Anode structure of Hall thruster

Abstract

The utility model provides an anode structure of a Hall thruster. The anode structure at least comprises a magnetic screen, a gas distribution ring and an anode, the magnetic screen at least comprises an inner ring and an outer ring which are concentrically arranged, and the outer wall of the inner ring and the inner wall of the outer ring are connected through a bottom ring to form an annular cavity with an opening in the top end. The gas distribution ring is arranged behind the annular cavity and divides the annular cavity into a first-stage gas buffer cavity and a second-stage gas buffer cavity in the axial direction; the anode is arranged in the secondary gas buffer cavity and is connected with the upper end surface of the gas distribution ring; the bottom ring is provided with a first through hole used for communicating a gas supply pipe with the first-stage gas buffer cavity. The gas distribution ring is provided with a second through hole communicated with the primary gas buffer cavity and the anode inner cavity; and the anode is provided with a third through hole which is communicated with the anode inner cavity and the secondary gas buffer cavity.

Description

TECHNICAL FIELD

[0001] The utility model relates to space propulsion technical field especially relates to a hall thruster anode structure. BACKGROUND

[0002] The hall thruster is widely applied in spacecraft position keeping, orbit transfer, attitude control and interstellar navigation and other tasks with the characteristics of simple structure, high efficiency and long service life. In recent years, along with the rapid development of commercial aerospace, krypton gas propellant is used in large quantities, but the ionization efficiency of krypton gas is low, and the working efficiency is low. In addition, the discharge stability of krypton gas thruster is poor, and the low-frequency oscillation with large amplitude will cause the thruster to extinguish, which affects the working stability of the thruster. Therefore, it is urgent to optimize the performance of the hall thruster. SUMMARY

[0003] To solve the above technical problems, the utility model provides a hall thruster anode structure, through reasonable optimization improvement to anode structure, increase the residence time of gas working medium in discharge channel, the anode structure of conical design makes the discharge channel cross section area gradually increases along the export direction, improves the overall performance of hall thruster.

[0004] The utility model provides a kind of hall thruster anode structure, at least including magnetic screen, gas distribution ring and anode;The magnetic screen at least includes concentrically arranged inner ring and outer ring, the inner ring outer wall and the outer ring inner wall are connected after being formed into annular cavity with top opening by bottom ring;The gas distribution ring is set in the annular cavity and is divided into first gas buffer cavity and secondary gas buffer cavity along the axial direction;The anode is set in the secondary gas buffer cavity, and is connected with the upper end surface of the gas distribution ring;Wherein, the bottom ring is equipped with first through-hole for connecting gas supply pipe and the first gas buffer cavity;The gas distribution ring is equipped with second through-hole for connecting the first gas buffer cavity and the anode inner cavity;The anode is equipped with third through-hole for connecting the anode inner cavity and the secondary gas buffer cavity.

[0005] In an embodiment, the cross section of the anode is conical structure, and the top adopts circular arc transition.

[0006] In an embodiment, the anode includes inner distribution ring and outer distribution ring spaced apart on the upper end surface of the gas distribution ring, and anode top provided on the top of the inner distribution ring and the outer distribution ring;The lower end surface of the anode top is provided with an extension section;The extension section extends into the inner distribution ring and the outer distribution ring, and forms the anode inner cavity with the outer side surface of the inner distribution ring and the inner side surface of the outer distribution ring.

[0007] In one embodiment, the third through hole comprises a plurality of first small holes evenly distributed on the inner distribution ring, and a plurality of second small holes evenly distributed on the outer distribution ring; each first small hole diverges from the anode inner cavity to the secondary gas buffer cavity; and each second small hole diverges from the anode inner cavity to the secondary gas buffer cavity.

[0008] In one embodiment, the angle between the axis of the first small hole and the tangent plane where the first small hole is located is X; and the angle between the axis of the second small hole and the tangent plane where the second small hole is located is Y; wherein the angle X is equal to the angle Y.

[0009] In one embodiment, the upper end surface of the gas distribution ring is provided with an inner ring boss and an outer ring boss with different diameters; the bottom of the inner distribution ring is provided with a groove matched with the inner ring boss; the bottom of the outer distribution ring is provided with a groove matched with the outer ring boss; and the second through hole is evenly distributed between the inner ring boss and the outer ring boss along the circumference of the gas distribution ring.

[0010] In one embodiment, the taper angle of the tapered structure ranges from 8° to 25°.

