Additional electrode ceramic channel structure for reducing wall surface energy loss

Abstract

The invention discloses an additional electrode ceramic channel structure for reducing energy loss of a wall surface, belongs to the field of Hall thrusters, and aims to solve the problem of energy loss caused by bombardment of a large number of ions near a channel outlet position to the wall surface when the conventional Hall thruster works. According to the scheme, a ceramic channel is an annular channel with an upper opening, circumferential cutting grooves are formed in the opposite positions of the inner ring wall face and the outer ring wall face of a channel outlet respectively, and an inner ring additional metal electrode and an outer ring additional metal electrode are embedded in the two circumferential cutting grooves respectively; each circumferential cutting groove is communicated with the outside through two symmetrical radial through holes; the inner electrode positive conductive column and the inner electrode negative conductive column are respectively inserted into two radial through holes symmetrically formed in the inner ring and are connected with the inner ring additional metal electrode; and the outer electrode positive conductive column and the outer electrode negative conductive column are respectively inserted into two radial through holes symmetrically formed in the outer ring and are connected with the outer ring additional metal electrode.

Description

Technical Field

[0001] The invention relates to a ceramic channel structure of a Hall thruster, belonging to the field of Hall thrusters. Background Art

[0002] Hall thruster is a widely used electric propulsion device. It has the advantages of simple structure, high reliability, high specific impulse, high efficiency and long life. It is suitable for high-precision on-orbit tasks such as attitude control of spacecraft, north-south position keeping, and deep space exploration. Its working principle is: a radial magnetic field is formed in the channel by an energized coil or a permanent magnet, and an axial electric field is formed between the anode and the cathode. The electrons emitted by the cathode move toward the anode under the action of the orthogonal electromagnetic field, and at the same time ionize the atoms through collision with them. The generated ions are accelerated and ejected under the action of the electric field to form thrust.

[0003] Hall thrusters generally use ceramic materials as the wall of the channel. Due to the existence of the wall sheath, the potential at the center of the channel will be higher than the potential at the wall, so there is an electric field component perpendicular to the wall in the electric field of the channel. This will cause the ions generated by partial ionization to collide with the wall under the action of the radial electric field component, resulting in energy loss. Summary of the invention

[0004] Aiming at the problem that a large number of ions bombard the wall near the channel outlet when the existing Hall thruster is working, causing energy loss, the present invention provides an additional electrode ceramic channel structure for reducing the wall energy loss.

[0005] The invention discloses an additional electrode ceramic channel structure for reducing wall energy loss. An additional metal electrode is arranged at the ceramic channel outlet. A positive electric field pointing to the channel is formed near the additional metal electrode. The positive electric field pointing to the channel is used to suppress the electric field of ions moving toward the wall.

[0006] Preferably, an additional electrode ceramic channel structure for reducing wall energy loss comprises a ceramic channel 1, an inner ring additional metal electrode 2, an outer ring additional metal electrode 3, an inner electrode positive conductive column 4, an inner electrode negative conductive column 5, an outer electrode positive conductive column 6 and an outer electrode negative conductive column 7;

[0007] The ceramic channel 1 is an annular channel with an upper opening, and circumferential grooves are respectively provided at relative positions of the inner ring wall and the outer ring wall at the channel outlet, and the inner ring additional metal electrode 2 and the outer ring additional metal electrode 3 are respectively embedded in the two circumferential grooves;

[0008] Each circumferential groove is connected to the outside world through two symmetrical radial through holes;

[0009] The inner electrode positive conductive column 4 and the inner electrode negative conductive column 5 are respectively inserted into two radial through holes symmetrically arranged on the inner ring and connected to the inner ring additional metal electrode 2;

[0010] The outer electrode positive conductive column 6 and the outer electrode negative conductive column 7 are respectively inserted into two radial through holes symmetrically arranged on the outer ring and connected to the outer ring additional metal electrode 3.

[0011] Preferably, the ceramic channel 1 is made of ceramic material.

[0012] Preferably, the ceramic channel 1 is integrally formed by using 3D ceramic printing technology.

[0013] Preferably, the inner ring additional metal electrode 2, the outer ring additional metal electrode 3, the inner electrode positive conductive column 4, the inner electrode negative conductive column 5, the outer electrode positive conductive column 6 and the outer electrode negative conductive column 7 are made of molybdenum.

[0014] Preferably, the inner electrode positive conductive column 4 and the inner electrode negative conductive column 5 are connected to the inner ring additional metal electrode 2 by welding, and the outer electrode positive conductive column 6 and the outer electrode negative conductive column 7 are connected to the outer ring additional metal electrode 3 by welding.

[0015] Preferably, the inner electrode positive conductive column 4 and the outer electrode positive conductive column 6 are connected to the Hall thruster power supply anode, and the inner electrode negative conductive column 5 and the outer electrode negative conductive column 7 are connected to the Hall thruster power supply negative electrode.

