An absorption ball shutdown device

Abstract

The present invention discloses an absorption ball stack stop device, comprising an upper ball storage tank and a lower ball storage tank, wherein the bottom end of the upper ball storage tank is connected to the lower ball storage tank through a ball drop tube, and the interior of the lower ball storage tank is connected to the upper ball storage tank through an absorption ball riser tube; a ball-injection tube is arranged at the ball outlet at the bottom end of the upper ball storage tank, and the ball-injection tube is driven by a power device to move up and down linearly, and when the ball-injection tube is lifted to a first position, the ball-injection tube is connected to the upper ball storage tank and the ball drop tube; when the ball-injection tube is lowered to a second position, the ball-injection tube blocks the upper ball storage tank and the ball drop tube; the inner cavity of the upper ball storage tank is connected to a negative pressure system. The absorption ball stack stop device of the present invention has a simple structure, does not require an intermediate transmission structure, does not require lubrication, will not fail due to jamming, and has a long service life.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear reactor safety, in particular to an absorbing ball reactor shutdown device. Background Art

[0002] A nuclear reactor, also known as an atomic reactor or reactor, is a device that can maintain a controllable self-sustaining chain nuclear fission reaction to achieve nuclear energy utilization. The pebble bed high temperature gas-cooled reactor uses spherical elements to pass through the core multiple times to achieve continuous operation without stopping the reactor.

[0003] There are two main ways to shut down a nuclear reactor. One is to control the number of neutrons in the core by driving the control rods to a certain depth. The other is to shut down the reactor by absorbing neutrons with boron carbide-containing absorber balls. The control rods are driven by the control rod drive mechanism and are used for reactor startup, power regulation and shutdown. If a control rod is stuck, the absorber ball shutdown system can be used as a second shutdown method. The absorber balls are released into the core reaction layer through the absorber ball shutdown device to achieve the purpose of safe shutdown.

[0004] At present, when the absorber ball shutdown system is in operation, the motor is required to drive the ball screw and valve stem to make the absorber ball in the ball storage tank fall into the core reflective layer to achieve safe shutdown. This shutdown method requires the use of transmission structures such as ball screws, which are not only complex in structure, but also because the transmission structure is set in a closed chamber and is in a high working environment, it is not easy to lubricate. Therefore, there is dry friction between the transmission structures, which has a short service life and is prone to jamming. Summary of the invention

[0005] In view of this, the present invention provides an absorbing ball shutdown device, which has a simple structure, does not require an intermediate transmission structure, does not require lubrication, will not fail due to jamming, and has a long service life.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An absorption ball shutdown device comprises an upper spherical storage tank and a lower spherical storage tank, wherein the bottom end of the upper spherical storage tank is connected to the lower spherical storage tank through a ball drop pipe, and the interior of the lower spherical storage tank is connected to the upper spherical storage tank through an absorption ball riser pipe;

[0008] A goal tube is provided at the ball outlet at the bottom end of the upper ball storage tank, and the goal tube is driven by a power device to move linearly up and down. When the goal tube is lifted to a first position, the goal tube is connected to the upper ball storage tank and the ball drop tube; when the goal tube is lowered to a second position, the goal tube blocks the upper ball storage tank and the ball drop tube;

[0009] The inner cavity of the upper spherical storage tank is communicated with a negative pressure system.

[0010] Optionally, the power device is an electric actuator, and the goal tube is driven by the electric actuator. When the goal tube is lifted to the top dead center position, the goal tube is connected to the upper ball storage tank and the ball drop tube; when the goal tube is lowered to the bottom dead center position, the goal tube blocks the upper ball storage tank and the ball drop tube.

[0011] Optionally, a lower pipe forging is fixedly connected to the ball outlet of the upper ball storage tank, the inner cavity of the lower pipe forging is slidably connected to the lower end of the ball inlet pipe, and a ball outlet channel is provided on the side surface of the lower end of the ball inlet pipe;

[0012] The outlet of the lower pipe forging is communicated with the inlet of the ball drop tube, and the inner diameter of the lower pipe forging is larger than the inner diameter of the ball drop tube.

[0013] Optionally, a pipe through hole is provided at the top end of the upper ball storage tank, and the upper end of the ball tube is connected to the electric actuator through the pipe through hole; the electric actuator is arranged in a sealed housing.

[0014] Optionally, the power device is a linear motor, the goal tube is driven by the linear motor, and the goal tube is connected to the mover of the linear motor; when the goal tube is lifted to the upper dead point, the inner cavity of the goal tube is connected with the inner cavity of the upper ball storage tank, and a goal is scored; when the goal tube is lowered to the lower dead point, the inner cavity of the goal tube is disconnected from the inner cavity of the upper ball storage tank, and the goal is stopped.

[0015] Optionally, a lower pipe forging is fixedly connected to the ball outlet of the upper ball storage tank, the inner cavity of the lower pipe forging is slidably connected to the lower end of the ball inlet pipe, and a ball outlet channel is provided on the side surface of the lower end of the ball inlet pipe;

[0016] When the goal tube is located at the upper dead point, the inner cavity of the upper ball storage tank is connected to the ball outlet passage correspondingly, which is a goal-scoring condition; when the goal tube is located at the lower dead point, the ball outlet passage is blocked by the side wall of the lower pipe forging, and goal-scoring stops.

[0017] Optionally, a ball channel is provided on the side wall of the lower pipe forging, one end of the ball channel is communicated with the inner cavity of the upper ball storage tank, and the other end is communicated with the inner cavity of the lower pipe forging;

[0018] The opening of one end of the ball channel for communicating with the inner cavity of the lower pipe forging is lower than the lower dead point of the ball tube. When the linear motor is powered off, the ball outlet channel is connected with the upper ball storage tank through the ball channel.

