KR20030016705A - Exhaust contamination gas decreasing system in diesel engine - Google Patents

Abstract

PURPOSE: A system for reducing pollution in exhaust gas for a diesel engine is provided to reduce the maximum temperature of combustion gas and to reduce the concentration of polluted materials by reducing the temperature of inflow mixed air. CONSTITUTION: A turbocharger supplies external air to an engine through an intercooler(4) and an air connecting line(3). The turbocharger is connected with suction and exhaust intakes. A bypass line(90) circulates exhaust gas toward a suction intake(5) by connecting the intakes. A distributor(30) controls first and second opening and shutting devices(70,80) in the bypass line. A vacuum pump(40) is connected with the distributor through a supply line(50). A fluid detector(10) controls air through a suction line(1). A controller(20) receives a pedal signal, an engine RPM(Revolution Per Minute) and an opened degree signal of the fluid detector by connecting through a signal line(60). A water injecting device injects water to the bypass line according to a control signal of the controller. Thereby, the concentration and the temperature of mixed air are reduced and the generation of polluted material in exhaust gas is reduced.

Description

Exhaust contamination gas reducing system in diesel engine}

The present invention relates to an exhaust gas pollution reduction system of a diesel engine, and more particularly, to an exhaust gas pollution reduction system of a diesel engine that is capable of reducing the amount of pollutants in the exhaust gas that is combusted by mixing water if necessary. will be.

In general, the exhaust gas of diesel engines contains a large amount of harmful components such as CO, HC, and NOx (nitrogen compounds). Of these, NOx has a characteristic of increasing the amount of NOx as the combustion temperature increases, thus reducing the amount of NOx. To this end, various methods for reducing the combustion temperature of the engine have been carried out.

As such, in order to reduce the amount of NOx, which is a pollutant, a method using an exhaust gas recirculation (EGR) device is generally used. Such an exhaust gas recirculation device includes a part of exhaust gas discharged after combustion in the intake mixer. In this case, the mixture is introduced into the combustion chamber, thereby lowering the density of the mixer and lowering the combustion temperature without changing the air-fuel ratio of the mixer.

That is, when the EGR needs to reduce the amount of NOx according to the operating state of the engine, when a part of the exhaust gas is supplied to the intake intake through the EGR valve and introduced into the combustion chamber together with the mixer, the EGR flows into the combustion chamber. Since the exhaust gas is an inert gas and the volume of the intake gas does not change, the density of the mixer is relatively lowered and the combustion speed is lowered by lowering the propagation speed of the flame. do.

Such an exhaust gas recirculation unit is a mediated turbine 8 driven by exhaust gas discharged through an exhaust line 9 connected to an exhaust intake 7 mounted on the engine 6, as shown in FIG. 1. A supercharger composed of a compressor (2) for compressing external air introduced through the furnace intake line (1), and an intercooler provided at the connection line (3) leading from the supercharger to the intake intake (5) mounted on the engine (6). (4) a second end of the bypass line 90, which is built in the engine head provided with the intake / exhaust intakes 5 and 7 and connects them to circulate exhaust gas toward the intake intake 5; Distributor 30 for controlling the 1/2 switchgear (70, 80), the vacuum pump 40 connected to the distributor 30 via the supply line 50 and a signal line for sending a control signal to the distributor (30) The pedal signal and engine speed (RPM) signal that the driver steps on while being connected via (60) It made of a line group (1) controller 20 that receives the two metrology signal of the flow rate detector 10 for controlling the amount of air flowing through.

Here, the distributor 30 is a solenoid type first and second valves 31 and 32 and first and second switch 70 and 80 in the valves 31 and 32 so as to receive signals from the controller 20 separately. Pressing lines 31 'and 32' are connected to each other.

In addition, the supply line 50 of the vacuum pump 40 and the signal line 60 of the controller 20 are also individually connected to the first and second valves 31 and 32 of the distributor 30, of course. to be.

On the other hand, the controller 20 may use a separate computer, but preferably, of course, using the ECU.

Accordingly, the logic signal is processed by the logic set according to the flow rate signal of the flow rate detector 10 transmitted to the controller 20, the depression amount signal of the accelerator pedal, and the signal of the rotational speed RPM according to the operating conditions of the engine 6. The result is transmitted through the first and second signal lines 61 and 62 connected to the first and second valves 31 and 32 of the distributor 30, respectively.

