KR101278925B1 - Combustion Type Regeneration System Using Combustion Gas Circulation for Diesel Particulate Filter - Google Patents

Abstract

The present invention utilizes combustion characteristics and combustion principles of various fuels (light oil, butane, ethanol, natural gas, etc.) rather than the conventional method of physically shaking off the regeneration of the soot filter. By using combustion gas recycling to recycle the soot filter which is not recycled by oxidizing the soot collected through the concentration control, the facility is simpler than the existing regeneration method, and the regeneration time is short and soot. It provides a combustion regeneration system of a high efficiency diesel engine particulate filter that can regenerate the particulate filter without damaging the filter.

Description

Combustion Type Regeneration System Using Combustion Gas Circulation for Diesel Particulate Filter

The present invention relates to a soot filter of a diesel engine, and more particularly, to a technique for regenerating a diesel engine soot filter using combustion gas recirculation in regenerating a soot filter that is discarded or poorly maintained.

In general, it is common to use diesel engines in trains, ships, and industrial vehicles, and the use of diesel engines is gradually increasing with the recent launch of diesel passenger cars.

This trend of increasing usage of diesel engines is due to particulate matter such as soot and SOF (Soluble Organic Fraction) contained in exhaust gas discharged from diesel engines (hereinafter referred to as 'soot'). Emissions are increasing, and these emissions are becoming a major source of environmental pollution, especially air pollution, and regulations are gradually tightening.

Diesel Particulate Filter (DPF), which collects and processes soot to prevent emissions of soot particles from diesel vehicles, etc. A variety of methods have been studied.

In general, known systems for treating exhaust gases passing through the exhaust system of diesel engines include diesel oxidation catalysts (DOC) which oxidize hydrocarbons (HC) to form CO2 and H2O and convert NO to NO2, and particulate matter ( A diesel engine particulate filter (DPF) that captures PM).

The particulate matter (PM) comprises soot or carbon, soluble organic matter (SOF), and ash (ie, lubricant additives, etc.). A diesel engine particulate filter (DPF) is disposed downstream of the diesel oxidation catalyst (DOC) in the exhaust gas stream.

The soot filter (DPF) applied to a diesel engine vehicle is a device that physically collects soot generated from an engine, and when a certain amount is accumulated, oxidizes soot collected by the exhaust heat of the engine and collects soot again. Has been applied to diesel passenger cars since 2006.

However, since the exhaust gas temperature of the engine is low and the collected soot is not oxidized smoothly in a vehicle in an urban area that operates at a low speed, soot is often trapped in the soot filter and thus the function of the soot filter frequently occurs.

In addition, due to the frequent problems in the smoke filter control system of a complex structure, the smoke filter of the poor reproduction is increasing day by day.

In addition, since 2006, smoke filters have been applied to passenger diesel vehicles in Korea. As the age of the car ages, soot filters that are disposed of with the car body are increasing.

Since the main structure of the soot filter is a structure in which a noble metal is coated on the ceramic carrier, if the collected soot is completely oxidized, it can exhibit performance comparable to a new product.

Nevertheless, as described above, the soot filter is discarded due to poor regeneration or is disposed with the car body due to the aging of the old situation, a situation in which a huge resource is wasted.

On the other hand, in order to recycle the soot filter of the regeneration failure, the conventional method is to physically shake off the collected soot. Since this method mainly removes the collected smoke by heating it to high temperature after soaking (soaking in water) process and blowing it with high-pressure air, it requires long regeneration process, large equipment is required, and due to physical impact Physical breakage of the soot collecting filter carrier may occur.

Patent Document 1: Republic of Korea Patent Publication No. 10-2010-0138343 (2010.12.31) Patent Document 2: Republic of Korea Patent Publication No. 10-2011-0013217 (2011.02.09) Patent Document 3: Republic of Korea Patent Application Publication No. 10-2007-0024064 ((2007.03.02) Patent Document 4: Republic of Korea Patent Publication No. 10-2007-0071097 (2005.07.07)

The present invention is to solve the above-mentioned problems, to provide a combustion regeneration device of a diesel engine soot filter to effectively recycle the diesel engine soot filter discarded or poor maintenance to recycle the soot collecting device. In order to improve the operating efficiency of the combustion type regeneration device by using the combustion gas recirculation.

