KR20190071077A - Engine system for exhausting water and method using the same - Google Patents

Abstract

Disclosed is an engine system for discharging condensate water and a control method using the same. The purpose of the preset invention is to provide the engine system for discharging condensate water, capable of discharging condensate water collected in an EGR cooler or an EGR path to the outside through an exhaust line, and the control method using the same. According to the embodiment of the present invention, the engine system for discharging condensate water includes: an engine including a combustion chamber generating a driving force by combustion of a fuel; a throttle valve controlling the amount of air supplied to the combustion chamber through the exhaust line in which suction gas supplied to the combustion chamber flows; a turbocharger including a turbine installed in the exhaust line in which exhaust gas discharged from the combustion chamber flows and discharged from the combustion chamber, wherein the turbocharger also includes a compressor installed in a suction line and compressing external air by rotating while being interworked with the turbine; an EGR device including an EGR line, the EGR cooler, and an EGR valve; a recirculation line diverged from the suction line on the upper part of the engine and joined to the EGR line between the EGR cooler and the EGR valve; and a recirculation valve installed in the recirculation line. The EGR line diverges from the exhaust line at a rear end of the turbocharger and is joined to the suction line. The EGR cooler is installed in the EGR line and cools the exhaust gas flowing in the EGR line. The EGR valve is installed in the EGR line at the lower part of the EGR cooler.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine system for discharging condensed water,

The present invention relates to an engine system and method for discharging condensed water, and more particularly, to an engine system and method for discharging condensed water that can discharge condensed water remaining in the EGR cooler through an exhaust line.

The engine of an automobile mixes and combusts the air from the outside with an appropriate ratio of fuel to generate power.

In the process of generating the power by driving the engine, it is necessary to sufficiently supply the outside air for the combustion so that the desired output and the combustion efficiency can be obtained. For this purpose, a turbocharger is used as a device for supercharging the combustion air to increase the combustion efficiency of the engine.

Generally, a turbocharger is a device that turns a turbine by using the pressure of exhaust gas discharged from an engine, and then supplies high-pressure air to the combustion chamber by using the rotational force to increase the output of the engine. The turbocharger is applied to most diesel engines, and recently it has also been applied to gasoline engines.

In addition, nitrous oxide (NOx) contained in the exhaust gas is regulated as a main air pollutant, and a lot of research is being conducted to reduce such NOx emissions.

Exhaust gas recirculation (EGR) systems are systems mounted on vehicles for the reduction of hazardous emissions. Generally, NOx is increased when the proportion of air in the mixer is high and the combustion is good. Therefore, the exhaust gas recirculation system is a system that mixes a part of the exhaust gas discharged from the engine (for example, 5 to 20%) back into the mixer to reduce the amount of oxygen in the mixer and obstruct combustion, thereby suppressing the generation of NOx.

A typical exhaust gas recirculation system is a low pressure EGR (low pressure EGR) system. The low pressure EGR device recirculates the exhaust gas that has passed through the turbine of the turbocharger to the intake passage at the front end of the compressor. At this time, the exhaust gas recirculated through the low pressure EGR cooler is cooled.

However, the exhaust gas recirculated by the exhaust gas recirculation system is generally very high in temperature and humidity. When the recirculated exhaust gas is cooled by the cooler, condensed water is generated, and the condensed water generated at this time accumulates in the EGR cooler or the recirculation passage (for example, the EGR passage). Condensate water has a very high acidity due to various harmful components contained in the exhaust gas, so that there arises a problem of corroding the EGR cooler or the recirculation passage.

The matters described in the background section are intended to enhance the understanding of the background of the invention and may include matters not previously known to those skilled in the art.

An object of the present invention is to provide an engine system for discharging condensed water, which is exhausted to the outside through an exhaust line, in an EGR cooler or an EGR passage, and a control method using the same. do.

According to an aspect of the present invention, there is provided an engine system for discharging condensed water, the engine including an engine including a combustion chamber for generating driving force by combustion of fuel, an intake line for introducing intake gas supplied to the combustion chamber, A throttle valve for controlling an amount of air supplied to the combustion chamber through a combustion chamber, a turbine provided in an exhaust line through which exhaust gas is exhausted from the combustion chamber and rotating by exhaust gas discharged from the combustion chamber, An EGR line branched from the exhaust line at the rear end of the turbocharger and joined to the intake line, an EGR line disposed in the EGR line for cooling the exhaust gas flowing through the EGR line, A cooler, and an EGR valve installed in the EGR line downstream of the EGR cooler Diverged from the EGR device, the intake line of said engine upstream including a may include a recycle line, and a recirculation valve disposed in the recirculation line to join the EGR line between the EGR cooler and the EGR valve.

