KR20020049975A - Plasma reaction unit having a variable type electrode - Google Patents

Abstract

PURPOSE: A plasma reactor having a variable electrode is provided to minimize power consumption and reduce exhaust gas according to the flow and concentration of the exhaust gas by varying the length of the electrode. CONSTITUTION: A negative pressure chamber(10) to which the negative pressure of an engine is applied has an inlet(12). A diaphragm(16) is fixed on the inner wall of the negative pressure chamber(10), and the center of the diaphragm(16) is movably installed by a spring(14). A reaction chamber(20) is adjacent to the negative pressure chamber(10). One end of an electrode(24) is fixed on the diaphragm(16) by interposing a pressure plate(18), and the other end of the electrode(24) is longitudinally arranged in the reaction chamber(20) and moves according to the movement of the diaphragm(16). A control unit(32) switches on/off a switching valve(30), and controls the negative pressure of the engine applied to negative pressure chamber(10).

Description

Plasma reactor with variable electrode {PLASMA REACTION UNIT HAVING A VARIABLE TYPE ELECTRODE}

The present invention relates to a plasma reactor having a variable electrode, and more particularly, a variable electrode capable of minimizing power consumption and maximizing exhaust gas reduction efficiency according to the flow and concentration of the exhaust gas by changing the length of the electrode. It is related with the plasma reactor provided.

Diesel engines are highly recommended as an alternative to meet the challenges of gasoline engines, such as thermal efficiency and fuel economy reduction, and the demands of users are rapidly increasing. However, as the use of diesel engines continues to increase, many countries around the world are tightening emission standards for diesel engines. In particular, in western developed countries, there is a strong demand for reducing pollutants emitted from diesel engines.

As these regulations are strengthened, especially in Europe and the United States, there is an urgent need for a new concept of exhaust purification system, which is free from the conventional aftertreatment system. Must be satisfied.

The diesel oxidation catalyst (DOC), which is a post-treatment device of an existing diesel engine, is too difficult to satisfy the new emission regulations in terms of efficiency, and the removal efficiency is very weak until the catalyst activation temperature is reached. In addition, diesel filter (DPF) is difficult to regenerate, causing environmental pollution, the back pressure is large, there is a problem that the output is reduced.

In order to solve these problems, various countermeasures are currently being taken by countries, and among them, an exhaust purification system using plasma that can simultaneously reduce NOx and PM has attracted much attention. On the basis of this background, the research on the plasma apparatus is continuously made, and the shape of the electrode in the plasma apparatus is recognized as a very important technology.

However, the plasma apparatus also has a low removal efficiency, which is a problem for commercialization. In addition, the NOx removal efficiency in the catalyst or plasma reactor is affected by the space velocity of the gas, but an attempt to simply control it by voltage is not very successful. This is due to the disadvantage that the conventional plasma reactor can not change the reactor volume which is a factor of the space velocity to a fixed shape.

As another method, a method of increasing the length of the electrode may be considered. NOx removal efficiency by the length of the electrode tends to be as shown in the graph of FIG. In the graph, the horizontal axis represents the electrode length, and the vertical axis represents the NOx removal rate. As the test conditions, the number of revolutions was 1200 rpm, the load was 7 kg · m, and the flow rate was 20 l / min. The result when there is no is shown.

In this graph, it can be seen that as the length of the electrode is simply increased, the NOx removal efficiency does not increase linearly. This means that there is a minimum electrode length to maximize the NOx removal efficiency. In addition, as the length of the electrode increases, the power consumption increases in proportion, resulting in a waste of power only when the increase in removal efficiency of NOx and particulate matter is not rapid.

The present invention for solving the above problems is to provide a plasma reactor having a variable electrode capable of maximizing the exhaust gas reduction efficiency while preventing power loss in the plasma reactor.

1 is a graph showing the change in electrode length and NOx,

2A and 2B are cross-sectional views showing changes in reaction volume during expansion and compression of the variable electrode of the present invention, respectively.

