KR20230063908A - Method for regenerating and cleaning sdpf - Google Patents

Abstract

The present invention relates to an SDPF regenerating and cleaning method. In order to ensure effective cleaning while preventing damage to an SDPF, the SDPF regenerating and cleaning method is provided. The SDPF regenerating and cleaning method of the present invention comprises: a first nozzling step to remove a heat source accumulated inside by spraying a compressed air into the SDPF; a regeneration step of heating and regenerating the SDPF from which the heat source has been removed; and a secondary nozzling step to remove a residual particle inside by spraying the compressed air into the regenerated SDPF.

Description

SDPF regeneration and cleaning method {METHOD FOR REGENERATING AND CLEANING SDPF}

The present disclosure discloses a regeneration and cleaning method for a diesel particulate filter (SDPF: SCR-Diesel Particulate Filter) including a selective catalyst reduction (SCR) function.

In general, an exhaust gas post-processing system for vehicles reduces environmental pollutants included in exhaust gas by utilizing devices such as DPF and SCR.

For example, a selective catalytic reduction (SCR) selectively removes nitrogen oxides (NOx) from exhaust gas. A particulate matter filter (Diesel Particulate Filter, hereinafter referred to as DPF) is for removing unburned carbon particles (PM, Soot) from exhaust gas.

The present applicant has previously filed Korean Patent No. 01569885 (Title of Invention: Regeneration Apparatus and Regeneration Method for Cleaning Waste Particulate Filter) and Korean Patent No. 2006832 (Invention Title Regeneration of Selective Reduction Catalyst Reduction Device for Vehicles) Cleaning devices) have been developed to clean and regenerate these particulate abatement devices.

Meanwhile, the exhaust gas of a diesel vehicle contains both nitrogen oxides and unburned particulate matter such as PM, and in order to remove them, both an SCR and a DPF need to be provided in the vehicle.

For example, in the case of a large diesel commercial vehicle, DPF and SCR are assembled and installed in series. DPF collects unburned PM from the engine and burns it periodically. The SCR is arranged in series at the rear of the DPF, and reduces nitrogen oxides in the exhaust gas to nitrogen and water vapor and discharges them into the atmosphere. However, since devices having different functions are separately arranged, space and weight are very disadvantageous.

Recently, SDPF (SCR-Diesel Particulate Filter, hereinafter referred to as SDPF), which solves the problem of space and weight at once by adding the function of SCR to DPF, has been developed and applied. Compared to DPF, SDPF has different chemical and physical properties of the catalyst coated on the inside, so many things must be considered for cleaning SDPF.

Therefore, when the conventional DPF cleaning method is applied as it is, thermal damage to the SDPF catalyst may be caused, resulting in functional damage. Therefore, the development of a new technology for cleaning the SDPF is required.

This task provides a method for regenerating and cleaning SDPF that can be effectively cleaned while preventing damage to SDPF.

The cleaning method of this embodiment may be a method for cleaning the SDPF in which the SCR and the DPF are integrally combined.

The cleaning method includes a first nozzle ringing step for removing a heat source accumulated therein by spraying compressed air into the SDPF, a regeneration step of heating and regenerating the SDPF from which the heat source has been removed, and spraying compressed air to the regenerated SDPF to clean the inside. A secondary nozzle ringing step may be included to remove residual particles.

The first nozzle ringing step may have a structure in which a heat source including soot and oil accumulated in the SDPF is removed by injecting compressed air through a nozzle at the rear end of the SDPF.

The regeneration step includes a heating step of heating the SDPF to ignite contaminants, detecting the SDPF temperature and detecting whether or not the detected temperature reaches a first temperature value within a set time, and SDPF temperature reaching the first temperature value. terminating the heating in this case, a blowing step of blowing an oxygen-containing gas to the SDPF to burn internal pollutants, a step of detecting whether the internal temperature of the SDPF after the blowing step has fallen below a set fourth temperature value, a step of detecting whether or not the SDPF temperature and repeating the blowing process when is equal to or greater than a fourth temperature value, and terminating regeneration when the temperature falls below the fourth temperature value.