[0019] The goal channel is an L-shaped channel, the vertical channel of the L-shaped channel is connected to the inner cavity of the upper ball storage tank, and the horizontal channel of the L-shaped channel is arranged corresponding to the ball outlet channel;

[0020] The length of the vertical channel of the L-shaped channel is greater than the size of the ball outlet channel, so that the ball outlet channel is blocked by the tube wall of the lower pipe forging in non-ball-scoring working conditions.

[0021] Optionally, a through-hole is provided at the top of the upper ball storage tank, and the upper end of the ball tube is connected to the linear motor through the through-hole; the linear motor is arranged in a sealed housing;

[0022] A limiting structure is arranged on the outer surface of the goal tube near the linear motor, and damping springs are arranged at both the upper and lower ends of the limiting structure.

[0023] Optionally, the sealed housing comprises a drive housing cylinder, an upper end of the drive housing cylinder is provided with a drive housing upper flange, and a lower end of the drive housing cylinder is provided with a drive housing lower flange;

[0024] The upper flange of the driving housing is connected to the top cover of the driving housing, the lower flange of the driving housing is connected to the connecting pipe flange, and one end of the connecting pipe flange away from the lower flange of the driving housing is connected to the upper surface of the top head of the pressure vessel by placing a connecting pipe seal.

[0025] Optionally, a middle connecting pipe is sealed and connected to the opening of the pipe-through hole, a connecting pipe flange is provided at the upper end of the middle connecting pipe, and the connecting pipe flange is connected to the connecting pipe flange;

[0026] The middle connecting pipe is sleeved on the outside of the ball tube, and the middle connecting pipe is sleeved in the inner longitudinal through hole of the placement pipe, and the inner cavity of the placement pipe is communicated with the inner cavity of the pressure container.

[0027] Optionally, the goal tube and the middle connecting tube are arranged at a certain distance, so that a sandwich cavity is formed between the goal tube and the middle connecting tube, and a heat insulating layer is arranged in the sandwich cavity.

[0028] Optionally, the negative pressure system includes a low-pressure buffer tank and a permanent magnet shielded compressor which are sequentially connected through a first pipeline, a ventilation cavity connected to the inner cavity of the upper spherical storage tank is provided in the insulation layer, the ventilation cavity is connected to the air inlet end and the air return end of the first pipeline, the low-pressure buffer tank is arranged close to the air inlet end of the first pipeline, and the permanent magnet shielded compressor is arranged close to the air return end of the first pipeline;

[0029] The side of the connecting flange is provided with a first hole and a second hole, wherein the first hole and the second hole are through holes penetrating through a side wall of one side of the connecting flange; the first hole and the second hole are both connected to the ventilation cavity.

[0030] Optionally, the ball drop tube comprises an upper pipe, a carbon fiber pipe and a lower pipe which are sequentially connected, the upper end of the upper pipe is connected to the upper ball storage tank, the lower end of the lower pipe is connected to the lower ball storage tank, and both ends of the carbon fiber pipe are connected to adjacent pipes through connecting sleeves;

[0031] The portion of the ball drop tube that passes through the hole of the reflective layer is a carbon fiber tube.

[0032] Optionally, the negative pressure system includes a low-pressure buffer tank and a permanent magnet shielded compressor which are sequentially connected through a second pipeline, the inlet end of the second pipeline is connected to the inner cavity of the upper spherical storage tank, and the outlet end of the second pipeline is also connected to the inner cavity of the upper spherical storage tank;

[0033] Alternatively, the negative pressure system includes an air pump connected through a third pipeline, the inlet end of the third pipeline is connected to the inner cavity of the upper ball storage tank, and the outlet end of the third pipeline is also connected to the inner cavity of the upper ball storage tank.

[0034] It can be seen from the above technical scheme that the absorption ball stack stop device provided by the present invention drives the axial up and down linear movement of the ball tube through the power device to realize the position change of the ball tube, thereby controlling whether the upper ball storage tank is connected with the ball drop tube. When connected, the absorption ball is released into the reflection layer channel and then enters the lower ball storage tank. After the absorption ball in the upper ball storage tank enters the lower ball storage tank, the control valve of the negative pressure system is opened. Due to the pressure difference, the absorption balls in the lower ball storage tank are all drawn back into the upper ball storage tank through the absorption ball riser, completing the absorption ball lifting and recovery process. The absorption ball stack stop device of the present invention uses the power device to directly drive the ball tube to move, has a simple structure, does not require an intermediate transmission structure, does not require lubrication, will not get stuck and fail, and has a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic cross-sectional view of a stack stop device driven by an electric actuator and absorbing balls provided in an embodiment of the present invention;

[0037] Figure 2 for Figure 1 A schematic diagram of the local enlarged structure of part I in FIG.

[0038] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure at AA in FIG.

[0039] Figure 4 for Figure 1 A schematic diagram of the partial enlarged structure of Part II;

[0040] Figure 5 A schematic cross-sectional view of a linear motor driven absorbing ball stop device provided in an embodiment of the present invention;

[0041] Figure 6 for Figure 5 A schematic diagram of the partial enlarged structure of Part III;

[0042] Figure 7 for Figure 6 Schematic diagram of the cross-sectional structure at BB in FIG.

[0043] Figure 8 for Figure 6 Schematic diagram of the cross-sectional structure at CC in FIG.

[0044] Fig. 9 for Figure 5 Schematic diagram of the local enlarged structure of part IV.