[0016] Beneficial effects of the present invention: The present invention adds a metal electrode at the channel outlet through structural design, provides a fixed positive potential to the additional electrode through a conductive column, forms an electric field at the wall position to suppress the movement of ions toward the wall, effectively reduces the bombardment of ions on the channel outlet wall, reduces wall energy loss, and better improves the efficiency of the thruster. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional structural schematic diagram of an additional electrode ceramic channel structure for reducing wall energy loss according to the present invention;

[0018] Figure 2 yes Figure 1 A schematic diagram of a half-cut three-dimensional structure;

[0019] Figure 3 It is a three-dimensional structural schematic diagram of the connection relationship between the additional metal electrode and the conductive column;

[0020] Figure 4 yes Figure 1 A schematic diagram of a half-cutaway three-dimensional structure of a device, in which an anode is installed at the bottom of the channel;

[0021] Figure 5 yes Figure 4 A sectional plan view of

[0022] Figure 6This is a comparison diagram of the radial electric field at the channel outlet under the additional electrode ceramic channel structure and the pure ceramic wall structure in Example 1;

[0023] Figure 7 This is a comparison result of the ion flux on the inner wall of the channel under the additional electrode ceramic channel structure and the pure ceramic wall structure in Example 1;

[0024] Figure 8 This is a comparison result of the ion flux on the outer wall of the channel under the additional electrode ceramic channel structure and the pure ceramic wall structure in Example 1;

[0025] Figure numerals: 1. Ceramic channel, 2. Additional metal electrode in the inner ring, 3. Additional metal electrode in the outer ring, 4. Inner electrode positive conductive column, 5. Inner electrode negative conductive column, 6. Outer electrode positive conductive column, 7. Outer electrode negative conductive column, 8. Anode, 9. Anode conductive column. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0028] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0029] Specific implementation method 1: The following is combined Figures 1 to 8 To illustrate this embodiment, the embodiment described in this embodiment is an additional electrode ceramic channel structure for reducing wall energy loss, wherein an additional metal electrode is arranged at the outlet of the ceramic channel, and a positive electric field pointing to the channel is formed near the additional metal electrode. The positive electric field pointing to the channel is used to suppress the movement of ions toward the wall.

[0030] An additional electrode ceramic channel structure for reducing wall energy loss comprises a ceramic channel 1, an inner ring additional metal electrode 2, an outer ring additional metal electrode 3, an inner electrode positive conductive column 4, an inner electrode negative conductive column 5, an outer electrode positive conductive column 6 and an outer electrode negative conductive column 7;

[0031] The ceramic channel 1 is an annular channel with an upper opening, and circumferential grooves are respectively provided at relative positions of the inner ring wall and the outer ring wall at the channel outlet, and the inner ring additional metal electrode 2 and the outer ring additional metal electrode 3 are respectively embedded in the two circumferential grooves;

[0032] Each circumferential groove is connected to the outside world through two symmetrical radial through holes;

[0033] The inner electrode positive conductive column 4 and the inner electrode negative conductive column 5 are respectively inserted into two radial through holes symmetrically arranged on the inner ring and connected to the inner ring additional metal electrode 2;

[0034] The outer electrode positive conductive column 6 and the outer electrode negative conductive column 7 are respectively inserted into two radial through holes symmetrically arranged on the outer ring and connected to the outer ring additional metal electrode 3.

[0035] The ceramic channel 1 is made of ceramic material.

[0036] The ceramic channel 1 is integrally formed by 3D ceramic printing technology, and then fine-tuned in size by mechanical processing.

[0037] The inner ring additional metal electrode 2, the outer ring additional metal electrode 3, the inner electrode positive conductive column 4, the inner electrode negative conductive column 5, the outer electrode positive conductive column 6 and the outer electrode negative conductive column 7 are made of molybdenum material.

[0038] The inner electrode positive conductive column 4 and the inner electrode negative conductive column 5 are connected to the inner ring additional metal electrode 2 by welding, and the outer electrode positive conductive column 6 and the outer electrode negative conductive column 7 are connected to the outer ring additional metal electrode 3 by welding.

[0039] The inner electrode positive conductive column 4 and the outer electrode positive conductive column 6 are connected to the Hall thruster power supply anode, and the inner electrode negative conductive column 5 and the outer electrode negative conductive column 7 are connected to the Hall thruster power supply negative electrode.

[0040] See also Figure 4 The anode 8 is installed at the bottom of the ceramic channel 1, and the anode 8 is connected to an external power source through an anode conductive column 9. The anode 8 is responsible for providing the anode voltage required for the thruster to work.

[0041] Working process: The inner electrode positive conductive column 4 and the outer electrode positive conductive column 6 are connected to the Hall thruster power supply anode, and the inner electrode negative conductive column 5 and the outer electrode negative conductive column 7 are connected to the Hall thruster power supply negative electrode. The inner electrode positive conductive column 4 and the outer electrode positive conductive column 6 are energized to provide a positive potential to the inner ring additional metal electrode 2 and the outer ring additional metal electrode 3, and a positive electric field pointing to the channel is formed near the additional metal electrode. This electric field can reduce the collision of ions with the wall. When electrons and ions collide with the additional electrode, current will pass through the inner electrode negative conductive column 5 and the outer electrode negative conductive column 7 to form a loop.