[0011] In any one of the above embodiments, an equal-height boss is arranged on the side of the inner ring outer ring and the outer ring inner ring close to the bottom ring, and the gas distribution ring is connected with the inner ring and the outer ring through the boss.

[0012] In one embodiment, the top of the magnetic screen is higher than the top of the anode.

[0013] In one embodiment, the number of first small holes is equal to the number of second small holes.

[0014] The Hall thruster anode structure of the utility model has at least one of the following beneficial effects:

[0015] First, the Hall thruster anode structure of the utility model sets small holes on the inner and outer distribution rings of the anode, so that the gas working medium rotates and flows out along the small holes of the anode, the axial flow rate of the gas is reduced, the residence time of the gas in the passage is prolonged, and thus the ionization efficiency of the working medium (especially krypton working medium) is significantly improved.

[0016] Second, the anode of the Hall thruster anode structure of the utility model is a tapered structure, so that the cross-sectional area of the discharge passage gradually increases in the outlet direction, the low-frequency discharge oscillation of the thruster is inhibited to a certain extent, and the discharge stability of the thruster is improved.

[0017] Third, the anode position of the Hall thruster anode structure of the utility model extends greatly to the downstream of the discharge passage, the length of the ionization acceleration zone is shortened, ion acceleration is more conducive, and the performance of the thruster is improved.

[0018] Four, the magnetic screen, the discharge channel, the anode and the gas distribution ring of the Hall thruster anode structure of the utility model adopt integrated structure design, the whole discharge channel is equipotential with the anode, compared with the traditional structure, greatly increase the anode surface area, reduce the electron heat deposition on the unit area of anode, reduce the anode temperature, improve the electron acceptance efficiency and the overall working performance of thruster.

[0019] Five, the Hall thruster anode structure structure of the utility model embodiment is simple, light, and greatly reduces the weight of the whole thruster.

[0020] After reading the detailed description and after viewing the drawings, those skilled in the art will recognize additional features and advantages. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed in the embodiments will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0022] Figure 1 It is the overall structure schematic diagram of the Hall thruster anode structure of the utility model embodiment.

[0023] Figure 2 It is the cross-sectional schematic diagram of the Hall thruster anode structure of the utility model embodiment.

[0024] Figure 3 It is the structure schematic diagram of the gas distribution ring and the anode butt joint part of the utility model embodiment.

[0025] Figure 4 It is the a-a cross-sectional schematic diagram of the Hall thruster anode structure of the utility model embodiment. DETAILED DESCRIPTION

[0026] The features and exemplary embodiments of each aspect of the utility model will be described in detail below, in order to make the purpose, technical scheme and advantages of the utility model more clear and clear, the utility model will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described here are only configured to explain the utility model, for example, to illustrate the principle of the utility model, and are not configured to limit the utility model. In addition, the components in the drawings are not necessarily drawn to scale. For example, the size of some components in the drawings can be enlarged for other components or areas to help understand the utility model embodiments.

[0027] The orientation words appearing in the following description are the directions shown in the drawings, and are not to limit the specific structure of the embodiments of the utility model. In the description of the utility model, it is to be explained that, unless otherwise specified, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected, it can be directly connected, or indirectly connected through an intermediate medium. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0028] In addition, the terms "including", "containing", "having" or any other variant thereof are intended to cover non-exclusive inclusion, so that the inclusion of a series of element structures or components not only includes those elements, but also includes other elements not explicitly listed or inherent in the structure, component. Without more limitation, the element defined by the statement "including" does not exclude the presence of other identical elements in the article or device including the element.

[0029] Spatial relationship terms such as "below", "under", "under", "low", "above", "on", "high" and the like are used to facilitate the description to explain the positioning of one element relative to the second element, indicating that these terms are intended to cover different orientations of the device in addition to the orientations shown in the drawings. In addition, for example, "one element is on / under another element" can mean that the two elements are in direct contact, or that there are other elements between the two elements. In addition, terms such as "first", "second" and the like are also used to describe various elements, regions, parts and the like, and should not be considered as limiting. Similar terms are used throughout the description to indicate similar elements.

[0030] For those skilled in the art, the utility model can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the invention by showing examples of the invention.

