Reactor top composite device and system for reactor internals of pebble-bed high-temperature gas cooled reactor

Abstract

The invention discloses a pebble-bed high-temperature gas cooled reactor internals and reactor top composite device and system.The pebble-bed high-temperature gas cooled reactor internals and reactor top composite device comprises a shell and a splitter plate arranged in the shell, and at least two first through holes are formed in the splitter plate and used for fuel balls to evenly pass through; the flow guide rod is arranged on the flow distribution plate and used for stirring the fuel balls to enable the fuel balls to enter the first through hole; the connecting plate is arranged below the splitter plate, at least two flow channels are formed in the connecting plate, the two ends of each flow channel are communicated with the interior of the shell and the outside respectively, and second through holes corresponding to the first through holes one to one are formed in the connecting plate. Fuel balls entering the ball collecting vessel are more uniformly distributed into a ball bed through the arrangement of the splitter plate, the phenomenon that the ball bed is stacked into a small hill is weakened, a coolant in a cavity area is effectively prevented from entering gaps of brick bodies of reactor internals through the arrangement of the lower shell, bypass flow is reduced, and therefore the safety and economical efficiency of a reactor are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of reactor engineering equipment, in particular to a pebble bed type high temperature gas-cooled reactor internal component top composite device and system. Background Art

[0002] The graphite spheres used as fuel elements in a pebble-bed high-temperature gas-cooled reactor (HTGR) enter the pebble bed through an inlet structure formed by the stacked bricks at the top of the reactor's internals. This brick inlet structure is connected to the fuel loading and unloading system, forming the fuel circulation inlet channel for the HTGR. The fuel elements enter the core space formed by the stacked ceramic internals and accumulate into a pebble bed. Furthermore, the design reserves a cavity area of a certain height above the pebble bed. However, due to the unique brick structure, this cavity area corresponds to dozens of gaps, creating coolant bypass channels. Furthermore, as the spheres enter the pebble bed through the current structure, they tend to accumulate, forming small hills. This further exacerbates the flow of coolant from the pebble bed into the gaps between the bricks, resulting in excessive bypass flow, which compromises the safe and stable operation of the core. To improve the core fuel element circulation pattern and reduce coolant bypass in the top region, improvements to the top structure are needed to mitigate bypass flow and enhance the safety and economic efficiency of the HTGR. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is that the fuel ball feed is uneven and easily forms accumulation and the coolant bypass flow is too large.

[0004] The above technical problems are solved by the following technical solutions: The present invention proposes a pebble bed type high temperature gas-cooled reactor internal component top composite device, which includes a shell and a diverter plate inside it, on which at least two first through holes are opened for uniform passage of fuel balls; a guide rod is arranged on the diverter plate, and is used to move the fuel balls so that they enter the first through holes; a connecting plate is arranged below the diverter plate, and at least two flow channels are arranged inside it, and the two ends of the flow channels are respectively connected to the inside of the shell and the outside world, and the connecting plate is provided with second through holes corresponding one to one with the first through holes.

[0005] In a preferred embodiment of the pebble bed type high temperature gas-cooled reactor internal component top composite device of the present invention: a first accommodating space is formed between the shell and the diverter plate, and the fuel balls enter the first accommodating space through the channel at the top of the shell.

[0006] In a preferred embodiment of the pebble bed type high temperature gas-cooled reactor internal component top composite device of the present invention: three through holes are opened on the diverter plate and the diverter plate is made of steel boron-containing material, the guide rod is rotatably matched with the diverter plate, and the through holes can pass through multiple fuel balls to prevent blockage.

[0007] In a preferred embodiment of the pebble bed type high temperature gas-cooled reactor internal component top composite device of the present invention: a second accommodating space is formed between the connecting plate and the shell, and the fuel balls enter the second accommodating space from the first accommodating space through the first through hole.

[0008] In a preferred embodiment of the pebble bed type high temperature gas-cooled reactor internal component top composite device of the present invention: side reflection layers are fixedly provided on both sides of the shell, the side reflection layers are formed by stacking graphite bricks, and a pebble bed is formed on the lower side of the second accommodating space.

[0009] In a preferred embodiment of the pebble bed type high temperature gas-cooled reactor internal component top composite device of the present invention: the connecting plate is formed by stacking bricks, and four flow channels are opened inside the connecting plate for supplying coolant to the pebble bed.

