Restarting regenerative ion-combustion thruster
By adding a flip-flopable blank to the ion thrust, the conversion to a combustion thrust after the ion thrust fails is solved, and the comprehensive performance and load utilization of the thrust are improved.
Patent Information
- Application Number
- CN202510632895.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-16
- Publication Date
- 2025-07-29
AI Technical Summary
After the gate assembly of the existing ion thrust fails, the thrust cannot continue to work, resulting in waste of components and limited life.
A rebootable regenerative ion-combustion thrust is designed. By adding a flip-flopable shutter to the ion thrust, the ion thrust is converted into a combustion thrust after failure, and the hollow cathode is used to generate high-temperature arc ignition fuel to form combustion thrust.
The restart of the ion thrust is achieved, the comprehensive performance of the thrust is improved, and the advantages of high specific impulse of the ion thrust and large thrust of the chemical engine are combined, which improves the load ratio of the spacecraft and the degree of integration of the thrust.
Smart Images
Figure CN120384855A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of spacecraft space propulsion, and particularly to a restartable regenerative ion-combustion thruster. Background Art
[0002] Electric thrusters have advantages such as high specific impulse and good thrust regulation accuracy. As a relatively mature representative among them, ion thrusters have been widely used in various space propulsion missions. However, the lifespan of ion thrusters is often restricted by various factors, and their failure modes can be classified into failures related to the hollow cathode, discharge chamber, and grid assembly according to the components where they occur. Among them, the failures occurring in the hollow cathode and the discharge chamber can be made to have a margin of more than three times the working life of the ion thruster determined by taking targeted measures, and they are not critical failure modes. According to the existing published literature, such as "Optimization of the Grid Ultimate Life of Ion Thrusters", it can be known that the key failure modes that ultimately restrict the ultimate working life of ion thrusters all occur in the grid assembly.
[0003] When the grid assembly fails, it can no longer function as an electric thruster itself, and the components of the thruster are also wasted to a large extent. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a restartable regenerative ion-combustion thruster in view of the above-mentioned deficiencies of the prior art. The restartable regenerative ion-combustion thruster can not only act as a neutralizer of the ion thruster by adding a flip-up baffle, but also reuse the housing of the failed ion thruster as one of the components of the combustion thruster to achieve the restart from an electric thruster to a combustion thruster.
[0005] To solve the above technical problem, the technical solution adopted by the present invention is as follows:
[0006] A restartable regenerative ion-combustion thruster includes a hollow cathode, a working medium inlet, a discharge chamber, a grid, N flip-up baffles, and a baffle flipping drive device; where N≥2.
[0007] The discharge chamber is a cylindrical chamber.
[0008] The hollow cathode is coaxially inserted into the center of the head of the discharge chamber.
[0009] The working medium inlet includes a discharge chamber inlet and a hollow cathode inlet; the working medium inlet is connected to the discharge working medium and the combustion propellant respectively through a switching valve.
[0010] The grid is arranged at the inner rear end of the discharge chamber.
[0011] N flip-up baffles are evenly hinged circumferentially at the outer tail end of the discharge chamber; each flip-up baffle includes an inner baffle and an outer baffle integrally provided; wherein, the longitudinal sections of the inner baffle and the outer baffle are both arc-shaped, and the arc radius at the intersection point of the inner baffle and the outer baffle is the smallest.
[0012] The N flip-up baffles can be flipped inward under the common drive of the baffle flipping drive device and form a Laval nozzle with the intersection point of the inner baffle and the outer baffle as the throat.
[0013] Let the maximum flipping angle between each inner baffle and the grid plane be α, and the angle between each outer baffle and the corresponding inner baffle be β; then α is determined according to the divergence angle of the plasma beam ejected in the discharge chamber, and β is determined according to the expansion ratio of the Laval nozzle.
[0014] α = 130°, β = 135°.
[0015] The expansion ratio of the Laval nozzle is 130 - 450.
[0016] It also includes a power conditioning unit. The positive pole of the power conditioning unit is connected to the inner wall of the discharge chamber housing, and the negative pole of the power conditioning unit is respectively connected to the hollow cathode and each flip-up baffle.
[0017] The material of the grid is C / C composite material, and the material of the hollow cathode is barium tungsten.