That is, the first and second valves 31 and 32 of the distributor 30 receiving the signal from the controller 20 transmit the vacuum pressure through the first and second supply lines 51 and 52 of the vacuum pump 40. The first and second switchgear 70 and 80 provided at both ends of the bypass line 90 are properly operated to circulate the exhaust gas discharged through the exhaust intake 7 toward the intake intake 5 so as to adjust the density of the mixer. This diminishes to reduce the production of pollutants in the exhaust gas.

However, such an exhaust gas recirculation apparatus is operated by introducing a high pressure exhaust gas into the compressor 8 of the supercharger, so that the operating region of the apparatus is determined by the difference between the exhaust pressure and the intake pressure, even though the small diesel Engines can range from about 40% to 50%, but most medium and large engines can only operate in fairly narrow areas.

Accordingly, there is an urgent need to expand the area of application of the exhaust gas recirculation unit, which is essential for the removal of exhaust gas contaminants in diesel engines, but this is rarely practical, so the exhaust gas recirculation unit operates in some possible application areas. In addition, the development of a device for lowering the maximum temperature of the combustion gas by lowering the temperature of the mixer flowing into the engine 6 is urgently required.

Accordingly, the present invention has been made in view of the above-mentioned matters, and it is possible to reduce the concentration of pollutants while lowering the maximum temperature of the combustion gas by lowering the temperature of the inflow mixer by containing water particles during operation of the exhaust gas recirculation apparatus. The purpose is.

The present invention for achieving the above object, by connecting the intake and exhaust intake connected to the turbocharger supplied to the engine through the intercooler and the air connection line by compressing the external air driven by the exhaust gas inlet exhaust gas A distributor for controlling the first and second opening and closing switches provided at both ends of the bypass line for circulating the intake intake, a vacuum pump connected to the distributor via a supply line, and a signal line for sending control signals to the distributor. And a controller that receives a pedal signal, an engine speed signal, and an opening amount signal of a flow detector for controlling the amount of air flowing through the intake line, and water injection means for injecting water into the bypass line according to the control signal of the controller. It is characterized by.

1 is a configuration diagram of an exhaust gas recirculation system of a general diesel engine

2 is a system for reducing exhaust gas pollution of a diesel engine according to the present invention.

3 is a partial cross-sectional view of the nozzle for water jet according to FIG.

<Description of the symbols for the main parts of the drawings>

1: Intake Line 2: Compressor

3: air connection line 4: intercooler

5: intake intake 6: engine

7: exhaust intake 8: turbine

9: exhaust line 10: flow rate detector

20 controller 30 dispenser

30 ', 31', 32 ': Pressurized line 31: First valve

32: second valve 40: vacuum pump

50: supply line 51, 52: first and second line

60: signal lines 61, 62: first and second signal lines

70,80: 1st and 2nd switchgear 90: bypass line

90 ': EGR cooler

100: water tank 110: pump

120: on-off valve 130: supply line

140: nozzle 150: pressure valve

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

Figure 2 shows the exhaust gas pollution reduction system of the diesel engine according to the present invention, the present invention is the engine through the intercooler (4) and the air connecting line (3) by compressing the outside air driven by the exhaust gas First and second opening and closing devices provided at both ends of the bypass line 90 for circulating the exhaust gas toward the intake intake 5 by connecting between intake and exhaust intakes 5 and 7 connected to the supercharger to be supplied to (6). Distributor 30 for controlling the 70, 80, the vacuum pump 40 connected to the distributor 30 via the supply line 50, the signal line 60 to send a control signal to the distributor 30 The controller 20 and the controller 20 which receive the signal of the opening degree of the flow rate detector 10 which controls the pedal signal and the engine speed (RPM) signal and the amount of air flowing through the intake line 1 while being connected via Water injection means for injecting water to the bypass line 90 in accordance with the control signal of It consists of.

Here, the water spray means is a water tank 100 for supplying water through the nozzle 140 provided at the end of the supply line 130 leading to the bypass line 9, the crankshaft and the fluid of the engine A pump 110 for pumping out water from the water tank 100 and connected to a clutch, and an opening / closing valve 120 for opening and closing the supply line 130 according to a control signal of the controller 20 and the opening / closing thereof. When the pressure of the valve 120 is excessively increased, the pressure valve 150 returns to the tank 100.

