KR101008721B1 - Apparatus for reducing particulate matter of diesel engine - Google Patents

Abstract

The present invention includes a filter disposed in a flow path through which exhaust gas is discharged from a diesel engine, a filter formed along the longitudinal direction of the housing and accommodated in the housing, the filter including an electrically divided unit filter unit, and the unit filter; Reduction of particulate matter in a diesel engine having a plurality of unit electrodes which individually transmit electric signals to each of the units, and a control unit which controls the electric signals supplied to the unit electrodes and allows each of the unit filter units to be independently heated. Provide a device.

Description

Apparatus for reducing particulate matter of diesel engine

The present invention relates to an apparatus for reducing particulate matter in a diesel engine, and more particularly, to an apparatus for reducing particulate matter in a diesel engine to reduce particulate matter contained in exhaust gas discharged from a diesel engine to be discharged to the atmosphere. .

Diesel engines employed in diesel vehicles, despite excellent fuel economy and power output, due to the characteristics of diesel engines, unlike gasoline engines, a large amount of particulate matter (Particulate Matter) is emitted when the exhaust gas is discharged. Particulate matter is recognized as the main cause of air pollution, and the regulation is being tightened. Accordingly, a diesel particulate filter (DPF) is installed in a diesel vehicle to reduce emissions of particulate matter.

The filter functions to capture and reduce particulate matter discharged from a diesel engine. In using a filter, however, the main problem is how to remove and regenerate the collected particulate matter. For example, a method of separating and cleaning a filter may be used. However, this method may be cumbersome, instead of having to install additional equipment in the diesel vehicle.

As another example, a method of burning particulate matter trapped in a filter may be used. This method installs an electric heater or a diesel burner on the side where exhaust gas flows into a filter, and raises the temperature of exhaust gas so that particulate matter can combust. However, since this method additionally installs an electric heater or a diesel burner, the structure is complicated and manufacturing costs can be increased. In addition, there may be a problem that the filter portion adjacent to the flame portion of the electric heater or diesel butter is overheated and shortens the life of the filter.

As another example, a method of adding an additive to a fuel or applying a catalyst to the filter may be used so that particulate matter collected in the filter can be burned even at low temperatures. However, the method of adding an additive to the fuel has a disadvantage in that it is necessary to use a fuel which contains a sulfur content, in particular, below a certain value. In addition, the method of applying the catalyst to the filter does not lower the temperature at which the particulate matter can burn as the method of adding the additive to the fuel, there is a problem that requires an additional heat source or additive.

Accordingly, the present invention is to provide a particulate matter reduction device of a diesel engine that can easily reduce particulate matter even with a relatively simple structure, and can increase the combustion efficiency for particulate matter while preventing the shortening of the lifetime of the diesel particulate filter. The purpose.

In order to achieve the above object, the present invention, the housing disposed in the flow path for exhaust gas from the diesel engine, and formed along the longitudinal direction of the housing is accommodated in the housing, the electrically divided unit filter unit A filter, a plurality of unit electrodes which individually transmit electric signals to each of the unit filter units, and a control unit which controls the electric signals supplied to the unit electrodes and allows each unit filter unit to be independently heated. It provides a particulate matter reduction device of a diesel engine provided.

The particulate matter reduction apparatus of the diesel engine according to the present invention does not use a separate power source, so the filter is directly heated by using a vehicle power source to burn and remove particulate matter, which may be more convenient than the method of separating and washing the filter. . And, compared with the method of heating the filter by an electric heater or a diesel burner, the structure can be simplified, thereby reducing the manufacturing cost.

In addition, in the particulate matter reduction apparatus of the diesel engine of the present invention, since the unit filter portion is individually heated, it is possible to reduce the power consumption than to form the filter integrally to heat the entire filter.

In addition, since the heating is relatively evenly performed without overheating in some regions of the filter, the life of the filter can be sufficiently secured.

In addition, since it is not necessary to add an additive to the fuel so that the particulate matter can be burned even at low temperatures, there may be an effect of not using only a specific fuel in the vehicle.

Hereinafter, the technical configuration of the present invention according to the accompanying drawings in detail.

1 is a block diagram of a particulate matter reduction apparatus of a diesel engine according to an embodiment of the present invention.

As shown in FIG. 1, the particulate matter reduction apparatus 100 of the diesel engine according to the present invention includes a housing 110, a filter 120, unit electrodes 131 and 132, and a controller 140. .