[0018] A planar injector connected to the discharge chamber air inlet is provided at the head of the discharge chamber.
[0019] The number N of the flip-up baffles is an even number. High-temperature resistant sealing materials are provided on the sides of each flip-up baffle, and the inner baffle is hermetically hinged to the outer tail end of the discharge chamber.
[0020] It has two working modes, namely: ion thrust mode and combustion thrust mode;
[0021] When the grid is within its own working life, the ion thrust mode is adopted; at this time, the working medium inlet is connected to the discharge working medium, each flip-up baffle is in the maximum outward flipped-open state, the inner wall of the discharge chamber housing and the hollow cathode are energized, the discharge working medium is ionized in the discharge chamber to form a plasma beam, which is accelerated and led out through the grid to form an ion thrust;
[0022] When the grid reaches its own working life, the combustion thrust mode is adopted. At this time, the working medium inlet is connected to the combustion propellant, and each flip-up baffle is driven by the baffle flipping drive device to flip inward to form a Laval nozzle with the intersection point of the inner baffle and the outer baffle as the throat;
[0023] The hollow cathode is energized to generate a high-temperature arc, which ignites and burns the fuel propellant injected into the discharge chamber through the working medium inlet to produce high-temperature gas; during the combustion process, the grid will oxidize and burn, and its products will be ejected through the Laval nozzle together with the high-temperature gas to form combustion thrust.
[0024] In the ion thrust mode, a ground voltage is applied to each flip-flap. The reverse-flow particles in the plasma plume extracted through the grid will be blocked and absorbed by the flip-flap, which can reduce the sputtering pollution of the thruster by the plasma.
[0025] The present invention has the following beneficial effects:
[0026] 1. Aiming at the current situation of the weak reliability and limited life of ion thrusters, the present invention realizes the restart of the ion thruster after failure based on the method of adding flip-flap baffles to the original structure of the ion thruster. The restarted thruster will work in the combustion mode.
[0027] 2. The present invention will achieve great reuse of the components of the thruster itself, and cleverly realize the sharing of the discharge chamber of the ion thruster and the structure of the chemical propulsion combustion chamber, which can improve the payload ratio of the spacecraft.
[0028] 3. The thruster of the present invention can work in two modes of electricity and combustion successively, and can better combine the advantages of the high specific impulse, adjustable thrust of the ion thruster and the large thrust of the chemical engine, so as to improve the comprehensive performance of the thruster and cover a wider range of mission types.
[0029] 4. The modification of the present invention can enhance both the ion propulsion and combustion propulsion modes. The flip-flap baffle can prevent the sputtering corrosion of the spacecraft by reverse-flow particles; the high-temperature arc generated during the operation of the hollow cathode also plays the role of an igniter in the combustion propulsion mode, simplifying the structure of the combustion thruster.
[0030] 5. On the basis of not affecting the structure of the ion thruster itself, the present invention combines electric propulsion and chemical propulsion by using the innovation that the flip-flap baffle forms a throat by inward buckling. The traditional ignition device is replaced by the way of hollow cathode arc ignition, which simplifies the structure of the igniter under chemical propulsion and improves the miniaturization and integration degree of the combined thruster. Description of the Drawings
[0031] Figure 1 Shows a schematic structural diagram of a restartable regenerative ion-combustion thruster of the present invention in the ion mode.
[0032] Figure 2 Shows a schematic system principle diagram of a restartable regenerative ion-combustion thruster of the present invention.
[0033] Figure 3Shows a schematic structural diagram of a restartable regenerative ion-combustion thruster of the present invention in the combustion mode.
[0034] Figure 4 Shows a half-sectional view of a restartable regenerative ion-combustion thruster of the present invention in the combustion mode.
[0035] Among them are:
[0036] 1. Discharge chamber air inlet; 2. Hollow cathode air inlet; 3. Hollow cathode; 4. Discharge chamber; 5. Grid.
[0037] 6. Reversible baffle; 61. Inner baffle; 62. Outer baffle; 63. Flip hinge point; 64. Throat. Specific embodiments
[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.
