KR100960234B1 - Optimization system of diesel particulate filter volum for a diesel automobile - Google Patents

Abstract

Disclosed is a system for optimizing the volume of a soot filter unit of a diesel vehicle for optimizing a volume of a diesel particulate filter (DPF) using various vehicle data in a diesel vehicle.

A system for optimizing the volume of a soot filter apparatus of a diesel vehicle, comprising: an oil dilution allowable amount estimating unit for estimating an oil dilution allowable amount so that a dilution amount of the engine oil does not exceed a predetermined limit; An optimal fuel consumption estimating unit for estimating an optimum exhaust filtering apparatus volume for minimizing fuel consumption; A back pressure estimating part for estimating a maximum allowable back pressure that minimizes the influence on the maximum power; A maximum power reduction amount and a maximum back pressure estimating section for estimating an allowable maximum power reduction amount and an allowable maximum back pressure; A minimum DPF volume estimator for estimating a minimum smoke filter volume required based on engine displacement; A multiplexer for multiplexing values calculated respectively by the oil dilution allowance estimating unit, the optimum fuel consumption estimating unit, the back pressure estimating unit, the maximum power decreasing amount / maximum back pressure estimating unit, and the minimum DPF volume estimating unit; And a DPF volume determining unit for determining an optimum DPF volume in consideration of a plurality of values for determining a DPF volume output from the multiplexer.

Diesel engine, DPF, oil dilution, DPF volume determination, DPF volume optimization

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diesel particulate filter (diesel particulate filter)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for optimizing the volume of a soot filter apparatus of a diesel vehicle for optimizing a volume of a diesel particulate filter (DPF) using various vehicle data in a diesel vehicle.

Generally, in spite of excellent fuel efficiency and output, the engine used in diesel car is burned in a state where the air excess ratio is large due to the characteristics of the diesel engine. Therefore, unlike the gasoline engine, the exhaust gas contains carbon monoxide (CO) (NOx) and particulate matter (PM) are emitted in a considerably large amount, while the emission amount of HC and HC is small.

The emission of particulate matter (PM) is greatly reduced through combustion control, but the particulate matter (PM) and the NOx have a reciprocal relationship with each other. As the NOx is reduced, the particulate matter (PM) PM), conversely, increases the Nox, which causes a somewhat difficult situation in reducing both quantities simultaneously.

Particularly, in recent years, particulate matter (PM) is the most important cause of polluting the air, and it is reported in various media and causes a great harm to the human body.

As a means of reducing particulate matter (PM), a diesel particulate filter (DPF) is installed in the exhaust system of a diesel vehicle. The DPF physically collects the particulate matter (PM) discharged from the diesel engine in the filter to minimize the particulate matter (PM) discharged into the atmosphere. By analyzing the traveling distance and the collection concentration detected by the differential pressure sensor, The temperature of the exhaust gas is raised to a predetermined temperature or higher through post injection control to perform regeneration for burning and removing particulate matter (PM) collected in the filter.

Globally, regulations on the emissions of automobiles, especially diesel cars, are being tightened. In the end, PM regulation was strengthened so that exhaust gas regulations could be satisfied only if a DPF system that removes more than 95% of PM emitted from diesel engines was installed. This strengthened PM regulation is the EU 5 regulation, and the only possible way to satisfy this regulation is the DPF installation.

At present, the price of DPF systems is very high compared to other systems. So every car maker is trying to minimize the volume of DPF within a range of performance and durability. However, these DPF volume optimizations are linked to many other factors, and they are also not easy to deal with with each engine and the vehicle it is equipped with, and have a blind spot that is difficult to objectify.

Conventional diesel vehicles have disadvantages in that they can not objectively and accurately consider many factors related to the determination of the DPF volume, and have limitations that vary depending on the engineer determining the volume.

Accordingly, the present invention has been made to solve the above problems occurring in the conventional diesel vehicle,

SUMMARY OF THE INVENTION It is an object of the present invention to provide a diesel engine exhaust filter device capable of more accurately simulating the DPF volume optimized for each engine and vehicle by objectifying and logicizing factors related to DPF volume optimization And to provide an optimization system.