The housing 110 is installed on a flow path through which exhaust gas is discharged from a diesel engine. Exhaust gas discharged from the diesel engine is introduced into the housing 110. Both sides of the housing 110 may have a structure in which exhaust pipes 181 and 182 may be installed to communicate with each other. Here, one of the exhaust pipes 181 and 182 leads the exhaust gas discharged from the diesel engine to the housing 110, and the other causes the exhaust gas passing through the housing 110 to be discharged into the muffler or the atmosphere.

The filter 120 is sized to be accommodated in the housing 110. The filter 120 functions to collect particulate matter contained in the exhaust gas flowing into the housing 110.

The filter 120 is formed along the longitudinal direction of the housing 110 and includes an electrically divided unit filter unit 121. For example, the filter 120 is formed in a cylinder or oval shape, and the unit filter unit 121 is formed to be divided at predetermined angles. If the unit filter unit 121 is divided every 90 degrees, the unit filter unit 121 is four, if the unit filter unit 121 is divided every 60 degrees, the unit filter unit 121 is There are six. If the cross-sectional area of the unit filter unit 121 is small and the heat generation volume is small and the resistance is large, one unit filter unit 121 may be configured by connecting a plurality of filter pieces in parallel.

The unit electrodes 131 and 132 separately transmit electric signals to the unit filter units 121. The unit electrodes 131 and 132 are supplied with power from the vehicle power source 150 to directly heat the filter. To this end, the unit electrodes 131 and 132 are made of a conductive material and disposed on the filter 120. The unit electrodes 131 and 132 may be electrically connected to the vehicle power source 150.

When the unit electrodes 131 and 132 are supplied with power from the vehicle power source 150, current may flow to each of the unit filter units 121. As a result, a resistance heat is generated in each unit filter unit 121 and is heated. When the unit filter unit 121 is heated in this manner, overheating does not occur in a portion of the unit filter unit 121, and the unit filter unit 121 is heated relatively evenly throughout the unit filter unit 121 and collected in the unit filter unit 121. The particulate matter is burned and the unit filter unit 121 may be regenerated. As a result, the regeneration efficiency of the filter can be increased.

Here, the vehicle power source 150 may be a power source that outputs 12V or 24V depending on the type of vehicle. Here, one of the unit electrodes 131 and 132 is electrically connected to the positive electrode of the vehicle power source 150, and the other is electrically connected to the negative electrode of the vehicle power source 150. The unit electrodes 131 and 132 and the vehicle power source 150 may be connected by wires so that power is transferred from the vehicle power source 150 to the unit electrodes 131 and 132.

The controller 140 controls the electric signal supplied to the unit electrode. In addition, the control unit 140 may allow each of the unit filter units 121 to be independently heated. The controller 140 may further include a temperature sensor 141. The temperature sensor 141 is for measuring the temperature of the filter. Here, the temperature sensor 141 may be installed not to contact the filter 120 in the housing 110. In this case, the temperature sensor 141 may be located at the side where the exhaust gas is introduced into the filter or at the side where the exhaust gas is discharged from the filter.

The temperature sensor 141 placed at the aforementioned position measures the temperature in the housing 110 to indirectly measure the temperature of the filter 120. Here, by setting the correlation between the temperature in the housing 110 and the temperature of the filter 120 in advance through experiments, it is possible to accurately measure the temperature of the filter 120. As another example, the temperature sensor 141 may be in contact with the filter 120 to directly measure the temperature of the filter. As the temperature sensor 141, a thermocouple or the like may be used.

The controller 140 receives the temperature information measured by the temperature sensor 141. The controller 140 controls the flow of the electrical signal supplied to the filter 120 so that the temperature of the filter 120 does not exceed the set temperature based on the provided temperature information. That is, the controller 140 compares the temperature value measured by the temperature sensor 141 with the set temperature value. At this time, if it is determined that the measured temperature value is lower than the set temperature value, the controller 140 turns on the power supplied to the filter 120 to allow the filter to be heated. If it is determined that the measured temperature value reaches the set temperature value, the controller 140 turns off the power supplied to the filter 120 so that the filter is no longer heated. This prevents the filter 120 from overheating beyond the limit temperature so as not to be damaged. The controller 140 may be configured to be independent of the electronic control apparatus of the vehicle, or may be configured to be integrated with the electronic control apparatus of the vehicle. In addition, the controller 140 may control the power by setting a measurement value of the current value flowing through the unit filter unit 121 as a control element.

An operation process of the particulate matter reduction apparatus 100 of the diesel engine will be described.

