An electromagnetically driven pellet injector and method for plasma rupture protection

Abstract

The present invention discloses an electromagnetically driven pellet injector and method for plasma rupture protection. The injector solves the shortcomings of the existing pellet injection technology system, which is complicated and requires additional liquid helium cryogenic system assistance, and has the advantages of fast pellet injection speed, small space occupation, and the ability to inject multiple solid pellets at one time. The multiple pellets are injected into different areas of the plasma in the form of shotguns, which can greatly enhance the plasma rupture mitigation effect. The successful development of the electromagnetically driven pellet injector provides a more effective impurity injection tool for the plasma rupture protection research work on EAST, and also provides reference significance for similar research on future fusion reactors.

Description

Technical Field

[0001] The invention relates to the fields of vacuum technology, high voltage technology, electromagnetic drive technology and magnetic confinement fusion, and in particular to an electromagnetic drive projectile injector and method dedicated to plasma rupture protection. Background Art

[0002] In the tokamak discharge test, the plasma rupture is difficult to avoid due to plasma control, magnetohydrodynamic instability, impurities, high-energy escape particles and other reasons. Especially in the discharge of maintaining steady-state high-parameter plasma, which is the main research content for achieving steady-state operation of tokamak fusion reactors, plasma rupture discharge can cause serious destructive effects, such as large heat load on the first wall, strong mechanical stress, large escape current, etc., and even cause serious damage to the filter target plate, first wall components and even the device. Although the operating limits of different parameters of existing tokamak discharges have been deeply studied, and the tokamak can be controlled in the "safe operation" area to avoid rupture, there are always some ruptures that are difficult to avoid. Therefore, in order to avoid or reduce the damage caused by rupture to large devices under high parameter conditions, it is necessary and important to carry out research on plasma rupture mitigation, which is also one of the current focuses of tokamak plasma physics research.

[0003] Experimental studies have found that if a certain amount of impurity particles can be quickly injected into the plasma before the rupture occurs, the harmfulness of the plasma rupture can be reduced to the lowest level to protect the safety of the device.

[0004] Due to the suddenness of plasma disruption, a fast-response impurity injection system is required to achieve rapid and accurate impurity particle injection. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the existing pellet injection technology system, such as being complicated and requiring an additional liquid helium cryogenic system to assist, and to provide an electromagnetically driven pellet injector and method dedicated to plasma rupture protection, which has the advantages of fast pellet injection speed, small space occupation, and the ability to inject multiple solid pellets at one time. The multiple pellets are injected into different areas of the plasma in a shotgun manner, which can greatly enhance the plasma rupture mitigation effect.

[0006] The technical scheme of the present invention is as follows: an electromagnetically driven projectile injector for plasma rupture protection, comprising a driving coil frame, a driving coil, a coil fixing clamp, a projectile chamber, a projectile supply pipe, a reset spring, an outlet flange, an attraction magnet frame, an attraction coil, and an attraction soft iron, wherein one side of the driving coil frame is connected to the attraction magnet frame, and the other side of the driving coil frame is connected to the outlet flange, and a reset spring is installed inside the connection between the driving coil frame and the outlet flange; the driving coil is wound around the outside of the driving coil frame and fixed to the driving coil frame by a coil fixing clamp; The attraction coil is wound around the outside of the attraction magnet frame, and an attraction soft iron is installed inside the attraction magnet frame; a conical projectile cavity with openings on the top and sides is installed inside the drive coil frame, and the projectile cavity can slide left and right inside the drive frame. When the projectile cavity moves to the reset spring side, it will be rebounded by the reset spring, and when the projectile cavity moves to the attraction soft iron side, it will be attracted and fixed by the energized attraction soft iron; when the projectile cavity moves to the attraction magnet side, the opening of the projectile supply pipe will be aligned with the upper opening of the projectile cavity, and the projectile will fall into the projectile cavity along the projectile supply pipe.

[0007] The projectile cavity is made of pure iron, and the cross-section of the cavity inside the projectile cavity is a conical structure with a small opening and a large interior. There are two smooth wing-shaped structures symmetrically located on both sides of the projectile cavity. The projectile cavity can slide back and forth in the groove inside the drive coil frame.

[0008] The inner wall of the driving coil frame is designed with a symmetrical smooth groove with an airfoil-shaped cross-section matching the shape of the projectile cavity.