[0045] in:

[0046] 1. Lower ball storage tank, 2. Connecting ferrule, 3. Absorbing ball riser, 4. Reflecting layer channel, 5. Dropping ball tube, 6. Ball tube connection section, 7. Absorbing ball, 8. Upper ball storage tank, 9. Pressure vessel top cover, 10. Sensor, 11. High temperature resistant cable, 12. Middle connecting pipe, 13. Insulating layer, 14. Place connecting pipe, 15. Connecting pipe flange, 16. Sealing gasket, 17. Connecting pipe flange, 18. Drive housing lower flange, 19. Electric actuator, 20. Drive housing upper flange, 21. Drive housing top cover, 22. Electrical penetrations, 23. Drive shell cylinder, 24. Connecting shaft, 25. Goal pipe, 26. Permanent magnet shielded compressor, 27. First pipeline, 28. Support frame, 29. Exhaust pipe, 30. First channel, 31. Second channel, 32. Hollow connecting bolt, 33. Ball outlet channel, 34. Lower pipe forging, 35. Skirt, 36. Carbon fiber pipe, 37. Electric control valve, 38. Low-pressure buffer tank, 39. Pressure gauge, 40. Stator, 41. Linear motor, 42. Damping spring, 43. Limiting structure, 44. Goal channel, 45. Ventilation cavity. DETAILED DESCRIPTION

[0047] The invention discloses an absorbing ball pile stop device, which has a simple structure, does not require an intermediate transmission structure, does not require lubrication, will not fail due to jamming, and has a long service life.

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] See also Figures 1 to 9 The absorption ball stack stop device of the present invention comprises an upper ball storage tank 8 and a lower ball storage tank 1. The bottom end of the upper ball storage tank 8 is connected to the lower ball storage tank 1 through a ball drop tube 5, and the interior of the lower ball storage tank 1 is connected to the upper ball storage tank 8 through an absorption ball riser 3. A goal tube 25 is provided at the ball outlet at the bottom end of the upper ball storage tank 8. The goal tube 25 is driven by a power device to move up and down linearly. When the goal tube 25 is lifted to the upper dead point position, it is the first position, and the goal tube 25 connects the upper ball storage tank 8 and the ball drop tube 5. When the goal tube 25 is lowered to the lower dead point position, it is the second position, and the goal tube 25 blocks the connection between the upper ball storage tank 8 and the ball drop tube 5. The first working position is a goal position, and the second working position is a stop goal position. The inner cavity of the upper ball storage tank 8 is connected to a negative pressure system.

[0050] The inner cavity of the upper ball storage tank 8 is connected to a negative pressure system, and the negative pressure system is used to suck the absorption ball 7 in the lower ball storage tank 1 back into the upper ball storage tank 8, so that the absorption ball 7 can be recycled and reused. The upper ball storage tank 8 is set at a higher height than the lower ball storage tank 1, so that when the goal tube 25 is located at the goal position, it is convenient for the absorption ball 7 to enter the lower ball storage tank 1 through the ball drop tube 5 under the action of gravity. The bottom end of the upper ball storage tank 8 is higher than the top of the reactor, and the top of the lower ball storage tank 1 is lower than the bottom end of the reactor. The ball drop tube 5 passes through the reflection layer channel 4, so that the absorption ball 7 passes through the reflection layer channel 4 to achieve neutron absorption. The goal tube 25 moves up and down under the drive of the power device, thereby realizing the switching of the device between the two working conditions of goal or stop goal.

[0051] The absorption ball stack stop device of the present invention drives the axial up and down linear movement of the ball tube 25 through the power device to achieve the position change of the ball tube 25, thereby controlling whether the upper ball storage tank 8 is connected with the ball drop tube 5. When connected, the absorption ball 7 is released into the reflection layer channel 4, and then enters the lower ball storage tank 1. After the absorption ball 7 in the upper ball storage tank 8 enters the lower ball storage tank 1, the control valve of the negative pressure system is opened. Due to the pressure difference, the absorption balls 7 in the lower ball storage tank 1 are all drawn back into the upper ball storage tank 8 through the absorption ball riser 3, completing the absorption ball 7 lifting and recovery process. The absorption ball stack stop device of the present invention uses the power device to directly drive the ball tube 25 to move, has a simple structure, does not require an intermediate transmission structure, does not require lubrication, will not be stuck and fail, and has a long service life.

[0052] Among them, the bottom end of the upper spherical storage tank 8 is connected with a skirt seat 35, and the skirt seat 35 is used to support the upper spherical storage tank 8. The bottom end of the skirt seat 35 is arranged on the inner ceramic stack internal component of the top head 9 of the pressure vessel.

[0053] Specifically, Figure 1 As shown, the power device is an electric actuator 19. When the goal tube 25 is lifted to a set height (upper dead center) driven by the electric actuator 19, the upper ball storage tank 8 is connected to the ball drop tube 5 to score a goal. When the goal tube 25 falls back to the lower dead center, the connection between the upper ball storage tank 8 and the ball drop tube 5 is blocked, and the goal is stopped. The electric actuator 19 is a linear electric actuator, and the connecting shaft 24 of the electric actuator 19 is connected to the upper end flange of the goal tube 25 by bolts.

[0054] In one embodiment, a lower pipe forging 34 is fixedly connected to the ball outlet of the upper ball storage tank 8. Figure 2 As shown, the upper end of the lower pipe forging 34 is welded to the ball outlet of the upper ball storage tank 8, and the lower end is welded to the upper end of the ball drop tube 5, and the outlet of the lower pipe forging 34 is connected to the inlet of the ball drop tube 5. The lower pipe forging 34 is provided with a through hole in the axial direction, and the lower end of the ball injection tube 25 is slidably connected in the through hole of the lower pipe forging 34, and a ball outlet channel 33 is provided on the side of the lower end of the ball injection tube 25. In the ball injection working condition, the ball injection tube 25 moves upward, and the ball outlet channel 33 is exposed from the lower pipe forging 34, and the absorption ball 7 in the upper ball storage tank 8 enters the ball drop tube 5 through the ball outlet channel 33.

[0055] Furthermore, in order to facilitate the support of the bottom end of the goal tube 25, the inner diameter of the lower pipe forging 34 is larger than the inner diameter of the ball drop tube 5, and the inner diameter of the goal tube 25 is the same as the inner diameter of the ball drop tube 5. In order to improve the structural strength of the ball outlet channel 33 of the goal tube 25, the end of the ball outlet channel 33 of the goal tube 25 is set as a goal tube connecting section 6, and the wall thickness of the goal tube connecting section 6 is thicker than the wall thickness of other parts of the goal tube 25, thereby increasing the service life of the goal tube connecting section 6 and improving the structural strength of this section. Among them, there are multiple ball outlet channels 33, and the multiple ball outlet channels 33 are evenly distributed around the axis of the goal tube connecting section 6 and are located at the same horizontal position. Refer to Figure 3 and Figure 7 As shown, four ball outlet channels 33 are provided.