First, in a state in which the vehicle power supply 150 is supplied to the vehicle electric field such as when the vehicle is started, the temperature sensor 141 measures the temperature of the filter 120 and transmits the temperature to the controller 140. If it is determined that the temperature value measured by the temperature sensor 141 is lower than the set temperature value, the controller 140 supplies power supplied from the vehicle power source 150 to the filter 120 to each of the unit electrodes 131 and 132. Allow power to be supplied. A current flows from each of the unit electrodes 131 and 132 to each of the unit filter units 121 so that resistance heat is generated in each of the unit filter units 121.

If current continues to flow to the unit filter unit 121, the temperature of the unit filter unit 121 is increased. When the temperature of the unit filter unit 121 rises high enough to burn the particulate matter collected in the unit filter unit 121, the particulate matter starts to combust. In the process of burning the particulate matter, the control unit 140, if it is determined that the temperature of the unit filter unit 121 reaches the set temperature, by turning off the power supplied to the unit filter unit 121, the temperature of the filter is no longer Do not rise.

Accordingly, damage to the unit filter unit 121 may be prevented because the temperature of the unit filter unit 121 exceeds the limit temperature. When the power is no longer supplied to the unit filter unit 121, the temperature of the unit filter unit 121 starts to decrease and becomes lower than the set temperature. Then, the controller 140 turns on the power supplied to the unit filter unit 121 to heat the unit filter unit 121. When the particulate matter is completely burned through this process, the unit filter unit 121 may be regenerated.

As described above, according to the present exemplary embodiment, since the particulate matter collected in the unit filter unit 121 is burned and removed by the method of directly heating the unit filter unit 121, it is more convenient than the conventional method of separating and washing the filter. Do. In addition, since the present embodiment is a method of heating the unit filter unit 121 by applying a current to the unit electrodes using the vehicle power source 150 without using a separate power source, the unit filter unit by an electric heater or a diesel burner. Compared to the manner in which the 121 is heated, the structure can be simplified. Accordingly, manufacturing cost can be reduced.

In addition, since the unit filter unit 121 is individually heated, it is possible to reduce the power consumption than the filter is integrally formed to heat the entire filter.

In addition, a phenomenon in which overheating occurs in a portion of the unit filter unit 121 may be prevented, and the life of the unit filter unit 121 may be sufficiently secured. In addition, according to this embodiment, it is not necessary to add an additive to the fuel so that the particulate matter can be burned even at a low temperature. Accordingly, only a specific fuel may not be used in the vehicle.

Meanwhile, the filter 120 may be formed in various structures in a range capable of collecting particulate matter. For example, the filter 120 may have a porous structure or a honeycomb structure. In addition, the filter 120 may be formed of a material such as silicon carbide that resists high heat. At this time, the filter 120 may be coated with a catalyst for lowering the temperature at which the particulate matter can be burned. In the case where the catalyst is coated on the filter 120, the conventional method needs to heat the entire exhaust gas. However, in the present invention, which is a direct heating method, the active point having the catalyst is heated to regenerate even at a lower exhaust gas temperature. This is done easily. In addition, the filter may be coated with an oxidation catalyst or a NOx storage reduction catalyst. Such an oxidation catalyst or a nitrogen oxide storage reduction catalyst may maintain the temperature of the filter to be suitable for the active temperature of the catalyst in the process of directly heating the unit filter unit 121 by applying an electrical signal to the unit electrodes.

On the other hand, it is preferable that the non-conductive adhesive layer 125 is interposed between adjacent unit filter units 121. The non-conductive adhesive layer 125 is made of a material which can adhere certain members and does not flow electricity. As an example of such a non-conductive adhesive layer 125 may be a silicone adhesive.

FIG. 2 is a perspective view illustrating unit electrodes formed in each unit filter unit in FIG. 1.

As shown in FIG. 2, as an example of the unit electrodes, the unit electrodes may include a first electrode 131 and a second electrode 132.

The first electrode 131 is formed at one side of the unit filter units 121 to transmit an electric signal to the unit filter units 121 in common. As shown in FIG. 2, the first electrode 131 may be formed of a band-shaped conductor and attached to the unit filter units 121. The first electrode 131 may be attached to one surface of the unit filter units 121 in a plate shape. It is possible. On the other hand, since the humidity in the housing 110 may be filled, it is advantageous that the unit electrode is formed only on a part of the unit filter portion 121 so that the moisture can escape to the outside.

The second electrode 132 is formed on the other side of the unit filter parts 121 and is electrically separated from each other of the unit filter parts 121.