[0039] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by terms such as "left side", "right side", "upper part", "lower part", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and "first", "second", etc. do not represent the importance of the components, so it cannot be understood as a limitation to the present invention. The specific dimensions adopted in this embodiment are only for illustrating the technical solution by way of example and do not limit the protection scope of the present invention.
[0040] As Figure 1 shown, a restartable regenerative ion-combustion thruster includes a hollow cathode 3, a working medium inlet, a discharge chamber 4, a grid 5, N reversible baffles 6, a baffle flipping drive device, and a power conditioning unit; among them, N≥2, preferably an even number, and in this embodiment, preferably N = 8.
[0041] The discharge chamber is a cylindrical chamber, and the inner wall of the housing of the discharge chamber is made of a high-temperature-resistant nickel-based alloy sheet as the anode.
[0042] The hollow cathode is coaxially inserted at the center of the head of the discharge chamber. The material of the hollow cathode is preferably barium tungsten, which has strong electron emission ability, good high-temperature resistance, and arc erosion resistance, so as to facilitate subsequent use as an igniter in the combustion thrust mode.
[0043] The working medium inlet includes a discharge chamber air inlet 1 and a hollow cathode air inlet 2.
[0044] As Figure 2 shown, the working medium inlet is connected to the discharge working medium and the combustion propellant respectively through a switching valve.
[0045] The present invention has two working modes, namely: ion thrust mode and combustion thrust mode.
[0046] A. Ion thrust mode
[0047] The working fluid inlet is connected to the discharge working fluid through a switching valve, that is, the working fluid filling device fills the discharge working fluid into the corresponding propellant tank through a pressurized gas cylinder, and the discharge working fluid is supplied to the discharge chamber inlet and the hollow cathode inlet through the corresponding solenoid valve and flow control valve. The discharge working fluid generally adopts inert gases such as Xe, Kr, Ar, etc.
[0048] B. Combustion thrust mode
[0049] The working fluid inlet is connected to the combustion propellant through a switching valve. In this embodiment, the oxygen filling device fills oxygen into the corresponding propellant tank through a pressurized gas cylinder, and then supplies oxygen to the hollow cathode inlet through the corresponding solenoid valve and flow control valve; the fuel filling device fills fuel into the corresponding propellant tank through a pressurized gas cylinder, and then supplies fuel to the discharge chamber inlet through the corresponding solenoid valve and flow control valve. Further, a plane injector connected to the discharge chamber inlet is provided at the head of the discharge chamber, which can inject the fuel in an atomized manner into the discharge chamber so as to be evenly mixed with oxygen, and better realize combustion. Furthermore, the plane injector is designed as an annular structure, surrounding the outer ring of the cathode inlet. A plurality of mixing zones are provided in the injector body along the direction of the atomized flame jet. Each mixing zone is respectively connected to the oxidant input pipeline and the fuel supply pipeline, so that the oxidant and fuel are sprayed into the mixing zone at an angle under high pressure to achieve atomization and full mixing.
[0050] The grid is arranged at the inner end of the tail of the discharge chamber. The material of the grid is preferably C / C composite material. The C / C composite material has a relatively small coefficient of thermal expansion and strong sputtering resistance, which can improve the reliability of the grid and extend its service life. At the same time, the C / C composite material has high oxidation sensitivity in an oxygen-containing ablation environment above 400 °C, that is, the C / C composite material will rapidly oxidize and burn in a high-temperature oxygen-containing environment. Therefore, when the thruster restarts, in the combustion mode, a bipropellant is adopted, and the oxidant is oxygen. The grid located in the combustion chamber will burn at high temperature, and its products will also be ejected as the gas expands. Thus, the "ejection" of the grid assembly after restart is completed.
[0051] N flip-up flaps are evenly hinged circumferentially at the outer end of the tail of the discharge chamber, and the preferred material is nickel-based alloy sheet.
[0052] Each flip-up flap includes an inner flap 61 and an outer flap 62 which are integrally arranged; wherein, the longitudinal sections of the inner flap and the outer flap are both arc-shaped, and the arc radius at the intersection point of the inner flap and the outer flap is the smallest, that is, the throat 64.
[0053] Furthermore, high-temperature resistant sealing materials are preferably provided on the sides of each flip-up baffle. A sealed hinge is provided between the inner baffle and the outer end of the discharge chamber, also known as the flip hinge point 63.
