A piston projectile injection system and method for plasma disruption mitigation

Abstract

The application provides a piston projectile injection system and method for plasma disruption protection, which comprises an air inlet cavity, a projectile acceleration cavity, a reset cavity, an air inlet flange, a gas discharge pipe, a feeding pipe, a projectile clamp, a reset gas pipe, an isolation sealing ring, an outlet flange, a reset limiting mechanism, an air inlet cavity gas discharge valve, a reset cavity air inlet valve and a reset cavity gas discharge valve. The technical problem that a large Roots pump differential air extraction is required in an existing spallation projectile injection system is overcome, high-pressure gas driving and a piston working principle are adopted, the acceleration of the projectile and the effective isolation and removal of the driving gas are realized, and the efficient impurity injection tool is provided for plasma disruption mitigation experiments.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vacuum technology, high gas driving, pellet injection and magnetic confinement fusion, in particular to a piston type pellet injection system and method applied to plasma disruption protection. BACKGROUND

[0002] In tokamak discharge experiments, due to plasma control, magnetohydrodynamic instability, impurities, high-energy escape particles and other reasons, plasma disruption is difficult to avoid. Especially in the discharge of maintaining a steady-state high-parameter plasma, which is the main research content of realizing the stable operation of a tokamak fusion reactor, plasma disruption discharge will cause serious damage, such as large thermal load of the first wall, strong mechanical stress, large escape current, and even serious damage to the divertor target plate, first wall components and even the device. Although the operating limits of different parameters of the existing tokamak discharge have been thoroughly studied, and the tokamak can be controlled in the "safe operation" region to avoid disruption, but there are still some disruptions that are difficult to avoid. Therefore, in order to avoid or reduce the damage of disruption to the large device under high parameter conditions, it is necessary and important to carry out research on plasma disruption mitigation, which is also one of the focuses of current tokamak plasma physics research.

[0003] Experimental research has found that if a certain amount of impurity particles can be rapidly injected into the plasma before the disruption occurs, the harmfulness of the plasma disruption can be reduced to the minimum to achieve the effect of protecting the safety of the device.

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

[0005] The present application overcomes the technical problem of the existing spallation pellet injection system requiring a large Roots pump differential pumping, and realizes the acceleration of the pellets and the effective isolation and removal of the driving gas by using high-pressure gas driving and piston working principle. It provides an efficient impurity injection tool for plasma disruption mitigation experiments.

[0006] To solve the above technical problems, the application provides a piston type pellet injection system for plasma disruption protection, which comprises an air inlet cavity, an acceleration cavity, a reset cavity, an air inlet flange, a gas discharge pipe, a feeding pipe, a pellet clamp, a reset gas pipe, an isolation sealing ring, an outlet flange, a reset limiting mechanism, an air inlet cavity gas discharge valve, a reset cavity air inlet valve and a reset cavity gas discharge valve. The pellet acceleration cavity is a sliding track of the pellet clamp, one end of which is connected with the air inlet cavity, and the other end is connected with the reset cavity. The pellet clamp is inside the pellet acceleration cavity and can slide left and right in the pellet acceleration cavity. The pellet feeding pipe is connected with the pellet acceleration cavity through a side hole of the pellet acceleration cavity. One end of the air inlet cavity is connected with a high-pressure air charging valve, and the other end is connected with the pellet acceleration cavity. The air inlet cavity gas discharge valve is connected with the air inlet cavity through a pipeline. One end of the reset cavity is connected with the pellet acceleration cavity, and the other end is the outlet flange. The reset cavity air inlet valve and the reset cavity gas discharge valve are connected with the reset cavity through pipelines.

[0007] The pellet clamp is made of Peek material and has a nearly elliptical structure. The structure is thick at one end and thin at the other end. The thick end is a sliding end, and the thin end is a pellet cavity. An isolation sealing ring structure is installed outside the thin end, which can ensure that the pellet clamp can realize gas sealing between the air inlet cavity and the reset cavity after being ejected to the final position. The nearly elliptical structure outside can ensure that the pellet clamp can only reciprocate left and right in the pellet acceleration cavity and cannot rotate. The internal structure of the pellet clamp is a hollow circular table structure with a slightly larger inlet, and a feeding hole is opened on the side surface. Solid particle pellets can fall into the pellet clamp through the pellet feeding pipe and the feeding hole.

