KR20170119551A - Cooling apparatus and method of Reducing agent injecting unit - Google Patents

Abstract

Disclosed is a reducing agent spraying unit cooling apparatus which prevents a reducing agent spraying unit for spraying a reducing agent in exhaust gas to reduce the harmful substances from being overheated by hot exhaust gas. When the temperature of the cooling water circulating in the reducing agent spraying unit is higher than the set temperature preliminarily inputted to the control unit, the cooling agent spraying unit cooling apparatus according to the present invention is characterized in that the cooling water direction control valve for interrupting the supply of the cooling water to the reducing agent spraying unit And the condensed water generated is allowed to flow so as to lower the temperature of the cooling water passing through the cooling water direction control valve.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a cooling apparatus and a method of controlling the same,

The present invention relates to a reducing agent injection unit cooling apparatus and a control method thereof, and more particularly, to a reducing agent injection unit cooling apparatus and method for controlling the reducing agent injection unit cooling apparatus, And a method for controlling the same.

Diesel engines are widely used as various industrial engines due to their high fuel efficiency and high reliability. Especially, the diesel engine is installed most with the gasoline engine as the main engine of the vehicle.

However, diesel engines tend to be incompletely combusted compared to highly volatile gasoline, resulting in the generation of large quantities of dust (PM) and nitrogen oxides (NOx), which are now regarded as major environmental pollutants. In particular, nitrogen oxides cause building corrosion and destruction of ecosystems as a major cause of acid rain, and cause various diseases such as pneumonia in the human body.

Recently, exhaust gas regulations for diesel vehicles are becoming strict. Korea is also adopting European standards as a standard for exhaust gas regulation of automobiles, and regulations are being tightened in accordance with recent Euro 6 standards. For example, according to Euro 6, the allowable emission of nitrogen oxides (NOx) should be reduced to 0.4 gkWh or less for medium and large diesel commercial vehicles.

Therefore, in the automotive industry, the development of technologies for reducing nitrogen oxides is a hot topic. In the past, technologies for completely burning nitrogen oxides have been developed as technologies for post-treatment of exhaust gases.

Exhaust gas post-treatment technologies are classified into two types. One is exhaust gas recirculation (EGR), which recirculates exhaust gas. The other is selective catalytic reduction (SCR), which is a selective catalytic reduction technique.

The difference between the two technologies is that EGR reduces the internal combustion temperature of the engine itself, thereby reducing the amount of nitrogen oxides generated at high temperatures around 2000 degrees. The SCR uses exhaust gas that is burned and discharged from the engine as a catalyst It is a cleansing technology.

However, in the case of EGR, since the exhaust gas is recirculated to the intake manifold side to reduce the nitrogen oxides, the combustion temperature itself is lowered and the output of the engine is reduced and the fuel consumption rate is increased. Further, there is a disadvantage that a heat-resistant device for protecting the EGR valve and an EGR cooler are separately required.

On the other hand, in the case of SCR, the fuel consumption is higher than that of EGR because there is no reduction in output, and it is not necessary to provide a heat resistance device at the level of the EGR valve. The principle of SCR is that ammonia (NH3) is injected into the exhaust gas as a reducing agent to react with the catalyst, thereby reducing nitrogen oxides to nitrogen and water which are harmless to the human body.

However, since the SCR system is mounted on the exhaust pipe in which the reducing agent injection unit flows at a high temperature exhaust gas, there is a possibility that the exhaust gas is overheated and damaged by the exhaust gas heat of high temperature during driving of the engine. Therefore, a technology for suppressing the temperature rise of the reducing agent injection unit is separately required There is a drawback to this.

As a technique for suppressing the temperature rise of the reducing agent injection unit, a technique has heretofore been known in which a cooling water channel is formed in a reducing agent injection unit and cooling water is flowed into the reducing agent injection unit to suppress temperature rise. However, it is pointed out that there is a limitation in cooling the reducing agent spraying unit only with summer cooling water having a high outside air temperature.

Japanese Patent Application Laid-Open No. 2008-169711 (Published July 24, 2008) Korean Registered Patent No. 10-1279404 (registered on June 23, 2013)

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a reducing agent spraying apparatus capable of effectively suppressing the overheating of the reducing agent spraying unit by further reducing the temperature of the cooling water by using condensed water discharged from a summer air conditioner evaporator, A unit cooling device, and a control method.