That is, the present invention uses combustion characteristics and combustion principles that match the characteristics of various fuels (light oil, butane, ethanol, natural gas, etc.) rather than physically shaking off the regeneration of the soot filter. By controlling the concentration of the combustion products in the combustion gas, the collected soot is oxidized to recycle and recycle the soot filter with poor regeneration. It is an object of the present invention to provide a combustion regeneration device of a diesel engine soot filter of high efficiency, which has a short regeneration time and can reproduce the soot filter without damaging the soot filter.

In order to achieve the above object, the present invention, for the recycling of the soot collecting device including a soot filter for collecting particulate matter contained in the exhaust gas discharged from the diesel engine, the soot collecting device is detachably mounted. As a regeneration system of filters,

A combustor installed to oxidize the soot trapped in the soot filter through fuel combustion; A blower for supplying air for fuel combustion to the combustor; A mass flow rate sensor for measuring a mass of air supplied to the blower; A first temperature sensor installed at a rear end of the combustor to detect whether a flame is lost; A second temperature sensor installed to measure a temperature of the combustion gas supplied to the front of the particulate collection device; A third temperature sensor installed between the diesel oxidation catalyst and the soot filter to be installed in front of the soot filter to evaluate the performance of the diesel oxidation catalyst constituting the soot collecting device together with the soot filter together with the second temperature sensor; ; A fourth temperature sensor installed at a rear end of the soot filter so as to calculate the oxidation progress rate of the collected soot by measuring the temperature of the front and rear of the soot filter together with the third temperature sensor; First and second oxygen sensors installed at the front and rear of the soot collecting device to adjust the combustion conditions of the combustor to measure the oxygen concentration; A combustion gas recirculation pipe connecting a rear side of the soot filter and a blower front side to recirculate the combustion gas exiting the soot filter; And a regeneration controller configured to control fuel combustion conditions in the combustor according to the detection signals from the third and fourth temperature sensors and the first and second oxygen sensors. to provide.

In the above configuration, the combustion gas recirculation pipe is provided with a combustion gas cooler for cooling the combustion gas returned to the front of the blower for the recirculation.

In the above configuration, in order to lower the temperature of the combustion gas returning to the blower, the combustion gas cooler is connected to a refrigerant cooler for cooling the refrigerant whose temperature has risen in the heat exchange process with the combustion gas to supply the combustion gas cooler again. It is characterized by.

In the above-described configuration, the intake air filter is further provided to prevent damage to the mass flow sensor due to the inflow of foreign matter in front of the mass flow sensor.

In the above-described configuration, a differential pressure sensor may be further provided which connects the front and rear of the soot filter, measures the pressure difference between the front and rear ends of the soot filter, measures the amount of soot collected in the filter, and determines whether the soot is oxidized. It is characterized by the presence.

In addition, in the above-described configuration, one side of the exhaust gas recirculation pipe connection point of the exhaust pipe connected to the rear of the exhaust filter is further provided with an exhaust flap for throttling the pipeline of the exhaust pipe to increase the recycle amount of the combustion gas. It features.

In the above-described configuration, a fifth temperature sensor for measuring the temperature of the mixed gas formed by mixing the combustion gas introduced for recirculation with the newly introduced air from the outside is further provided at the front end of the blower. .

On the other hand, in the above-described configuration, characterized in that it further comprises a computer having a monitor device for receiving and displaying the playback progress status through mutual communication with the playback controller, and displays the diagnostic status of the playback system.

The present invention can contribute to resource recycling by effectively preventing the situation that a huge resource is wasted by being discarded due to poor maintenance and poor regeneration or with old car body. That is, the present invention contributes to resource recycling by regenerating the diesel engine particulate filter discarded due to poor maintenance or poor regeneration.

Meanwhile, the present invention adopts a combustion type and a combustion gas recirculation method, which is simpler than a conventional regeneration method, and has a shorter regeneration time and oxidizes the soot trapped in the soot filter without damaging the soot filter, thereby regenerating the soot filter ( It can contribute to the development of soot filter technology considering car maintenance and environment.

In particular, when combustion of fuels such as diesel, butane, ethanol, natural gas, etc., the temperature of the combustion gas is high and the concentration of oxygen in the combustion gas is high, so the collected soot cannot be oxidized smoothly. By recycling to the combustor it is possible to optimize the oxidation reaction of the collected soot using the principle of lowering the combustion temperature and lowering the oxygen concentration in the combustion gas by using an inert material such as carbon dioxide in the recycle gas.

