KR20000045746A - Device for oxidizing discharging gas in intermittent method for diesel vehicle - Google Patents

Abstract

PURPOSE: A device for oxidizing discharging gas in an intermittent method for a diesel vehicle is provided to maintain the durability of a filter while forcibly oxidizing the discharging gas from a diesel engine. CONSTITUTION: A difference between the values detected in a first pressure sensor(16) and a second pressure sensor(18) is over an established value and an ECM(24) turns off an on/off valve(40) to open a bypass valve(42). Then, the ECM opens a fuel supplying valve(26) for supplying fuel to the inside of a first discharging pipe while opening a compressed air supplying valve(32). The fuel and the compressed air supplied to the first discharging pipe become mixed air of fuel and air. The ECM controls an igniter(36) for generating flame to oxidize the particular material accumulated in a ceramic filter(14). Then, the oxidation is operated in the first discharging pipe for being detected by a temperature sensor(38). The detected value is fed to the ECM for turning on the on/off valve while closing the bypass valve. Thus, the temperature by the oxidation in the first discharging pipe is cooled while discharging the discharging gas through the ceramic filter.

Description

Exhaust gas oxidizer for diesel vehicles by intermittent method

The present invention relates to an exhaust gas oxidizer for a diesel vehicle using an intermittent method. More specifically, the pressure difference is measured by a pressure sensor provided before and after the exhaust gas generated during combustion of a diesel engine. The present invention relates to an exhaust gas oxidizer for a diesel vehicle by an intermittent method in which an exhaust gas is intermittently oxidized to secure durability of a ceramic filter.

In general, the exhaust gas emitted from diesel engine combustion can be divided into nitrogen oxides (N0 _X ) and particulate matter, and their production conditions are generated in opposition to each other. Is solved by the post-processing device.

The post-treatment method is generally a method of filtering particulate matter using a filter, and among them, a method using a ceramic filter having a high filtration efficiency capable of removing more than 80% of particulate matter with a large heat resistance temperature and a low back pressure is widely used. Is being studied.

When particulate matter is filtered and accumulated in the ceramic filter, the engine back pressure is increased, which adversely affects the performance and operation of the engine, thereby requiring periodic oxidation.

Oxidation of particulate matter with an ignition temperature of 500-600 ° C can be categorized into forced oxidation using an electric heater or burner, and natural oxidation by lowering the ignition temperature of particulate matter using a catalyst or fuel additive. .

In the case of coating the oxidation catalyst on the surface of the filter without using the additional heat source to lower the ignition temperature of the particulate material to about 300-400 ° C. and naturally oxidizing, the particulate matter is deposited and oxidized on the oxidation catalyst coated on the filter surface. There is a problem in reducing the efficiency of the catalyst, there is a disadvantage that sulfur dioxide gas (SO ₂ ) discharged from the engine is oxidized in the form of sulfate by the catalyst is discharged. There is also a method of oxidizing particulate matter at less than 300 ℃ using iron and copper as fuel additives, but there is a case that the oxidation problem occurs between 300-400 ℃, the amount of additives should be increased. Although more complex and less economical than natural oxidation, a forced oxidation method that does not have this secondary contamination problem is a common practice these days. In addition, in the case of the electric heater, there is a difficult problem in obtaining sufficient power in an automobile, and in the case of the burner method, the structure of the system is complicated.

Although there have been many studies on the post-treatment apparatus of the forced oxidation method, the biggest problem in the oxidation of the post-treatment apparatus is due to the damage of the filter due to the high temperature and temperature gradient of the filter which occurs repeatedly during oxidation. There was a problem that it is difficult to maintain durability.

Accordingly, the present invention has been invented to solve the above problems, when the exhaust gas discharged from the diesel engine is oxidized by a forced oxidation method, exhaust gas for diesel vehicles by the intermittent method to maintain the durability of the filter. The object is to provide an oxidizer.

In order to achieve the above object, the present invention provides a device for intermittently oxidizing exhaust gas discharged from an engine, comprising: a first exhaust pipe and a second exhaust pipe provided to separate and discharge the exhaust gas discharged from the engine Wow; A ceramic filter provided to filter particulate matter discharged when exhaust gas is discharged from a rear end of the first exhaust pipe; First and second pressure sensors provided to sense pressure before and after the ceramic filter; A temperature sensor provided at one side of the first pressure sensor; A burner device provided to oxidize particulate matter applied to the ceramic filter in front of the first pressure sensor; An on / off valve provided in front of the burner device; The second exhaust pipe and the bypass valve for controlling the exhaust gas; An ECM controlling an on / off valve and a bypass valve and controlling a burner device according to values sensed by the first and second pressure sensors and a temperature sensor; Characterized in that made.