According to the present invention, there is provided a system for optimizing the volume of a soot filter apparatus for a diesel vehicle,

An oil dilution allowable amount estimating unit for estimating an oil dilution allowable amount so that the dilution amount of the engine oil does not exceed a predetermined limit;

An optimal fuel consumption estimating unit for estimating an optimum exhaust filtering apparatus volume for minimizing fuel consumption;

A back pressure estimating part for estimating a maximum allowable back pressure that minimizes the influence on the maximum power;

A maximum power reduction amount and a maximum back pressure estimating section for estimating an allowable maximum power reduction amount and an allowable maximum back pressure;

A minimum DPF volume estimator for estimating a minimum smoke filter volume required based on engine displacement;

A multiplexer for multiplexing values calculated respectively by the oil dilution allowance estimating unit, the optimum fuel consumption estimating unit, the back pressure estimating unit, the maximum power decreasing amount / maximum back pressure estimating unit, and the minimum DPF volume estimating unit;

And a DPF volume determining unit for determining an optimum DPF volume in consideration of a plurality of values for determining a DPF volume output from the multiplexer.

Further, the oil dilution allowable amount estimating unit may calculate,

The fuel injection quantity is calculated by inputting the torque, engine speed (rpm) and regeneration average time (aver.Regen Time) required when the vehicle runs in general, and then the oil is diluted (oil dilution amount estimating means for estimating an amount of oil dilution;

A maximum oil dilution amount calculation unit for calculating a maximum oil dilution amount of the engine oil based on the estimated oil dilution amount and the required engine oil change period;

(DPF volume_oil) which does not exceed the allowable oil dilution amount by the calculated maximum oil dilution amount by inputting the engine raw PM, the maximum soot loading amount, and the maximum allowable oil dilution amount. And an oil dilution allowable amount calculating unit that calculates the oil dilution allowable amount.

Further, the optimal fuel-

A fuel consumption change calculation unit for calculating a fuel consumption change trend as the DPF volume is changed by receiving input of engine raw PM, maximum amount of soot, and post fuel injection amount;

A back pressure presumption unit for receiving the engine raw PM amount, a maximum soot amount, a DPF contour, and an average exhaust flow and estimating a back pressure;

A fuel consumption deterioration estimating unit that receives a fuel efficiency deteriorated by the estimated back pressure and an increase in back pressure and estimates a fuel consumption deterioration trend according to a DPF volume change;

And an optimal fuel consumption determining unit determining an intersection of the fuel consumption change calculated by the fuel consumption change calculating unit and the fuel consumption trend calculated by the fuel consumption deterioration estimating unit as an optimal volume (DPF volume_fe) in terms of fuel consumption.

In addition,

An exhaust gas flow estimator for estimating an exhaust gas flow required by the target maximum power;

The DPF volume (DPF volume_power), which determines the DPF volume_power that does not exceed the maximum permissible backpressure by inputting the estimated exhaust gas flow (ex. Gas flow [g / s], DPF contour, exhuast gas temperature) And a determination section.

In addition, the maximum power reduction amount and maximum back pressure estimating unit may calculate,

The amount of engine oil consumption that affects the vehicle mileage, DPF type and ash accumulation to be warranted, and the ash content of the engine oil as the input value increase the back pressure according to the accumulation of ash An estimated back pressure increase estimator;

(DPF volume_ash) that determines the maximum power reduction amount and the maximum back pressure that can minimize the DPF volume, based on the estimated back pressure increase amount, the allowable maximum power reduction amount, and the allowable maximum back pressure as input values, And a maximum back pressure determination section.

In addition, the minimum DPF volume estimating unit estimates,

A minimum DPF volume determiner that calculates the minimum required DPF volume (DPF volume_min) based on the ratio of the engine displacement to the required DPF volume, the engine displacement to be applied at present, and the like.

According to the present invention, the factors related to the optimization of the DPF volume can be objectified and logicized, so that it is possible to more accurately optimize the DPF volume optimized for each engine and the vehicle.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

FIG. 1 is a block diagram showing a configuration of a system for optimizing the volume of a soot filter apparatus of a diesel vehicle according to the present invention. The system includes an oil dilution allowable amount estimating unit 110, an optimal fuel consumption estimating unit 120, a back pressure estimating unit 130, A minimum DPF volume estimating unit 150, a multiplexer 160, and a DPF volume determining unit 170. The minimum DPF estimating unit 140, the minimum DPF volume estimating unit 150,

The oil dilution allowable amount estimating unit 110 estimates the oil dilution allowable amount to prevent the dilution amount of the engine oil from exceeding a predetermined limit. The torque estimating unit 110 estimates the oil dilution allowable amount based on the torque and the engine rotation speed an oil dilution estimating unit 111 for estimating an oil dilution amount of the total injection amount after calculating a fuel injection amount based on rpm and aver. A maximum oil dilution amount calculation unit 112 for calculating a maximum oil dilution amount of the engine oil based on the estimated oil dilution amount and a required engine oil change period; (DPF volume_oil) that does not exceed the allowable oil dilution amount by the calculated maximum oil dilution amount by inputting the engine raw PM, maximum soot loading and maximum allowable oil dilution amount And an oil dilution allowable amount calculating unit 113 for calculating the oil dilution allowable amount.

