KR20170020596A - METHOD AND SYSTEM FOR REGENERATING NOx CONVERSION APPARATUS - Google Patents

Abstract

The present invention provides a method for regenerating a nitrogen oxide purification apparatus for a vehicle, which comprises: a calculation step of calculating time elapsing from time to perform nitrogen oxide regeneration; a determination step of determining whether the calculated time exceeds predetermined critical time; and a shortening step of shortening and correcting predetermined desulfurization performing time to predetermined time in accordance with excessive time when the calculated time exceeds the critical time.

Description

Technical Field [0001] The present invention relates to a method and system for regenerating a nitrogen oxide-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regeneration method and system for a nitrogen oxide purification apparatus for a vehicle, and more particularly, to a regeneration method and system for a nitrogen oxide purification apparatus for a vehicle that regenerate by reducing a regeneration point of time.

As the regulation of exhaust gas is strengthened, the application of an apparatus for absorbing and purifying nitrogen oxides for the removal of nitrogen oxides (NOx) among exhaust gas components generated when the lean-burn internal combustion engine operates is expanding.

Nitrogen oxide purification system removes / purifies nitrogen oxides through periodic heavy operating conditions (l <1) exposure after temporarily adsorbing / occluding nitrogen oxides under normal operating conditions (l> 1). That is, in order to continuously maintain the nitrogen oxide purification performance of the nitrogen oxide purification apparatus, it is necessary to expose the rich atmosphere to the atmosphere. Changing the engine operation mode from the lean burn internal combustion engine to the rich operation condition causes a large torque fluctuation or deteriorates the combustion stability The operation mode change is made within a limited range.

가 질소산화물 흡장 성능을 발휘할 수 없는

형태의 화합물로 변환되기 때문이다.For example, in the case of frequent driving in the city center, since the vehicle is mostly operated under a low load condition, if the engine operating mode is changed to a rich condition, the combustion stability is likely to deteriorate, As a result, the nitrogen oxide purification performance of the nitrogen oxide purification apparatus deteriorates. This is due to the complete oxidation of the noble metal and the nitrogen oxide storage material in the nitrogen oxide purifying device, and the typical nitrogen oxide storage material BaO

Can not exhibit nitrogen oxide absorption performance

Type compound. &Lt; / RTI &gt;

는 고온 농후 분위기에 일정 시간 노출되면 다시금 BaO와

형태의 질소산화물 흡장 물질로 변환될 수 있는데, 이때 필요한 고온 농후 분위기는 질소산화물 정화 장치의 탈황 과정(DeSOx: Desulfation)과 매우 유사한 조건이라고 할 수 있다.However, the nitrogen oxide storage capability can not be exhibited

Is exposed to a high-temperature rich atmosphere for a certain period of time,

Type nitrogen oxide storage material. At this time, the high-temperature rich atmosphere required is very similar to the desulfation process (DeSOx: Desulfation) of the nitrogen oxide purification apparatus.

Therefore, in the case of the internal combustion engine in which the normal operating condition is the lean burn condition, the air-fuel ratio of the exhaust gas must be made rich at times in order to desorb / purge the nitrogen oxide occluded in the nitrogen oxide purification device. This requires a change of the operation mode of the internal combustion engine, accompanied by a large torque fluctuation or deterioration of the combustion stability, so that the operation mode change is performed within a limited range. As a result, as the change to the rich operation mode is restricted, not only the absorption / regeneration of the nitrogen oxide newly generated by the nitrogen oxide occluded in the nitrogen oxide purification apparatus is prevented, but also the complete oxidation of the noble metal or the occlusion material in the nitrogen oxide purification apparatus There has been a problem that the reaction can not ultimately function as a nitrogen oxide purification device.

It should be understood that the foregoing description of the background art is merely for the purpose of promoting an understanding of the background of the present invention and is not to be construed as an admission that the prior art is known to those skilled in the art.

KR 10-2000-0038931 A (2000.07.05)

It is an object of the present invention to provide a regeneration method and system for maintaining the activity of a nitrogen oxide purification apparatus for a vehicle that performs regeneration of a nitrogen oxide purification apparatus.

According to another aspect of the present invention, there is provided a method for regenerating a nitrogen oxide purification apparatus for a vehicle, the method comprising: a calculation step of calculating a time elapsed from a point at which NOx regeneration is performed; A determination step of determining whether the calculated time exceeds a predetermined threshold time point; And a shortening step of shortening the preset desulfurization execution time by a set time according to the time exceeded when the calculated time exceeds the critical time point.

And the critical point is set to a maximum time under a condition that the nitrogen oxide purification performance of the nitrogen oxide purification apparatus is not deteriorated according to the calculated time.