The blowing step may include blowing an oxygen-containing gas to the SDPF after the heating is finished, detecting whether or not the SDPF temperature reaches the second temperature value, continuing blowing the SDPF when the temperature does not reach the second temperature value, and 2 Ending blowing when the temperature value is reached, detecting whether the SDPF temperature reaches the third temperature value after the blowing ends, maintaining the blowing end state when the SDPF temperature does not reach the third temperature value, and Resuming blowing to the SDPF when the temperature value is reached, and repeating the above process at least twice or more may be included.

The regeneration step may include detecting whether the SDPF temperature has decreased below a fourth temperature value in a state in which the blowing step has been performed once or less, reheating the SDPF when the SDPF temperature has decreased below the fourth temperature value, and SDPF Detecting the temperature and detecting whether or not the detected temperature has reached the fifth temperature value within a set time, proceeding with the blowing step when the SDPF temperature reaches the fifth temperature value, and regenerating when the SDPF temperature has not reached the fifth temperature value It may further include the step of terminating.

The temperature value of the SDPF may be selected from a higher value among temperature values detected from at least two temperature sensors installed at different depths inside the SDPF through the rear end.

The setting time may be 8 minutes.

The first temperature value may be 200 °C to 400 °C.

The second temperature value may be 400 °C to 600 °C.

The third temperature value may be 400°C.

The fourth temperature value may be 500°C.

The fifth temperature value may be 350°C.

According to the present embodiment as described above, the cleaning operation can be performed even for the SDPF, which is difficult to clean in the prior art.

SDPF can be effectively regenerated and cleaned without damaging the filter and catalyst by carrying out primary nozzle ringing in consideration of the catalyst of SDPF, which is vulnerable to high temperatures, and performing secondary nozzle ringing after regeneration at low temperature.

1 is a schematic process diagram showing the entire process of the SDPF regeneration and cleaning method according to the present embodiment.
2 is a schematic flow chart showing the regeneration process of the SDPF regeneration and cleaning method according to the present embodiment.
3 is a schematic view showing the arrangement structure of temperature sensors inserted into the SDPF carrier in the SDPF regeneration and cleaning method according to the present embodiment.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described so that those skilled in the art can easily practice it. As can be easily understood by those skilled in the art to which the present invention pertains, the embodiments described below may be modified in various forms without departing from the concept and scope of the present invention. Where possible, identical or similar parts are indicated using the same reference numerals in the drawings.

The terminology used below is only for referring to specific embodiments and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. As used herein, the meaning of "comprising" specifies a particular characteristic, region, integer, step, operation, element, and/or component, and specifies another specific characteristic, region, integer, step, operation, element, element, and/or group. does not exclude the presence or addition of

All terms including technical terms and scientific terms used below have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. The terms defined in the dictionary are additionally interpreted as having a meaning consistent with the related technical literature and the currently disclosed content, and are not interpreted in an ideal or very formal meaning unless defined.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the following examples are only preferred examples of the present invention, but the present invention is not limited to the following examples.

In the following description, substances to be removed, such as soot, ash, soot, and oil, accumulated inside the SDPF are collectively referred to as contaminants.

The SDPF cleaning process of this embodiment can be cleaned through, for example, a filter cleaning device (Korean Patent Registration No. 01569885 or Korean Patent Registration No. 2006832) filed by the present applicant.

1 and 2 show the process sequence of the SDPF regeneration and cleaning method according to the present embodiment.

As shown, the cleaning method of the present embodiment includes a first nozzle ringing step for removing a heat source accumulated therein by spraying compressed air to the SDPF, a regeneration step for heating and regenerating the SDPF from which the heat source has been removed, and a regenerated SDPF. A second nozzle ringing step may be performed to remove residual particles therein by spraying compressed air therein.

The first nozzle ringing step may be performed by injecting high-pressure compressed air through a nozzle into the SDPF. Heat sources including soot and oil accumulated inside the SDPF can be removed through the primary nozzle ring. Accordingly, it is possible to effectively prevent the temperature of the SDPF from excessively increasing in a subsequent regeneration process.

Inside the SDPF, components such as soot and oil are accumulated without being removed. Therefore, when the regeneration process is performed on the SDPF as it is, the temperature of the SDPF rises to a high temperature due to a heat source such as soot or oil, causing thermal damage to the SCR catalyst.

