Hall thruster ceramic channel heat dissipation structure

Abstract

The utility model discloses a Hall thruster ceramic channel heat dissipation structure, and relates to the field of Hall thruster heat dissipation. The problem that the temperature of the ceramic wall face of a discharge channel of an existing Hall thruster is too high is solved. The device comprises a ceramic discharge channel, an annular heat pipe, an inner magnetic pole, a bottom plate, an inner magnetic screen, an outer magnetic pole, an outer coil frame and an outer magnetic screen. The heat pipe is installed between the ceramic channel and the inner magnetic screen, one end of the heat pipe is directly contacted with the wall surface of the ceramic channel, and the other end is directly contacted with the bottom plate. According to the utility model, the temperature of the ceramic wall surface is conducted to the bottom plate by using the principle of phase change in the heat pipe, and then the bottom plate directly radiates and transfers the heat to space, thereby achieving the purpose of reducing the temperature of the ceramic wall surface.

Description

Technical Field

[0001] This utility model relates to the field of heat dissipation in ceramic discharge channels of Hall thrusters. Background Technology

[0002] Hall thrusters are currently the most widely used electric propulsion devices, offering advantages such as high efficiency, high specific impulse, and long lifespan compared to traditional chemical propulsion devices. Their working principle is as follows: the discharge channel is typically made of ceramic; a metal anode and a hollow cathode are used to activate the thruster. Electrons emitted from the hollow cathode move towards the anode, where they are confined by a magnetic field at the channel exit and collide with the neutral gas ejected from the anode, causing ionization. The resulting ions are accelerated and ejected under the influence of an axial electric field, generating thrust. Electrons diffuse towards the anode under the influence of collisions, forming a stable discharge. Ions in the plume recombine with electrons emitted from the hollow cathode, thus maintaining electroneutrality.

[0003] The heat generated during the operation of the Hall thruster mainly consists of two parts. One part is that ions, under the action of electric field force, accelerate towards the outlet and are not ejected from the channel, but are splashed onto the wall surface, where the ion energy is converted into heat. The other part is that electrons drift towards the anode under the action of electric and magnetic fields, and the heat generated when electrons recombine with the anode.

[0004] These two sources of heat result in a high wall temperature for the ceramic channel, which in turn conducts and radiates heat to the magnetic circuit and coil, leading to higher temperatures in the magnetic circuit and coil. Higher coil temperatures accelerate the aging of the coil insulation and may even cause it to burn out. Higher magnetic circuit temperatures cause a rapid decrease in magnetic permeability. The combined effect of these two factors alters the magnetic field configuration and magnetic field strength of the thruster, thereby reducing the thruster's performance and operational stability. Summary of the Invention

[0005] This invention addresses the problem of high wall temperature and poor heat dissipation in the ceramic discharge channel of a Hall thruster by providing a heat dissipation structure for the ceramic channel of a Hall thruster.

[0006] A Hall thruster ceramic channel heat dissipation structure includes an annular heat pipe, an inner magnetic pole, a ceramic discharge channel, an inner magnetic screen, a base plate, an outer magnetic pole, an outer coil frame, and an outer magnetic screen. The outer magnetic pole is placed inside the outer coil frame, which is connected to the base plate. The ceramic discharge channel is placed within a cavity formed by the outer magnetic pole, the inner magnetic pole, and the base plate. The inner and outer magnetic screens are respectively placed between the outer magnetic pole, the inner magnetic pole, and the ceramic discharge channel. The annular heat pipe is placed between the ceramic discharge channel and the inner magnetic screen.

[0007] One end of the annular heat pipe is in direct contact with the ceramic channel wall, and the other end is in contact with the base plate through the heat pipe mounting base.

[0008] The annular heat pipe is made of 316 stainless steel and is oxidized at high temperature. The internal working fluid is water.

[0009] The beneficial effects of this invention are that the annular heat pipe has excellent thermal conductivity. Through the contact between the annular heat pipe and the ceramic channel, a large amount of heat can be carried away by the evaporation and condensation of the working fluid inside the annular heat pipe, resulting in excellent thermal protection. This reduces the temperature of the ceramic channel, providing protection, lowering the temperature of the inner coil and inner magnetic circuit, and improving the lifespan and operational stability of the thruster. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the working principle of a ring-shaped heat pipe.

[0011] Figure 2 A three-dimensional model of the installed annular heat pipe;

[0012] Figure 3 This is a schematic diagram showing the position of the ceramic channel heat dissipation structure of the Hall thruster described in this utility model installed on the Hall thruster.

[0013] Reference numerals: 1. Annular heat pipe, 2. Inner magnetic pole, 3. Ceramic discharge channel, 4. Inner magnetic screen, 5. Base plate, 6. Outer magnetic pole, 7. Outer coil frame, 8. Outer magnetic screen. Detailed Implementation

[0014] The implementation of the technical solution of this utility model will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art.

