KR101519761B1 - Device and method for cooling SCR urea dosing unit of vehicle - Google Patents

Abstract

The present invention relates to an apparatus for cooling a thermally damaged peripheral object and an SCR urea dosing unit for a vehicle and a method therefor. More specifically, the apparatus for cooling a thermally damaged peripheral object and an SCR urea dosing unit for a vehicle and the method therefor cool an urea dosing unit injecting an urea to an SCR catalyst and a thermally damaged peripheral object to prevent thermal damage. Thus, the present invention provides the apparatus for cooling a thermally damaged peripheral object and an SCR urea dosing unit for a vehicle and the method therefor directly supplies an air to the urea dosing unit inside a muffler room and the thermally damaged peripheral object using an air compressor installed in a vehicle to easily cool the urea dosing unit and the thermally damaged peripheral object. Moreover, the air cooling the urea dosing unit and the thermally damaged peripheral object is left inside the muffler room to prevent the temperature of the inside of the muffler room from being increased due to heat transfer by increase in the temperature of a DPF.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a SCR urea dosing unit for a vehicle,

More particularly, the present invention relates to a urea dosing unit for spraying urea onto an SCR catalyst and a vehicle SCR for cooling the surrounding hot rolled product And an apparatus and a method for cooling the urea dosing unit and the surrounding hot water product.

Considering the fact that the exhaust gas discharged from the diesel engine contains nitrogen oxide (hereinafter referred to as NOx) which causes serious air pollution, a catalytic reduction method for removing NOx is used.

To this end, a Diesel Particulate Filter (DOC) or a Diesel Particulate Filter (DOC), which is a kind of exhaust gas post-treatment device for physically collecting and burning PM (particulate matter) A selective catalytic reduction (SCR) catalyst is continuously installed to remove the catalyst effectively.

The DPF system is a system for collecting soot in the exhaust gas. It is a system that collects the black smoke from the muffler of a diesel vehicle. Since the captured smoke must eventually be eliminated, the operation of raising the temperature to high temperature This is called regeneration.

At this time, the regeneration is referred to as automatic regeneration during running, and the manual regeneration is performed directly by the idle idle (IDLE). The temperature during regeneration rises to 600 ° C, so the temperature in the muffler room rises excessively.

The SCR catalyst system is a system capable of effectively reducing NOx by injecting urea (Urea, urea water), which is a kind of reducing agent, into the SCR catalyst. As shown in FIG. 2, Quot; refers to a method of reducing NOx by injecting urea into an SCR catalyst by using a urea dosing unit 22 which is an exhaust gas purifying catalyst.

That is, in the SCR catalyst system, the urea injected into the exhaust pipe is pyrolyzed by heat in the exhaust pipe or in contact with the SCR catalyst to be catalytically decomposed so that one molecule of the urea is converted into two-component ammonia, and the converted ammonia is converted into nitrogen oxide And SCR (Selective Catalyst Reduction) reaction of the reaction product, thereby discharging harmless nitrogen and water, which are the products of the reaction, to the outside.

At this time, when the temperature in the muffler room rises, the ambient heat of the urea hose, the connector, and the wiring connected to the urea dosing unit including the urea dosing unit rises due to the heat of conduction, May melt or explode.

The temperature of the muffler room where the DPF and the SCR are present rises due to the regeneration process of the DPF system as described above. If the temperature in the muffler room rises excessively, the urea dosing unit and the surrounding deteriorated product (urea hose, Connector, and wiring) is deteriorated.

In view of such a problem of heat dissipation, conventionally, as shown in FIG. 1, at least one cooling fan 26 is mounted on the wall surface of the muffler room 24 to draw outside air into the muffler room, A reduction method is applied.

However, since the cooling fan installed in the muffler room is surprisingly expensive (about 10 to 150,000 won), the installation cost of the cooling fan is excessively consumed.

Also, if the frequency of operation of the cooling fan is excessive, the durability is degraded, and a lot of trouble diagnosis logic is inputted to detect it, which complicates the system and increases the investment cost.

Further, since the outside air introduced by the cooling fan does not directly flow into the urea dosing unit but flows into the entire volume of the muffler room, the urea dosing unit and the surrounding hot rolled products can not be cooled quickly and may be damaged.

Particularly, due to the temperature rise of the urea dosing unit, the tip portion of the urea dosing unit is clogged or the component is changed, which eventually lowers the NOx purifying efficiency of the SCR catalyst.

Further, it is necessary to form a hole in the wall panel of the muffler room located on the rear wall of the muffler room for installing the cooling fan, that is, to attach a separate bracket for supporting the cooling fan, There are disadvantages.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a muffler room in which a cooling fan is excluded and air is directly supplied to a urea dosing unit and a surrounding hot- It is possible to easily cool the surrounding hot rolled products and to prevent the air in the urea dosing unit and the surrounding hot rolled products from being cooled in the muffler room while preventing the temperature in the muffler room from rising due to the heat generated by the temperature rise of the DPF And an object of the present invention is to provide an SCR urea dosing unit for a vehicle and an apparatus and a method for cooling a peripheral deteriorated product.