According to an aspect of the present invention,

A reducing agent spraying unit cooling apparatus for circulating cooling water in a reducing agent spraying unit equipped with a spray nozzle for spraying a reducing agent into an exhaust gas to prevent overheating,

A cooling water circulation line connected to the reducing agent injection unit so that the cooling water can circulate through the cooling water flow channel inside the reducing agent injection unit;

A cooling water circulating line for supplying cooling water to the reducing agent spraying unit to control the flow rate of the cooling water supplied to the cooling water flow channel or to allow or block the supply of the cooling water to the cooling water flow channel, A cooling water direction control valve in which a condensed water flow channel is formed;

A condensate storage tank for storing condensed water when the air conditioner is operated; And

And a condensate water supply valve installed in a condensed water supply line connecting the condensate storage tank and the cooling water directional control valve to allow or block the supply of condensed water to the condensed water flow channel,

And when the condensate water control valve is opened, condensate is supplied to the cooling water direction control valve to lower the temperature of the cooling water passing through the cooling water direction control valve.

Here, if the temperature of the cooling water is higher than the pre-input temperature of the control unit, the condensate water valve may be opened and condensed water may be supplied to the cooling water directional control valve.

For example, the condensate intermittent valve is installed in a side cooling water circulation line through which the cooling water exiting the reducing agent injection unit flows, and when the water temperature of the cooling water flowing through the cooling water circulation line is a certain temperature or more, The temperature sensitive material may include a temperature sensitive material.

As another example, the condensate water shut-off valve may be an electronic control valve that is operated in accordance with an electric signal output from a temperature sensor installed in a cooling water circulation line.

According to an aspect of the present invention, there is provided a reductant injection unit cooling apparatus comprising: a condensed water collecting part for collecting condensed water formed on a surface of an evaporator when an air conditioner is operated; And a condensate transfer line configured to transfer the condensed water collected in the condensed water collection unit to the condensed water storage tank.

According to another aspect of the present invention as a solution to the problem,

Determining whether the temperature of the cooling water circulating through the reducing agent injection unit is higher than a pre-input set temperature;

When the temperature of the cooling water is higher than a pre-set set temperature, a condensate water control valve is provided to flow the condensed water to the cooling water direction control valve for interrupting the supply of the cooling water to the reducing agent injection unit to lower the temperature of the cooling water passing through the cooling water direction control valve Performing a control to open the control unit;

Performing control to switch the condensate water valve to the closed position so that the condensed water supply can be interrupted when the temperature of the cooling water falls below the set temperature by supplying the condensed water to the cooling water direction control valve, ≪ / RTI >

According to the reducing agent spraying unit cooling apparatus and the control method of the present invention, the temperature of the cooling water supplied to the reducing agent spraying unit can be lowered by using the condensed water discharged from the air conditioner evaporator. Therefore, it is possible to effectively prevent the reductant spraying unit from being overheated even in the summer when it is difficult to sufficiently cool the reducing agent spraying unit only by the cooling water, and the damage due to overheating can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a nitrogen oxide reduction apparatus comprising a reducing agent injection unit and a cooling device applied thereto according to an embodiment of the present invention; FIG.
2 is a schematic diagram of a reducing agent injection unit cooling apparatus according to an embodiment of the present invention.
FIG. 3A and FIG. 3B are views showing a preferred embodiment of a condensate intermittent valve applied to the reducing agent injection unit cooling apparatus according to the present invention. FIG.
4 is a schematic view showing another preferred embodiment of the reducing agent injection unit cooling apparatus;
5 is a control logic for controlling the reducing agent injection unit cooling device according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. It is to be understood that the terms "comprises", "having", and the like in the specification are intended to specify the presence of stated features, integers, steps, operations, elements, parts or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, the terms " part, "" unit," " module, "and the like, which are described in the specification, refer to a unit for processing at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software .

In the following description with reference to the accompanying drawings, the same reference numerals are given to the same constituent elements, and a duplicate description thereof will be omitted. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

1 is a schematic diagram of a nitrogen oxide reduction apparatus including a reducing agent injection unit and a cooling apparatus applied to the embodiment of the present invention. Hereinafter, the configuration of the nitrogen oxide reduction apparatus will be schematically described.

Referring to FIG. 1, the nitrogen oxide reduction apparatus includes an SCR reactor 20 including an SCR catalyst. A reducing agent injection unit 30 for injecting the reducing agent U into the exhaust gas toward the SCR reactor 20 is connected to the exhaust line in front of the SCR reactor 20 on the basis of the exhaust gas flow, And is connected to the pipe 32 so that the reducing agent U of the reducing agent storage tank 35 can be supplied to the reducing agent injection unit 30.