[0054] Under the common drive of the baffle flip drive device, N flip-up baffles can flip inward and form a Laval nozzle with the intersection point of the inner baffle and the outer baffle as the throat.
[0055] Let the maximum flip angle between each inner baffle and the grid plane be α, and the angle between each outer baffle and the corresponding inner baffle be β. Then α is determined according to the divergence angle of the plasma beam ejected in the discharge chamber, and β is determined according to the expansion ratio of the Laval nozzle. In this embodiment, preferably α = 130°, β = 135°, and the expansion ratio of the Laval nozzle is preferably 130 - 450.
[0056] The positive electrode of the power conditioning unit is connected to the inner wall of the discharge chamber housing, and the negative electrode of the power conditioning unit is connected to the hollow cathode and each flip-up baffle respectively.
[0057] The present invention switches between two working modes according to the service life of the grid.
[0058] A. Ion thrust mode - the flip-up baffle is in the open state
[0059] When the grid is within its own service life, the ion thrust mode is adopted. At this time, the working fluid inlet is connected to the discharge working fluid, and each flip-up baffle is in the maximum outward flip-open state as shown in Figure 1 . The inner wall of the discharge chamber housing and the hollow cathode are energized. The hollow cathode generates a large number of electrons that bombard the working fluid in the discharge chamber, realizing the avalanche generation of plasma. After power is supplied to the grid, the plasma is accelerated and extracted to form an ion thrust.
[0060] In the ion thrust mode, a ground voltage is applied to each flip-up baffle. The backflow particles in the plasma plume extracted through the grid will be blocked and absorbed by the flip-up baffle, which can reduce the sputtering pollution of the plasma to the thruster, and thus the original neutralizer can be omitted. Each flip-up baffle remains at the ground potential, enabling it to neutralize the backflow particles reaching the sailboard and avoiding damage to the spacecraft caused by the plasma.
[0061] B. Chemical combustion mode - the flip-up baffle is in the closed state
[0062] As the working time of the thruster in the ion thrust mode increases, as its key failure mode, various problems often occur in the grid assembly, restricting the service life of the thruster. When the thruster can no longer work in the ion thrust mode, it is restarted to the chemical combustion mode.
[0063] That is, when the grid reaches its own working life, the combustion thrust mode is adopted. At this time, the working fluid inlet is connected to the combustion propellant. Each flip flapper is driven by a flapper flipping drive device (preferably an electric hinge) to flip inward. A Laval nozzle with the intersection point of the inner flapper and the outer flapper as the throat is specifically as shown in Figure 3 and Figure 4 . At this time, the internal space of the discharge chamber acts as the combustion chamber of a chemical thruster.
[0064] The hollow cathode is energized. During the startup process, the emitter inside it will be heated to thousands of degrees, and local high-temperature arcs are generated during the startup process. Therefore, it has the condition to ignite the bipropellant fuel. Thus, the fuel propellant sprayed into the discharge chamber through the working fluid inlet is ignited and burned to generate high-temperature gas; during the combustion process, the grid will oxidize and burn, and its products will be accelerated and ejected together with the high-temperature gas through the throat of the Laval nozzle to form combustion thrust, realizing the reuse of the thruster structure and system.
[0065] Since the C / C grid will be oxidized and burned at the very beginning, and its products will also be discharged with the gas flow, it will not affect the gas ejection process in the chemical mode.
[0066] The above-mentioned use of arc startup technology for ignition, on the one hand, after the cathode starts and operates stably, it can provide good electron emission performance for the ion propulsion mode; on the other hand, during the startup process of the cathode, the generated high-temperature arc also acts as an igniter in the combustion propulsion mode.
[0067] The present invention integrates the discharge chamber of the ion thruster, the hollow cathode, the combustion chamber and the igniter required for chemical propulsion on the same thruster, cancels the neutralizer of the ion thruster, and installs metal flip baffles outside. By changing the shape of the flip baffles, the secondary utilization of the discharge chamber and the cathode is realized.
[0068] The integrated thruster contains all the components required for the two modes. The two propulsion modes work in sequence, that is, after the electric thruster's life ends, it transforms into the combustion propulsion mode. Compared with the original situation where the two thrusters exist separately, not only the utilization rate of the spacecraft payload (thruster structure) resources is improved, but the innovative new structure can also have a more beneficial auxiliary effect on both propulsion modes.
