CN102781157A - Planar jet flow plasma generating device - Google Patents

Abstract

The invention discloses a planar jet plasma generating device, which mainly solves the problems of poor plasma stability, high temperature, small area, uneven distribution of density and flow velocity in the current jet plasma generating device. The whole device includes a plasma generating chamber (2), a power supply device (3) and an air pressure regulating device (5). The jet cavity (4) is connected; the inlet end of the flow guiding device (1) is connected with the air pressure adjustment device (5) at the gas outlet end of the plasma jet cavity (4), and electrodes are opened on the plasma jet cavity (4) The through hole and the observation window are used for applying an orthogonal electromagnetic two-dimensional field; the power supply device (3) provides power for the plasma generation cavity (2). The invention prolongs the duration of plasma, reduces the temperature of plasma, expands the area of uniform plasma, and can be used to study the influence of electromagnetic field on jet plasma.

Description

Plane Jet Plasma Generator

technical field

The invention belongs to the field of gas discharge plasma, and in particular relates to a plane jet plasma generating device, which can be used to generate large-area uniform jet plasma and quantitatively study the influence of electromagnetic two-dimensional field on plasma fluid.

Background technique

The study of the influence of the electromagnetic two-dimensional field on the plasma fluid is the basis of the spacecraft loading research. The real experiment needs a plasma generation device that can generate a large-area density controllable and uniform two-dimensional distribution of uniform flow for a long time. The existing devices for generating plasma on the ground mainly include shock tubes, plasma jets, and glow plasma jets. These devices have the following insurmountable shortcomings:

1. The shock tube uses the instantaneous high temperature generated by the high pressure difference to generate plasma, which lasts for a very short time, has poor stability, and is difficult to control.

2. The plasma temperature generated by the plasma jet is high, the plasma density and distribution are difficult to control, and the external electrodes are ablated at high temperature, and there are metal ions in the plasma, which causes the error of the electromagnetic weakening experiment.

3. Although the plasma generated by glow discharge can work for a long time, the electron density can be continuously adjusted, and it is relatively stable, but the generated plasma is basically a long arc turbulent plasma with a two-dimensional density. The distribution area is small and uneven, so it is impossible to quantitatively study the influence of the electromagnetic two-dimensional field on the plasma fluid.

Contents of the invention

The purpose of the present invention is to provide a planar jet plasma generating device for the above-mentioned deficiencies in the prior art, so as to prolong the duration, reduce the temperature, and expand the area of uniform plasma.

To achieve the above object, the present invention includes: a plasma generation chamber 2, a power supply device 3 and an air pressure regulating device 5, the power supply device 3 provides power for the plasma generation chamber 2, and is characterized in that: the left side of the plasma generation chamber 2 The side and the right side are respectively connected with a flow guiding device 1 and a plasma jet cavity 4; the air inlet end of the flow guiding device 1 and the gas outlet end of the plasma jet cavity 4 are connected with an air pressure regulating device 5, and the plasma jet cavity 4 There are electrode through holes and observation windows for applying an orthogonal electromagnetic two-dimensional field; the gas is filled into the flow guide device 1 from the air pressure adjustment device 5, and flows into the plasma generation chamber 2 after being stabilized by the flow guide device. Plasma is generated by discharge in the plasma generation cavity, flows into the plasma jet cavity 4 , and then flows out through the air pressure regulating device 5 .

Preferably, the flow guide device 1 includes: a needle valve 101, a first flange 102, a baffle 103 and a first air gauge 106; one end of the needle valve 101 is fixed on the left end of the first flange 102, and the other end is connected to the left end of the first flange 102. The air pressure regulating device 5 is connected; the first air gauge 106 is fixed on the lower end of the first flange 102 for measuring the air pressure of inflation; the baffle plate 103 is placed in the right end groove of the first flange 102; the first flange 102 passes through The knob is connected with the plasma generation cavity 2 .

Preferably, the plasma generation chamber 2 includes: a second flange 206, a cylindrical electrode 201, a cylindrical electrode 204 and a third flange 207; the second flange 206 and the third flange 207 are connected At the through-hole ends on both sides of the cylindrical electrode 201, which are left and right symmetrical; the upper and lower sides of the cylindrical electrode 201 are respectively fixed with circular hollow covers 205, and are sealed by squeezing the first sealing rubber pad 203; the circular tubular electrode 204 Insert the cylindrical electrode 201 through the central hole of the circular hollow cover 205, fix it coaxially on the upper and lower ends of the cylindrical electrode 201, and squeeze the second sealing rubber pad 208 through the nut to seal; the cylindrical electrode 204 It is connected to the power supply device 3 through wires; the third flange 207 is connected to the plasma jet cavity 4 .