The optimal fuel economy estimating unit 120 performs a function of estimating the optimum exhaust filtering apparatus volume for minimizing the fuel consumption. The optimal fuel consumption estimating unit 120 estimates the engine PM amount (raw PM), the maximum soot amount A fuel consumption change calculation unit 121 that receives a fuel injection amount and calculates a fuel consumption change trend as the DPF volume changes; A back pressure presumption part 122 for estimating a back pressure based on the engine raw PM amount, a maximum soot amount, a DPF contour, and an average exhaust flow, ; A fuel consumption deterioration estimating unit 123 that receives fuel consumption deteriorated by the estimated back pressure and an increase in back pressure and estimates the fuel consumption deterioration trend according to the DPF volume change; And an optimal fuel consumption determining unit 124 that determines the point at which the fuel consumption change calculating unit and the fuel consumption deterioration estimating unit respectively calculate the fuel consumption trend as an optimum volume (DPF volume_fe) in terms of fuel consumption.

The back pressure estimation unit 130 performs a function of estimating a maximum allowable back pressure that minimizes the influence on the maximum power and estimates an exhaust gas flow required by the target maximum power An exhaust gas flow estimating unit 131; The DPF volume (DPF volume_power), which determines the DPF volume_power that does not exceed the maximum permissible backpressure by inputting the estimated exhaust gas flow (ex. Gas flow [g / s], DPF contour, exhuast gas temperature) And a determination unit 132. [

The maximum power reduction amount and maximum back pressure estimating unit 140 performs a function of estimating an allowable maximum power reduction amount and an allowable maximum back pressure, a back pressure increase estimating section 141 for estimating an increase in back pressure according to accumulation of ash as an input value of engine oil consumption amount and ash content of engine oil affecting type and ash accumulation; (DPF volume_ash) that determines the maximum power reduction amount and the maximum back pressure that can minimize the DPF volume, based on the estimated back pressure increase amount, the allowable maximum power reduction amount, and the allowable maximum back pressure as input values, And a maximum back pressure determiner 142.

The minimum DPF volume estimating unit 150 performs a function of estimating the required minimum smoke filtering apparatus volume based on the engine exhaust amount. The minimum DPF volume estimating unit 150 receives the ratio of the engine exhaust amount to the required DPF volume, And a minimum DPF volume determiner 151 for calculating a minimum DPF volume (DPF volume_min).

The multiplexer 160 multiplexes the values calculated by the oil dilution allowance estimating unit, the optimum fuel consumption estimating unit, the back pressure estimating unit, the maximum power reduction amount / maximum back pressure estimation unit, and the minimum DPF volume estimating unit, The determination unit 170 determines the optimal DPF volume considering a plurality of values for determining the DPF volume output from the multiplexer 160. [

The volume optimization system for a diesel particulate filter according to the present invention configured as described above includes a volume 110-150 for simulating volume optimized for each group and a volume 110-150 for determining the final DPF volume among the volume optimized in all groups (160, 170).

First, the post-fuel injection is applied in the diesel engine to regenerate the DPF.

As a side effect of the fuel back-injection, the injected fuel does not escape 100% of the exhaust gas exhaust process, and some of it is dissolved in the engine oil on the cylinder wall surface, so that the fuel dilutes the engine oil and is one of the most important functions of engine oil. Which can eventually adversely affect the engine durability. This is called oil dilution. In a system equipped with a DPF, the DPF volume should be determined such that the oil dilution does not exceed a certain limit.

In order to calculate this, the oil dilution amount estimating unit 111 of the oil dilution amount estimating unit 110 estimates the oil dilution amount estimating unit 111 based on the torque, the engine speed (rpm) and the regeneration averaging time (aver.Regen Time is used as an input to estimate the amount of fuel injection and then the amount of oil dilution of the total injection amount is estimated.

The maximum oil dilution amount calculation unit 112 calculates the maximum oil dilution amount of the engine oil based on the estimated oil dilution amount and the required engine oil change period, (DPF volume_oil) that does not exceed the allowable oil dilution amount by the calculated maximum oil dilution amount by inputting the raw PM, maximum soot loading amount, and maximum allowable oil dilution amount do.