1A is a configuration diagram of a regeneration system of a diesel engine particulate filter according to the present invention;
2 is a conceptual diagram for explaining the action of the diesel oxidation catalyst (DOC) in the diesel engine particulate collector of FIG.
3 is a graph showing the optimum combustion conditions of soot
4 is a graph showing the temperature difference ΔT between the front and rear ends of the soot filter according to the time when the soot filter is regenerated.
5 is a graph showing the pressure difference ΔP between the front and rear ends of the soot filter according to the oxidation progress during the soot filter regeneration process.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings of FIGS. 1 to 5.

1 to 5, the present invention is for recycling of the smoke collecting device 6 including a particulate filter (6a) for collecting particulate matter contained in the exhaust gas discharged from the diesel engine, A regeneration system of a soot filter in which a soot collecting device is detachably mounted,

A combustor 3 installed to oxidize the soot collected in the soot filter 6a through fuel combustion; A blower (2) for supplying air for fuel combustion to the combustor (3); A mass flow sensor 1 for measuring the mass of air supplied to the blower 2; A first temperature sensor 4a installed at the rear end of the combustor 3 so as to detect whether the flame is lost; A second temperature sensor 4b installed to measure the temperature of the combustion gas supplied to the front of the particulate collection device 6; It is installed in front of the soot filter (6a) to evaluate the performance of the diesel oxidation catalyst (6b) constituting the soot collecting device (6) together with the soot filter (6a) with the second temperature sensor (4b). A third temperature sensor 4c provided between the diesel oxidation catalyst 6b and the particulate filter 6a; In addition to the third temperature sensor 4c, a fourth temperature sensor installed at a rear end of the soot filter 6a to measure the temperature of the front and rear of the soot filter 6a to calculate the oxidation progress rate of the collected soot. (4d); First and second oxygen sensors 7a and 7b which are installed before and after the soot collecting device 6 to adjust the combustion conditions of the combustor 3 to measure the oxygen concentration; A combustion gas recirculation pipe (10) connecting the rear side of the particulate filter (6a) and the front side of the blower (2) so that the combustion gas exiting the particulate filter (6a) is recycled; A regeneration controller 8 for controlling fuel combustion conditions in the combustor 3 in accordance with detection signals from the third and fourth temperature sensors 4c and 4d and the first and second oxygen sensors 7a and 7b; It is configured to include.

At this time, on the combustion gas recirculation pipe 10, a combustion gas cooler 11 for cooling the combustion gas returned to the front of the blower 2 for the recirculation is provided.

In addition, the combustion gas cooler 11 cools the refrigerant having a higher temperature in the heat exchange process of lowering the temperature of the combustion gas returned to the blower 2 to supply the combustion gas cooler 11 to the combustion gas cooler 11. Is connected.

On the other hand, the refrigerant cooler 12 is provided with a cooling fan 13 for cooling the refrigerant. In addition, the combustion gas recirculation pipe 10 is provided with a combustion gas recirculation control valve 15 for controlling the pipeline so as to control the recirculation of the combustion gas.

In addition, one side of a connection pipe connecting the combustion gas cooler 11 and the refrigerant cooler 12 is provided with a pump 14 for refrigerant flow.

In addition, a refrigerant control valve 16 for controlling the refrigerant flow is provided at the other side of the connection pipe connecting the combustion gas cooler 11 and the refrigerant cooler 12.

On the other hand, the intake air filter 17 is further provided in front of the mass flow sensor 1 to prevent damage of the mass flow sensor due to the inflow of foreign matter.

Then, the differential pressure sensor 18 is connected to the front and rear of the soot filter 6a and measures the pressure difference between the front and rear ends of the soot filter 6a to measure the amount of soot collected in the filter and determine whether the soot is oxidized. May be further provided.

Further, an exhaust flap 19 (exhaust flap) is further provided at one side of the exhaust gas recirculation pipe connection point of the exhaust pipe connected to the rear of the particulate filter 6a to throttle the conduit of the exhaust pipe to increase the recycle amount of the combustion gas. This is preferred.

Further, a fifth temperature sensor 4e for measuring the temperature of the mixed gas formed by mixing the combustion gas introduced for recirculation and newly introduced air from the outside is further provided in front of the blower 2.

In addition, the regeneration system of the present invention receives and displays the oxidation progress state of the soot accumulated in the soot filter through mutual communication with the regeneration controller 8, and displays a diagnosis state of an abnormality of the regeneration system. It further comprises a computer 9 having a monitor device.

Meanwhile, a diesel oxidation catalyst 6b (DOC: Diesel Oxidation Catalyst (DOC)) is installed inside the smoke packaging device, and installed in front of the smoke filter 6a (that is, upstream of the smoke filter 6a in the combustion gas flow). do.