[0056] In order to facilitate the electric actuator 19 to drive the ball tube 25, a through hole is provided at the top of the upper ball storage tank 8, and the upper end of the ball tube 25 is connected to the driving end of the electric actuator 19 through the through hole. In order to avoid radiation leakage, the electric actuator 19 is arranged in a sealed housing.

[0057] In another embodiment, if Figure 5 As shown, the power device is a linear motor 41, which controls the axial up and down linear motion of the goal tube 25 to achieve the position change of the goal tube 25, thereby controlling whether the upper ball storage tank 8 is connected to the ball drop tube 5. When the goal tube 25 is lifted to a set height (upper dead center) driven by the linear motor 41, the inner cavity of the goal tube 25 is connected to the inner cavity of the upper ball storage tank 8 through the ball outlet channel 33, and a ball is scored. When the goal tube 25 falls back to the lower dead center, the inner cavity of the goal tube 25 is separated from the inner cavity of the upper ball storage tank 8, and the goal is stopped.

[0058] In the normal power-on working state, the linear motor 41 controls the axial movement of the goal tube 25, controls whether the goal channel at the end of the goal tube 25 is connected to the inner cavity of the upper ball storage tank 8, and thus controls whether the absorption ball 7 is released. In the case of a power outage, the magnetic force of the linear motor 41 disappears, and the goal tube 25 falls to the initial position under the action of its own gravity, and the initial position is a position lower than the set lower dead point. At this time, the linear motor 41 cannot limit the position of the goal tube 25. Under the action of gravity, the bottom end of the goal tube 25 contacts the upper end surface of the ball drop tube 5, and the inner cavity of the goal tube 25 is connected to the inner cavity of the upper ball storage tank 8 through the goal channel 44. The absorption ball 7 passively falls into the reflection layer channel 4 of the core, realizing passive shutdown, thereby ensuring the safety of the reactor in the event of an unexpected power outage.

[0059] Specifically, Figure 6As shown, the ball outlet of the upper ball storage tank 8 is fixedly connected to a lower pipe forging 34, the upper end of the lower pipe forging 34 is welded to the ball outlet of the upper ball storage tank 8, and the lower end is welded to the upper end of the ball drop tube 5, and the outlet of the lower pipe forging 34 is connected to the inlet of the ball drop tube 5. A through hole is axially arranged on the lower pipe forging 34, and the inner cavity of the through hole of the lower pipe forging 34 is slidably connected to the lower end of the ball tube 25, and a ball outlet channel 33 is arranged on the side surface of the lower end of the ball tube 25. A ball channel 44 is arranged on the side wall of the lower pipe forging 34, and one end of the ball channel 44 is connected to the inner cavity of the upper ball storage tank 8, and the other end is connected to the inner cavity of the through hole of the lower pipe forging 34.

[0060] In the goal-scoring condition, the goal tube 25 is located at the upper dead center, and the inner cavity of the goal tube 25 is connected to the inner cavity of the upper ball storage tank 8 through the ball outlet channel 33, so that a goal is scored. At this time, the outlet of the goal channel 44 may or may not be connected to the ball drop tube 5. When connected, it assists in scoring. In the non-goal-scoring condition, the linear motor 41 drives the goal tube 25 to the lower dead center, and the ball outlet channel 33 is blocked by the side wall of the lower pipe forging 34. At the same time, the side wall of the goal tube 25 located at the lower end of the ball outlet channel 33 blocks the goal channel 44, so that no goal can be scored.

[0061] Further, the ball channel 44 is an L-shaped channel, the vertical channel of the L-shaped channel is connected to the inner cavity of the upper ball storage tank 8, and the transverse channel of the L-shaped channel is arranged correspondingly to the ball outlet channel 33. The corresponding arrangement here means that the number of the two is the same, and the channel diameters of the two are the same or different, as long as the aperture alignment position of the two can allow the absorption ball 7 to pass through. The transverse channel of the L-shaped channel can be a horizontal channel or an inclined channel. When it is an inclined channel, one end of the transverse channel close to the vertical channel is higher and the other end is lower, so as to facilitate the absorption ball 7 to flow to the ball outlet channel 33 on the ball tube 25.

[0062] In order to facilitate the blocking of the ball outlet channel 33 in the non-ball outlet working condition, the length of the vertical channel of the L-shaped channel is greater than the size of the ball outlet channel 33, so that the ball outlet channel 33 is blocked by the pipe wall of the lower pipe forging 34 in the non-ball outlet working condition. It can be understood that the diameter of the ball outlet channel 33 and the diameter of the ball outlet channel 44 are both greater than the diameter of the absorbing ball 7. The length of the side wall of the ball outlet channel 33 at the lower end of the ball outlet channel 33 is slightly greater than the length of the ball outlet channel 44.

[0063] In order to facilitate the linear motor 41 to drive the ball tube 25, a through hole is provided at the top of the upper ball storage tank 8, and the upper end of the ball tube 25 is connected to the mover of the linear motor 41 through the through hole. In order to avoid radiation leakage, the linear motor 41 is arranged in a sealed housing.

[0064] When the power device is a linear motor 41, in order to limit the up and down travel range of the goal tube 25, a limiting structure 43 is provided on the outer surface of the goal tube 25 near the position of the linear motor 41, and a damping spring 42 is provided at both the upper and lower ends of the limiting structure 43. The damping spring 42 is sleeved on the goal tube 25. Specifically, the limiting structure 43 is a limiting boss, and the limiting boss and the damping spring 42 are both located in the cavity of the support frame 28. One end of the damping spring 42 at the upper end is limited by the connecting flange of the linear motor 41, and the other end is limited by the upper surface of the limiting boss. One end of the damping spring 42 at the lower end is limited by the connecting pipe flange 17, and the other end is limited by the lower surface of the limiting boss. The axial length of the inner cavity of the support frame 28 is equal to the maximum travel of the goal tube 25. The stator 40 of the linear motor 41 is fixedly connected to the flange at the upper end of the support frame 28.