That is, when the first electrode 131 is formed in front of the unit filter parts 121 into which the exhaust gas flows, the second electrode 132 is formed behind the unit filter parts 121 through which the exhaust gas is discharged. do. Meanwhile, since the wires connected to the first and second electrodes 132 may be exposed to high heat, it is preferable that the wires are coated with a heat resistant coating material resistant to high temperatures.

3 is a perspective view illustrating a modified example of unit electrodes formed in each of the unit filter units in FIG. 1.

As a modified example of the unit electrodes, as shown in FIG. 3, the first electrode 231 among the unit electrodes is formed at one side of the unit filter units 121 and electrically separated from each other of the unit filter units 121. Is formed. The first electrode 131 allows each of the unit filter parts 121 to be independently heated.

The first electrode 131 is grounded while being electrically connected to the negative electrode of the vehicle power source 150 to function as a ground electrode, and the second electrode 132 is electrically connected to the positive electrode of the vehicle power source 150 to be a power electrode. It is desirable to function as. This is because of the high degree of contamination of the particulate matter in the portion in which the exhaust gas flows in the unit filter units 121, the particulate matter may be accumulated, the first electrode 131 may be energized by the particulate matter. In this case, since the first electrode 131 is grounded, it is possible to prevent the first electrode 131 from being energized and damaged.

The unit electrodes 231 and 132 may have a plurality of wires formed in a net shape and may be embedded in the unit filter units 121 or attached to an outer surface thereof. Such a structure allows power to be uniformly applied to the unit filter units 121 so that overheating does not occur in a portion of the unit filter units 121 and is uniformly heated throughout the unit filter units 121. . Here, the thickness of the wire is preferably made of 0.1mm to 0.5mm. If the thickness of the wire is 0.1 mm or less, it may be damaged by oxidation or the like, and if it is 0.5 mm or more, exhaust gas may be difficult to be discharged through the unit filter parts 121.

The controller 140 may sequentially apply an electrical signal to each of the unit filter units 121.

4 and 5 are schematic diagrams illustrating a state in which power is sequentially applied to each of the unit filter units and is heated.

Here, the unit filter unit is defined as being the first, second, third, and fourth unit filter units 121a, 121b, 121c, and 121d in the counterclockwise direction.

First, referring to FIG. 4, power is applied to the first unit filter unit 121a by the control unit 140 to heat the first unit filter unit 121a. A part of the heat of the first unit filter unit 121a is transferred to the second and fourth unit filter units 121b and 121d, and the second and fourth unit filter units 121b and 121d are also heated.

Next, as shown in FIG. 5, power is applied to the second unit filter unit 121b by the controller 140 to heat the second unit filter unit 121b. Here, since the second unit filter unit 121b is heated by receiving heat from the first unit filter unit 121a, power consumed to heat the second unit filter unit 121b is the first unit filter unit. It becomes smaller than when heating 121a. Although not shown, power is applied to the third and fourth unit filters 121c and 121d by the controller 140 to heat the entire filter.

Meanwhile, referring back to FIG. 1, an insulating member 160 may be further provided between the housing 110 and the filter. The heat insulating member 160 is interposed between the housing 110 and the filter to prevent heat generated from the filter from being transferred to the housing 110. Accordingly, the housing 110 may be prevented from being repeatedly deformed or overheated and damaged. The heat insulating member 160 may be formed of a material having excellent heat resistance, such as vermiculite containing mica.

On the other hand, a power amplifier 170 for amplifying the power supplied from the vehicle power supply 150 may be further provided. The power amplifier 170 may increase the voltage supplied from the vehicle power source 150 to the filter 120 to supply the filter. That is, when the temperature of the filter 120 does not rise to the set temperature because the voltage supplied to the filter 120 is low, the power amplifier 170 may sufficiently increase the temperature of the filter 120 to the set temperature. The voltage is increased to enable supply to the filter 120.

Since the resistance of the filter 120 is lowered as the temperature of the filter is increased by power supply, it may be efficient to increase the voltage as the temperature of the filter 120 is lowered and to lower the voltage as the temperature of the filter 120 is higher. Therefore, it is preferable that the power amplification unit 170 can adjust the amplification factor. In this case, the amplification factor of the power amplifier 170 may be controlled by the power controller 140, and the energization time may be adjusted by frequency modulation.

6 is a configuration diagram showing an operating state of the particulate matter reduction apparatus of the diesel engine according to a modification of the present invention.