In this way, the heat source inside the SDPF may be discharged to the outside as the primary nozzle ringing process is performed. Therefore, it is possible to prevent thermal damage to the SCR catalyst by inducing low-temperature regeneration in a later process.

In this embodiment, the first nozzle ringing step may be performed through the rear end of the SDPF. The rear end of the SDPF may refer to a rear end along the traveling direction of the exhaust gas.

When the primary nozzle ring is completed, the SDPF regeneration process proceeds.

As shown in FIG. 2 , the regeneration process may include a heating step to ignite the SDPF internal contaminants and a blowing step to burn the SDPF internal contaminants.

When the regeneration process is initiated, heat is applied to the inside of the SDPF through a burner or the like to heat the SDPF. Thus, contaminants inside the SDPF may be ignited by heat.

In the heating step, the internal temperature of the SDPF is detected to detect whether the detected temperature reaches the first temperature value T1 within a set time, and when the SDPF temperature reaches the first temperature value T1, the heating is terminated. can The first temperature value T1 can be understood as a burner termination temperature and a blowing start temperature.

The SDPF internal temperature value may be detected through a temperature sensor.

The temperature value of the SDPF can be detected from at least two temperature sensors installed at different depths inside through the rear end of the SDPF. A relatively high value among the temperature values detected from the two temperature sensors is selected as the SDPF internal temperature value, and process control can be performed based on this temperature value.

As shown in FIG. 3, in this embodiment, one temperature sensor 100 of the two temperature sensors is inserted to a depth D within 5 cm from the rear end of the SDPF to detect the internal temperature, and the other temperature sensor ( 110) can be inserted at a position (L) about half of the total length of the SDPF to detect the internal temperature. Therefore, the temperature of the inner center of the SDPF as well as the temperature of the rear end can be accurately detected, and through this, the SDPF regeneration process can be performed more accurately.

The device burner is driven to raise the internal temperature of the SDPF. Whether the burner is normally turned on/off may be checked through a temperature sensor.

In the heating step, when the internal temperature of the SDPF reaches the first temperature value T1 within a set time, the burner is turned off and heating is terminated. In this embodiment, the set time is within 8 minutes, and the first temperature value T1 may be 200°C to 400°C. More preferably, the temperature value may be 300 degrees.

In the heating step, if the set time and temperature value are out of the above range, the internal temperature of the SDPF is too low to properly regenerate, or the internal catalyst may be damaged due to a high temperature. For example, when the first temperature value is not reached even after a set time period of 8 minutes, the cleaning operation may be terminated as the plate remains in a state in which contaminants to be removed are hardly remaining inside the SDPF.

When the first temperature value T1 is reached, the burner is stopped to end heating, and the blower is driven to forcibly blow outside air containing oxygen.

In this embodiment, the blowing process includes the step of blowing an oxygen-containing gas to the SDPF after the heating is finished, the step of detecting whether or not the SDPF temperature reaches the second temperature value T2, and the SDPF temperature reaching the second temperature value T2. Continue blowing when the temperature does not reach and end the blowing when the second temperature value T2 is reached, detecting whether or not the SDPF temperature reaches the third temperature value T3 after the blowing ends, and 3 When the temperature value T3 is not reached, the blowing end state is maintained, and when the third temperature value T3 is reached, blowing is resumed using the SDPF, and the above process is repeated at least twice. .

It can be understood that the second temperature value T2 is an upper temperature limit for determining end of blowing, and the third temperature value T3 is a lower temperature limit for determining resumption of blowing.

Blown air is supplied to the SDPF to supply oxygen for combustion while regeneration of the SDPF is in progress. In this process, contaminants ignited by the heat of the burner and attached to the embers are burned by the air forcedly supplied into the SDPF, turning them into cleanable ash.

The blowing process is performed to maintain a low temperature range to prevent damage to the SCR catalyst inside the SDPF.

In this embodiment, the second temperature value T2 may be 400°C to 600°C. When the second temperature value T2 is lower than 400°C, combustion is not performed properly, and when it exceeds 600°C, damage to the SCR catalyst may occur.