As preferably, the plasma jet cavity 4 includes: a fourth flange 403, a cuboid cavity 401 and a horn-shaped guide groove 404; the fourth flange 403 is fixed on the left side of the cuboid cavity 401; the horn The big horn mouth of type diversion groove 404 is fixed on the right side of cuboid cavity body 401; The small horn mouth of horn shape diversion groove 404 is fixed with air extraction valve 405, and this air extraction valve 405 is connected with air pressure regulating device 5; The left and right sides of the rectangular parallelepiped cavity 401 are provided with a first diversion groove 408 and a second diversion groove 409; the front and rear sides of the rectangular parallelepiped cavity 401 are provided with observation windows 402, and the observation windows 402 are sealed and fixed, and externally applied Magnetic field: a first through hole 410 and a second through hole 411 are opened on the upper side of the cuboid cavity 401 , and electrodes are inserted into the two through holes to apply an electric field.

Preferably, the air pressure regulating device 5 includes: a second air gauge 501, an air pump 502 and an air tank 503; the air tank 503 is connected with the needle valve 101, and the air pump 502 is connected with the air valve 405; the second air gauge 501 is fixed The suction port of the suction pump 502 is used to measure the suction pressure.

Compared with the existing ground plasma device, the present invention has the following advantages:

1. The present invention improves the stability of the air flow and forms a uniform flow field due to the adoption of the flow guiding device.

2. The present invention prolongs the duration of the plasma and improves the repeatability of the test due to the use of the plasma generation chamber and the principle of low-pressure glow discharge.

3. Due to the use of the plasma jet cavity, the present invention expands the area of the uniform flow velocity region of the plasma jet, and can apply an orthogonal electromagnetic field to the plasma, realizing the research on the electromagnetic suppression method of the plasma. The present invention will be further described below in conjunction with accompanying drawing:

Description of drawings

Fig. 1 is the plan view of the overall structure of the jet plasma generating device of the present invention;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is a structural diagram of the plasma jet cavity in the present invention.

Detailed ways

Referring to Fig. 1 and Fig. 2, the planar jet plasma generating device of the present invention comprises: a flow guiding device 1, a plasma generating chamber 2, a power supply device 3, a plasma jet chamber 4 and an air pressure regulating device 5, the plasma The generating cavity 2 is respectively connected with the flow guide device 1, the power supply device 3 and the plasma jet cavity 4, and the air pressure regulating device 5 is respectively connected with the flow guide device 1 and the plasma jet cavity 4, and the plasma jet cavity 4 is opened. There are electrode through holes and observation windows, which are used to apply an orthogonal electromagnetic two-dimensional field; the gas is filled into the flow guide device 1 from the air pressure adjustment device 5, and flows into the plasma generation chamber 2 after being stabilized by the flow guide device. Plasma is generated by discharge in the plasma jet generation cavity, flows into the plasma jet cavity 4, and then flows out through the air pressure regulating device 5. in:

The deflector 1 includes a needle valve 101, a first flange 102, a baffle 103 and an air gauge 106; one end of the needle valve 101 is fixed on the left end of the first flange 102, and the baffle 103 is placed on the right end of the first flange 102. In the slot, evenly arranged circular through holes 107 are opened on the baffle plate 103;

The plasma generation cavity 2 includes a cylindrical electrode 201, a circular shell cover 205, a cylindrical electrode 204, a second flange 206 and a third flange 207; the left and right symmetrical sides of the cylindrical electrode 201 are provided with Through holes, the second flange 206 and the third flange 207 are respectively connected to the through hole ends of the left and right sides of the cylindrical electrode 201 by welding; The upper and lower sides, and are sealed by squeezing the first sealing rubber pad 203; the cylindrical electrode 201 is grounded; the cylindrical electrode 204 is inserted into the cylindrical electrode 201 through the central hole of the circular hollow cover 205, and is connected with the cylinder Tubular electrode 201 is coaxially placed, and the upper and lower ends of round tubular electrode 204 are fixed with fastening nuts and circular hollow cover 205, and are sealed by extruding second sealing rubber pad 208;