[0069] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept scope of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.
Claims
1. A restartable regenerative ion-combustion thruster, characterized in that: It includes a hollow cathode, a working medium inlet, a discharge chamber, a grid, N flippable baffles and a baffle flipping drive device; where N≥2; The discharge chamber is a cylindrical chamber; The hollow cathode is coaxially inserted at the center of the head of the discharge chamber; The working medium inlet includes a discharge chamber inlet and a hollow cathode inlet; the working medium inlet is connected to the discharge working medium and the combustion propellant respectively through a switching valve; The grid is arranged at the inner end of the tail of the discharge chamber; The N flippable baffles are evenly hinged circumferentially at the outer end of the tail of the discharge chamber; each flippable baffle includes an integrally arranged inner baffle and an outer baffle; where the longitudinal sections of the inner baffle and the outer baffle are both arc-shaped, and the arc radius of the intersection point of the inner baffle and the outer baffle is the smallest; The N flippable baffles can be driven jointly by the baffle flipping drive device to flip inward and form a Laval nozzle with the intersection point of the inner baffle and the outer baffle as the throat.
2. The restartable regenerative ion-combustion thruster according to claim 1, characterized in that: Let the maximum flipping angle between each inner baffle and the grid plane be α, and the angle between each outer baffle and the corresponding inner baffle be β; then α is determined according to the divergence angle of the plasma beam ejected in the discharge chamber, and β is determined according to the expansion ratio of the Laval nozzle.
3. The restartable regenerative ion-combustion thruster according to claim 2, wherein: α＝130°，β＝135°。 4. The restartable regenerative ion-combustion thruster according to claim 1, characterized in that: The expansion ratio of the Laval nozzle is 130 - 450.
5. The restartable regenerative ion-combustion thruster according to claim 1, characterized in that: It also includes a power conditioning unit. The positive pole of the power conditioning unit is connected to the inner wall of the discharge chamber housing, and the negative pole of the power conditioning unit is connected to the hollow cathode and each flippable baffle respectively.
6. The restartable regenerative ion-combustion thruster according to claim 1, characterized in that: The material of the grid is C / C composite material, and the material of the hollow cathode is barium tungsten.
7. The restartable regenerative ion-combustion thruster according to claim 1, wherein: A plane injector connected to the discharge chamber inlet is arranged at the head of the discharge chamber.
8. The restartable regenerative ion-combustion thruster according to claim 1, characterized in that: The number N of the flippable baffles is an even number. High-temperature resistant sealing materials are arranged on the sides of each flippable baffle, and the inner baffle is hermetically hinged to the outer end of the tail of the discharge chamber.
9. The restartable regenerative ion-combustion thruster according to claim 1, characterized in that: It has two working modes, namely: ion thrust mode and combustion thrust mode; When the grid is within its own working life, the ion thrust mode is adopted; at this time, the working medium inlet is connected to the discharge working medium, each flippable baffle is in the maximum outward flipping open state, the inner wall of the discharge chamber housing and the hollow cathode are electrified, the discharge working medium is ionized in the discharge chamber to form a plasma beam, which is accelerated and led out through the grid to form an ion thrust; When the grid reaches its own working life, the combustion thrust mode is adopted. At this time, the working medium inlet is connected to the combustion propellant, and each flippable baffle is driven by the baffle flipping drive device to flip inward to form a Laval nozzle with the intersection point of the inner baffle and the outer baffle as the throat; The hollow cathode is electrified to generate a high-temperature arc to ignite and burn the fuel propellant sprayed into the discharge chamber through the working medium inlet to generate high-temperature gas; during the combustion process, the grid will be oxidized and burned, and its products will be ejected together with the high-temperature gas through the Laval nozzle to form a combustion thrust.
10. The restartable regenerative ion-combustion thruster according to claim 9, wherein: In the ion thrust mode, a ground voltage is applied to each flippable baffle, and the reflux particles in the plasma plume led out through the grid will be blocked and absorbed by the flippable baffle, which can reduce the sputtering pollution of the plasma to the thruster.