More preferably, the second temperature value T2 may be 500°C. Even when blowing ends, the SDPF temperature does not immediately drop, and the temperature may continue to rise for a while due to the combustion of contaminants inside the SDPF. Accordingly, when the second temperature value T2 is controlled to be 500° C., damage to the SCR catalyst can be reliably prevented even if the internal temperature rises after the blowing ends.

When the SDPF temperature reaches the second temperature value T2 by the blowing, the blowing ends.

As the blowing ends, the SDPF temperature gradually drops. When the internal temperature of the SDPF drops to the third temperature value T3, blowing starts again.

In this embodiment, the third temperature value T3 may be preferably set to 400°C. Accordingly, when the internal temperature of the SDPF is lowered to 400° C., blowing is resumed and the internal temperature is raised again.

In a state where the internal temperature of the SDPF is higher than 400° C., the internal combustion of the SDPF continues, so there is no need to specifically restart the blowing. In addition, if the internal temperature of the SDPF is lower than 400° C., combustion of contaminants may be turned off, and thus, if blowing is not resumed, poor combustion of contaminants may occur.

Therefore, in this embodiment, the third temperature value T3 may be preferably set to 400°C. When the third temperature value T3 is set higher than the above value, not only energy waste due to unnecessary blowing, but also equipment failure may occur due to frequent on/off driving of the blower. When the third temperature value T3 is set lower than 400° C., combustion may not be performed properly, resulting in poor regeneration, and since the burner must be restarted, energy and time may be wasted.

As the blowing resumes, the temperature inside the SDPF rises. And, when the internal temperature of the SDPF increases again and reaches the second temperature value T2, the blowing ends. As the blowing ends, the temperature inside the SDPF drops. Thus, after the blowing starts, the blowing is stopped when the temperature rises to the second temperature value T2, and the cycle is resumed when the temperature lowers to the third temperature value T3 again, and the cycle is repeated.

As described above, the SDPF regeneration process proceeds as the blowing process is started after the heating is finished, and the blowing is repeatedly turned on/off between the second temperature value T2 and the third temperature value T3.

In addition, in the regeneration process of the present embodiment, in a state in which the above-described blowing process is repeated two or more times, it is detected whether the internal temperature of the SDPF falls below the set fourth temperature value (T4), and the SDPF temperature is determined to be the fourth temperature value ( T4) or higher, the blowing process is repeated, and regeneration is terminated when the temperature falls below the fourth temperature value T4.

The fourth temperature value T4 can be understood as a temperature value for determining whether to end reproduction.

Here, the number of times of the blowing process means that one cycle is when the blowing is stopped after the blowing is started, the blowing is raised to the second temperature value (T2), and then the blowing is resumed when the blowing is lowered to the third temperature value (T3). It can mean the number of iterations.

In this embodiment, the fourth temperature value T4 may be 300°C. When the fourth temperature value T4 is higher than 300°C, the regeneration operation may be finished with internal contaminants remaining, and when the fourth temperature value T4 is lower than 300°C, an unnecessary blowing process may continue.

The blowing start and blow end processes are repeatedly performed according to the upper limit temperature value and the lower limit temperature value.

When the temperature of the SDPF falls below 300° C., which is the fourth temperature value T4, while the number of blows is two or more, it is determined that there are no contaminants to be burned inside the SDPF and that all are removed, and regeneration can be terminated. .

When the internal temperature of the SDPF is still equal to or higher than the fourth temperature value T4 in a state in which the blowing process is repeated two or more times, the blowing process is continuously repeated.

Meanwhile, in the regeneration process of the present embodiment, when the temperature of the SDPF is lowered to a predetermined value or less during the blowing process one or less times, it is determined that cleaning is unnecessary and the regeneration process may be terminated.

To this end, it is detected whether the SDPF temperature drops below the fourth temperature value T4 in a state where the blowing process is performed one or less times in the regeneration process, and when the SDPF temperature drops below the fourth temperature value T4, the SDPF Reheating, detecting the SDPF temperature, detecting whether or not the detected temperature reaches the fifth temperature value T5 within a set time, and proceeding with the blowing step when the SDPF temperature reaches the fifth temperature value T5 A process of terminating regeneration when the 5 temperature value T5 is not reached may be further included.

The fifth temperature value T5 may be understood as a temperature value for determining whether to immediately end the regeneration process.