In addition, as the DPF volume increases in relation to fuel economy, the back pressure during driving also increases, leading to deterioration of fuel efficiency. Conversely, as the DPF volume decreases, the regeneration cycle becomes shorter and fuel economy deteriorates due to frequent regeneration. By optimizing the two opposite factors, the optimal DPF volume can be calculated to minimize fuel consumption.

That is, the fuel economy change calculating unit 121 of the optimal fuel economy estimating unit 120 receives the engine raw PM amount, the maximum soot amount, and the post-fuel injection amount, Calculates a fuel consumption change trend, and provides it to the optimal fuel consumption determination unit 124. [ Here, as the DPF volume increases, the regeneration cycle increases and fuel consumption deteriorates exponentially.

The back pressure presumption unit 122 receives the engine raw PM amount, the maximum soot amount, the DPF contour, and the average exhaust flow to estimate the back pressure The fuel consumption deterioration estimating unit 123 receives the fuel consumption deteriorated by the estimated back pressure and the back pressure increase and estimates the fuel consumption deterioration trend according to the DPF volume change and provides the estimated fuel consumption deterioration to the optimum fuel consumption determining unit 124. Here, as the DPF volume increases, the fuel pressure deteriorates due to the increased back pressure during normal driving.

The optimal fuel consumption determining unit 124 determines the point where the fuel consumption trend calculated by the fuel consumption change calculating unit 121 and the fuel consumption deterioration estimating unit 123 respectively meet as the optimum volume DPF volume_fe .

On the other hand, in a diesel engine, the maximum power is determined by various boundary conditions, and an important factor affecting the boundary condition is the back pressure on the exhaust system. The most backpressure component in the exhaust system is the DPF, which limits the maximum power by the backpressure of the DPF and can be simulated as follows.

That is, the exhaust gas flow estimating unit 131 of the back pressure estimating unit 130 estimates the exhaust gas flow required by the target maximum power, Determines the DPF volume_power that does not exceed the maximum allowable back pressure by inputting the estimated exhaust gas flow (ex. Gas flow [g / s], DPF contour, exhuast gas temperature) do.

In addition, in the diesel vehicle equipped with the DPF system, ash accumulation is a new consideration that is different from the previous system. This ash accumulation means that the back pressure on the exhaust system increases as the mileage of the vehicle increases, and this increase in backpressure due to ash accumulation results in decreasing the maximum power of the engine. Therefore, the volume of the DPF that can minimize the amount of reduction of the maximum power to a certain degree of vehicle driving distance is required. It is necessary to estimate the DPF volume which can satisfy the maximum power reduction required. Also, the DPF volume should be determined so that the peak backpressure, which increases with the accumulation of the ash, does not exceed the maximum allowable backpressure of the engine components.

To this end, the maximum power reduction amount and the back pressure increase estimating section 141 of the maximum back pressure estimating section 140 calculate the amount of engine oil consumption that affects the vehicle travel distance, DPF type and ash accumulation to be guaranteed, The ash content is used as an input to estimate the back pressure increase with ash accumulation. The maximum power reduction amount and maximum back pressure determination unit 142 determines a maximum power reduction amount capable of minimizing the DPF volume based on the estimated back pressure increase amount, the allowable maximum power reduction amount, and the allowable maximum back pressure as input values, The maximum back pressure is determined (DPF volume_ash).

It is also possible to consider the DPF volume divided by the DPF volume based on the engine displacement to limit the minimum volume through bench marking. This takes into account the trends of other DPF systems and can generally absorb the factors that were not taken into account when determining the DPF volume.

To this end, the minimum DPF volume determiner 151 of the minimum DPF volume estimator 150 calculates the minimum required DPF volume (DPF volume_min) based on the ratio of the engine displacement to the required DPF volume, do.

When the optimized volumes for the respective factors for determining the DPF volume are estimated through this process, the multiplexer 160 multiplexes the optimized volumes and transmits them to the DPF volume determination unit 170. The DPF volume determination unit 170 The final DPF volume of the optimized volume is determined.

1 is a block diagram showing the configuration of a system for optimizing the volume of a soot filter apparatus for a diesel vehicle according to the present invention.

FIG. 2 is a block diagram showing an embodiment of the oil dilution allowable amount estimating unit of FIG. 1; FIG.

3 is a block diagram illustrating an embodiment of the optimal fuel-economy estimator of FIG.