A reducing agent supply pump 37 is installed in the reducing agent supply pipe 32 for connecting the reducing agent storage tank 35 and the reducing agent injection unit 30. The reducing agent supply pump 37 takes out a reducing agent such as urea water from the reducing agent storage tank 35 and discharges the reducing agent to the reducing agent spraying unit 30 side at a predetermined pressure. The reducing agent spraying unit 30 is connected to the reducing agent spraying unit A reducing agent control valve 310 for controlling the amount of the reducing agent injected through the reducing agent control valve 310 is installed.

The reducing agent control valve 310 is operated according to an instruction of the ECU 100 and the ECU 100 controls the reducing agent control valve 310 based on the information obtained by the sensors S1 and S2 disposed before and after the SCR reactor 20. [ The control value is determined. The opening amount of the reducing agent control valve 310 is adjusted according to the control value determined by the ECU 100 so that the reducing agent can be injected into the exhaust gas at the optimum injection amount and timing in accordance with the exhaust gas temperature and the concentration of the harmful substances.

A cooling water flow channel (300) is formed in the reducing agent spraying unit (30). The cooling water flow channel 300 is provided with a coolant flow channel 300 for supplying cooling water to the coolant flow channel 300 while suppressing a temperature rise so that the coolant supplied from the outside flows through the coolant flow channel 300 and the reductant injection unit 30 exposed to a high temperature environment is not overheated, A circulation line (52) connects the reducing agent spraying unit (30) and the cooling water tank (55) in a coolant circulating manner.

In the cooling water circulation line 52, a cooling water direction control valve 50 is provided in the side cooling water circulation line 52a for supplying the cooling water to the reducing agent injection unit 30. The cooling water direction control valve 50 is operated in accordance with the ECU 100 command based on the exhaust gas temperature information obtained from the above-described sensor to allow / block the supply of cooling water to the reducing agent injection unit 30 by switching the cooling water flow path The flow rate of the cooling water to be supplied is controlled.

On the cooling water circulation line 52a in front of the cooling water directional control valve 50 on the basis of the cooling water flow so that the cooling water C1 can be circulated along the circulation path formed by the cooling water circulation line 52, And a condensate flow channel 500 is formed in the cooling water direction control valve 50 so that the condensed water supplied from the outside can circulate inside and further cool the cooling water.

The condensate water C2 to be supplied to the condensate flow channel 500 is stored in the condensate water storage tank 75. The condensed water stored in the condensed water storage tank 75 may be the condensed water generated in the evaporator 82 when the air conditioner is operated and the stored condensed water C2 may be stored in the condensed water storage tank 75 and the cooling water directional control valve 50 May be supplied to the cooling water directional control valve (30) side through the condensed water supply line (72) when the condensate water valve (70) on the connecting condensate water supply line (72) is opened.

Hereinafter, the reducing agent spraying unit cooling apparatus according to the embodiment of the present invention, which is composed of the cooling water circulation line 52, the cooling water direction control valve 50, the condensed water storage tank 75 and the condensate water shutoff valve 70 do.

2 is a schematic view of a reducing agent injection unit cooling apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the reducing agent injection unit 30 cooling apparatus includes a cooling water circulation line 52, a cooling water direction control valve 50, a condensate storage tank 75, and a condensate intermittent valve 70. The cooling water circulation line 52 is connected to the cooling water supply port SP and the discharge port DP of the cooling water flow channel 300 so that the cooling water circulates through the cooling water flow channel 300 inside the reducing agent injection unit 30, The cooling water direction control valve 50 is provided in the side cooling water circulation line 52 for supplying cooling water to the injection unit 30. [

The cooling water direction control valve 50 is operated in accordance with ECU 100 command based on the exhaust gas temperature information obtained from the above-described sensor to allow / block the supply of cooling water to the reducing agent injection unit 30, And a condensate flow channel 500 is formed therein so that the condensed water C2 supplied from the condensed water storage tank 75 through the condensed water supply line 72 can circulate therein.

The condensate water storage tank 75 stores low temperature condensate water C2 generated by the evaporator 82 when the air conditioner is operated and the condensate water valve 70 connects the condensate water storage tank 75 and the cooling water direction control valve 50 And the condensed water is supplied to the condensed water flow channel (500) formed in the cooling water directional control valve (50). That is, the supply of the condensed water to the condensed water flow channel 500 is allowed or blocked according to the opening / closing state of the condensed water control valve 70.

The condensate intermittent valve 70 is installed in the side cooling water circulation line 52 through which the cooling water exiting the reducing agent injection unit 30 flows and is expanded in volume as the temperature of the cooling water flowing in the cooling water circulation line 52 rises (See FIG. 3A) or an electronic control (not shown) operated under the control of the ECU 100 receiving the output signal of the temperature sensor S3 on the cooling water circulation line 52 Valve (Figure 3b).