[0065] When the power device is a linear motor 41, there are three positions of the goal tube 25: an upper dead center position, a lower dead center position and an initial position. The height of the upper dead center position is higher than that of the lower dead center position, and the height of the lower dead center position is higher than that of the initial position.

[0066] Specifically, the sealed shell includes a drive shell cylinder 23 with openings at the upper and lower ends, a drive shell upper flange 20 is provided at the upper end of the drive shell cylinder 23, and a drive shell lower flange 18 is provided at the lower end of the drive shell cylinder 23. The drive shell upper flange 20, the drive shell lower flange 18 and the drive shell cylinder 23 are an integrated structure. The drive shell upper flange 20 is connected to the drive shell top cover 21, and the drive shell top cover 21 is used to seal the upper end opening of the drive shell cylinder 23. The drive shell lower flange 18 is connected to the pipe flange 15, and the end face of the pipe flange 15 is used to install the power device, such as the electric actuator 19 or the linear motor 41. The electric actuator 19 or the linear motor 41 is sleeved in the inner cavity of the drive shell cylinder 23. The electric actuator 19 or the linear motor 41 is fixed on the support frame 28, and the flange part of the support frame 28 is connected to the end face of the pipe flange 15. The end of the pipe flange 15 away from the lower flange 18 of the driving housing is sealed and connected to the upper surface of the top head 9 of the pressure vessel through the placement pipe 14. The pressure vessel is used to contain the reactor. The placement pipe 14 is provided with an axial through cavity for the ball tube 25 to pass through. The placement pipe 14 is sealed and welded with the pipe flange 15.

[0067] Among them, the middle connecting pipe 12 is sealed and connected at the opening of the through-hole, and the upper end of the middle connecting pipe 12 is provided with a connecting pipe flange 17, and the connecting pipe flange 17 is connected to the connecting pipe flange 15. The end of the support frame 28 is in contact with the connecting pipe flange 17, and the two are stacked together and connected to the connecting pipe flange 15 through a connecting piece. Further, the middle connecting pipe 12 is sleeved on the outside of the ball tube 25, and the middle connecting pipe 12 is sleeved in the internal longitudinal through hole where the connecting pipe 14 is placed, and the inner cavity of the connecting pipe 14 is connected to the inner cavity of the pressure vessel. A sealing gasket 16 is provided between the contact surface of the connecting pipe flange 17 and the connecting pipe flange 15.

[0068] In order to prevent the heat in the upper ball storage tank 8 from leaking into the cavity of the top drive shell cylinder 23, an insulating layer 13 is provided in the sandwich cavity between the ball tube 25 and the middle connecting tube 12. The insulating layer 13 is a composite silicate material or other commonly used heat-insulating materials, which can effectively prevent the heat in the upper ball storage tank 8 from leaking into the cavity of the drive shell cylinder 23, so that the cavity of the drive shell cylinder 23 maintains a relatively low temperature environment, thereby ensuring the service life of the power device.

[0069] Further, the inner top surface of the upper ball storage tank 8 is provided with a detection device for detecting the height of the absorption ball 7, and the detection device is used to detect the height of the absorption ball 7 in the upper ball storage tank 8. The detection device is connected to a high temperature resistant cable 11, and the high temperature resistant cable 11 extends into the inner cavity of the drive shell cylinder 23 through a channel provided in the insulation layer 13. An electrical penetration 22 is provided on the drive shell top cover 21, and the high temperature resistant cable 11 is led out through the electrical penetration 22 together with the cable of the power device. The electrical penetration 22 ensures the electrical continuity and sealing of the electrical conductor that penetrates the sealed drive shell cylinder 23. The electrical penetration 22 is a finished product in the prior art, and its structure is not repeated here. The detection device is electrically connected to the controller. The detection device is a sensor 10 or a guided wave radar level meter. The high temperature resistant cable 11 passes through the cavity between the middle connecting pipe 12 and the ball tube 25, passes through the support frame 28 and the drive shell cylinder 23, and finally leads out from the electrical penetration 22. It can be understood that a longitudinal channel is provided in the heat-insulating layer 13 at the cavity position between the middle connecting tube 12 and the ball tube 25 so that the high-temperature resistant cable 11 can pass through.

[0070] In a specific embodiment, the negative pressure system includes a low-pressure buffer tank 38 and a permanent magnet shielded compressor 26 connected in sequence through a first pipeline 27, and a ventilation cavity 45 connected to the inner cavity of the upper spherical storage tank 8 is provided in the insulation layer 13, and the ventilation cavity 45 is connected to the air inlet end and the air return end of the first pipeline 27. The low-pressure buffer tank 38 is arranged near the air inlet end of the first pipeline 27, and the permanent magnet shielded compressor 26 is arranged near the air return end of the first pipeline 27. The air inlet end and the air return end of the first pipeline 27 are both provided with an electric control valve 37, and the first pipeline 27 between the low-pressure buffer tank 38 and the permanent magnet shielded compressor 26 is also provided with an electric control valve 37, which is convenient for controlling the air path of the first pipeline 27. The low-pressure buffer tank 38 reduces the unevenness of the suction pipeline flow, and the low-pressure buffer tank 38 is provided to connect the upper spherical storage tank 8, and no additional air source is required. The electric control valve 37 is controlled by the controller. The first pipeline 27 is also provided with a pressure gauge 39, which is used to detect the pressure of the airflow in the first pipeline 27. The pressure gauge 39 can be arranged at different positions of the first pipeline 27 according to the needs of use. The return air end of the first pipeline 27 is connected to the exhaust pipe 29, and the exhaust pipe 29 is a part of the first pipeline 27.