[0010] In a preferred embodiment of the pebble bed type high temperature gas-cooled reactor internal component top composite device of the present invention: a support plate is axially fixedly provided on the outer side of the shell for fixing the device above the pebble bed.

[0011] In a preferred embodiment of the pebble bed type high temperature gas-cooled reactor internal component top composite device of the present invention: the channel on the top of the shell is used to connect with the fuel loading and unloading system, and the length of the shell covers the height of the cavity area to suppress coolant bypass.

[0012] In a preferred embodiment of the pebble bed type high temperature gas-cooled reactor internal component top composite device of the present invention: the shell is cylindrical and made of steel.

[0013] To solve the above technical problems, the present invention also provides the following technical solutions: a pebble bed type high temperature gas cooled reactor internal component top composite system includes a pebble bed type high temperature gas cooled reactor internal component top composite device.

[0014] The beneficial effects of the present invention are as follows: through the arrangement of the diverter plate, the fuel balls entering the ball collecting dish are more evenly distributed into the ball bed, reducing the phenomenon of the ball bed piling up into small hills; the arrangement of the lower shell effectively blocks the coolant in the cavity area from entering the gaps in the bricks of the internal components of the reactor, reducing bypass flow, thereby improving the safety and economy of the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings of the embodiments of the present invention. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Among them:

[0016] Figure 1 This is a schematic diagram of the top composite device of the internal components of the pebble bed high temperature gas-cooled reactor;

[0017] Figure 2 This is a partial schematic diagram of the top composite device of the internal components of the pebble bed high-temperature gas-cooled reactor;

[0018] Figure 3 This is a schematic diagram of the fuel ball path of the top composite device of the pebble bed high temperature gas-cooled reactor internals;

[0019] Figure 4 This is the coolant flow diagram of the top composite device of the internal components of the pebble bed high temperature gas-cooled reactor;

[0020] Figure 5 Schematic diagram of the side reflector and pebble bed. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to specific embodiments and the accompanying drawings.

[0022] The terms used in the present invention are those commonly used in the art in view of the functions of the present invention, but these terms may vary according to the intentions of those skilled in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but rather as the meanings of the terms and the overall description of the present invention.

[0023] Reference Figures 1 to 4 This embodiment provides a pebble bed type high temperature gas-cooled reactor internal component top composite device.

[0024] Specifically, the pebble-bed high-temperature gas-cooled reactor internals and top assembly assembly includes a shell 4 and, within it, a manifold plate 1 with at least two first through-holes 11 for uniform passage of fuel spheres; a guide rod 2 disposed on manifold plate 1 for manipulating the fuel spheres into the first through-holes 11; and a connecting plate 3 disposed below manifold plate 1. The connecting plate 3 has at least two flow channels 31 disposed within it, connecting the interior of the shell 4 to the outside world at both ends. The connecting plate 3 has second through-holes corresponding one-to-one with the first through-holes 11. If only one through-hole were available for the fuel spheres to pass through, the fuel spheres would pile up on the bed, unevenly distributed, and the coolant would not reach all of them. The manifold plate 1 has three through-holes 11, allowing the fuel spheres to enter the bed evenly under the manipulation of the guide rod 2. The flow channels 31 and the second through-holes do not overlap and do not interfere with each other, allowing the coolant to flow into the bed through the flow channels 31 at the same time as the fuel spheres enter, cooling the fuel spheres.

[0025] Furthermore, a first accommodation space M is formed between the shell 4 and the manifold 1. Fuel balls enter this space M through a channel at the top of the shell 4. This space M is divided into two parts: the channel at the top of the shell 4 is used to transport the fuel balls. The other part, the area between the manifold 1 and the channel, is a ball collecting pan. This pan is made of a steel cylinder and serves as a buffer for fuel balls flowing downward from the channel. The height of the pan is 500 mm.

[0026] Furthermore, the manifold plate 1 is formed with three first through-holes 11 and is made of a boron-containing steel material. Each first through-hole 11 has a diameter of 300 mm. A guide rod 2 is centrally located in the manifold plate 1 and rotates with the manifold plate 1. The guide rod 2 comprises a vertical rod and a perpendicular horizontal rod. The vertical rod is perpendicular to the manifold plate. The horizontal rod rotates to evenly distribute the fuel balls within the ball collection dish. The first through-holes 11 can accommodate multiple fuel balls and prevent them from becoming stuck. The second through-holes have the same diameter as the first through-holes 11 and correspond one-to-one, allowing the fuel balls to smoothly pass through the first and second through-holes 11 and enter the ball bed.