The operation of the present invention configured as described above is as follows.

First, a soot collecting device 6 having a soot filter 6a as a regeneration object is provided for the regeneration through soot oxidation of the diesel engine soot filter 6a. Install on.

Subsequently, the blower 2 and the combustor 3 are operated for regeneration by soot oxidation of the soot filter 6a.

At this time, the air flowing into the blower passes through the intake air filter 17, and the mass flow sensor 1 connected to the rear of the intake air filter 17 measures the amount of air introduced into the blower 2.

In addition, fuel is supplied from the fuel tank 20 to the combustor 3 as the fuel supply control valve 5 installed in the pipeline connecting the fuel tank 20 and the combustor 3 is opened.

When the ignition is performed while the mixed air mixed with fuel and air is supplied to the combustor 3 as described above, the combustor 3 stably combusts the fuel, thereby oxidizing the soot trapped in the soot filter 6a. Will be made.

Meanwhile, as described above, a control process for optimizing fuel combustion is performed in the process of oxidizing the soot trapped in the soot filter 6a through combustion of the fuel.

To this end, first, the first temperature sensor 4a provided at the rear end of the combustor 3 detects whether the flame is lost in the combustor 3.

Then, through the second temperature sensor 4b which is installed to measure the combustion gas temperature in front of the soot collecting device 6 and the third temperature sensor 4c which is installed at the rear end of the diesel oxidation catalyst 6b of the soot collecting device. The performance of the diesel oxidation catalyst 6b is evaluated. An exothermic reaction occurs in the diesel oxidation catalyst 6b, and the performance of the diesel oxidation catalyst 6b can be evaluated through the size of the reaction heat (see FIG. 2).

Then, the temperature of the front and rear of the particulate filter (6a) is detected through a third temperature sensor (4c) and the fourth temperature sensor (4d), and through the temperature before and after the detected particulate filter (6a) The oxidation progress rate of the collected soot is calculated.

The oxidation progress rate may be calculated by using a difference of temperature values respectively detected by the second and third temperature sensors 4b and 4c installed in front and rear of the soot filter 6a. Initially, the difference in temperature detected before and after the soot filter 6a is not high. As the oxidation progresses, the difference in temperature detected by the second and third temperature sensors 4b and 4c before and after the soot filter 6a gradually increases and is collected. When the oxidation of the soot is completed, the temperature before and after the soot filter 6a becomes almost the same (see Fig. 4).

Detecting the oxygen concentration before and after the soot filter 6a is carried out in the combustion gas exiting the soot filter 6a after being introduced into the oxygen concentration in the combustion gas immediately after exiting the combustor 3 and the oxidation of soot. The purpose is to control the air-fuel ratio so that the amount of air required for optimal combustion can be adjusted by analyzing the oxygen concentration.

Thus, the amount of fuel and air supplied to the combustor 3 is adjusted to optimize the combustion state of the fuel according to the analysis of the calculated oxidation progress rate and the detected oxygen concentration.

Meanwhile, the fifth temperature sensor 4e installed at the front of the blower 2 measures the temperature of the mixed gas formed by mixing the combustion gas introduced for recirculation with the newly introduced air from the outside, and the fifth temperature sensor Combustion conditions are controlled according to the temperature value measured at 4e to adjust the mixed gas temperature measured by the fifth temperature sensor 4e to an e temperature for optimum combustion.

If the measurement temperature of the fifth temperature sensor 4e is too high, the blower 2 may be damaged, so that the blower 2 is not damaged through the measurement temperature of the fifth temperature sensor 4e. The temperature is controlled so that the temperature is not within the range.

On the other hand, the oxidation progress rate of the soot may be calculated by detecting the oxygen concentration before and after the soot filter 6a.

When combustion of fuels such as diesel, butane, ethanol, natural gas, etc., the temperature of the combustion gas is high and the concentration of oxygen in the combustion gas is not able to oxidize the collected soot smoothly. By recycling to (3), the oxidation reaction of the collected soot can be optimized using the principle of lowering combustion temperature and lowering oxygen concentration in the combustion gas by using an inert material such as carbon dioxide in the recycle gas.

On the other hand, referring to Figure 3, when the soot filter (6a) as described above, as the optimum combustion conditions for the soot filter regeneration, the temperature of the combustion gas to be adjusted within the range of 550 ℃ ~ 650 ℃, mixed air The oxygen concentration of is preferably to be adjusted to a concentration in the range of 5% to 9%.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Therefore, it is to be understood by those skilled in the art that the above-described embodiments are to be considered as illustrative and not restrictive, and therefore, the invention is not limited to the above description but may be modified within the scope and equivalents of the appended claims. Will be called.

