the reduced amount of the agent to be sprayed stored in the target map until the driving completion condition of the burner 50 is satisfied.

The control unit 100 includes an input signal unit for receiving a signal input from the engine speed sensor 107 and the sensing units 101, 102, 103, 104 and 105, and a controller for determining the state of the exhaust gas purifier according to the input signal. And an output signal portion for transmitting an operation signal to the abatement supply portion 75, the air supply portion 72 and the igniter 55 in accordance with the operation determined by the device control portion, do.

It will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the spirit and scope of the invention as set forth in the appended claims.

FIG. 8 is a perspective view showing a burner of an exhaust gas purifying apparatus according to another embodiment of the present invention, FIG. 9 is a rear cut-away perspective view of a burner of an exhaust gas purifying apparatus according to another embodiment of the present invention, FIG. 10 is a sectional view showing a burner of an exhaust gas purifying apparatus according to another embodiment of the present invention, and FIG. 11 is a perspective view showing a holding block of an exhaust gas purifying apparatus according to another embodiment of the present invention.

8 to 11, a burner 250 of an exhaust gas purifying apparatus according to another embodiment of the present invention includes a housing 252 having a suction port 252a and a discharge port 252b through which exhaust gas passes, A mixer 254 installed in the housing 252 for mixing fuel and air, igniters 255a and 255b installed in the mixer 254, and a mixture of fuel and air supplied to the mixer 254 And a flow generating unit 257 for weighting the fluid.

Mixing pipe 254 is supplied with a mixture of a reducing agent and air supplied from an abatement supply unit 75 (see FIG. 1) and air supplied from an air supply unit 72 (see FIG. 1) (252).

At this time, the reducing agent and the air flow in a whirling manner by the flow generating part 257 installed in the mixing tube 254, so that the reducing agent and the air are effectively mixed.

The mixing pipe 254 is formed in a cylindrical shape and the outer end of the mixing pipe 254 is formed with a connection hole portion 254b through which the fuel supply pipe is connected. (254).

A plurality of insertion holes 254c are formed on the outer circumferential surface of the mixing tube 254 so that an air supply pipe 257c for supplying the air supplied from the air supply unit to the mixing tube 254 can be connected.

Therefore, the mixture flowing from the outer end of the mixing tube 254 and the air introduced from the outer peripheral surface of the mixing tube 254 are mixed in the mixing tube 254, and by the operation of the flow generating part 257 And moves into the housing 252 along the mixing tube 254 while flowing in a whirl.

The nozzles 257d are installed at the ends of the fuel supply pipe 258a and the air supply pipe 257c and the nozzles 257d are installed in the mixing pipe 254 so that the connection pipe 258a and the supply pipe 257c So that the speed of the reducing agent and air injected into the mixing pipe 254 is increased.

The air supply pipe 257c is provided with a plurality of branch valves 257e so that the air supply channel can be branched into a plurality of air supply channels and the plurality of air supply pipes 257c connected to the branch valve 257e are connected to the mixing pipe 254c And is connected to the peripheral surface.

The air supplied to the mixing pipe 254 along one air supply pipe 257c flows to the plurality of air supply pipes 257c while passing through the branch valve 257e and flows into the mixing pipe 257c along the circumferential surface of the mixing pipe 254, (254).

The air introduced into the mixing pipe 254 through the outer end of the mixing pipe 254 and the air introduced into the mixing pipe 254 in the direction of the circumferential surface of the mixing pipe 254 are mixed with each other in the mixing pipe 254, The flow is weighted and effective mixing is achieved.

The flame is supplied from the first igniter 255a and the second igniter 255b installed on the circumference of the mixing tube 254 when the mixer is moved into the housing 252 to generate a flame.

The suction port of the present embodiment is provided with the guide pipe 259 having the plurality of guide hole portions 259a so that the exhaust gas flowing into the housing 252 along the suction port 252a is guided along the guide pipe 259 to the housing 252 .

Therefore, it is possible to prevent the exhaust gas flowing into the housing 252 from being injected directly into the flame, and to prevent the flame from being blown or turned off by the exhaust gas flowing into the housing 252.

The housing 252 is provided with a pore tube 256 coupled to the mixing tube 254 and guiding the flame and allowing exhaust gas to pass therethrough and the pore tube 256 and the guide tube 259 are installed in parallel.

The exhaust gas flowing into the housing 252 flows into the housing 252 along the guide pipe 259 and the flame generated in the mixing pipe 254 extends along the perforated pipe 256, And the extension direction of the flame is parallel.

The exhaust gas flowing into the housing 252 along the guide pipe 259 is injected into the housing 259 while passing through the inner end of the guide pipe 259 and is collided with the inner wall of the housing 252, And is contacted to the porous pipe 256 while the traveling direction is switched.

A part of the exhaust gas flowing into the housing 252 through the guide pipe 259 is injected through the guide hole 259a and contacts the porous pipe 256. After passing through the flame, 252).

Therefore, it is possible to effectively prevent the flame from being blown or turned off by the exhaust gas flowing into the housing 252 through the suction port 252a.

The flow generating portion 257 includes a swirler 257a installed in the mixing pipe 254 and for flowing fuel and air passing through the mixing pipe 254. [

The swirler 257a is formed in a fan shape and is installed in the mixing pipe 254 so as not to be rotated, so that the mixer passing through the swirler 257a moves in a whirling manner.

The swirler 257a rotates the mixer and the air flowing in from the end portion and the circumferential surface of the mixing tube 254 in a whirling manner, so that the mixture of the mixer and the air is increased.