According to an aspect of the present invention, there is provided an air compressor comprising: an air compressor mounted on a vehicle; An air spraying pipe extending from an air outlet of the air compressor to an adjacent position of the urea dosing unit in the muffler room and injecting air when the temperature in the muffler room is raised to a certain temperature; The SCR urea dosing unit for a vehicle and the peripheral deterioration product cooling device are provided.

In one embodiment of the present invention, a solenoid valve that is openably mounted in the air injection pipe; A controller for controlling opening and closing of the solenoid valve; And a temperature sensor for providing the controller with temperature information in the muffler room for determining the opening and closing time of the solenoid valve.

According to another aspect of the present invention, there is provided a method for controlling a temperature in a muffler room, the method comprising: monitoring a temperature in a muffler room; Controlling the opening of the solenoid valve mounted at the outlet of the air compressor when the temperature in the muffler room rises above a reference value; Air from the air compressor is injected into the urea dosing unit and the surrounding hot rolled products through the air spraying pipe to cool the urea dosing unit and the surrounding hot rolled products; The SCR urea dosing unit cooling method for a vehicle.

Further, the air cooled by the urea dosing unit and the surrounding hot rolled product remains in the muffler room, thereby cooling the muffler room to lower the temperature inside the muffler room.

Further, when the temperature in the muffler room is below the reference value, the solenoid valve is controlled to be closed.

Particularly, in the idling state of the vehicle, when the atmospheric temperature is equal to or higher than the reference temperature and the regeneration operation of the DPF is equal to or longer than the reference time, the solenoid valve is opened as a procedure for manual regeneration, whereby air from the air compressor is supplied to the urea dosing unit So that it is supplied to the vicinity of the surrounding hot rolled products.

On the other hand, in the case of automatic regeneration and normal driving, when the temperature in the muffler room rises above the reference value, the solenoid valve is controlled to be opened so that air from the air compressor is supplied to the vicinity of the urea dosing unit and the surrounding heat- do.

Through the above-mentioned means for solving the problems, the present invention provides the following effects.

First, by using the air compressor mounted on the vehicle, cooling air can be directly supplied to the urea dosing unit in the muffler room and the surrounding deteriorated product, so that the urea dosing unit and the surrounding deteriorated product can be easily cooled.

Secondly, the air cooled in the urea dosing unit and the surrounding hot rolled products can stay in the muffler room, and the temperature in the muffler room can be prevented from rising due to the heat due to the temperature rise of the DPF.

Third, Unlike other conventional cooling fan, it is possible to cool the Urea dosing unit, the surrounding hot rolled products, and the muffler room without additional cost by using the air compressor mounted on the vehicle. have.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a cooling fan installation state for cooling a conventional muffler room and a urea dosing unit and a surrounding hot rolled product;
FIG. 2 is a schematic view showing a SCR urea dosing unit for a vehicle and an apparatus for cooling a peripheral deteriorated product according to the present invention.
3 is a schematic view showing a mounting position of the air compressor used in the present invention,
4 is a flowchart showing an embodiment of a SCR urea dosing unit for a vehicle and a method for cooling a surrounding deteriorated product according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As described above, during the regeneration process of the DPF collecting the ammonia of the exhaust gas discharged from the diesel engine, the temperature of the DPF is greatly increased and the heat of conduction of the DPF is transferred into the muffler room where the SCR exists (in the case of the DPF- So that the temperature of the muffler room rises and the temperature of the urea dosing unit and the surrounding hot rolled product rises. As a result, the durability life of the urea dosing unit is deteriorated due to the deterioration. Also, Even when the vehicle is running at a high load.

It is generally known that when the temperature of the urea supplied to the urea dosing unit reaches about 70 캜 or higher over the entire service interval, the urea is thermally damaged.

Further, in the case of the peripheral deteriorated product of the urea dosing unit, that is, the urea hose, the connector, the wiring, etc., the heat-resistant temperature is low.

In order to prevent the urea dosing unit and the surrounding hot rolled products from being opened, it is desirable that the urea dosing unit and the surrounding hot rolled products are cooled while the internal temperature of the muffler room is lowered.

To this end, the present invention is focused on the point that it is possible to cool the urea dosing unit and lower the internal temperature of the muffler room by using the air of the air compressor.

FIG. 2 is a block diagram showing a SCR urea dosing unit for a vehicle and a device for cooling a surrounding deteriorated product according to the present invention.

One end of the air injection pipe 14 having a predetermined length is connected to the air outlet of the air compressor 10 mounted on the vehicle, that is, the air compressor 10 mounted at a position interlocked with the diesel engine as shown in Fig. 3 , And the other side end of the air injection tube (14) enters the inside of the muffler room (24) and is extended to the adjacent position of the urea dosing unit (22).

Therefore, when the temperature in the muffler room 24 rises to a certain temperature, the air from the air compressor 10 is injected through the air injection pipe 14 toward the urea dosing unit 22 and the surrounding burned product, And remains in the muffler room 24, thereby cooling the urea dosing unit 22 and lowering the temperature in the muffler room 24.