[0031] If the Hall thruster uses krypton gas as the working medium, due to its small atomic radius, high ionization energy and fast atomic motion speed, it stays in the discharge channel for a short time, so it is easy to cause poor ionization performance. In addition, the efficiency of krypton gas thruster is usually lower than that of xenon gas under the same power, the heat loss caused by electron energy deposition is intensified, causing the anode temperature to increase. For high-power Hall thrusters, the voltage is higher, the current is larger, and the anode will also face the problem of huge heat load brought by large electron current, which will cause the anode to appear red phenomenon, and in severe cases, the anode will self-melt. In addition, the discharge stability of krypton gas thruster is poor, and severe low-frequency oscillation with large amplitude will cause the thruster to extinguish, affecting the working stability of the thruster.

[0032] The advantage of the krypton propellant thruster lies in higher specific impulse, however, the anode of the traditional structure is far away from the discharge channel, the acceleration zone of the ions in the channel is longer, the energy loss of the ions on the wall surface is intensified, the thrust is reduced, and the specific impulse is reduced.

[0033] Therefore, the anode structure must be reasonably optimized and improved to better exert the performance of the thruster under the krypton gas propellant. Figure 1 and Figure 2 The Hall thruster anode structure provided by the application comprises at least a magnetic screen 1, a gas distribution ring 2 and an anode 3. The magnetic screen 1 is an annular cavity with one end open, and the gas distribution ring 2 is a thin-walled annular structure, which is arranged in the annular cavity of the magnetic screen 1. The magnetic screen 1 comprises at least an inner ring 11 and an outer ring 12 arranged concentrically, and the outer wall of the inner ring 11 and the inner wall of the outer ring 12 are connected by a bottom ring 13 to form an annular cavity with one end open. The gas distribution ring 2 is arranged in the annular cavity of the magnetic screen 1 and divides the annular cavity into a first gas buffer cavity A and a second gas buffer cavity B (metal discharge channel) along the axial direction. The first buffer cavity A is located at the lower end surface of the gas distribution ring 2, and the second buffer cavity B is located at the upper end surface of the gas distribution ring 2. The anode 3 is arranged in the second gas buffer cavity B and connected to the upper end surface of the gas distribution ring 2.

[0034] In the embodiment, the bottom ring 13 is provided with a first through hole for connecting the gas supply pipe 4 and the first gas buffer cavity A, the gas supply pipe 4 is inserted into the first through hole and fixed by welding along the circumference, and the gas supply pipe 4 provides the gas propellant for the Hall thruster anode structure of the embodiment. The gas distribution ring 2 is provided with a second through hole for connecting the first gas buffer cavity A and the inner cavity C of the anode 3, and the anode 3 is provided with a third through hole for connecting the inner cavity C of the anode 3 and the second gas buffer cavity B.

[0035] The Hall thruster anode structure of the embodiment provides the gas propellant through the gas supply pipe 4, first, the first gas buffer cavity A buffers the flow. The gas that has been subjected to the first flow uniformity passes through the second through hole into the inner cavity C of the anode 3, and then passes through the third through hole into the gas buffer cavity B (metal discharge channel) for secondary buffering and output. Figure 2 The flow path of the gas propellant is marked.

[0036] In view of the higher voltage and larger current of the high-power Hall thruster, the anode also faces the problem of huge thermal load caused by large electron current, which easily leads to redness of the anode and even self-melting of the anode. Based on this, the magnetic screen, the gas distribution ring, the anode and the discharge channel in the embodiment of the application are designed in an integrated manner, and the entire discharge channel is at the same potential as the anode. Compared with the traditional anode structure, the anode surface area is greatly increased, the anode temperature is reduced, the electron acceptance efficiency is increased, and the overall working performance of the Hall thruster is improved. At the same time, the entire structure also bears the functions of plasma discharge, gas distribution and magnetic conduction, and the component structure is simple and light, thereby reducing the weight of the thruster.

[0037] Referring to Figure 2 In one embodiment, the cross section of the anode 3 is a conical structure, and the conical angle ranges from 8° to 25°. The conical anode can gradually increase the cross-sectional area of the discharge channel (secondary buffer cavity) towards the outlet side, thereby inhibiting low-frequency discharge oscillation of the thruster to some extent and improving the discharge stability of the thruster. As a more optimal choice, the conical angle of the anode 3 ranges from 8° to 15°. In order to facilitate processing, the top of the anode 3 can adopt a circular arc transition.

[0038] During the working process of the thruster, the anode needs to withstand the energy deposition caused by frequent sputtering bombardment of electrons, and in addition, the anode cannot affect the original magnetic field configuration, so the material of the anode is selected to be non-magnetic stainless steel.