The engine system for discharging condensed water according to an embodiment of the present invention further includes a controller for controlling operations of the throttle valve, the turbocharger, the EGR valve, and the bypass valve, The opening and closing of the throttle valve, the EGR valve, and the recirculation valve can be controlled according to the operation region.

The controller may block the throttle valve and the EGR valve and open the recirculation valve when a tip-out occurs in an operating region in which the turbocharger is operated.

A control method of an engine system for discharging condensed water according to another embodiment of the present invention is a control method for an engine system including an engine, an EGR apparatus, and a turbocharger, A step of detecting a signal of a vehicle speed and an accelerator pedal sensor, a step of determining, by a controller, whether or not it is an operation region in which a turbocharger is operated from a required torque and a required speed, Determining whether or not a tip-out occurs, opening and closing a throttle valve for controlling an intake air amount supplied to the engine in accordance with an operation region and tip-out of the turbocharger operated by the controller, Opening and closing of the EGR valve of the EGR device, branching at the intake line upstream of the engine, joining to the EGR line between the EGR cooler and the EGR valve May comprise regulating the opening and closing of the recirculation valve installed in the recirculation line.

The throttle valve and the throttle valve may be disconnected and the recirculation valve may be opened when a tip-out occurs in an operation region where the turbocharger is operated.

According to the engine system for discharging the condensed water according to the embodiment of the present invention and the control method using the same, the condensed water which has been accumulated in the EGR cooler or the EGR passage is discharged to the outside through the exhaust line, It is possible to prevent the EGR cooler or the EGR passage from being corroded.

These drawings are for the purpose of describing an exemplary embodiment of the present invention, and therefore the technical idea of the present invention should not be construed as being limited to the accompanying drawings.
1 is a conceptual diagram showing the configuration of an engine system for discharging condensed water according to an embodiment of the present invention.
2 is a block diagram showing the configuration of an engine system for discharging condensed water according to an embodiment of the present invention.
3 is a flowchart illustrating an operation of an engine system for discharging condensed water according to an embodiment of the present invention.
4 is a view for explaining a process of discharging condensed water according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. .

Hereinafter, an engine system for discharging condensed water according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram showing the configuration of an engine system for discharging condensed water according to an embodiment of the present invention. And FIG. 2 is a block diagram showing the configuration of an engine system for discharging condensed water according to an embodiment of the present invention.

1 and 2, an engine system (hereinafter referred to as an engine system) for discharging condensed water according to an embodiment of the present invention includes an engine 20, a turbocharger 70, an intercooler 16, A low pressure EGR device 50, an operation information sensing unit 80, and a controller 90.

The engine 20 includes a plurality of combustion chambers 21 that generate a driving force by combustion of fuel. The engine 20 is provided with an intake line 10 through which the intake gas supplied to the combustion chamber 21 flows and an exhaust line 30 through which the exhaust gas discharged from the combustion chamber 21 flows.

An intake manifold 23 for distributing the air supplied to a plurality of combustion chambers 21 is provided at the front end of the engine 20 and a throttle valve 25 is installed in the intake manifold 23. The amount of air supplied to the combustion chamber 21 through the intake manifold 23 is adjusted according to the amount of opening of the throttle valve 25.

The exhaust line 30 may be provided with an exhaust gas purifier 60 for purifying various harmful substances contained in the exhaust gas discharged from the combustion chamber 21. The exhaust gas purifying apparatus 60 may include a lean NOx trap (LNT), a diesel oxidation catalyst, and a diesel particulate filter for purifying nitrogen oxides.

The turbocharger 70 compresses the intake gas (outside air + recycle gas) flowing through the intake line 10 and supplies the compressed air to the combustion chamber 21. The turbocharger 70 includes a turbine 71 provided in the exhaust line 30 and rotated by an exhaust gas discharged from the combustion chamber 21 and a turbine 71 rotating in conjunction with the turbine 71 to compress the intake gas And a compressor (72).