At this time, a solenoid valve 16 for blocking or allowing the flow of air is mounted inside the air injection pipe 14 adjacent to the outlet of the air compressor 10 so as to be openable and closable.

A controller 18 is connected to the solenoid valve 16 for opening or closing the solenoid valve 16.

An input element for determining a time for controlling the opening or closing of the solenoid valve 16 is a temperature sensor 12 for measuring the temperature of the muffler room and providing it to the controller 18 in the muffler room 24, Respectively.

Hereinafter, the SCR urea dosing unit for a vehicle and the method for cooling a surrounding hot rolled product of the present invention based on the above configuration will be described.

First, the step of monitoring the temperature in the muffler room 24 proceeds.

That is, the internal temperature of the muffler room is measured by the temperature sensor 12 mounted in the muffler room 24, and is transmitted to the controller 18.

When the controller 18 determines that the temperature transmitted from the temperature sensor 12 is equal to or higher than the reference value, the solenoid valve 16 mounted on the outlet-side air injection pipe 14 of the air compressor 10 is controlled to be opened.

At this time, the internal temperature of the muffler room is higher than the reference value because the heat of conduction generated during the regeneration of the DPF is transferred into the muffler room where the SCR is present, and the temperature of the muffler room rises to the temperature of the urea dosing unit and the surrounding burned product .

Subsequently, air from the air compressor 10 is injected into the urea dosing unit 22 through the air injection pipe 14, thereby cooling the urea dosing unit 22 and the surrounding hot rolled products.

The air that has cooled the urea dosing unit 22 and the surrounding hot rolled product remains in the muffler room 24, thereby cooling the muffler room 24 to lower the temperature.

Accordingly, since the air from the air compressor is directly supplied to the urea dosing unit in the muffler room, it is possible to prevent the urea dosing unit and the surrounding hot water products from being deteriorated together with the cooling of the urea dosing unit and the surrounding hot water products, It is possible to lower the temperature within the chamber.

On the other hand, when the temperature in the muffler room 24 becomes equal to or lower than the reference value, the solenoid valve 16 is closed and the operation of the unnecessary air compressor can be stopped.

As a preferred embodiment of the present invention, in order to more precisely control the temperature control in the muffler room, the controller controls the opening of the solenoid valve in the idle period of the diesel engine during regeneration of the DPF.

 4, when the regeneration of the DPF starts with the engine starting of the diesel engine, it is checked whether the atmospheric temperature is higher than the reference temperature (atmospheric temperature 25 ° C or higher) in the idling state of the vehicle. (10 minutes or more) is checked by the controller. When the air temperature is equal to or higher than the reference temperature and the regeneration operation time exceeds the reference time, the solenoid valve 16 is opened .

The air from the air compressor 10 is injected into the urea dosing unit 22 and the surrounding hot rolled products and simultaneously supplied into the muffler room 24 and the muffler room 24 including the urea dosing unit 22 and the surrounding hot rolled products ) Can be precisely adjusted to be below the reference value.

As described above, since the air can be directly supplied to the urea dosing unit in the muffler room by using the air compressor mounted on the vehicle, the urea dosing unit and the surrounding hot-rolled products can be easily cooled, thereby preventing the urea dosing unit and the surrounding hot- The durability can be improved and the air cooled by the urea dosing unit and the surrounding hot rolled products can stay in the muffler room and the temperature in the muffler room can be prevented from rising due to the heat generated by the temperature rise of the DPF.

10: Air Compressor
12: Temperature sensor
14: Air sprayer
16: Solenoid valve
18:
20: SCR catalyst
22: urea dosing unit
24: muffler room
26: Cooling fan
28: DPF

Claims (7)

delete delete Monitoring the temperature in the muffler room (24);
When the temperature in the muffler room (24) rises above a reference value, opening control of the solenoid valve (16) mounted at the outlet position of the air compressor (10) is performed;
Air from the air compressor 10 is injected into the urea dosing unit 22 and the surrounding hot rolled products through the air injection pipe 14 to cool the urea dosing unit 22 and the surrounding hot rolled products;
Lt; / RTI >
When the atmospheric temperature is equal to or higher than the reference temperature and the regeneration operation of the DPF 18 is equal to or longer than the reference time in the idling state of the vehicle, the solenoid valve is opened so that the air from the air compressor is circulated around the urea dosing unit The SCR urea dosing unit for the vehicle and the method for cooling the peripheral deteriorated product.

The method of claim 3,
The air cooled by the urea dosing unit (22) and the surrounding hot rolled products remains in the muffler room (24) to perform a cooling action to lower the temperature in the muffler room, and a cooling method for the surrounding hot rolled products .
The method of claim 3,
And closing control of the solenoid valve (16) is performed when the temperature in the muffler room (24) is below the reference value.
delete The method of claim 3,
A step of controlling the opening of the solenoid valve 16 when the temperature in the muffler room 24 rises above a reference value and a step of cooling the urea dosing unit 22 and the surrounding hot rolled products by air from the air compressor 10 Is performed in the case of automatic regeneration and general running. The method for cooling an SCR urea dosing unit for a vehicle and a surrounding deteriorated product.

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