The burner device is provided with a fuel supply valve to open and close the fuel supplied from the fuel pump to the first exhaust pipe in the control of the ECM, the first pipe is provided with a nozzle for injecting fuel when the fuel supply valve is opened. Compressor is provided to supply compressed air to the fuel side injected from the nozzle, the compressor outlet side is provided with a compressed air supply valve, the compressed air supply valve is opened by the control of the ECM, the compressed air supply A swirler is provided to mix compressed air and fuel introduced into the first exhaust pipe by opening the valve and opening the fuel supply valve. The swirler provides spark to the mixed air in which fuel and compressed air are mixed by the swirler. It characterized in that the igniter is provided so that it can be.

1 is a view showing an exhaust device provided with an exhaust gas oxidizer for a diesel vehicle according to the control method according to the present invention.

2 is a view showing the configuration of an exhaust gas oxidizer for a diesel vehicle according to the control method according to the present invention.

Explanation of symbols on the main parts of the drawings

10: first exhaust pipe 12: second exhaust pipe

14 ceramic filter 16 first pressure sensor

18: second pressure sensor 20: burner device

22: fuel pump 24: ECM

26: fuel supply valve 28: nozzle

30: compressor 32: compressed air supply valve

34: Swallower 36: Igniter

38: temperature sensor 40: on / off valve

42: bypass valve

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing an exhaust device provided with an exhaust gas oxidizing apparatus for a diesel vehicle according to the present invention according to the present invention, and FIG. 2 is a configuration diagram of the exhaust gas oxidizing apparatus for the diesel vehicle according to the present invention according to the present invention. The figure which shows.

As shown in the drawing, an exhaust pipe piped from the engine is branched into the first exhaust pipe 10 and the second exhaust pipe 12 so as to oxidize and exhaust the exhaust gas discharged from the diesel engine in the exhaust pipe.

The first exhaust pipe 10 is provided with a ceramic filter 14 built in from the rear end thereof. The first pressure sensor 16 and the first exhaust pipe 10 may be configured to sense internal pressure before and after the ceramic filter 14. Two pressure sensors 18 are provided.

A burner device 20 is provided at the front side of the first pressure sensor 16, and the burner device 20 supplies fuel supplied from the fuel pump 22 to the inside of the first exhaust pipe 10 to the ECM 24. A fuel supply valve 26 that is opened and closed by control is provided, and a nozzle 28 for injecting fuel when the fuel supply valve 26 is opened is provided in the first pipe 10, and the fuel is discharged from the nozzle 28. Compressor 30 is provided to compress the outside air when the injection, the compressor 30 is provided with a compressed air supplying valve 32 at the outlet side, the compressed air supply valve 32 is ECM (24) Is opened by the control of.

When the compressed air supply valve 32 and the fuel supply valve 26 are opened, a swirler 34 capable of mixing compressed air and fuel when the fuel is introduced into the first exhaust wave 10 is provided. Is provided, the igniter 36 is provided by the swirler 34 to provide a spark to the mixed air mixed with fuel and compressed air.

On the other hand, a temperature sensor 38 for measuring the temperature after oxidizing the particulate matter applied to the ceramic filter 14 by the burner device 20 is provided on one side of the first pressure sensor 16.

On the other hand, when the exhaust gas discharged from the exhaust manifold flows into the first exhaust pipe 10 side, there is provided an on / off valve 40, the second exhaust pipe 12 side is provided with the first exhaust When the exhaust gas is oxidized at the pipe 10 side, a bypass valve 42 is provided so that the exhaust gas can be discharged to the second exhaust pipe 12 side, and these on / off valves 42 and bypass valves 44 are provided. Is controlled according to the generated values of the first and second pressure sensors 16 and 18 and the temperature sensor 38, which is controlled by the ECM 24.

When the exhaust gas oxidizer for the diesel vehicle according to the present invention provided with the intermittent method is oxidized in the exhaust gas discharged from the diesel engine, the second exhaust pipe side 12 as shown in FIGS. 1 and 2 is provided. The bypass valve 42 provided at is always closed and exhaust gas from the engine is discharged to the first exhaust pipe 10 to pass through the ceramic filter 14.

At this time, the ECM 24 receives the pressure values sensed by the first pressure sensor 16 and the second pressure sensor 18 provided before and after the ceramic filter 14, and the pressure difference between them is a predetermined value. Will be compared.