[0008] The pellet acceleration cavity is a hollow cylindrical structure, and the internal hollow structure is consistent with the shape of the pellet clamp, which is a nearly elliptical structure and has the same size as the pellet clamp. The difference is within the positive and negative tolerances, so that the pellet clamp can only slide left and right in the pellet acceleration cavity and cannot rotate, thereby ensuring that the side hole of the pellet clamp is always upward and only a small amount of driving gas can flow out through the gap between the two.

[0009] Meanwhile, the application provides a piston type pellet injection method for plasma disruption protection, which is characterized by the following operation steps.

[0010] (1) Close the valve connected with the outlet flange, the pellet feeding pipe valve and the air inlet cavity gas discharge valve.

[0011] (2) open the reset cavity inlet valve, and slowly fill a certain amount of high-pressure gas into the reset cavity through the inlet valve, and because of the pressure difference between the two ends of the projectile clamp, the projectile clamp will move to the other end of the projectile accelerating cavity under the push of the high-pressure gas until it hits the reset limiting mechanism, at which time the feeding port of the projectile clamp is aligned with the projectile feeding pipe.

[0012] (3) open the feeding valve, and then put the granular projectile into the projectile clamp from the projectile feeding pipe, and close the feeding pipe valve after feeding is completed.

[0013] (4) open the reset cavity exhaust valve, and use the air extractor set to exhaust the gas inside the reset cavity.

[0014] (5) open the valve at the outlet flange of the projectile, and then quickly fill a certain amount of high-pressure gas into the inlet cavity through the high-pressure filling valve, at which time the projectile clamp will move to the other side of the projectile accelerating cavity at high speed under the drive of the high-pressure gas.

[0015] (6) when the isolation sealing ring of the projectile clamp hits the reset cavity, the projectile clamp will be blocked and cannot continue to move forward, and the granular projectile in the projectile clamp will continue to move forward at high speed due to inertia, so as to be ejected at high speed. Because the isolation sealing ring is installed on the projectile clamp, under the pressure of the high-pressure gas, the projectile clamp will be sealed with the reset cavity, and the high-pressure drive gas cannot enter the reset cavity, so as not to enter the plasma with the projectile, thereby ensuring that only the projectile is injected into the plasma.

[0016] (7) open the inlet cavity exhaust valve to release the high-pressure propellant gas inside the inlet cavity and the projectile accelerating cavity.

[0017] (8) close the outlet flange valve, the projectile feeding pipe valve and the inlet cavity exhaust valve, open the reset cavity inlet valve, and then fill a certain amount of high-pressure gas into the reset cavity, at which time the projectile clamp will move to the other end of the projectile accelerating cavity under the push of the high-pressure gas until it hits the reset limiting mechanism, at which time the feeding port of the projectile clamp is aligned with the projectile feeding pipe, waiting for the next feeding and launching, so that a complete projectile launching is completed.

[0018] By adopting the high-pressure gas drive and the piston working principle, the present application realizes efficient acceleration of the projectile and effective isolation and removal of the drive gas, so that the system structure is greatly simplified, and a large Roots pump set is not needed as a differential air extraction system, so that a higher drive gas pressure can be used, and the projectile can obtain a higher launching speed, thereby providing an efficient impurity injection tool for plasma breakdown mitigation experiments. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present application. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] like Figure 1 As shown, a piston-type projectile injection system for plasma fracture protection includes an inlet chamber 13, a projectile acceleration chamber 4, a reset chamber 14, an inlet flange 1, a vent pipe 2, a projectile feeding pipe 3, a projectile clamp 5, a reset air pipe 6, an isolation sealing ring 7, an outlet flange 8, a reset limiting mechanism 9, an inlet chamber vent valve 10, a reset chamber inlet valve 11, and a reset chamber vent valve 12. The projectile acceleration chamber 4 is the sliding track of the projectile clamp 5, with one end connected to the air inlet chamber 13 and the other end connected to the reset chamber 14. The projectile clamp 5 is located inside the projectile acceleration chamber 4 and can slide left and right inside the projectile acceleration chamber 4. The projectile feeding pipe 3 is connected to the projectile acceleration chamber 4 through a side opening. One end of the air inlet chamber 13 is connected to the high-pressure charging valve, and the other end is connected to the projectile acceleration chamber 4. The air inlet chamber vent valve 10 is connected to the air inlet chamber 13 through the vent pipe 2. One end of the reset chamber 14 is connected to the projectile acceleration chamber 4, and the other end is the outlet flange 8. The reset chamber air inlet valve 11 and vent valve 12 are connected to the reset chamber 14 through the reset air pipe 6. The projectile clip 5 is made of Peek material. Its exterior has a nearly elliptical structure, with one thicker section and one thinner section. The thicker section is the sliding end, and the thinner section is the projectile cavity. An isolation sealing ring 7 is installed on the outside of the thinner section to ensure a gas seal between the air intake chamber 13 and the reset chamber 14 after the projectile clip 5 is ejected to its final position. The nearly elliptical exterior structure ensures that the projectile clip 5 can only reciprocate left and right within the projectile acceleration chamber 4 and cannot rotate. The internal structure of the projectile clip 5 is a hollow frustum structure with a large inner hole and a small outer hole. A feed hole is opened on its side, allowing solid projectile particles to fall into the projectile clip 5 from the projectile feeding pipe 3 and the feed hole. The projectile acceleration chamber 4 is a hollow cylindrical structure. Its hollow internal structure is consistent with the shape of the projectile clip 5, both being nearly elliptical structures. Its size is the same as that of the projectile clip, with a difference of positive and negative tolerance. This allows the projectile clip 5 to slide left and right inside it, but not rotate, thus ensuring that the side opening of the projectile clip 5 always faces upwards, and ensuring that only a very small amount of driving gas can flow out through the gap between the two.