[0009] The electromagnetically driven projectile injection method for plasma rupture protection of the present invention comprises the following projectile launching steps:

[0010] (1) First, the attraction coil is energized, and the attraction soft iron is magnetized to generate a magnetic field, thereby attracting the pellet cavity made of soft iron to stop near it, so that the upper opening of the pellet cavity is aligned with the opening of the pellet supply pipe. At this time, the external pellets will fall into the pellet cavity along the pellet supply pipe, thereby completing the pellet supply;

[0011] (2) Secondly, disconnect the power supply of the pull-in coil to put the projectile in a state ready to be launched;

[0012] (3) Then, a strong pulse current is passed through the driving coil, and a strong pulse magnetic field is generated near the projectile cavity. The projectile cavity is subjected to a strong electromagnetic force and moves the projectile inside it rapidly toward the inside of the driving coil frame along the smooth groove inside it;

[0013] (4) After the drive coil is energized, the pull-in coil is powered again after a delay of 10ms; 10ms: The function of the pull-in coil is to absorb the rebounding projectile cavity and stop it. According to calculations, the entire time from the projectile cavity launching to rebounding is about 10ms. Therefore, in order to ensure that the projectile cavity can be attracted by the pull-in coil after rebounding, the pull-in coil must be energized again after 10ms;

[0014] (5) When the projectile chamber moves to the outlet flange position, it will collide with the reset spring. Under the action of the spring force, the projectile chamber will be quickly rebounded, and the projectile inside the projectile chamber will continue to move forward under the action of inertia, thereby being injected into the tokamak device at an extremely fast speed. The rebounded projectile chamber will be attracted by the reset soft iron that has been energized again and stop, entering the next launch state.

[0015] The beneficial effects of the present invention compared with the prior art are:

[0016] (1) The present invention overcomes the shortcomings of the existing projectile injection technology system, such as complex structure, large footprint, and the need for additional liquid helium cryogenic system assistance. The system structure is very compact and does not take up too much external space.

[0017] (2) The present invention adopts electromagnetic driving technology to realize the rapid driving of impurity projectiles. By adjusting the driving current, a huge electromagnetic driving force can be obtained, so the projectile can reach a speed of several hundred meters or even thousands of meters, while the ordinary projectile injection system can only reach a speed of 200-500m / s.

[0018] (3) The present invention can inject dozens of solid pellets of different sizes at one time. Multi-particle pellets are injected into different areas of the plasma in a shotgun manner, which can greatly enhance the plasma disruption mitigation effect, while the existing pellet system can only inject one pellet at a time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0020] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0021] like Figure 1As shown, the present invention is an electromagnetically driven projectile injector for plasma rupture protection, comprising a driving coil frame 1, a driving coil 2, a coil fixing clamp 3, a projectile chamber 4, a projectile supply pipe 5, a reset spring 6, an outlet flange 7, an attraction magnet frame 8, an attraction coil 9, and an attraction soft iron 10; wherein one side of the driving coil frame 1 is connected to the attraction magnet frame 8, and the other side of the driving coil frame 1 is connected to the outlet flange 7, and a reset spring 6 is arranged inside the connection between the driving coil frame 1 and the outlet flange 7; the driving coil 2 is wound around the outside of the driving coil frame 1 and fixed to the driving coil frame 1 with the coil fixing clamp 3; the attraction coil 9 It is wound around the outside of the attraction magnet skeleton 8, and an attraction soft iron 10 is installed inside the attraction magnet skeleton 8; a conical projectile cavity 4 with openings on the top and sides is installed inside the driving coil skeleton 1, and the projectile cavity 4 can slide back and forth left and right inside the driving coil skeleton 1. When the projectile cavity 4 moves to the side of the reset spring 6, it will be rebounded by the reset spring 6, and when the projectile cavity 4 moves to the side of the attraction soft iron 10, it will be attracted and fixed by the energized attraction soft iron 10; when the projectile cavity 4 moves to the side of the attraction soft iron 10, the opening of the projectile supply pipe 5 will be aligned with the upper opening of the projectile cavity 4, and at this time, the external projectile will fall into the projectile cavity 4 along the projectile supply pipe 5.