4 is a block diagram showing an embodiment of the back pressure estimation unit of FIG.

5 is a block diagram showing an embodiment of the maximum power reduction amount and maximum back pressure estimation unit of FIG.

6 is a block diagram illustrating an embodiment of the minimum DPF volume estimator of FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

110: Oil dilution allowable amount estimating unit 120: Optimum fuel consumption estimating unit

130:

140: maximum power reduction amount and maximum back pressure estimation unit

150: Minimum DPF volume estimator 160: Multiplexer

170: DPF volume determining unit

Claims (6)

A system for optimizing the volume of a smoke filtering device in a diesel vehicle, An oil dilution allowable amount estimating unit for estimating an oil dilution allowable amount so that the dilution amount of the engine oil does not exceed a predetermined limit; An optimal fuel consumption estimating unit for estimating an optimum exhaust filtering apparatus volume for minimizing fuel consumption; A back pressure estimating part for estimating a maximum allowable back pressure that minimizes the influence on the maximum power; A maximum power reduction amount and a maximum back pressure estimating section for estimating an allowable maximum power reduction amount and an allowable maximum back pressure; A minimum DPF volume estimator for estimating a minimum smoke filter volume required based on engine displacement; A multiplexer for multiplexing values calculated respectively by the oil dilution allowance estimating unit, the optimum fuel consumption estimating unit, the back pressure estimating unit, the maximum power decreasing amount / maximum back pressure estimating unit, and the minimum DPF volume estimating unit; And a DPF volume determining unit for determining an optimal DPF volume in consideration of a plurality of values for determining a DPF volume output from the multiplexer. The method according to claim 1, wherein the oil dilution allowable- The fuel injection quantity is calculated by inputting the torque, the engine speed (rpm) and the regeneration average time (aver. Regen Time) required when the vehicle travels in general, and then the oil is diluted dilution amount estimating means for estimating an amount of oil dilution; A maximum oil dilution amount calculation unit for calculating a maximum oil dilution amount of the engine oil based on the estimated oil dilution amount and the required engine oil change period; (DPF volume_oil) which does not exceed the allowable oil dilution amount by the calculated maximum oil dilution amount by inputting the engine raw PM, the maximum soot loading amount, and the maximum allowable oil dilution amount. Wherein the oil dilution allowable amount calculating unit calculates an oil dilution allowable amount calculating unit. 2. The fuel cell system according to claim 1, A fuel consumption change calculation unit for calculating a fuel consumption change trend as the DPF volume is changed by receiving input of engine raw PM, maximum amount of soot, and post fuel injection amount; A back pressure presumption unit for receiving the engine raw PM amount, a maximum amount of soot, a DPF contour, and an average exhaust flow and estimating a back pressure; A fuel consumption deterioration estimating unit that receives a fuel efficiency deteriorated by the estimated back pressure and an increase in back pressure and estimates a fuel consumption deterioration trend according to a DPF volume change; And an optimal fuel consumption determining unit determining an intersection of the fuel consumption change calculated by the fuel consumption change calculating unit and the fuel consumption trend calculated by the fuel consumption deterioration estimating unit as the optimum volume (DPF volume_fe) in terms of fuel consumption. Volume optimization system. The apparatus according to claim 1, An exhaust gas flow estimator for estimating an exhaust gas flow required by the target maximum power; The DPF volume (DPF volume_power), which determines the DPF volume_power that does not exceed the maximum permissible backpressure by inputting the estimated exhaust gas flow (ex. Gas flow [g / s], DPF contour, exhuast gas temperature) And a determination unit for determining a volume of the diesel particulate filter. The apparatus according to claim 1, wherein the maximum power reduction amount and maximum back pressure estimation unit comprises: Backpressure estimating an increase in backpressure due to ash accumulation as input values of engine oil consumption, engine oil consumption, and ash content affecting vehicle mileage, DPF type and ash accumulation to be guaranteed, An increase estimator; (DPF volume_ash) that determines the maximum power reduction amount and the maximum back pressure that can minimize the DPF volume, based on the estimated back pressure increase amount, the allowable maximum power reduction amount, and the allowable maximum back pressure as input values, And a maximum back pressure determination unit for determining a maximum back pressure of the diesel particulate filter. The apparatus of claim 1, wherein the minimum DPF volume estimator comprises: And a minimum DPF volume determiner for calculating a minimum DPF volume (DPF volume_min) required by receiving a ratio of an engine displacement to a required DPF volume and an engine displacement to be applied at present. system.

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