[0022] This invention also proposes a piston-type projectile injection method for plasma fracture protection, the specific steps of which are as follows:

[0023] (1) Close the valve connected to the outlet flange 8, the valve of the shot feed pipe 3, and the air release valve 10 of the air inlet chamber.

[0024] (2) Open the reset chamber inlet valve 11, through the inlet valve 11 to the reset chamber 14 slowly fill a certain amount of high pressure gas, because the projectile clamp 5 both ends exist pressure difference, so the projectile clamp 5 will be driven by the high pressure gas to the other end of the projectile acceleration chamber 4 movement, until the reset limit mechanism 9, at this time the projectile clamp 5 feed port is just with the projectile feeding pipe 3 alignment.

[0025] (3) Open the feed valve, then the particle projectile from the projectile feeding pipe 3 into the projectile clamp 5, feeding complete close the valve 3.

[0026] (4) Open the reset chamber exhaust valve 12, using the air pump set to remove the gas inside the reset chamber 14.

[0027] (5) Open the projectile outlet flange 8 valve, then use high pressure gas valve to the inlet chamber 13 quickly fill a certain amount of high pressure gas, at this time the projectile clamp 5 will be driven by the high pressure gas carrying the internal particle projectile high speed to the other side of the acceleration chamber 4 movement.

[0028] (6) When the projectile clamp 5 isolation sealing ring 7 hit the reset chamber 14, the projectile clamp 5 will be blocked and can not continue to forward, while the particle projectile in the projectile clamp 5 will continue to move forward at high speed, so as to be high speed. Because the projectile clamp 5 is installed with isolation sealing ring 7, therefore under the action of high pressure gas, the projectile clamp 5 will be sealed with the reset chamber 14, high pressure driving gas can not enter the reset chamber 14, thus will not be with the projectile into the plasma, so as to ensure that only the projectile is injected into the plasma.

[0029] (7) Open the inlet chamber exhaust valve 10, the high pressure propellant gas inside the inlet chamber 13 and the projectile acceleration chamber 4 is discharged.

[0030] (8) Close the outlet flange 8 valve, projectile feeding pipe 3 valve, inlet chamber exhaust valve 10. Open the reset chamber inlet valve 11, then fill a certain amount of high pressure gas into the reset chamber 14, at this time the projectile clamp 5 will be driven by the high pressure gas to the other end of the projectile acceleration chamber 4 movement, until the reset limit mechanism 9, at this time the projectile clamp 5 feed port is just with the projectile feeding pipe 3 alignment, waiting for the next time feeding launch, so as to complete a complete projectile launch.