An exhaust bypass line 32 branched from the exhaust line 30 upstream of the turbine 71 and joining to the exhaust line 30 downstream of the turbine 71 is formed in the exhaust bypass line 32, A wastegate valve 34 is provided. The waste gate valve 34 is operated by a control signal of the controller 90 and the amount of exhaust gas supplied to the turbine 71 is adjusted according to the amount of opening of the wastegate valve 34.

The low pressure exhaust gas recirculation apparatus (LP-EGR) 50 includes a low pressure EGR line 52, a low pressure EGR cooler 56, and a low pressure EGR valve 54. In the embodiment of the present invention, a low-pressure EGR apparatus is described as an example, but another type of EGR apparatus (for example, a high-pressure EGR apparatus) may be applied.

The low pressure EGR line 52 branches at the exhaust line 30 at the rear end of the turbocharger 70 and joins to the intake line 10. The low pressure EGR cooler 56 is disposed in the low pressure EGR line 52 and cools the exhaust gas flowing through the low pressure EGR line 52. The low-pressure EGR valve 54 is disposed at a position where the low-pressure EGR line 52 and the intake line 10 join together and regulates the amount of exhaust gas flowing into the intake line 10. [ Here, the exhaust gas supplied to the intake line 10 through the low-pressure EGR line 52 is referred to as a recirculating gas.

The intake line (10) is provided with an intercooler (16). The intercooler 16 cools the intake gas flowing through the intake line 10 through heat exchange with the cooling water. That is, since the intake gas compressed by the turbocharger 70 is expanded and expanded in temperature, the oxygen density of the intake gas supplied to the combustion chamber 21 is lowered, It is difficult to output the torque. Therefore, the intake gas is cooled through the intercooler 16 to increase the density of the intake gas, thereby improving the combustion efficiency of the engine 20. [

The engine system according to the embodiment of the present invention differs from the EGR cooler 56 in that the EGR cooler 56 is branched from the intake line 100 upstream of the engine so as to discharge the condensed water, And an EGR line 52 between the EGR valve 54 and the recirculation line 12 and a recirculation valve 14 installed at a point where the intake line 10 and the recirculation line 12 join together Preferably, the recirculation valve 14 is integrally formed at the inlet or outlet of the intercooler 16. [

The controller 90 controls the operation of the engine 20, the turbocharger 70, the wastegate valve 34, the EGR valve 54, the throttle valve 25 and the recirculation valve 14 .

The controller 90 may be provided with one or more processors operating according to a set program, and the set program is configured to perform each step of the engine control method according to the embodiment of the present invention.

The controller 90 determines whether the turbocharger 70 is in an operation region in accordance with the driver's requested torque and the required speed sensed by the operation information sensing unit 80, And controls the opening and closing of the recirculation valve 14 in accordance with the control signal.

The operation information sensing unit 80 measures the driver's requested torque and the required speed, and transmits the measured required torque and the requested speed to the controller 90. The driver's requested torque and the required speed can be sensed through an acceleration pedal sensor (APS) provided in the vehicle.

The controller 90 determines whether the turbocharger 70 is operated in the operation region from the required torque sensed by the operation information sensing unit 80 and the required speed. For example, the operating region in which the turbocharger 70 is operated is a high-speed high-load region, and the region in which the turbocharger 70 is not operated may be a relatively low-speed low-load region.

The operation information sensing unit 80 senses whether a tip-out occurs by the driver at the time of driving the vehicle, and transmits the sensed tip-out to the controller 90. Whether or not a tip-out occurs can be determined from the current speed of the vehicle and a signal output from an acceleration pedal sensor (APS) and a brake pedal sensor (BPS).

Hereinafter, the operation of the engine system according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating an operation of an engine system for discharging condensed water according to an embodiment of the present invention.

3, the operation information sensing unit 80 detects operation information including a required torque, a required speed, a vehicle speed, an APS signal, and a BPS signal of the engine 20, And transmits the requested speed to the controller 90 (S10).

The controller 90 controls the opening and closing of the throttle valve 25, the EGR valve 54 and the recirculation valve 14 according to whether the turbocharger 70 is in the operating region in which the turbocharger 70 is operated and whether a tip- .

The controller 90 determines whether the vehicle is in an operation region in which the turbocharger 70 operates from the required torque and the requested speed, and whether the driver tip-outs during acceleration.