[0071] Among them, the internal pressure of the low-pressure buffer tank 38 is lower than the internal pressure of the upper spherical storage tank 8. Due to the pressure difference between the upper spherical storage tank 8 and the low-pressure buffer tank 38, the upper spherical storage tank 8 and its connected pipelines generate negative pressure. Under the action of negative pressure, the absorption balls 7 in the lower spherical storage tank 1 are all sucked back to the upper spherical storage tank 8 along the absorption ball riser 3. The gas in the low-pressure buffer tank 38 is recompressed back into the upper spherical storage tank 8 by the permanent magnet shielded compressor 26, so that the gas circulation can be realized. If the space volume ratio and pressure difference between the low-pressure buffer tank 38 and the upper spherical storage tank 8 are large enough, the suction process of the absorption ball 7 can be completed once. If the space volume ratio and pressure difference are not large enough, the suction process of the absorption ball 7 can be completed through multiple cycles.

[0072] The absorption ball riser 3 is a stainless steel tube, and the upper end of the absorption ball riser 3 is welded to the upper spherical storage tank 8. The lower end of the absorption ball riser 3 extends into the inner bottom of the lower spherical storage tank 1. The bottom surface of the lower spherical storage tank 1 is an arc-shaped surface with a low middle and high surroundings, and the bottom end of the absorption ball riser 3 is a trumpet-shaped tube.

[0073] Further, such as Figure 4 and Fig. 9As shown, the side of the take-over flange 15 is provided with a first hole 30 and a second hole 31, both of which are through holes penetrating the side wall of one side of the take-over flange 15. The first hole 30 and the second hole 31 are both connected to the ventilation cavity 45. The first hole 30 and the second hole 31 are both connected to the ventilation cavity in the insulation layer 13 through a hollow connecting bolt 32. The head of the hollow connecting bolt 32 is placed in a groove on the inner wall of the middle connecting pipe 12, and the tail is threadedly connected in the first hole 30 or the second hole 31. One end of the first pipeline 27 is connected to the first hole 30, and the other end is connected to the second hole 31. The first hole 30 and the second hole 31 are arranged in parallel. The second hole 31 is connected to the end of the exhaust pipe 29.

[0074] Specifically, the ball drop tube 5 includes an upper pipe, a carbon fiber pipe 36 and a lower pipe which are connected in sequence. The lower end of the upper pipe is connected to the upper end of the carbon fiber pipe 36 through a connecting sleeve 2, and the lower end of the carbon fiber pipe 36 is connected to the upper end of the lower pipe through a connecting sleeve 2. In other embodiments, the two ends of the carbon fiber pipe 36 are connected to adjacent pipes by brazing, diffusion welding or pre-embedded connection methods. The part of the ball drop tube 5 that passes through the reflective layer channel 4 is a carbon fiber pipe 36. The upper end of the upper pipe is connected to the upper ball storage tank 8, and the lower end of the lower pipe is connected to the lower ball storage tank 1. The carbon fiber pipe 36 is added to the reflective layer channel 4 as a descending pipe for the absorption ball 7, so that the entire system is in a closed state. When preparing to restart the stack, the absorption ball 7 in the carbon fiber pipe 36 in the reflective layer channel 4 can be 100% sucked back to the upper ball storage tank 8, and the recovery efficiency of the absorption ball 7 is high. The upper pipe and the lower pipe are stainless steel pipes.

[0075] In another specific embodiment, the negative pressure system includes a low-pressure buffer tank 38 and a permanent magnet shielded compressor 26 connected in sequence through a second pipeline, the inlet end of the second pipeline is connected to the inner cavity of the upper spherical storage tank 8, and the outlet end of the second pipeline is also connected to the inner cavity of the upper spherical storage tank 8. The specific structure of the negative pressure system in this embodiment refers to the negative pressure system in the previous embodiment, and will not be repeated here. The difference between the two is that in this embodiment, the second pipeline is directly connected to the inner cavity of the upper spherical storage tank 8, and does not rely on the ventilation cavity 45 on the insulation layer as an intermediate structure.

[0076] In another specific embodiment, the negative pressure system includes an air pump connected through a third pipeline, the inlet end of the third pipeline is connected to the inner cavity of the upper spherical storage tank 8, and the outlet end of the third pipeline is also connected to the inner cavity of the upper spherical storage tank 8. In this embodiment, the negative pressure generating device is set to the air pump, and the air pump is used instead of the permanent magnet shielded compressor 26.

[0077] The electric actuator 19 is a linear electric actuator, which has the function of realizing linear up and down movement. The electric actuator 19 is fixed on the support frame 28, and the entire ball tube 25 runs through the support frame 28, the middle connecting pipe 12 and the lower pipe forging 34. The electric actuator 19 can drive the ball tube 25 to move up and down in a certain fixed stroke in the vertical direction. When the ball tube 25 moves up to the upper dead point, the ball outlet channel 33 completely slides out from the lower pipe forging 34, and when it moves down to the lower dead point, the ball outlet channel 33 is completely blocked by the lower pipe forging 34. The fixed stroke here is the height difference between the upper dead point and the lower dead point.

[0078] When the absorbing ball shutdown device of the present invention uses the linear electric actuator 19 as the power source, after the ball storage shutdown device is started, the ball tube 25 moves upward to the top dead center position under the action of the electric actuator 19, the inner cavity of the lower tube forging 34 is connected with the inner space of the upper ball storage tank 8, and the absorbing ball 7 enters the tube cavity of the ball tube 25 along the ball outlet channel 33 on the ball tube connecting section 6. The absorbing ball 7 enters the ball drop tube 5 under the action of gravity, and flows through the reflection layer channel 4 to absorb neutrons, thereby realizing the emergency shutdown function.