At this time, the exhaust gas is continuously discharged to the first exhaust pipe 10 to accumulate particulate matter in the ceramic filter 14. At this time, the first and second pressures before and after the ceramic filter 14 are accumulated. When the sensors 16 and 18 apply it to the ECM 24 side, the ECM 24 determines that a large amount of particulate matter accumulates in the ceramic filter 14 when the ECM 24 compares with a predetermined value and exceeds a predetermined value. The burner device 20 is controlled to oxidize the accumulated particulate matter of the filter 14.

This will be described in detail as follows.

The ECM 24 may be configured such that the difference between the values sensed by the first pressure sensor 16 and the second pressure sensor 18 provided before and after the ceramic filter 14 is equal to or greater than a predetermined value, the first exhaust pipe 10. The on / off valve 40 provided at the front is turned off, and the bypass valve 42 provided at the second exhaust pipe 12 side is opened.

Thereafter, the ECM 24 opens the fuel supply valve 26 provided at the outlet side of the fuel pump 22 so as to supply fuel into the first exhaust pipe 10 and from the compressor 30. The compressed air supply valve 32 is opened to supply the compressed air to the inside of the first exhaust pipe 10.

On the other hand, the fuel and compressed air supplied into the first exhaust pipe 10 is a mixer in which fuel and air are mixed by a swirler 34, and in this state, the igniter 36 is moved to the ECM 24. ) Controls the flame to oxidize the particulate matter accumulated in the ceramic filter 14. Thereafter, when the oxidation occurs in the first exhaust pipe 10, the temperature sensor 38 senses this and applies it to the ECM 24. The ECM 24 is provided on the first exhaust pipe 10. The on-off valve 40 is turned on, and the bypass valve 12 provided on the second exhaust pipe 12 side is controlled to close, so that the temperature due to oxidation in the first exhaust pipe 10 is discharged from the engine. In addition to cooling with the exhaust gas, the exhaust gas is discharged through the ceramic filter 14.

Therefore, the particulate matter accumulated in the ceramic filter 14 only when the difference between the values sensed by the first and second pressure sensors 16 and 18 before and after the ceramic filter 14 is greater than or equal to the value of the predetermined ECM 24. By oxidizing, the durability of the ceramic filter 14 can be ensured.

As described above, the particulate matter accumulated in the ceramic filter is oxidized at an appropriate time, so that the durability of the ceramic filter can be maintained for a long time as compared with the conventional continuous dissolution.

Claims (2)

In the device for intermittently oxidizing the exhaust gas discharged from the engine, A first exhaust pipe 10 and a second exhaust pipe 12 provided to separate and discharge the exhaust gas discharged from the engine; A ceramic filter 14 provided at a rear end of the first exhaust pipe 10 to filter particulate matter discharged when exhaust gas is discharged; A first pressure sensor 16 and a second pressure sensor 18 provided to sense pressure before and after the ceramic filter 14; A temperature sensor 38 provided at one side of the first pressure sensor 16; A burner device 20 provided to oxidize particulate matter applied to the ceramic filter 14 in front of the first pressure sensor 16; An on / off valve 40 provided in front of the burner device 20; The second exhaust pipe 12 has a bypass valve 42 for controlling the exhaust gas; The on / off valve 40 and the bypass valve 42 and the burner device 20 are controlled according to the values sensed by the first and second pressure sensors 16 and 18 and the temperature sensor 40. To ECM 24; Exhaust gas oxidizer for a diesel vehicle according to the intermittent method, characterized in that made. The method of claim 1, The burner device 20 is provided with a fuel supply valve 26 to open and close the fuel supplied from the fuel pump 22 to the inside of the first exhaust pipe 10 under the control of the ECM 24, and the first pipe A nozzle 28 for injecting fuel when the fuel supply valve 26 is opened is provided in the 10, and a compressor 30 is provided to supply compressed air to the fuel side injected from the nozzle 28. A compressed air supplying valve 32 is provided at the outlet side of the compressor 30, and the compressed air supply valve 32 is opened by the control of the ECM 24, and the compressed air supply valve 32 is opened and fuel is supplied. A swirler 34 is provided to mix compressed air and fuel introduced into the first exhaust pipe 10 by opening the valve 26, and the fuel and compressed air are mixed by the swirler 34. It is equipped with an igniter 36 to provide a spark to the mixed air Exhaust gas oxidizer for a diesel vehicle by the intermittent method, characterized in that.