[0042] The following examples further illustrate the difference in wall energy loss between an additional electrode channel structure for reducing wall energy loss and a pure ceramic wall.

[0043] Example 1, the thruster discharge process is simulated using a widely used SPT-100 Hall thruster with a standard size, a channel inner diameter of 36mm, an outer diameter of 50mm, and a discharge channel axial length of 20mm. The pure ceramic wall is made of BN ceramic wall. The additional electrode structure is installed at 16-19mm of the channel length, with a total length of 3mm. Molybdenum material is selected as the additional metal electrode, and the ceramic wall structure is made of BN ceramic wall. Under the conditions of an anode voltage of 900V and a krypton gas flow rate of 40sccm, the radial potential distribution at the channel outlet is as follows: Figure 6 As shown. Under the condition of pure ceramic wall, the potential difference between the inner wall and the outer wall and the center of the channel is -17.1V and 5.5V. Under the condition of adding metal electrodes, the potential difference between the inner wall and the outer wall and the center of the channel is 80.1V and 83.8V. Obviously, the potential difference between the wall and the center of the channel can be effectively increased under the condition of adding metal electrodes, which effectively reduces the impact of ions on the wall, thereby reducing the energy loss of the wall.

[0044] The statistical results of ion flux on the inner and outer walls of the channel are as follows: Figure 7 and Figure 8 As shown. Under the condition of pure ceramic wall, the peak value of ion flux on the inner and outer walls is 2.15×10 21 / m 2 ·s and 1.75×10 21 / m 2 ·s, under the condition of adding metal electrodes, the peak ion flux of the inner and outer walls is 3.8×10 20 / m 2 ·s and 4.04×10 20 / m 2 ·s. Under the condition of metal additional electrode, the ion flux on the inner and outer walls is significantly reduced. It can be seen that the additional metal electrode wall structure of the present invention can effectively reduce the bombardment of ions on the wall, thereby reducing the wall energy loss.

[0045] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. An additional electrode ceramic channel structure for reducing wall energy loss, characterized in that: An additional metal electrode is arranged at the outlet of the ceramic channel, and a positive electric field pointing to the channel is formed near the additional metal electrode. The positive electric field pointing to the channel is used to suppress the electric field of ions moving toward the wall.

2. The additional electrode ceramic channel structure for reducing wall energy loss according to claim 1, characterized in that: It comprises a ceramic channel (1), an inner ring additional metal electrode (2), an outer ring additional metal electrode (3), an inner electrode positive conductive column (4), an inner electrode negative conductive column (5), an outer electrode positive conductive column (6) and an outer electrode negative conductive column (7); The ceramic channel (1) is an annular channel with an upper opening, and circumferential grooves are respectively provided at relative positions of the inner ring wall surface and the outer ring wall surface at the channel outlet, and the inner ring additional metal electrode (2) and the outer ring additional metal electrode (3) are respectively embedded in the two circumferential grooves; Each circumferential groove is connected to the outside world through two symmetrical radial through holes; The inner electrode positive conductive column (4) and the inner electrode negative conductive column (5) are respectively inserted into two radial through holes symmetrically arranged on the inner ring and connected to the inner ring additional metal electrode (2); The outer electrode positive conductive column (6) and the outer electrode negative conductive column (7) are respectively inserted into two radial through holes symmetrically arranged on the outer ring and connected to the outer ring additional metal electrode (3).

3. The additional electrode ceramic channel structure for reducing wall energy loss according to claim 2, characterized in that: The ceramic channel (1) is made of ceramic material.

4. The additional electrode ceramic channel structure for reducing wall energy loss according to claim 2, characterized in that: The ceramic channel (1) is integrally formed using 3D ceramic printing technology.

5. The additional electrode ceramic channel structure for reducing wall energy loss according to claim 2, characterized in that: The inner ring additional metal electrode (2), the outer ring additional metal electrode (3), the inner electrode positive conductive column (4), the inner electrode negative conductive column (5), the outer electrode positive conductive column (6) and the outer electrode negative conductive column (7) are made of molybdenum material.

6. The additional electrode ceramic channel structure for reducing wall energy loss according to claim 2, characterized in that: The inner electrode positive conductive column (4) and the inner electrode negative conductive column (5) are connected to the inner ring additional metal electrode (2) by welding, and the outer electrode positive conductive column (6) and the outer electrode negative conductive column (7) are connected to the outer ring additional metal electrode (3) by welding.

7. The additional electrode ceramic channel structure for reducing wall energy loss according to claim 2, characterized in that: The inner electrode positive conductive column (4) and the outer electrode positive conductive column (6) are connected to the Hall thruster power supply anode, and the inner electrode negative conductive column (5) and the outer electrode negative conductive column (7) are connected to the Hall thruster power supply negative electrode.

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