And the threshold point is changed and set in accordance with at least one of the operation state of the engine, the nitrogen oxide storage amount in the nitrogen oxide purification apparatus, and the temperature of the nitrogen oxide purification apparatus.

The preset desulfurization execution time is changed according to at least one of the operation state of the engine, the sulfur content in the nitrogen oxide purification unit, and the temperature of the nitrogen oxide purification unit.

The setting time corrected for shortening the time of performing the desulfurization in the shortening step is shortened based on the time that the calculated time exceeds the critical point.

In order to accomplish the above object, a regeneration system of a nitrogen oxide purification apparatus for a vehicle according to the present invention includes: a calculation unit for calculating a time elapsed from a point at which NOx regeneration has been performed; A determination unit for determining whether the time calculated by the operation unit exceeds a predetermined threshold time point; And a correcting unit for performing a shortening correction of the preset desulfurization execution time according to the time exceeded when the time calculated by the determination unit exceeds the threshold time, by the set time.

Wherein the threshold time point of the determination unit is set to a maximum time under a condition that the nitrogen oxide purification performance of the nitrogen oxide purification apparatus does not deteriorate according to the time calculated by the operation unit.

And the critical point of time of the determination unit is changed according to at least one of an operation state of the engine, a nitrogen oxide storage amount in the nitrogen oxide purification apparatus, and a temperature of the nitrogen oxide purification apparatus.

The desulfurization performing time point of the correcting unit is changed according to at least one of the operating condition of the engine, the sulfur content of the nitrogen oxide purification unit, and the temperature of the nitrogen oxide purification unit.

And the set time of the correcting unit is shortened based on a time when the calculated time exceeds the critical time point.

According to the regeneration method of a nitrogen oxide purification apparatus for a vehicle having the above-described structure, the nitrogen oxide purification apparatus can maintain its activity, and the purification efficiency of the nitrogen oxide purification apparatus can be stably maintained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart of a method for regenerating a nitrogen oxide purification apparatus for a vehicle according to an embodiment of the present invention. FIG.
2 is a view for explaining a regeneration method of the nitrogen oxide purification apparatus for a vehicle shown in Fig.
3 is a configuration diagram of a regeneration system of a nitrogen oxide purification apparatus for vehicles according to an embodiment of the present invention.

Hereinafter, a method and system for regenerating a nitrogen oxide purification apparatus for a vehicle according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a view for explaining a regeneration method of the nitrogen oxide purification apparatus for a vehicle shown in FIG. 1, and FIG. 3 is a view for explaining a regeneration method of a nitrogen oxide purification apparatus for a vehicle according to an embodiment of the present invention. 1 is a configuration diagram of a regeneration system of a nitrogen oxide purification apparatus for a vehicle according to an embodiment of the present invention.

FIG. 1 is a flowchart of a method for regenerating a nitrogen oxide purification apparatus for a vehicle according to an embodiment of the present invention. The regeneration method for a nitrogen oxide purification apparatus for a vehicle according to the present invention calculates the elapsed time from the point at which NOx regeneration was last performed (S100); A determination step (S200) of determining whether the calculated time exceeds a predetermined threshold time point; And a shortening step (S300) of shortening the preset desulfurization execution time according to the time exceeded when the calculated time exceeds the threshold time point by the set time.

In the calculation step S100 and the determination step S200, an operation or determination is performed based on the NOx regeneration point, and in the shortening step S300, the desulfurization point of the nitrogen oxide purification apparatus is shortened.

That is, according to the present invention, the time when the NOx regeneration is performed is calculated (S102), and when the NOx regeneration is not performed, the NOx regeneration is compared with the threshold point (S202) The performance is carried out ahead of the short-time corrected time, thereby simultaneously inducing the NOx regeneration to be performed together.

Here, the time point at which the NOx regeneration is performed is continuously checked, and the NOx regeneration is not performed, so that the desulfurization execution time is continuously shortened to correct the desulfurization execution time, so that the desulfurization execution time can be performed faster than the initial set time have. Therefore, when the nitrogen oxide purification apparatus does not satisfy the long term rich condition, the desulfurization cycle of the nitrogen oxide purification apparatus is shortened, and the desulfurization is performed faster than the set time, so that the activity of the storage material of the nitrogen oxide purification apparatus can be restored.

In order to facilitate understanding of the present invention, the regeneration of the nitrogen oxide purification apparatus includes NOx regeneration and SOx regeneration, wherein the NOx regeneration is performed at a shorter cycle than the SOx regeneration and the temperature at which regeneration is performed is also performed at a relatively low temperature . For example, NOx regeneration may be performed at short intervals of several minutes, and the temperature may be between 200 and 450 degrees. However, SOx regeneration may be performed at intervals of several hours to several days, Lt; / RTI &gt;

If the regeneration of NOx is not performed from the time of the last regeneration to the time when the regeneration exceeds the critical point, the amount of NOx accumulated in the nitrogen oxide purification apparatus may exceed the allowable value, and the purification performance of the nitrogen oxide purification apparatus may be weakened .