[Explanation of symbols on the main parts of the drawings]

10: negative pressure chamber 12: inlet hole

14: Spring 16: Diaphragm

18: pressure plate 20: reaction chamber

22: guide 24: electrode

Plasma reactor equipped with a variable electrode of the present invention for achieving the above object is a negative pressure chamber having a vacuum inlet hole, the circumference is fixed on the inner wall of the negative pressure chamber, the central portion is a predetermined range by a spring A diaphragm arranged to be movable in the chamber, a reaction chamber disposed adjacent to the negative pressure chamber, and one end of which is fixed to the diaphragm in the negative pressure chamber via a pressure plate, and the other end is disposed in the reaction chamber in a longitudinal direction to move the diaphragm. And a control unit which controls the negative pressure of the engine acting on the negative pressure chamber by turning on / off the valve based on the electrode moving in the longitudinal direction and the concentration and flow rate of the exhaust gas.

Hereinafter, with reference to the accompanying Figure 2 will be described in detail a plasma reactor having a variable electrode according to a preferred embodiment of the present invention.

2A and 2B are cross-sectional views showing changes in reaction volume during expansion and compression of the variable electrode of the present invention, respectively.

As shown in these figures, in order to minimize the power consumption and reduce the exhaust gas in accordance with the flow and concentration of the exhaust gas in the preferred embodiment of the present invention by using the engine negative pressure electrode disposed in the reaction chamber 20 The structure which varies the length of is employ | adopted.

To this end, a negative pressure chamber 10 having an inlet 12 through which vacuum is applied is disposed adjacent to the reaction chamber 20. In the negative pressure chamber 10, a diaphragm 16 which moves left and right by an engine negative pressure acting through the inlet hole 12 is provided. The circumference of this diaphragm 16 is fixed on the inner wall of the negative pressure chamber 10, and the center part is arrange | positioned so that a movement is possible in the predetermined range by the spring 14. As shown in FIG. The front surface of the reaction chamber 20 facing the negative pressure chamber 10 is attached with a guide 22 for guiding the longitudinal movement of the electrode 24.

One end of the electrode 24 is fixed to the central portion of the diaphragm 16 opposite to the side on which the spring 14 is mounted by the pressure plate 18. And the other end of the electrode 24 is arrange | positioned freely in the longitudinal direction in the reaction chamber 20, and moves to the longitudinal direction in the reaction chamber 20 according to the action of the diaphragm 16. As shown in FIG.

On the other hand, the control unit 32 controls the negative pressure of the engine acting on the negative pressure chamber 10 by turning on / off the valve 30 based on the concentration and flow rate 34 of the exhaust gas input from the sensor unit. And serves to change the length of the electrode 24 in the reaction chamber 20.

In the plasma reactor having a variable electrode having such a configuration, when the control unit 32 determines that the maximum reaction chamber volume is required based on the concentration and the flow rate 34 of the exhaust gas, the control valve 32 is closed. Shut off the negative pressure of the engine. As a result, the diaphragm 16 is urged to the right by the spring 14 as shown in FIG. 2A. As a result, the length of the electrode 24 in the reaction chamber 20 is increased while the electrode 24 moves to the right. It is the maximum.

On the other hand, when the control unit 32 determines that the minimum reaction chamber volume is required based on the concentration and the flow rate 34 of the exhaust gas, the on / off valve 30 is opened to apply the negative pressure of the engine to the negative pressure chamber 10. Let's do it. As a result, the diaphragm 16 overcomes the force of the spring 14 by the engine negative pressure and is pressurized to the left side as shown in FIG. The length of 24 is minimum.

According to the present invention described above, by varying the length of the electrode disposed in the reaction chamber by the action of the negative pressure there is an advantage that can minimize the power consumption according to the flow and concentration of the exhaust gas and maximize the exhaust gas reduction efficiency.

Claims (2)

A negative pressure chamber 10 having an inlet hole 12 in which negative pressure of the engine is applied; The circumference of the diaphragm 16 is fixed on the inner wall of the negative pressure chamber 10, the central portion is arranged to be movable within a predetermined range by the spring 14, A reaction chamber 20 disposed adjacent to the negative pressure chamber 10, One end is fixed to the diaphragm 16 in the negative pressure chamber 10 via the pressure plate 18, and the other end is disposed in the longitudinal direction in the reaction chamber 20 in the longitudinal direction as the diaphragm 16 moves. A moving electrode 24, And a control unit 32 configured to control the negative pressure of the engine acting on the negative pressure chamber 10 by turning on / off the valve 30 based on the concentration and flow rate of the exhaust gas. Plasma reactor. The method of claim 1, Plasma reactor with a variable electrode, characterized in that the guide 22 for guiding the longitudinal movement of the electrode 24 is installed on the front of the reaction chamber 20 facing the negative pressure chamber (10).