The mixer, which is mixed while being swirled by the swirler 257a, is burned by the flames supplied from the first igniter 255a and the second igniter 255b to provide the flame.

The mixing pipe 254 is formed with a connection hole portion 254b connected to the reduction material supply portion 75 (see FIG. 1) and a mounting hole portion 254a provided with the igniter 255a and 255b, A step 266 is formed between the hole 254b and the mounting hole 254a to increase the inner diameter.

The reducing agent supplied along the connection hole portion 254b is mixed with the air in the mixing pipe 254, passes through the igniter 255a, 255b, and starts to be burned to generate a flame.

At this time, the mixture of the reducing agent and air passes through the step 266, and the inner diameter of the flow path is rapidly expanded. Therefore, the vortex of the mixer is generated at the edge portion generated by the step 266, do.

Therefore, it is possible to prevent the flame from being turned off or blown by the flow rate of the exhaust gas.

In addition, since the present embodiment further includes the flame holding portion 260 that prevents the flame injected from the mixing pipe 254 from being turned off by the flow velocity of the exhaust gas, it is possible to prevent the flame from being turned off or blown more effectively .

The flame holding part 260 includes a holding block 262 which is inserted into the porous pipe 256 and prevents a mixture of the reducing material and the air generating the flame from being discharged to the outside of the porous pipe 256.

The holding block 262 suppresses the movement of the mixer introduced into the housing 252 toward the discharge port 252b to a certain extent so that the mixer in which the combustion progresses is kept in the holding block 262, So that it is prevented from being formed long outside.

The holding block 262 is formed in a cylindrical shape including a metal foam material and an inclined portion 264 for narrowing the inner diameter of the holding block 262 is formed at the end of the holding block 262 opposed to the discharge port 252b do.

Since the metal foam forming the holding block 262 is made of a porous material, the time required for the mixer to stay inside the holding block 262 is increased, and the mixer passing through the holding block 262 is formed by the inclined portion 264 The time for staying in the holding block 262 is further increased.

Therefore, the flame generated by the burning of the mixer is formed to be long outside the holding block 262 while the mixer stays in the holding block 262 for a long time, thereby effectively preventing the flame from being turned off or blown.

This makes it possible to provide an exhaust gas purifying apparatus and a control method thereof capable of reducing the time required for raising the temperature of the exhaust gas in the flow field in which the flow rate of the exhaust gas fluctuates significantly and the amount of injection of fuel and air.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. .

Further, although the exhaust gas purifying apparatus has been described as an example, the purifying apparatus of the present invention can also be used for products other than the exhaust gas purifying apparatus.

Accordingly, the true scope of the present invention should be determined by the following claims.

10: internal combustion engine 12: fuel tank
14: fuel injection pump 30: exhaust pipe
32: oxidation catalyst section 34: filter section
50, 250: burner 52, 252: housing
52a, 252a: suction port 52b, 252b: discharge port
54, 254: mixing tube 55a, 255a: first igniter
55b, 255b: second igniter 54a, 254a:
54b, 254b: connection hole portion 56, 256:
56a, 256a: ventilation hole portion 57, 260: flame holding portion
57a, 262: holding block 58: preheating part
58a, 258a: fuel supply pipe 72: air supply part
72a: first air pump 72b: second air pump
75: Reduction Provided Benefit 75a: First Fuel Pump
75b: second fuel pump 77: OBD indicator
78: Flow control valve 80: Mixing part
82: main body 84: first injection section
86: second injection part 87: guide part
87a: Guide rod 87b: Guide groove
88: heater 100:
101: first temperature sensor 102: second temperature sensor
103: third temperature sensor 104: fourth temperature sensor
107: engine speed sensor 264:
266:

Claims (7)

A reducing agent supply unit for supplying a reducing agent for extracting a foreign substance by reacting with a foreign matter contained in the exhaust gas of the internal combustion engine;
An air supply unit for supplying air to be mixed with the reducing material supplied from the reduction material supply unit;
A post-treatment unit for filtering foreign matter contained in the exhaust gas;
A burner for heating the exhaust gas and burning the foreign matters filtered by the post-processing unit;
A mixer for mixing the reducing agent supplied from the reduction providing unit and the air supplied from the air supply unit and supplying the mixture to the burner so as to be reacted with the exhaust gas;
An engine speed detecting sensor for measuring the number of revolutions per minute of the internal combustion engine;
A sensing unit for measuring a temperature or a pressure of the exhaust gas before and after the burner and the post-treatment unit; And
And a control unit for determining an injection amount of the reduction material supply unit and the air supply unit according to a signal received from the engine speed detection sensor and the sensing unit,
The air-
A first air pump for supplying air to the mixing portion to be mixed with a reducing agent supplied from the reduction providing portion; And
And a second air pump for supplying air to the mixer of the air supplied from the mixer and the reducing agent so as to be mixed,
The post-
An oxidation catalyst unit for reacting a foreign substance contained in the exhaust gas passed through the burner to extract foreign matter and a filter unit for filtering foreign substances contained in the exhaust gas passing through the oxidation catalyst unit,
The sensing unit includes:
A first temperature sensor for measuring the temperature of the exhaust gas passing through the inlet of the burner;
A second temperature sensor for measuring the temperature of the exhaust gas passing through the inlet of the oxidation catalyst portion;
A third temperature sensor for measuring the temperature of the exhaust gas passing through the outlet of the oxidation catalyst unit;
A fourth temperature sensor for measuring the temperature of the exhaust gas passing through the outlet of the filter unit; And
And a pressure sensor for measuring an outlet pressure of the oxidation catalyst unit.
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