Therefore, if the NOx purifying device can not be exposed to the rich combustion atmosphere in which the NOx regeneration can be performed until the NOx regeneration point exceeds the critical point, the SOx regeneration which can be exposed for a relatively longer time than the NOx regeneration from the high temperature to the rich atmosphere And the regeneration performance of the nitrogen oxide purification apparatus is recovered by performing the time earlier than the preset time.

The present invention will now be described in more detail. The time point at which the NOx regeneration was last performed in the calculation step S100 is a point in time when the NOx regeneration was most recently performed, It can be a recent point.

If the nitrogen oxide is stored and accumulated again after the last NOx regeneration point and the lean burn state is continuously maintained, the deterioration of the purification performance may occur due to exceeding the storage capacity of the nitrogen oxide purification apparatus.

Therefore, the critical point of the determination step S200 may be a maximum value that can be expected to prevent the nitrogen oxide purification performance of the nitrogen oxide purification apparatus from deteriorating between the last rich operation end point in which NOx regeneration has been performed and the rich operation in which the next NOx regeneration is performed Time can be set. That is, if the time point at which the NOx regeneration is last performed exceeds the threshold time point, it is determined that the nitrogen oxide purification performance deteriorates.

The threshold time point can be variously set according to the intention of the designer, but it is preferable that the threshold point is changed or set by at least one of the operating state of the engine, the nitrogen oxide storage amount in the nitrogen oxide purification apparatus, and the temperature of the nitrogen oxide purification apparatus .

For example, the threshold can be set to be shorter than a preset time when the engine performs lean-burn or when the nitrogen oxide storage amount of the purifier is decreased, or when the temperature of the purifier is lowered. To this end, map data may be provided which take the elements as inputs and output a critical time point.

Of course, according to the designer's intention, the fixed point of view may be determined in consideration of the factors, and the critical point of time may be determined in consideration of other factors in addition to the elements.

The predetermined desulfurization execution time may be changed according to at least one of the operation state of the engine, the sulfur content in the nitrogen oxide purification unit, and the temperature of the nitrogen oxide purification unit.

For example, when the engine performs lean burning, when the sulfur poisoning amount of the purifier is increased, or when the temperature of the purifier is lowered, the time of desulfurization can be further shortened. To this end, map data for outputting the time of desulfurization may be provided by inputting the operation state of the engine, the sulfur content in the nitrogen oxide purification apparatus, and the temperature value of the nitrogen oxide purification apparatus, similar to the critical point.

The time point set by the operating state of the engine, the sulfur content in the nitrogen oxide purification apparatus, and the temperature of the nitrogen oxide purification apparatus may be a basic time point of the desulfurization execution time. In the set basic time point, It can be accelerated.

Meanwhile, in the shortening step (S300), the shortening correction time of the desulfurization execution time may be shortened based on the time that the calculated time exceeds the critical point. For example, in the shortening step S300, the set time may be shortened in proportion to the time that the calculated time exceeds the threshold time point. Here, the set time may be variously configured according to the function set by the designer, but it is preferable that the set time is shortened in proportion to the exceeding time.

For example, assuming that the last purification time is 0, the critical point is 5 minutes, and the desulfurization execution time is 120 hours, if the lean burn operation is maintained for more than 5 minutes in the calculation step S100, If it is in proportion to the elapsed time, that is, 1 minute or 2 minutes, the desulfurization execution time may be shortened by 12 hours and 24 hours, respectively, according to a predetermined function. This is only one embodiment, and the degree of proportionality, the function to be applied and the like can be variously set according to the designer's intention or reproduction apparatus.

In the shortening step (S300), the SOx regeneration and the NOx regeneration of the nitrogen oxide purification apparatus are performed by adjusting the operation state of the engine to the rich operation state so that the desulfurization is performed when the time reaches the shortened desulfurization execution time. It is preferable to reset the shortened time value to the initial value again. The initial value may be 1 or may be a value specified separately depending on the function.

Therefore, in the present invention, the activity of the nitrogen oxide purification apparatus can be maintained, and the purification efficiency of the nitrogen oxide purification apparatus can be stably maintained.

Meanwhile, the regeneration system of the nitrogen oxide purification apparatus for a vehicle according to the present invention may include a calculation unit 100 for calculating the elapsed time from the time point when the NOx regeneration was last performed; A determination unit (200) for determining whether the time calculated by the operation unit (100) exceeds a predetermined threshold time point; And a correcting unit 300 for shortening the preset desulfurization execution time by a set time according to an exceeding time when it is determined that the time calculated by the determining unit 200 exceeds a critical time point.