[0022] To the implementation method of the present invention:

[0023] (1) First, the attraction coil 9 is energized, and the attraction soft iron 10 is magnetized to generate a magnetic field, thereby attracting the pellet cavity 4 made of soft iron to park near it, so that the upper opening of the pellet cavity 4 is aligned with the opening of the pellet supply pipe 5. At this time, the external pellets will fall into the pellet cavity along the pellet supply pipe, thereby completing the pellet supply;

[0024] (2) Secondly, disconnect the power supply of the pull-in coil 9 to put the projectile in a state ready for launch;

[0025] (3) Then, a strong pulse current is passed through the driving coil 2, and a strong pulse magnetic field is generated near the projectile cavity 4. The projectile cavity 4 is subjected to a strong electromagnetic force and moves the projectile inside it rapidly toward the inside of the driving coil frame 1 along the smooth groove inside it;

[0026] (4) After the drive coil 2 is energized, the pull-in coil 9 is powered again after a delay of 10 ms;

[0027] (5) When the projectile chamber 4 moves to the position of the return spring installed inside the outlet flange 7, it will collide with the return spring 6. Under the action of the elastic force of the return spring 6, the projectile chamber 4 will be quickly rebounded, and the projectile inside the projectile chamber 4 will continue to move forward under the action of inertia, thereby being injected into the tokamak device at an extremely fast speed. The rebounded projectile chamber 4 will be attracted by the return soft iron 10 that has been energized again and stop, entering the next launch state.

Claims

1. An electromagnetically driven projectile injector for plasma disruption protection, characterized in that: The invention comprises a driving coil frame, a driving coil, a coil fixing clamp, a pellet chamber, a pellet supply pipe, a reset spring, an outlet flange, an attracting magnet frame, an attracting coil and an attracting soft iron; wherein one side of the driving coil frame is connected to the attracting magnet frame, and the other side of the driving coil frame is connected to the outlet flange, and a reset spring is installed inside the connection between the driving coil frame and the outlet flange; the driving coil is wound around the outside of the driving coil frame and fixed to the driving coil frame with a coil fixing clamp; the attracting coil is wound around the attracting magnet frame The frame is outside, and the attraction magnet frame is installed with attraction soft iron; a conical projectile cavity with openings on the top and sides is installed inside the driving coil frame, and the projectile cavity slides left and right inside the driving frame. When the projectile cavity moves to the reset spring side, it will be rebounded by the reset spring, and when the projectile cavity moves to the attraction soft iron side, it will be attracted and fixed by the energized attraction soft iron; when the projectile cavity moves to the attraction magnet side, the opening of the projectile supply pipe will be aligned with the upper opening of the projectile cavity, and the projectile will fall into the projectile cavity along the projectile supply pipe.

2. The electromagnetically driven projectile injector for plasma disruption protection according to claim 1, characterized in that: The projectile cavity is made of pure iron, and the cross-section of the internal cavity of the projectile cavity is a conical structure with a small opening and a large interior. There are two smooth wing-shaped structures symmetrically located on both sides of the projectile cavity. The projectile cavity slides back and forth left and right in the groove inside the driving coil frame.

3. The electromagnetically driven projectile injector for plasma disruption protection according to claim 1, characterized in that: The inner wall of the driving coil frame is designed with a symmetrical smooth groove with an airfoil-shaped cross-section matching the shape of the projectile cavity.

4. A method for realizing the electromagnetically driven projectile injector for plasma disruption protection as claimed in claim 1, characterized in that: Here are the steps: (1) When the attraction coil is energized, the attraction soft iron will be magnetized to generate a magnetic field, thereby attracting the projectile cavity made of soft iron to stop near it, so that the upper opening of the projectile cavity is aligned with the opening of the projectile supply pipe. At this time, the external projectile will fall into the interior of the projectile cavity along the projectile supply pipe, thereby completing the projectile supply; (2) disconnecting the power supply of the pull-in coil to put the projectile in a state ready to be launched; (3) A strong pulse current is passed through the driving coil, and a strong pulse magnetic field is generated near the projectile cavity. The projectile cavity is subjected to a strong electromagnetic force and moves the projectile inside it rapidly toward the inside of the driving coil frame along the smooth groove inside the projectile cavity; (4) After the drive coil is powered on, power is supplied to the pull-in coil again after a delay of 10ms; (5) When the projectile chamber moves to the outlet flange position, it will collide with the reset spring. Under the action of the spring force, the projectile chamber will be quickly rebounded, and the projectile inside the projectile chamber will continue to move forward under the action of inertia and be injected into the vacuum chamber of the tokamak device at an extremely fast speed. The rebounded projectile chamber will be attracted by the reset soft iron that has been energized again and stop, entering the next launch state.

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