[0079] When the stack is ready to be restarted, the electric actuator 19 is turned on, and the electric actuator 19 drives the goal tube 25 to move downward, and the goal tube 25 falls back to the initial position. The ball outlet channel 33 on the goal tube 25 is blocked by the lower pipe forging 34, and the absorption ball 7 cannot enter the ball drop tube 5 from the ball outlet channel 33. At this time, the electric control valve 37 between the upper ball storage tank 8 and the low-pressure buffer tank 38 is started, and the gas in the upper ball storage tank 8 is continuously extracted. The absorption ball 7 in the lower ball storage tank 1 is sucked back to the upper ball storage tank 8 along the absorption ball riser 3 under the action of negative pressure, completing the absorption ball recovery process. In this embodiment, the absorption ball stack shutdown device relies on the electric actuator 19 to control the rise and fall of the goal tube 25, does not require an intermediate transmission structure, and has the advantages of rapid response and simple structure.

[0080] When the absorption ball shutdown device of the present invention uses the linear motor 41 as the power source, the ball tube 25 serves as the moving part of the linear motor 41. After the absorption ball shutdown device is started, the controller of the electric control device gives the linear motor 41 an upward electrical signal, and the ball tube 25 moves upward to the top dead center position under the action of the linear motor 41, and the ball outlet channel 33 is connected with the space in the upper ball storage tank 8, and the absorption ball 7 enters the tube cavity of the ball tube 25 along the ball outlet channel 33 on the ball tube connecting section 6 of the ball tube 25, enters the ball drop tube 5 under the action of gravity, and flows through the reflection layer channel 4 to absorb neutrons, thereby realizing the emergency shutdown function.

[0081] When the reactor is ready to be restarted, the linear motor 41 is turned on to lower the goal tube 25 back to the bottom dead center position. At this time, the side wall of the lower tube forging 34 blocks the ball outlet channel 33. At the same time, the lower end side wall of the goal tube 25 blocks the lower end opening of the goal channel 44, and the absorption ball 7 cannot enter from the ball outlet channel 33. At this time, the reactor is started.

[0082] When the whole plant is in a power outage state, the ball tube 25 falls to the initial position (lowest position) under the action of gravity, and the absorption ball 7 flows from the ball channel 44 through the ball outlet channel 33 and falls, realizing passive shutdown. The safe shutdown of the reactor in the case of power outage is ensured, and the safety performance is improved.

[0083] The working conditions of the electric actuator 19, the linear motor 41, the electric control valve 37, the low-pressure buffer tank 38 and the permanent magnet shielded compressor 26 of the present invention are all controlled by the controller.

[0084] The absorption ball shutdown device of the present invention adds a carbon fiber pipe 36 in the reflective layer channel 4 as a descending pipe for the absorption ball 7, and the pipe is connected to the upper ball storage tank 8. The whole system is in a closed state. When preparing to restart the stack, the absorption ball 7 in the carbon fiber pipe 36 in the reflective layer channel 4 can be 100% sucked back to the upper ball storage tank 8, and the absorption ball 7 recovery efficiency is high. A low-pressure buffer tank 38 is arranged on the negative pressure system, and the low-pressure buffer tank 38 is directly connected to the inner space of the upper ball storage tank 8, and no additional gas source is required. The gas in the low-pressure buffer tank 38 is compressed back to the upper ball storage tank 8 by the permanent magnet shield compressor 26, so that the gas can be recycled.

[0085] The absorbing ball shutdown device of the present invention has a simple structure and reliable operation and can shut down the reactor safely.

[0086] In the description of this solution, it should be understood that the terms "upper", "lower", "vertical", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship 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 therefore cannot be understood as a limitation on this solution.

[0087] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this solution, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0088] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0089] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An absorption ball shutdown device, characterized in that: It comprises an upper spherical storage tank (8) and a lower spherical storage tank (1), wherein the bottom end of the upper spherical storage tank (8) is connected to the lower spherical storage tank (1) via a ball drop pipe (5), and the interior of the lower spherical storage tank (1) is connected to the upper spherical storage tank (8) via an absorption ball riser pipe (3); A ball-injection tube (25) is provided at the ball outlet at the bottom end of the upper ball storage tank (8). The ball-injection tube (25) is driven by a power device to move linearly up and down. When the ball-injection tube (25) is lifted to a first position, the ball-injection tube (25) is connected to the upper ball storage tank (8) and the ball-dropping tube (5); when the ball-injection tube (25) is lowered to a second position, the ball-dropping tube (25) blocks the upper ball storage tank (8) and the ball-dropping tube (5). The inner cavity of the upper spherical storage tank (8) is connected to a negative pressure system; The power device is a linear motor (41), the goal tube (25) is driven by the linear motor (41), and the goal tube (25) is connected to the mover of the linear motor (41); when the goal tube (25) is lifted to the upper dead point, the inner cavity of the goal tube (25) is communicated with the inner cavity of the upper ball storage tank (8), and a ball is scored; when the goal tube (25) is lowered to the lower dead point, the inner cavity of the goal tube (25) is disconnected from the inner cavity of the upper ball storage tank (8), and the goal is stopped; A lower pipe forging (34) is fixedly connected to the ball outlet of the upper ball storage tank (8); the inner cavity of the lower pipe forging (34) is slidably connected to the lower end of the ball inlet pipe (25); and a ball outlet channel (33) is provided on the side surface of the lower end of the ball inlet pipe (25); When the goal tube (25) is located at the top dead center, the inner cavity of the upper ball storage tank (8) is correspondingly connected to the ball outlet passage (33), which is a goal-scoring condition; when the goal tube (25) is located at the bottom dead center, the ball outlet passage (33) is blocked by the side wall of the lower pipe forging (34), and goal-scoring stops.

2. The absorbing ball shutdown device according to claim 1, characterized in that: The power device is an electric actuator (19), and the goal tube (25) is driven by the electric actuator (19). When the goal tube (25) is lifted to the top dead center position, the goal tube (25) is connected to the upper ball storage tank (8) and the ball drop tube (5); when the goal tube (25) is lowered to the bottom dead center position, the goal tube (25) blocks the upper ball storage tank (8) and the ball drop tube (5).