That is, the present invention checks the time when the NOx regeneration is performed through the calculation unit 100, and if the NOx regeneration is not performed through the determination unit 200, So that the desulfurization performance is carried out before the shortened correction time, thereby simultaneously inducing the NOx regeneration to be performed together.

The critical point of time of the determination unit 200 may be set to a maximum time under a condition that the nitrogen oxide purification performance of the nitrogen oxide purification apparatus does not deteriorate according to the time calculated by the operation unit 100. [ That is, if the time point at which the NOx regeneration is last performed exceeds the threshold time point, it is determined that the nitrogen oxide purification performance deteriorates.

Here, the critical point of time of the determination unit 200 may be changed according to at least one of an operation state of the engine, a nitrogen oxide storage amount in the nitrogen oxide purification apparatus, and a temperature of the nitrogen oxide purification apparatus. That is, it is possible to set the critical point to be shorter than a predetermined time when the engine performs lean-burn or the nitrogen oxide storage amount of the purifier is decreased, or when the temperature of the purifier is lowered.

The desulfurization execution time of the correction unit 300 may be changed according to at least one of the operation state of the engine, the sulfur content of the nitrogen oxide purification unit, and the temperature of the nitrogen oxide purification unit. That is, the point of time set by the operating state of the engine, the sulfur poisoning amount in the nitrogen oxide purification apparatus, and the temperature of the nitrogen oxide purification apparatus may be a basic point of time for performing the desulfurization, and at the set basic point, Can be made more advanced.

On the other hand, the set time of the correcting unit 300 may be shortened based on a time when the calculated time exceeds the threshold time point. That is, in the correction unit 300, the set time may be shortened in proportion to the time that the calculated time exceeds the threshold time point.

As a result, the SOx regeneration and the NOx regeneration of the nitrogen oxide purification apparatus are performed by regulating the operation state of the engine to the rich operation state so that the desulfurization occurs when the time reaches the shortened desulfurization execution time, It is desirable to reset the shortened time value back to its initial value.

According to the regeneration system of the nitrogen oxide purification apparatus for a vehicle having the above-described structure, the activity of the nitrogen oxide purification apparatus can be maintained, and the purification efficiency of the nitrogen oxide purification apparatus can be stably maintained.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, 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 following claims It will be apparent to those of ordinary skill in the art.

S100: Operation step S200: Judgment step
S300: Shortening step 100:
200: determination unit 300:

Claims (10)

Calculating an elapsed time from a point at which NOx regeneration is performed;
A determination step of determining whether the calculated time exceeds a predetermined threshold time point; And
And a shortening step of performing a shortening correction of the preset desulfurization execution time according to the time exceeded when the calculated time exceeds the threshold time point by a set time. The method according to claim 1,
Wherein the threshold time point is set to a maximum time under a condition that the nitrogen oxide purification performance of the nitrogen oxide purification apparatus does not deteriorate according to the calculated time. The method according to claim 1,
Wherein the threshold time point is changed and set in accordance with at least one of an operation state of the engine, a nitrogen oxide storage amount in the nitrogen oxide purification apparatus, and a temperature of the nitrogen oxide purification apparatus. The method according to claim 1,
Wherein the preset desulfurization execution time is changed according to at least one of the operating state of the engine, the sulfur content in the nitrogen oxide purification unit, and the temperature of the nitrogen oxide purification unit. The method according to claim 1,
Wherein the shortening correction time at the time of performing the desulfurization in the shortening step is shortened based on a time at which the calculated time exceeds the critical point and is exceeded. An operation unit for calculating the elapsed time from the time point when the NOx regeneration is performed;
A determination unit for determining whether the time calculated by the operation unit exceeds a predetermined threshold time point; And
And a correcting unit for shortening the predetermined desulfurization execution time by a set time according to an exceeding time when it is determined that the time calculated by the judging unit exceeds a critical time point. The method of claim 6,
Wherein the critical time point of the determination unit is set to a maximum time under a condition that the nitrogen oxide purification performance of the nitrogen oxide purification apparatus does not deteriorate according to the time calculated by the calculation unit. The method of claim 6,
Wherein the critical point of time of the determination unit is changed and set in accordance with at least any one of an operation state of the engine, a nitrogen oxide storage amount in the nitrogen oxide purification apparatus, and a temperature of the nitrogen oxide purification apparatus. . The method of claim 6,
Wherein the temperature of the desulfurization of the reforming unit is changed according to at least one of the operating condition of the engine, the sulfur content of the nitrogen oxide purification unit, and the temperature of the nitrogen oxide purification unit. . The method of claim 6,
Wherein the set time of the correcting unit is shortened based on a time when the calculated time exceeds the threshold time point.

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