[0015] Specific implementation method one: See Figure 2 This embodiment describes a Hall thruster ceramic channel heat dissipation structure, which includes an annular heat pipe and a mounting base.

[0016] The condenser end of the annular heat pipe is connected to the mounting base by welding.

[0017] In this embodiment, please refer to the specific instructions during use. Figure 3 The annular heat pipe 1 is evacuated. The ceramic discharge channel 3 is made of BN ceramic. The annular heat pipe 1 is installed between the ceramic discharge channel 3 and the inner magnetic screen 4. The outer wall of the annular heat pipe 1 is in contact with the inner magnetic pole wall of the ceramic discharge channel 3 to increase the contact between the annular heat pipe 1 and the ceramic discharge channel 3 and increase the heat conduction efficiency. The inner wall of the annular heat pipe 1 is in contact with the inner magnetic screen to reduce the radiative heat transfer between the ceramic discharge channel and the inner magnetic screen and to improve the heat transfer between the inner magnetic screen 4 and the annular heat pipe 1.

[0018] Considering the thermal expansion problem caused by thermal stress in the ceramic discharge channel, the annular heat pipe 1 is not arranged compactly to prevent the ceramic discharge channel 3 from cracking due to thermal expansion when it comes into contact with the annular heat pipe 1.

[0019] When the Hall thruster reaches a stable state, the annular heat pipe 1, after contacting the ceramic discharge channel, transfers heat to the pipe wall, core, and working fluid. The working fluid, upon heating, absorbs latent heat of vaporization and becomes steam. The steam pressure in the evaporation section is higher than that in the condensation section, thus creating a pressure difference. This pressure difference drives the steam from the evaporation section through the adiabatic section to the condensation section. When the steam condenses in the condensation section, it releases latent heat of vaporization, which is transferred through the core and pipe wall to the Hall thruster base plate 5. The base plate 5 then transfers the heat to space via radiation. Due to evaporation, a meniscus forms in the capillary pores of the core where the working fluid enters the evaporation section. This creates a capillary pump force, drawing the condensate from the condensation section through the adiabatic section back to the evaporation section, completing one cycle. This reduces radiative heat transfer from the ceramic discharge channel 1 to the inner magnetic screen 4 and from the inner magnetic screen to the inner magnetic pole 2.

[0020] The annular heat pipe 1 is made of 316 stainless steel, and the internal working fluid is water. The 316 stainless steel is subjected to high-temperature oxidation treatment. The annular heat pipe 1 material and the internal working fluid will undergo chemical changes at high temperatures. The high-temperature oxidation treatment of 316 stainless steel will prevent this chemical change.

[0021] The present invention has been disclosed above with reference to preferred embodiments, but it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed structure and technical content to create equivalent embodiments without departing from the scope of the present invention, and such modifications or alterations shall still fall within the scope of the present invention.

Claims

1. A ceramic channel heat dissipation structure for a Hall thruster, characterized in that, It includes an annular heat pipe (1), an inner magnetic pole (2), a ceramic discharge channel (3), an inner magnetic screen (4), a base plate (5), an outer magnetic pole (6), an outer coil frame (7), and an outer magnetic screen (8). The annular heat pipe (1) is installed between the ceramic discharge channel (3) and the inner magnetic screen (4). One end of the heat pipe (1) is in contact with the wall of the ceramic discharge channel (3), and the other end is in contact with the base plate (5) through the mounting base.

2. The Hall thruster ceramic channel heat dissipation structure according to claim 1, characterized in that, The material of the ceramic discharge channel (3) is BN ceramic.

3. The Hall thruster ceramic channel heat dissipation structure according to claim 1, characterized in that, The material of the inner magnetic shield (4) is DT4C.

4. The Hall thruster ceramic channel heat dissipation structure according to claim 1, characterized in that, The annular heat pipe (1) consists of three parts: an evaporation section, an adiabatic section, and a condensation section.

5. The Hall thruster ceramic channel heat dissipation structure according to claim 1, characterized in that, The annular heat pipe (1) is made of 316 stainless steel.

6. The Hall thruster ceramic channel heat dissipation structure according to claim 1, characterized in that, The annular heat pipe (1) is subjected to high-temperature oxidation treatment.

7. The Hall thruster ceramic channel heat dissipation structure according to claim 1, characterized in that, The annular heat pipe (1) uses water as the working fluid.

8. The Hall thruster ceramic channel heat dissipation structure according to claim 1, characterized in that, The inside of the annular heat pipe (1) is a vacuum.

9. The Hall thruster ceramic channel heat dissipation structure according to claim 1, characterized in that, The annular heat pipe (1) has a mounting base at the condenser end.

10. The Hall thruster ceramic channel heat dissipation structure according to claim 1, characterized in that, The base plate (5) is made of DT4C.

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