Power supply unit 3, including a controllable AC power supply, with an output voltage range of 0-500V, a maximum power of 1KW, and an output frequency of 20KHz;

Referring to Fig. 3, the plasma jet cavity 4 includes a fourth flange 403, a cuboid cavity 401 and a trumpet-shaped diversion groove 404; the left and right sides of the cuboid cavity 401 are provided with a first diversion groove 408 and a second Two diversion grooves 409 are used to stabilize the flow rate of the plasma jet. There are observation windows 402 on the front and rear sides, which are sealed and fixed by fastening nuts for observing the plasma jet. The upper side of the cuboid cavity 401 has two openings. A through hole 410 and 411, an electrode 412 is inserted in the first through hole 410 and the second through hole 411, the electrode is connected to a DC voltage source 413, an electric field is applied, and a constant magnetic field perpendicular to the electric field is applied outside the observation window 402; The fourth flange 403 is connected to the left end of the rectangular parallelepiped cavity body 401 by welding, the large bell mouth of the horn-shaped diversion groove 404 is connected to the right end of the rectangular parallelepiped cavity body 401 by welding, and the air extraction valve 405 is fixed on the small bell mouth;

The air pressure regulating device 5 includes an air gauge 501 , an air extraction pump 502 and an air tank 503 ; the air pressure gauge 501 is connected to the air extraction pump 502 through a conduit for measuring the air pressure at the air extraction valve 405 .

The structural relationship between the above components is as follows:

The other end of the needle valve 101 of the flow guiding device 1 is connected to the air pressure regulating device 5, the first flange 102 is fixed with the second flange 206 of the plasma generation chamber 2 by a fastening knob 105, and is sealed by pressing the third The rubber pad 104 is sealed; the circular tubular electrode 204 of the plasma generation cavity 2 is connected with the power supply unit 3 by a wire; the third flange 207 of the plasma generation cavity 2 adopts the fastening knob 406 and the The fourth flange 403 is connected and sealed by squeezing the fourth sealing rubber pad 407; the AC voltage source of the power supply device 3 supplies power to the plasma generation chamber 2, one end of which is connected to the circular tubular electrode 204, and the other end is grounded. Adjust the power supply voltage to control the plasma electron density generated by the plasma generation chamber 2 between 10 ⁸ cm ⁻³ and 10 ¹² cm ⁻³ ; The air pump 502 of the air pressure regulating device 5 is connected to the needle valve 101 of the flow guiding device 1, and the needle valve is adjusted by observing the values of the air pressure gauge 501 of the air pressure regulating device 5 and the pressure gauge 106 of the flow guiding device 1 The air intake rate of 101 is used to control the air pressure in the plasma generation cavity 2 and the flow rate in the plasma jet cavity 4 .

The working principle of the present invention is as follows:

First, tighten the fastening knob 105, the fastening knob 202 and the fastening knob 406, and close the needle valve 101; then turn on the air pump 502, start pumping air, and wait until the barometer 501 is stabilized at 20Pa, open the needle valve 101, and inject air into the plasma. The cavity 2 is filled with inert gas or air, and the air pressure starts to rise at this time, and the pumping is continued to fill the cavity with inert gas or air; when the barometer 501 is maintained at 20Pa again, the barometer 106 is maintained at a certain value of 50-300Pa When setting the value, turn on the power supply device 3 and output 500V AC voltage; at this time, the voltage between the outer wall of the cylindrical electrode 204 and the inner wall of the cylindrical electrode 201 rises rapidly, and a radial electric field is formed, and a small amount of free gas in the gas The electrons are accelerated by the electric field and collide with the atoms and molecules in the gas, and transfer their own kinetic energy to the atoms and molecules, causing them to ionize free electrons and positive ions, thereby increasing the electron density, which will also increase the electron density. Increase the recombination rate of electrons and ions, and eventually, the production rate and disappearance rate of electrons will reach a balance, and the electron density will stabilize. At this time, the gas in the plasma generating chamber 2 is ionized, realizing glow discharge. Due to the air pressure difference generated by the flow guiding device 1 and the plasma jet cavity 4, the flow guiding effect of the baffle plate 103 and the flow guiding groove of each device forms a stable and uniform flow field flowing from the flow guiding device 1 to the plasma jet cavity 4, At the same time, due to the low air pressure in the plasma generation cavity 2 and the plasma jet cavity 4, the free path of the electrons is very long, and the electrons will diffuse into the entire plasma jet cavity 4 along with the stable and uniform flow field, forming a large area of electrons. Plasma planar jet with uniform density and velocity. Then turn on the DC voltage source 413, and apply an orthogonal constant magnetic field outside the observation window 402. At this time, the experiment of the influence of the electric field and the magnetic field on the jet plasma can be carried out.