As shown in FIG. 6, in the modified example of the particulate matter reduction apparatus 200 of the diesel engine of the present invention, the flow paths 181a and 181b are formed to be divided into a plurality, and the housing 110 is formed in the flow path ( 181a and 181b), respectively. In this case, a valve 190 may be disposed in the flow paths 181a and 181b. The valve 190 controls the flow of the exhaust gas, and guides the exhaust gas to any one of the plurality of flow paths 181a and 181b.

For example, the valve 190 may be a 3-way valve disposed at a branch point of the flow path. The three-way valve allows the incoming exhaust gas to be selectively moved to any one of the plurality of branched flow paths 181a and 181b. In addition, as another example of the valve 190, it is also possible to install the valve after each branching point in the flow path (181a, 181b) to allow the exhaust gas to move to any one of the filters (120a, 120b).

  The particulate matter reduction apparatus 200 of the diesel engine of the present invention having such a structure sends the exhaust gas to the filter 120a which is not being regenerated so that the exhaust gas does not flow into the regenerated filter 120b. Accordingly, in heating and regenerating the filter 120b, it is possible to prevent the heated filter 120b from being cooled by the exhaust gas and consuming much power.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and any person skilled in the art to which the present invention pertains may have various modifications and equivalent other embodiments. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a block diagram of a particulate matter reduction apparatus of a diesel engine according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating unit electrodes formed in each unit filter unit in FIG. 1.

3 is a perspective view illustrating a modified example of unit electrodes formed in each of the unit filter units in FIG. 1.

4 and 5 are schematic diagrams illustrating a state in which power is sequentially applied to each of the unit filter units and is heated.

6 is a configuration diagram showing an operating state of the particulate matter reduction apparatus of the diesel engine according to a modification of the present invention.

<Description of the symbols for the main parts of the drawings>

100..Diesel reduction device of diesel engine

110. Housing 120. Filter

121. Unit filter unit 131, 132 Unit electrodes

131. First electrode 132. Second electrode

140. Controller 141. Temperature sensor

150. Vehicle power supply 160. Insulation member

170. Power amplifier 181, 182 Exhaust pipes

Claims (12)

A housing disposed in a flow path through which exhaust gas is discharged from the diesel engine; A filter formed along the longitudinal direction of the housing and accommodated in the housing, the filter including electrically divided unit filter parts; A plurality of unit electrodes configured to individually transmit an electrical signal to each of the unit filter units; And And a controller configured to control an electric signal supplied to the unit electrode so that each of the unit filter units may be independently heated. The method of claim 1, The particulate matter reduction apparatus of the diesel engine, characterized in that the non-conductive adhesive layer is interposed between the unit filter unit adjacent to each other of the unit filter unit. The method of claim 1, The unit electrode is: A first electrode formed at one side of the unit filter parts to transmit an electric signal to the unit filter parts in common; And And a second electrode formed on the other side of the unit filter parts and electrically separated from each other of the unit filter parts. The method of claim 1, The unit electrode is: A first electrode formed at one side of the unit filter parts and electrically separated from each other of the unit filter parts; And And a second electrode formed on the other side of the unit filter parts and electrically separated from each other of the unit filter parts. The method of claim 1, The control unit, Apparatus for reducing particulate matter in a diesel engine, characterized in that the electrical signal is sequentially applied to each of the unit filter. The method of claim 1, The unit electrode, the particulate matter reduction apparatus of the diesel engine, characterized in that a plurality of wires are formed in the form of a net embedded in the unit filter portion or attached to the outer surface of the unit filter portion. The method of claim 1, The particulate matter reduction apparatus of the diesel engine, characterized in that it further comprises a heat insulating member interposed between the housing and the filter. The method of claim 7, wherein The insulating member is a particulate matter reduction device of a diesel engine, characterized in that formed of vermiculite containing mica. The method of claim 1, A power amplifier configured to amplify the vehicle power supplying the electric signal to the controller; The power amplification unit is a particulate matter reduction device of a diesel engine, characterized in that the amplification rate is controlled by the control unit. The method of claim 1, The particulate matter reduction device of the diesel engine, characterized in that the filter is made of silicon carbide (silicon carbide). The method of claim 1, The particulate matter reduction apparatus of the diesel engine, characterized in that the filter is coated with an oxidation catalyst or a NOx storage reduction catalyst. The method of claim 1, The flow path is formed to branch into a plurality, the housing is disposed in each of the flow path, the flow path is reduced particulate matter of the diesel engine, characterized in that a valve for discharging the exhaust gas to any one of the plurality of flow paths Device.

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