[0039] Referring to Figure 2 and Figure 3 In one embodiment, in order to facilitate the processing and forming of the anode, the anode 3 includes an inner distribution ring 31 and an outer distribution ring 32 which are arranged at the upper end surface of the gas distribution ring 2, and an anode top 33 arranged at the top of the inner distribution ring 31 and the outer distribution ring 32. The lower end surface of the anode top 33 is provided with an extension section which extends into the inner distribution ring 31 and the outer distribution ring 32. The extension section of the anode top 33 and the outer side surface of the inner distribution ring 31 and the inner side surface of the outer distribution ring 32 form an anode inner cavity C.

[0040] When assembling the anode 3 and the gas distribution ring 2, the inner distribution ring 31 and the outer distribution ring 32 can be directly welded to the upper end surface of the gas distribution ring 2.

[0041] Alternatively, the inner ring boss 21 and the outer ring boss 22 can be arranged on the upper end surface of the gas distribution ring 2. The bottom of the inner distribution ring 31 is provided with a groove matched with the inner ring boss 21, and the bottom of the outer distribution ring 32 is provided with a groove matched with the outer ring boss 22. In this embodiment, the inner ring boss 21 is fixed by welding after being matched and limited by the groove of the inner distribution ring 31, and the outer ring boss 22 is fixed by welding after being matched and limited by the groove of the outer distribution ring 32. Then, the anode top 33 is abutted between the inner distribution ring 31 and the outer distribution ring 32, and is limited by the extension section between the outer ring of the inner distribution ring 31 and the inner ring of the outer distribution ring 32. Finally, the anode top 33 is circumferentially welded and fixed with the inner distribution ring 31 and the outer distribution ring 32.

[0042] It should be noted that the distance from the inner ring boss 21 to the inner ring 11 is equal to the distance from the outer ring boss 22 to the outer ring 12.

[0043] The inner ring boss 21 and the outer ring boss 22 are equal in height, and the height is less than the thickness of the gas distribution ring 2, so as to reduce the weight as much as possible without affecting the subsequent welding.

[0044] The tapered anode structure in this embodiment can gradually increase the cross-sectional area of the discharge channel to the outlet side, to some extent, inhibit the low-frequency discharge oscillation of the thruster, and improve the discharge stability of the thruster. The anode position is greatly extended to the downstream of the discharge channel, which shortens the length of the ionization acceleration zone, and is more conducive to ion acceleration and improves the performance of the thruster.

[0045] Referring to Figure 3 and Figure 4 In the above embodiment, the second through hole for connecting the first gas buffer cavity A and the anode inner cavity C is arranged between the inner ring boss 21 and the outer ring boss 22. Specifically, the second through hole is a plurality of small holes 23 uniformly distributed between the inner ring boss 21 and the outer ring boss 22 along the circumference of the gas distribution ring 2. Further, the number of small holes 23 can be 10 or 12.

[0046] Referring to Figure 4 In one embodiment, the third through hole includes a plurality of first small holes 311 uniformly distributed on the inner distribution ring 31, and a plurality of second small holes 321 uniformly distributed on the outer distribution ring 32. The number of first small holes 311 is the same as the number of second small holes 321. It should be noted that the small holes 311 and the small holes 321 can be straight holes or inclined holes.

[0047] As preferred, the small holes 311 and 321 are inclined small holes, each first small hole 311 diverges from the anode inner cavity C to the secondary gas buffer cavity B in a circumferential direction, and each second small hole 321 diverges from the anode inner cavity C to the secondary gas buffer cavity B in a circumferential direction. It is particularly noted that the rotating directions of the gas working substance after passing through the first small hole and the second small hole are the same. That is, from a certain angle, if the gas working substance diverging from the first small hole rotates counterclockwise along the secondary gas buffer cavity B, the gas working substance diverging from the second small hole must also rotate counterclockwise along the secondary gas buffer cavity B.

[0048] Further, the angle between the axis of the first small hole and the tangent plane where the first small hole is located is an acute angle X, and the angle between the axis of the second small hole and the tangent plane where the second small hole is located is an acute angle Y. The angle X is equal to the angle Y, and the angle X and the angle Y are in the range of 15° to 40°.