The above examples are only for reference and description of the present invention, and do not constitute any limitation to the content of the present invention.

Claims (10)

1. plane jet plasma generating device; Comprise: plasma generation cavity (2), supply unit (3) and barometric control unit (5); Supply unit (3) provides power supply for plasma generation cavity (2), it is characterized in that: the left side of plasma generation cavity (2) and right side are connected with guiding device (1) and plasma jet cavity (4) respectively; The outlet side of the inlet end of guiding device (1) and plasma jet cavity (4) is connected with barometric control unit (5), and plasma jet cavity (4) has electrode through hole and observation window, is used to apply quadrature electromagnetism two dimensional field; Gas charges into guiding device (1) from barometric control unit (5); Behind the guiding device current stabilization, flow in the plasma generation cavity (2); Discharge generation plasma in the plasma generation cavity; Flow in the plasma jet cavity (4), flow out through barometric control unit (5) again.

2. device according to claim 1 is characterized in that: guiding device (1) comprising: needle-valve (101), first flange (102), baffle plate (103) and first barometer (106);

One end of needle-valve (101) is fixed on the left end of first flange (102), and the other end is connected with barometric control unit (5);

First barometer (106) is fixed on the lower end of first flange (102), is used to measure the air pressure of inflation;

Baffle plate (103) is placed in the right-hand member groove of first flange (102);

First flange (102) is connected with plasma generation cavity (2) through knob.

3. device according to claim 2 is characterized in that having on the baffle plate (103) evenly distributed manhole (107), so that it is even to flow into the air-flow of plasma generation cavity (2).

4. device according to claim 1 is characterized in that plasma generation cavity (2) comprising: second flange (206), cylinder electrode (201), tubular electrode (204) and the 3rd flange (207);

Second flange (206) and the 3rd flange (207) are connected the symmetrical both sides of cylinder electrode (201) through hole end;

Cylinder electrode (201) both sides up and down is fixed with circular hollow lid (205) respectively, and seals through extruding first seal gasket (203).

Tubular electrode (204) inserts in the cylinder electrode (201) through the centre bore of circular hollow lid (205), the coaxial two ends up and down that are fixed on cylinder electrode (201), and push second seal gasket (208) through nut and seal;

Tubular electrode (204) is connected with supply unit (3) through lead;

The 3rd flange (207) is connected with plasma jet cavity (4).

5. device according to claim 2; First flange (102) that it is characterized in that guiding device (1) adopts tightening knob (105) fixing with second flange (206) of plasma generation cavity (2), and seals through extruding the 3rd seal gasket (104).

6. device according to claim 1 is characterized in that plasma jet cavity (4) comprising: the 4th flange (403), cuboid cavity (401) and trumpet type guiding gutter (404);

The 4th flange (403) is fixed on the left side of cuboid cavity (401);

The typhon mouth of trumpet type guiding gutter (404) is fixed on the right side of cuboid cavity (401);

The toy trumpet mouth of trumpet type guiding gutter (404) is fixed with extraction valve (405), and this extraction valve (405) is connected with barometric control unit (5).

7. device according to claim 6 is characterized in that the left and right sides of cuboid cavity (401) has first guiding gutter (408) and second guiding gutter (409); The both sides, front and back of cuboid cavity (401) have observation window (402), observation window (402) sealing and fixing, and the outside applies magnetic field; The upside of cuboid cavity (401) has first through hole (410) and second through hole (411), in these two through holes, inserts electrode and applies electric field.

8. according to claim 4 or 6 described devices, it is characterized in that the 3rd flange (207) and the 4th flange (403) are fixing through tightening knob (406), and seal through extruding the 4th seal gasket (407).

9. device according to claim 1 is characterized in that barometric control unit (5) comprising: second barometer (501), aspiration pump (502) and gas tank (503);

Gas tank (503) is connected with needle-valve (101), and aspiration pump (502) is connected with extraction valve (405);

Second barometer (501) is fixed on the bleeding point of aspiration pump (502), is used for measuring the air pressure of bleeding.

10. device according to claim 1 is characterized in that the employing aluminum of plasma generation cavity (2) and plasma jet cavity (4) and plating nickel on surface.

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