Claims

1. A piston-driven pellet injection system for plasma disruption shielding, characterized by: The application relates to a pellet feeding device, which comprises an air inlet cavity, a pellet accelerating cavity, a reset cavity, an air inlet flange, a gas exhaust pipe, a pellet feeding pipe, a pellet clamp, a reset gas pipe, an isolation sealing ring, an outlet flange, a reset limiting mechanism, an air inlet cavity gas exhaust valve, a reset cavity air inlet valve and a reset cavity gas exhaust valve. One end of the pellet accelerating cavity is connected with the pellet clamp sliding track, and the other end is connected with the reset cavity. The pellet clamp is located in the pellet accelerating cavity and can slide left and right in the pellet accelerating cavity. The pellet feeding pipe is connected with the pellet accelerating cavity through a side hole of the pellet accelerating cavity. One end of the air inlet cavity is connected with a high-pressure air charging valve, and the other end is connected with the pellet accelerating cavity. The air inlet cavity gas exhaust valve is connected with the air inlet cavity through a pipeline. One end of the reset cavity is connected with the pellet accelerating cavity, and the other end is the outlet flange. The reset cavity air inlet valve and the reset cavity gas exhaust valve are connected with the reset cavity through pipelines. The air inlet flange is located at one end of the air inlet cavity. The air inlet cavity gas exhaust valve is connected with the air inlet cavity through the gas exhaust pipe. The reset cavity air inlet valve and the reset cavity gas exhaust valve are connected with the reset cavity through the reset gas pipe. When the pellet clamp is in contact with the reset limiting mechanism, the pellet feeding pipe is aligned with the pellet feeding pipe.

2. A piston-driven pellet injection system for plasma disruption mitigation according to claim 1, characterized in that: The pellet clamp is made of Peek material and has an elliptical structure. The structure is thick at one end and thin at the other end. The thick end is a sliding end, and the thin end is a pellet cavity. An isolation sealing ring structure is arranged outside the thin end, so that the pellet clamp can realize gas sealing between the air inlet cavity and the reset cavity after being shot to the final position. The near-elliptical structure ensures that the pellet clamp can only reciprocate left and right in the pellet accelerating cavity and cannot rotate. The thin end of the pellet clamp has a hollow circular cone structure with a large inlet, and a feeding hole is formed in the side surface. Solid particle pellets fall into the pellet clamp from the pellet feeding pipe and the feeding hole.

3. A piston-driven pellet injection system for plasma disruption mitigation according to claim 1, characterized in that: The pellet accelerating cavity has a hollow cylindrical structure. The internal hollow structure is consistent with the shape of the pellet clamp, and both are elliptical structures. The size of the pellet accelerating cavity is the same as that of the pellet clamp, and the difference is a positive or negative tolerance. The pellet clamp can only slide left and right in the pellet accelerating cavity and cannot rotate, so that the side hole of the pellet clamp is always upward, and only a small amount of driving gas can flow out through the gap between the pellet accelerating cavity and the pellet clamp.

4. An injection method for a piston-driven pellet injection system for plasma disruption protection according to any one of claims 1 to 3, characterized in that, The pellet feeding device comprises the following steps: (1) closing the valve connected with the outlet flange, the pellet feeding pipe valve and the air inlet cavity gas exhaust valve; (2) opening the reset cavity air inlet valve, slowly charging a certain amount of high-pressure gas into the reset cavity through the air inlet valve, and because of the pressure difference between the two ends of the pellet clamp, the pellet clamp moves to the other end of the pellet accelerating cavity under the push of the high-pressure gas until the reset limiting mechanism is contacted, and at this time, the feeding port of the pellet clamp is aligned with the pellet feeding pipe; (3) opening the feeding valve, then putting the particle pellets into the pellet clamp from the pellet feeding pipe, and closing the feeding pipe valve after the feeding is completed; (4) opening the reset cavity gas exhaust valve, and using an air extractor to exhaust the gas in the reset cavity. (5) open the valve at the projectile outlet flange, then use the high pressure inflation valve to quickly fill a certain amount of high pressure gas into the intake cavity, at this time the projectile clip will be driven by the high pressure gas to move at high speed to the other side of the projectile acceleration cavity; (6) when the isolation sealing ring of the projectile clip hits the reset cavity, the projectile clip will be blocked and unable to continue to move forward, while the particle projectiles in the projectile clip will continue to move forward at high speed due to inertia, so as to be ejected at high speed, since the projectile clip is provided with the isolation sealing ring, under the pressure of the high pressure gas, the projectile clip will be sealed with the reset cavity, so the high pressure driving gas cannot enter the reset cavity, and thus will not enter the plasma with the projectile, so as to ensure that only the projectile is injected into the plasma; (7) open the intake cavity gas release valve to release the high pressure propellant gas in the intake cavity and the projectile acceleration cavity; (8) close the outlet flange valve, the projectile feeding pipe valve and the intake cavity gas release valve, open the reset cavity intake valve, then fill a certain amount of high pressure gas into the reset cavity, at this time the projectile clip will be driven by the high pressure gas to move to the other end of the projectile acceleration cavity until it hits the reset limiting mechanism, at this time the feeding port of the projectile clip is aligned with the projectile feeding pipe, waiting for the next feeding and launching.

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