For example, when the blowing process starts at 300°C and the internal temperature of the SDPF reaches 500°C and the blowing is stopped and the temperature drops to 400°C and then immediately drops below 300°C, the burner can be restarted to heat the SDPF. can In addition, regeneration can be terminated when the internal temperature of the SDPF does not exceed the set value even through burner reheating.

In this embodiment, the set time is within 8 minutes, and the fifth temperature value T5 may be 350°C.

If the set time and the fifth temperature value T5 are out of the above range, SDPF regeneration failure may occur or energy may be wasted due to unnecessary regeneration work. For example, when the fifth temperature value T5 is higher than 350° C., the regeneration operation ends with the contaminants remaining inside the SDPF, and thus a regeneration defect may occur. In addition, when the fifth temperature value (T5) is lower than 350 °C, there is a problem in that energy is wasted unnecessarily because the regeneration operation is continued while there are no contaminants to be burned inside the SDPF.

In this way, when the fifth temperature value T5 is not reached even after the set time of 8 minutes, the cleaning operation may be finished without leaving the SDPF with almost no contaminants to be removed.

When the regeneration operation is completed, a second nozzle ringing process is performed to clean and remove burnt contaminants inside the SDPF. Like the first nozzle ringing process, the second nozzle ringing process may be performed by injecting high-pressure compressed air into the inside through the rear end of the SDPF. Through the secondary nozzle ring, particles such as ash remaining after burning inside the SDPF can be completely removed by discharging them to the outside.

Accordingly, SDPF can be effectively regenerated while preventing damage to the internal catalyst through the above-described process.

Although exemplary embodiments of the present invention have been shown and described as described above, various modifications and other embodiments may be made by those skilled in the art. All of these modifications and other embodiments are to be considered and included in the appended claims, without departing from the true spirit and scope of the present invention.

10: housing 20: burner
30: duct 40: blower
50: frame 61: first thermometer
62: second thermometer 63: third thermometer
64: fourth thermometer 66: controller
70: rail 72: bogie
74: elevator 76: elevator member
78: inclined plate

Claims (4)

As a cleaning method for regenerating SDPF for cleaning SDPF in which SCR and DPF are integrally combined,
The first nozzlering step to remove the heat source accumulated inside by blowing compressed air into the SDPF, the regeneration step to heat and regenerate the SDPF from which the heat source has been removed, and spray compressed air to the regenerated SDPF to remove residual particles inside. A method for regenerating and cleaning SDPF that includes a second nozzlering step for removal. According to claim 1,
The regeneration step includes a heating step of heating the SDPF to ignite contaminants, detecting the SDPF temperature and detecting whether or not the detected temperature reaches a first temperature value within a set time, and SDPF temperature reaching the first temperature value. terminating the heating in this case, a blowing step of blowing an oxygen-containing gas to the SDPF to burn internal pollutants, a step of detecting whether the internal temperature of the SDPF after the blowing step has fallen below a set fourth temperature value, a step of detecting whether or not the SDPF temperature and repeating the blowing process when is greater than or equal to a fourth temperature value and terminating regeneration when it falls below the fourth temperature value. According to claim 2,
The blowing step may include blowing an oxygen-containing gas to the SDPF after the heating is finished, detecting whether or not the SDPF temperature reaches the second temperature value, continuing blowing the SDPF when the temperature does not reach the second temperature value, and 2 Ending blowing when the temperature value is reached, detecting whether the SDPF temperature reaches the third temperature value after the blowing ends, maintaining the blowing end state when the SDPF temperature does not reach the third temperature value, and A method for regenerating and cleaning an SDPF, comprising resuming blowing to the SDPF when the temperature value is reached, and repeating the above process at least twice. According to claim 2 or 3,
The regeneration step may include detecting whether the SDPF temperature has decreased below a fourth temperature value in a state in which the blowing step has been performed once or less, reheating the SDPF when the SDPF temperature has decreased below the fourth temperature value, and SDPF Detecting the temperature and detecting whether or not the detected temperature has reached the fifth temperature value within a set time, proceeding with the blowing step when the SDPF temperature reaches the fifth temperature value, and regenerating when the SDPF temperature has not reached the fifth temperature value SDPF regeneration and cleaning method further comprising the step of terminating.

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