3. The absorbing ball shutdown device according to claim 2, characterized in that: A lower pipe forging (34) is fixedly connected to the ball outlet of the upper ball storage tank (8); the inner cavity of the lower pipe forging (34) is slidably connected to the lower end of the ball inlet pipe (25); and a ball outlet channel (33) is provided on the side surface of the lower end of the ball inlet pipe (25); The outlet of the lower pipe forging (34) is communicated with the inlet of the ball drop tube (5), and the inner diameter of the lower pipe forging (34) is greater than the inner diameter of the ball drop tube (5).

4. The absorbing ball shutdown device according to claim 2, characterized in that: The top end of the upper ball storage tank (8) is provided with a pipe through hole, and the upper end of the ball tube (25) is connected to the electric actuator (19) through the pipe through hole; the electric actuator (19) is arranged in a sealed housing.

5. The absorbing ball shutdown device according to claim 1, characterized in that: A ball channel (44) is provided on the side wall of the lower pipe forging (34); one end of the ball channel (44) is in communication with the inner cavity of the upper ball storage tank (8), and the other end is in communication with the inner cavity of the lower pipe forging (34); The opening of one end of the ball channel (44) for communicating with the inner cavity of the lower pipe forging (34) is lower than the lower dead point of the ball tube (25); when the linear motor (41) is powered off, the ball outlet channel (33) is communicated with the upper ball storage tank (8) through the ball channel (44); The ball-ball channel (44) is an L-shaped channel, the vertical channel of the L-shaped channel is in communication with the inner cavity of the upper ball storage tank (8), and the horizontal channel of the L-shaped channel is arranged corresponding to the ball outlet channel (33); The length of the vertical channel of the L-shaped channel is greater than the size of the ball outlet channel (33), so that the ball outlet channel (33) is blocked by the tube wall of the lower tube forging (34) in a non-ball-balling working condition.

6. The absorbing ball shutdown device according to claim 1, characterized in that: A pipe through hole is provided at the top end of the upper ball storage tank (8), and the upper end of the ball tube (25) is connected to the linear motor (41) through the pipe through hole; the linear motor (41) is arranged in a sealed housing; A limiting structure (43) is provided on the outer surface of the goal tube (25) near the linear motor (41), and damping springs (42) are provided at both the upper and lower ends of the limiting structure (43).

7. The absorbing ball shutdown device according to claim 4 or 6, characterized in that: The sealed housing comprises a drive housing cylinder (23), an upper end of the drive housing cylinder (23) is provided with a drive housing upper flange (20), and a lower end of the drive housing cylinder (23) is provided with a drive housing lower flange (18); The drive housing upper flange (20) is connected to the drive housing top cover (21), the drive housing lower flange (18) is connected to the pipe flange (15), and one end of the pipe flange (15) away from the drive housing lower flange (18) is sealed and connected to the upper surface of the pressure vessel top cover (9) by placing a pipe (14).

8. The absorbing ball shutdown device according to claim 7, characterized in that: A middle connecting pipe (12) is sealedly connected to the opening of the pipe-through hole, a connecting pipe flange (17) is provided at the upper end of the middle connecting pipe (12), and the connecting pipe flange (17) is connected to the connecting pipe flange (15); The middle connecting pipe (12) is sleeved on the outside of the ball tube (25), the middle connecting pipe (12) is sleeved in the internal longitudinal through hole of the placement pipe (14), and the inner cavity of the placement pipe (14) is connected to the inner cavity of the pressure container.

9. The absorbing ball shutdown device according to claim 8, characterized in that: The goal tube (25) and the middle connecting tube (12) are arranged at a certain distance, so that a cavity is formed between the goal tube (25) and the middle connecting tube (12), and a heat insulating layer (13) is arranged in the cavity.

10. The absorbing ball shutdown device according to claim 9, characterized in that: The negative pressure system comprises a low-pressure buffer tank (38) and a permanent magnet shielded compressor (26) which are connected in sequence via a first pipeline (27); a ventilation cavity connected to the inner cavity of the upper spherical storage tank (8) is provided in the thermal insulation layer (13); the ventilation cavity is connected to the air inlet end and the air return end of the first pipeline (27); the low-pressure buffer tank (38) is arranged close to the air inlet end of the first pipeline (27); and the permanent magnet shielded compressor (26) is arranged close to the air return end of the first pipeline (27); A first hole (30) and a second hole (31) are provided on the side of the connecting flange (15); the first hole (30) and the second hole (31) are through holes penetrating a side wall of the connecting flange (15); and the first hole (30) and the second hole (31) are both in communication with the ventilation cavity.

11. The absorbing ball shutdown device according to claim 1, characterized in that: The ball drop tube (5) comprises an upper pipe, a carbon fiber pipe (36) and a lower pipe which are sequentially connected and arranged, the upper end of the upper pipe is connected to the upper ball storage tank (8), the lower end of the lower pipe is connected to the lower ball storage tank (1), and both ends of the carbon fiber pipe (36) are connected to adjacent pipes via connecting sleeves (2); The portion of the ball drop tube (5) that passes through the reflective layer hole (4) is a carbon fiber tube (36).

12. The absorbing ball shutdown device according to claim 1, characterized in that: The negative pressure system comprises a low-pressure buffer tank (38) and a permanent magnet shielded compressor (26) which are connected in sequence via a second pipeline, wherein the inlet end of the second pipeline is connected to the inner cavity of the upper spherical storage tank (8), and the outlet end of the second pipeline is also connected to the inner cavity of the upper spherical storage tank (8); Alternatively, the negative pressure system comprises an air pump connected via a third pipeline, the inlet end of the third pipeline is connected to the inner cavity of the upper spherical storage tank (8), and the outlet end of the third pipeline is also connected to the inner cavity of the upper spherical storage tank (8).

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