Specifically, when the driver tip-outs during acceleration of the vehicle, the controller 90 controls the throttle valve (not shown) to block the supply of air to the combustion chamber 21 to reduce the output of the engine 20. [ (Step S30).

The controller 90 controls the EGR valve 54 to be shut off and controls the recirculation valve 14 to be opened.

Thus, when a tip-out occurs when the turbocharger 70 is operated, the throttle valve 25 is shut off to shut off the air supplied to the combustion chamber 21 to reduce the engine output. At this time, turbocharged air is formed in the intake line 10 between the downstream of the compressor 72 of the turbocharger 70 and the throttle valve 25 due to the inertia of the turbine 71 of the turbocharger 70.

The high temperature and high humidity exhaust gas flowing into the EGR line 52 is cooled by the EGR cooler 56 to generate condensed water, and the generated condensed water is condensed in the EGR cooler 56.

At this time, when the EGR valve 54 is shut off and the recirculation valve 14 is opened, high pressure air formed in the intake line 10 flows backward through the recirculation line 12 and the EGR line 52 to the EGR cooler 56, And the condensed water remaining in the EGR cooler 56 flows backward through the EGR line 52 and the exhaust line 30 to be discharged to the outside (see FIG. 4).

As described above, since the condensed water that has been accumulated in the EGR cooler is discharged to the outside, it is possible to prevent the strongly acidic condensed water from becoming condensed in the condensed water, thereby preventing the EGR cooler and peripheral parts from being corroded by the strongly acidic condensed water.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And it goes without saying that the invention belongs to the scope of the invention.

10: Intake line
12: recirculation line
14: recirculation valve
16: intercooler
20: engine
21: Combustion chamber
23: Intake manifold
30: Exhaust line
32: Exhaust bypass line
34: Waste gate valve
50: EGR device
52: EGR line
54: EGR valve
56: EGR cooler
60: Exhaust gas purifier
70: Turbocharger
72: Turbine
74: Compressor
80: Operation information detecting unit
90:

Claims (5)

An engine including a combustion chamber that generates driving force by combustion of fuel:
A throttle valve for controlling an amount of air supplied to the combustion chamber through an intake line through which an intake gas supplied to the combustion chamber flows;
A turbocharger which is provided in an exhaust line through which exhaust gas discharged from the combustion chamber flows and which is rotated by an exhaust gas discharged from the combustion chamber, and a compressor provided in the intake line and rotating in conjunction with the turbine to compress outside air;
An EGR line branched from the exhaust line at the rear end of the turbocharger and joined to the intake line, an EGR cooler disposed in the EGR line for cooling the exhaust gas flowing through the EGR line, and an EGR An EGR device including a valve;
A recirculation line branching from the intake line upstream of the engine and joining to the EGR line between the EGR cooler and the EGR valve; And
A recirculation valve installed in the recirculation line;
. The method according to claim 1,
Further comprising a controller for controlling operations of the throttle valve, the turbocharger, the EGR valve, and the bypass valve,
Wherein the controller regulates opening and closing of the throttle valve, the EGR valve, and the recirculation valve in accordance with an operation region in which the turbocharger is operated. 3. The method of claim 2,
The controller
Wherein the throttle valve and the EGR valve are closed when a tip-out occurs in an operation region where the turbocharger is operated, and the recirculation valve is opened. A control method for an engine system including an engine, an EGR device, and a turbocharger,
Detecting a demand torque, a required speed, a vehicle speed, and a signal of an accelerator pedal sensor from an operation information sensing unit;
Determining, by the controller, whether or not the engine is in an operating region in which the turbocharger is operated from the required torque and the required speed;
Determining, by the controller, whether a tip out occurs from a signal of the vehicle speed and accelerator pedal sensor;
Opening and closing of a throttle valve for controlling the amount of intake air supplied to the engine in accordance with whether the turbocharger is operated and whether the engine is tip-out, opening and closing an EGR valve of the EGR device, Regulating the opening and closing of the recirculation valve provided in the recirculation line branching from the intake line of the EGR cooler and joining to the EGR line between the EGR cooler and the EGR valve;
And a control system for controlling the engine system. 5. The method of claim 4,
Wherein the throttle valve and the throttle valve are closed when a tip-out occurs in an operation region where the turbo charger operates, and the recirculation valve is opened.

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