The nozzle 140 uses a pintle nozzle as shown in FIG. 3.

In addition, the bypass line 90 is connected between the rear end of the exhaust intake 7 and the front end of the intake intake 5 so that the EGR cooler 90 'is exposed to the outside of the engine head. The water is circulated to the intake intake 5.

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

First, as in the conventional case described above, the density of the mixer is reduced to reduce the generation of pollutants in the exhaust gas. That is, the controller 20 causes the flow rate signal of the flow rate detector 10 and the depression amount signal of the accelerator pedal and the engine ( When the result processed by the logic set according to the signal of the RPM (RPM) according to the operating conditions of 6) is sent to the distributor 30, the distributor 30 receiving the signal of the controller 20 is a vacuum pump ( The exhaust gas discharged through the exhaust intake (7) is operated by appropriately operating the first and second openers (70, 80) provided at both ends of the bypass line (90) by receiving the vacuum pressure of 40. Circulation to reduce the density of the mixer, reducing the generation of pollutants in the exhaust gas.

At the same time, the water spraying means according to the present invention pumps the water in the water tank 100 while the pump 110 is rotated together through the fluid clutch by the crankshaft rotated together with the operation of the engine tank 100 Will create my pressure.

Subsequently, when a situation in which pollutants are generated above a reference value by measuring, for example, an engine temperature or a rotational speed (RPM) according to the set condition of the controller 20 is recognized, the present invention is a mixer introduced into the engine. At the same time lowering the density of the temperature is lowered, that is, the controller 20 opens the open valve 120 of the water injection means 100 through the supply line 130 connected to the bypass line 90 As a result, the water supplied through the supply line 130 is sprayed through the nozzle 140 and the temperature is reduced by the water through the EGR cooler 90 'of the bypass line 90. The mixed exhaust gas is mixed with a mixer flowing into the intake intake 5 to reduce the density of the mixer flowing into the engine and to enter the combustion chamber at a lowered temperature.

In other words, the hot exhaust gas is cooled down with water, and the exhaust gas is mixed with the mixer flowing into the combustion chamber of the engine to simultaneously reduce the density and temperature of the mixer, and to reduce Nox, PM, Co, etc. in the exhaust gas. Will reduce the production of pollutants.

On the other hand, when the controller 20 determines that the temperature reduction of the mixer is no longer necessary and closes the opening valve 120 to operate the water injection means, the tank 100 is continuously rotated together with the crankshaft pump 110. In this way, if the pressure in the tank 100 rises above a certain level, the pressure valve 150 provided in the tank 100 is opened by the elevated pressure to discharge water to prevent the pressure rise. Of course.

As described above, according to the present invention, the exhaust gas is introduced into the mixer and the density thereof is reduced, while the density of the mixture is also introduced into the engine while the temperature is also reduced. There is an effect that can reduce the production of the material double.

Claims (3)

A distributor 30 for controlling the first and second openers 70 and 80 provided at both ends of the bypass line 90 for circulating the exhaust gas to the intake intake 5, and a supply line to the distributor 30. A pedal signal and an engine speed (RPM) signal and an intake line (1) which the driver steps on while being connected via a vacuum pump 40 connected through a 50 and a signal line 60 which sends a control signal to the distributor 30 through a medium. And a water injection means for injecting water into the bypass line 90 according to the control signal of the controller 20 and the controller 20 receiving the opening amount signal of the flow rate detector 10 for controlling the amount of air flowing through Exhaust gas pollution reduction system of diesel engine. The water tank of claim 1, wherein the water spraying means comprises a water tank 100 for supplying water through a nozzle 140 provided at an end of a supply line 130 leading to the bypass line 9, and an engine. Opening and closing valve 120 is connected to the crankshaft and the fluid clutch to open and close the supply line 130 in accordance with the control signal of the pump 110, the controller 20 for pumping out water from the water tank 100. And a pressure valve 150 which returns to the tank 100 when the pressure of the on / off valve 120 is excessively increased. The system of claim 1, wherein the bypass line (90) is exposed to the outside of the engine head while the EGR cooler (90 ') is installed.