[0049] The gas working substance rotates and flows out through the anode small holes of the embodiment, which reduces the axial flow speed of the gas working substance, prolongs the residence time of the gas working substance in the discharge channel (the secondary gas buffer cavity), and improves the ionization efficiency of the working substance (especially the krypton working substance).

[0050] The anode of the embodiment of the application adopts a structure separated by an inner distribution ring and an outer distribution ring, so as to facilitate the machining of the small holes on the inner and outer distribution rings.

[0051] Referring to Figure 3 In any one of the above embodiments, in order to facilitate the positioning and installation of the gas distribution ring, an equal-height boss T is arranged on the outer ring of the inner ring 11 and the inner ring of the outer ring 12 close to one side of the bottom ring, the gas distribution ring 2 is arranged on the side away from the bottom ring of the two bosses, and is axially positioned through the bosses, and is fixedly connected with the inner ring 11 and the outer ring 12 through circumferential welding.

[0052] In the above embodiments, the top of the magnetic screen is higher than the top of the anode, that is, the top end of the anode top is lower than the outlet of the discharge channel by 1 mm to 3 mm. The anode position extends downstream of the discharge channel, which shortens the length of the ionization acceleration zone, increases the magnetic field gradient, is more conducive to ion acceleration, and improves the performance of the thruster.

[0053] The above embodiments can be combined with each other and have corresponding technical effects.

[0054] The anode structure of the Hall thruster of the application is reasonably optimized and improved, which improves the ionization rate of the gas working substance (especially the krypton working substance with high ionization energy), reduces the anode temperature, and improves the performance of the thruster.

[0055] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A Hall thruster anode structure, characterized by, At least comprising: a magnetic screen, a gas distribution ring and an anode; the magnetic screen at least comprises an inner ring and an outer ring arranged concentrically, the outer wall of the inner ring and the inner wall of the outer ring are connected by a bottom ring to form a ring-shaped cavity with an open top end; the gas distribution ring is arranged in the ring-shaped cavity to divide it into a first gas buffer cavity and a second gas buffer cavity along the axial direction; the anode is arranged in the second gas buffer cavity and connected with the upper end surface of the gas distribution ring; wherein the bottom ring is provided with a first through hole for connecting the gas supply pipe and the first gas buffer cavity; the gas distribution ring is provided with a second through hole connecting the first gas buffer cavity and the inner cavity of the anode; the anode is provided with a third through hole connecting the inner cavity of the anode and the second gas buffer cavity.

2. The Hall thruster anode structure of claim 1, wherein, The cross section of the anode is a conical structure, and the top part adopts a circular arc transition.

3. The Hall thruster anode structure of claim 2, wherein, The anode comprises an inner distribution ring and an outer distribution ring arranged at the upper end surface of the gas distribution ring, and an anode top arranged at the top of the inner distribution ring and the outer distribution ring. The lower end surface of the anode top is provided with an extension section; the extension section extends into the inner distribution ring and the outer distribution ring, and forms the inner cavity of the anode with the outer side surface of the inner distribution ring and the inner side surface of the outer distribution ring.

4. The Hall thruster anode structure of claim 3, wherein, The third through hole comprises a plurality of first small holes uniformly distributed around the inner distribution ring, and a plurality of second small holes uniformly distributed around the outer distribution ring.

5. The Hall thruster anode structure of claim 4, wherein, The angle between the axis of the first small hole and the tangent plane is X; the angle between the axis of the second small hole and the tangent plane is Y; wherein the angle of X is equal to the angle of Y.

6. The Hall thruster anode structure of claim 3, wherein, The upper end surface of the gas distribution ring is provided with an inner ring boss and an outer ring boss with different diameters; the bottom of the inner distribution ring is provided with a groove matched with the inner ring boss, and the bottom of the outer distribution ring is provided with a groove matched with the outer ring boss; The second through hole is uniformly distributed between the inner ring boss and the outer ring boss along the circumference of the gas distribution ring.

7. The Hall thruster anode structure of claim 2, wherein, The taper angle of the conical structure ranges from 8° to 25°.

8. The Hall thruster anode structure of any of claims 1 to 7, wherein, An equal-height boss is arranged on the side of the inner ring outer ring and the outer ring inner ring close to the bottom ring, and the gas distribution ring is connected with the inner ring and the outer ring through the boss.

9. The Hall thruster anode structure of claim 8, wherein, The top of the magnetic screen is higher than the top of the anode.

10. The Hall thruster anode structure of claim 5, wherein, The number of first small holes is equal to the number of second small holes.

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