The present invention is applicable to the field of resource recycling and the environment, and in particular, the present invention is highly applicable to the field of automobile maintenance and automobile development, and thus has high industrial applicability.

1: mass flow sensor 2: blower
3: combustor 4a: first temperature sensor
4b: second temperature sensor 4c: third temperature sensor
4d: fourth temperature sensor 4e: fifth temperature sensor
5: Fuel supply control valve 6: Soot collection device
6a: Soot filter 6b: Diesel oxidation catalyst
7a: first oxygen sensor 7b: second oxygen sensor
8: Playback Controller 9: Computer
10: flue gas recirculation pipe 11: flue gas cooler
12: refrigerant cooler 13: cooling fan
14: pump 15: combustion gas recirculation control valve
16: Refrigerant control valve 17: Intake air filter
18: differential pressure sensor 19: exhaust flap
20: fuel tank

Claims (8)

Recycling system of a soot filter detachably mounted for recycling the soot collecting device 6 including a soot filter 6a for collecting particulate matter contained in exhaust gas discharged from a diesel engine ( regeneration system);
A combustor 3 installed to oxidize the soot collected in the soot filter 6a through fuel combustion;
A blower (2) for supplying air for fuel combustion to the combustor;
A mass flow rate sensor (1) for measuring the mass of air supplied to the blower (2);
A first temperature sensor 4a installed to detect whether the flame of the combustor 3 is lost;
A second temperature sensor 4b installed to measure the temperature of the combustion gas supplied to the front of the particulate collection device 6;
The diesel oxidation catalyst 6b and the soot filter 6 may be evaluated together with the second temperature sensor 4b to evaluate the performance of the diesel oxidation catalyst 6b constituting the soot collecting device 6 together with the soot filter 6a. A third temperature sensor 4c provided between 6a);
In addition to the third temperature sensor 4c, a fourth temperature sensor installed at a rear end of the soot filter 6a to measure the temperature of the front and rear of the soot filter 6a to calculate the oxidation progress rate of the collected soot. (4d);
First and second oxygen sensors 7a and 7b installed to measure oxygen concentration before and after the soot collecting device 6 so as to adjust combustion conditions of the combustor 3;
A combustion gas recirculation pipe (10) connecting a rear side of the particulate filter (6a) and a front side of the blower (2) to recirculate the combustion gas exiting the particulate filter (6a);
A regeneration controller (8) for controlling fuel combustion conditions in the combustor (3) in accordance with detection signals from the third and fourth temperature sensors (4c, 4d) and the first and second oxygen sensors (7a, 7b); And
An exhaust flap (19) for throttling a pipe of the exhaust pipe to increase the recycled amount of the combustion gas at one side of the combustion gas recirculation pipe connection point of the exhaust pipe connected to the rear of the particulate filter (6a); Regeneration system of a diesel engine particulate filter, characterized in that comprises a. The method of claim 1,
On the combustion gas recirculation pipe 10,
Combustion gas cooler (11) is provided for cooling the combustion gas returning to the front of the blower (2) for the recirculation of the diesel engine particulate filter regeneration system. 3. The method of claim 2,
In the combustion gas cooler 11, to cool down the temperature of the combustion gas returning to the blower 2 for recirculation, the refrigerant whose temperature rises in the heat exchange process with the combustion gas is cooled again to the combustion gas cooler 11. Regeneration system of a diesel engine particulate filter, characterized in that the refrigerant cooler 12 for supplying is connected. The method of claim 1,
Intake air filter (17) in front of the mass flow sensor (1) is characterized in that the diesel engine particulate filter regeneration system further comprising. The method of claim 1,
The differential pressure sensor 18 which connects the front and rear of the soot filter 6a and measures the pressure difference between the front and rear ends of the soot filter 6a measures the amount of soot collected in the filter and determines whether the soot is oxidized. Regeneration system of a diesel engine particulate filter, characterized in that provided. delete The method of claim 1,
Diesel engine, characterized in that further provided with a fifth temperature sensor (4e) for measuring the temperature of the mixed gas formed by mixing the combustion gas introduced for recirculation and the newly introduced air from the outside in front of the blower (2) Regeneration system of soot filter. The method of claim 1,
And a computer (9) having a monitor device for receiving and displaying a regeneration progress state through mutual communication with the regeneration controller (8), and for displaying a diagnosis state of the regeneration system. Regeneration system.

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