The temperature of the cooling water is higher than the temperature preliminarily inputted to the ECU (in the case of the electronically controlled valve, in the case of the temperature responsive valve, the opening temperature of the valve can be set as desired by selecting a spring having an appropriate elastic modulus) When the condensate water shut-off valve 70 is opened, the low-temperature condensate water C2 is supplied to the cooling water direction control valve 50 and performs heat exchange with the cooling water C1 passing through the cooling water direction control valve 50.

In other words, the cooling water C1 passing through the cooling water directional control valve 50 is heat-exchanged with the low-temperature condensate C2 flowing through the cooling water flow channel 300 when the condensate water valve 70 is opened And the cooling water whose temperature is lowered by depriving of heat is supplied to the reducing agent spraying unit 30 through the cooling water circulation line 52, thereby suppressing the overheating of the reducing agent spraying unit 30.

In other words, the reducing agent spraying unit 30 cooling apparatus according to the present invention can be used in a summer, an air conditioner evaporator (not shown) which is difficult to sufficiently cool the reducing agent spraying unit 30 exposed to a high temperature environment by only cooling water cooled to a predetermined temperature while circulating the radiator The temperature of the cooling water is further lowered to the reducing agent spraying unit 30 by using the condensed water discharged from the reducing agent spraying unit 82 so that the overheating of the reducing agent spraying unit 30 can be more effectively suppressed.

FIG. 4 is a perspective view of a reducing agent spraying unit cooling apparatus according to another embodiment of the present invention. Referring to FIG. 4, the reducing agent spraying unit cooling apparatus according to another preferred embodiment of the present invention collects condensed water formed on the surface of the evaporator 82 And a condensed water moving line 92 provided to allow the condensed water collected in the condensed water collecting part 90 to be transferred to the condensed water storage tank 75.

The condensate collection unit 90 is disposed under the evaporator 82 of the HVAC unit (Heating, Ventilation, Air Conditioning unit) 82 capable of implementing heating, ventilation, And the condensate transfer line 92 may be a heat insulating pipe connecting the condensate to the condensate storage tank 75 side without heat loss.

The condensed water collecting unit 90 is located above the condensate storage tank 75 so that the condensed water collected through the condensed water collecting unit 90 can be smoothly moved to the condensate storage tank 75 through the condensate transfer line 920 And the pump P may be disposed in the middle of the condensate transfer line 92 so that the condensed water collected in the condensed water collection unit 90 may be periodically forced to the condensed water storage tank 75.

The cooling process of the reducing agent spraying unit implemented in the reducing agent spraying unit cooling apparatus configured as described above will be described in connection with the control of the cooling apparatus. An example is the case where the condensate control valve is in the form of an electronic control valve that is opened and closed under ECU control.

Referring to the control logic of FIG. 5 and FIG. 2, it is determined whether the temperature of the cooling water circulating in the reducing agent injection unit 30 is higher than a pre-set set temperature. Specifically, the ECU 100 determines whether the temperature of the cooling water is higher than the preset temperature from the temperature sensor output information provided on the cooling water circulation line 52, and opens the condensed water control valve 70 when the temperature is higher than the preset temperature And outputs a control command for controlling the motor.

The cooling water directional control valve 50 for switching the supply of the cooling water to the reducing agent injection unit 30 is switched to the open position by the opening signal outputted by the ECU 100 to the condensate water shutoff valve 70, The low temperature condensate flows into the condensate flow channel 500 of the condenser 500. The low temperature condensed water C2 flowing into the condensate flow channel 500 exchanges heat with the cooling water C1 passing through the cooling water direction control valve 50 and the cooling water C1 is heat-consumed in the process.

In other words, the cooling water (C1) passing through the cooling water directional control valve (50) is heat-exchanged with the low-temperature condensate (C2) flowing in accordance with the opening of the condensate water valve (70) Is supplied to the cooling water flow channel (300) of the reducing agent spraying unit (30) through the cooling water circulation line (52), thereby suppressing the temperature rise of the reducing agent spraying unit (30).

If the temperature of the cooling water that has passed through the reducing agent injection unit 30 by the supply of the condensed water to the cooling water direction control valve 50 following the opening of the condensate water control valve 70 is detected through the temperature sensor, The ECU 100 performs control to switch the condensate water valve 70 to the closed position so that the supply of the condensed water to the cooling water directional control valve 50 side is blocked.

According to the present invention, the temperature of the cooling water supplied to the reducing agent spraying unit can be lowered by using the condensed water discharged from the air conditioner evaporator. Therefore, it is possible to effectively prevent the reductant spraying unit from being overheated even in the summer when it is difficult to sufficiently cool the reducing agent spraying unit only by the cooling water, and the damage due to overheating can be prevented.

In the foregoing detailed description of the present invention, only specific embodiments thereof have been described. It is to be understood, however, that the invention is not to be limited to the specific forms thereof, which are to be considered as being limited to the specific embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. .

10: Exhaust pipe 20: SCR reactor
30: Reducing agent injection unit 32: Reducing agent supply pipe
35: Reducing agent storage tank 37: Reducing agent supply pump
50: Cooling water direction control valve 52: Cooling water circulation line
55: Coolant tank 70: Condensate valve
72: Condensate supply line 75: Condensate storage tank
80: HVAC unit 82: Evaporator
90: Condensate collection part 92: Condensate transfer line
100: ECU 300: cooling water flow channel
310: Reducing agent control valve 500: Condensate flow channel

Claims (7)

1. A reducing agent spraying unit cooling device for circulating cooling water in a reducing agent spraying unit (30) equipped with a spray nozzle for spraying a reducing agent into an exhaust gas to prevent overheating,
When the temperature of the cooling water C1 circulating in the reducing agent spraying unit 30 is higher than the set temperature, the cooling water direction control valve 50 for interrupting the supply of the cooling water to the reducing agent spraying unit 30 is charged with the condensed water C2 To flow through the cooling water direction control valve (50) to lower the temperature of the cooling water (C1) passing through the cooling water direction control valve (50).
1. A reducing agent spraying unit cooling device for circulating cooling water in a reducing agent spraying unit (30) equipped with a spray nozzle for spraying a reducing agent into an exhaust gas to prevent overheating,
A cooling water circulation line (52) connected to the reducing agent spraying unit (30) so that cooling water can circulate through the cooling water flow channel (300) in the reducing agent spraying unit (30);
A cooling water circulation line (52) for supplying cooling water to the reducing agent spraying unit (30) so as to control the flow rate of cooling water to be supplied to or shut off the supply of cooling water to the cooling water flow channel (300) A cooling water direction control valve (50) in which a condensed water flow channel (500) is formed so that the supplied condensed water can circulate inside;
A condensate water storage tank 75 for storing condensate water C2 when the air conditioner is operated; And
A condensate intermittent valve 70 installed in a condensate supply line 72 connecting the condensate storage tank 75 and the cooling water directional control valve 50 to allow or block the supply of condensate to the condensate flow channel 500, ≪ / RTI >
And the condenser water C2 is supplied to the cooling water directional control valve 50 when the condensate water valve 70 is opened to reduce the temperature of the cooling water C1 passing through the cooling water directional control valve 50. [ Device.
3. The method of claim 2,
Wherein when the temperature of the cooling water is higher than a temperature preliminarily inputted to the control unit (ECU), the condensed water control valve (70) is opened and condensed water is supplied to the cooling water directional control valve (50).
The method of claim 3,
The condensate water control valve (70)
And the coolant circulation line 52 is provided with a cooling water circulation line 52b through which the cooling water exiting the reducing agent injection unit 30 flows. When the water temperature of the cooling water flowing through the cooling water circulation line 52 is a certain temperature or more, Wherein the temperature-responsive valve is a temperature-sensitive valve including a temperature-sensitive material.
The method of claim 3,
The condensate water control valve (70)
Is an electronic control valve operated in accordance with an electric signal output from a temperature sensor (S3) provided in a cooling water circulation line (52).
3. The method of claim 2,
A condensed water collecting part 90 for collecting condensed water formed on the surface of the evaporator 82 when the air conditioner is operated; And
And a condensate transfer line (92) configured to transfer the condensed water collected in the condensed water collection section (90) to the condensate storage tank (75).
Determining whether the temperature of the cooling water circulating through the reducing agent injection unit is higher than a pre-input set temperature;
When the temperature of the cooling water is higher than a pre-set set temperature, a condensate water control valve is provided to flow the condensed water to the cooling water direction control valve for interrupting the supply of the cooling water to the reducing agent injection unit to lower the temperature of the cooling water passing through the cooling water direction control valve Performing a control to open the control unit;
Performing control to switch the condensate water valve to the closed position so that the condensed water supply can be interrupted when the temperature of the cooling water falls below the set temperature by supplying the condensed water to the cooling water direction control valve, Way.

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