[0027] Among them, such as Figure 3 and Figure 4 As shown, the connecting plate 3 is formed by a number of bricks stacked and connected. Four flow channels 31 are opened inside the connecting plate 3 to prevent the coolant from entering the gaps between the bricks and reduce coolant bypass. The flow channel 31 and the second through hole do not overlap. The fuel balls pass through the diverter plate 1 and the connecting plate 3 and finally fall into the ball bed. The coolant enters the flow channel and then flows downward until it flows onto the ball bed. A second accommodating space J is formed between the connecting plate 3 and the shell 4. The fuel balls enter the second accommodating space J from the first accommodating space M through the first through hole 11. The channel at the top of the shell 4 is used to connect to the fuel loading and unloading system. The fuel balls fall into the ball bed. The length of the shell 4 covers the height of the cavity area. The shell 4 outside the second accommodating space J can prevent the coolant from bypassing the side reflection layer, thereby suppressing bypass.

[0028] Preferably, the housing 4 is cylindrical and made of steel.

[0029] Preferably, the height of the guide bar 2 is 500 mm, and the length of the horizontal bar is 1000 mm.

[0030] Preferably, a support plate 41 is axially fixedly provided on the outer side of the shell for fixing the device above the ball bed.

[0031] When in use, the device is first fixed to the top area of the internal components of the reactor through the support plate 41. The fuel balls enter the composite device from the top through the fuel loading and unloading system, first enter the ball collecting dish from the channel at the top of the shell 4, and then under the rotation of the guide rod, the fuel balls roll and distribute in the ball collecting dish, evenly enter the three through holes 11, and then fall into the core ball bed through the second accommodating space J. The coolant enters from the flow channel and then flows downward to the ball bed.

[0032] In summary, the setting of the diverter plate allows the fuel balls entering the ball collecting dish to be more evenly distributed into the ball bed, reducing the phenomenon of the ball bed piling up into small hills. The setting of the lower shell effectively blocks the coolant in the cavity area from entering the gaps in the bricks of the internal components of the reactor, reducing bypass flow, thereby improving the safety and economy of the reactor.

[0033] Finally, it should be pointed out that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways without departing from the scope of the present invention.

Claims

1. A pebble bed type high temperature gas-cooled reactor internals top assembly device, characterized by: including the housing (4) and its interior, A manifold plate (1) is provided with at least two first through holes (11) for uniformly passing the fuel balls; A guide rod (2) is provided on the diverter plate (1) and is used to move the fuel ball so that the fuel ball enters the first through hole (11); A connecting plate (3) is arranged below the diverter plate (1), and has at least two flow channels (31) arranged therein. The two ends of the flow channels (31) are respectively connected to the interior of the shell (4) and the outside. The connecting plate (3) is provided with second through holes corresponding one to one with the first through holes (11).

2. The pebble bed type high temperature gas-cooled reactor internals top assembly device according to claim 1, characterized in that: A first accommodating space (M) is formed between the shell (4) and the diverter plate (1), and the fuel balls enter the first accommodating space (M) through a channel at the top of the shell (4).

3. The pebble bed type high temperature gas-cooled reactor internals top assembly device according to claim 2, characterized in that: The diverter plate (1) is provided with three through holes and is made of a steel boron-containing material. The guide rod (2) is rotatably engaged with the diverter plate (1), and the through holes (11) can pass through a plurality of the fuel balls to prevent clogging.

4. The pebble bed type high temperature gas-cooled reactor internals top assembly device according to claim 3, characterized in that: A second accommodating space (J) is formed between the connecting plate (3) and the shell (4), and the fuel ball enters the second accommodating space (J) from the first accommodating space (M) through the first through hole (11).

5. The pebble bed type high temperature gas-cooled reactor internals top assembly device according to claim 4, characterized in that: Side reflection layers (5) are fixedly provided on both sides of the shell (4), and the side reflection layers (5) are formed by stacking graphite bricks. A ball bed (6) is formed on the lower side of the second accommodating space (J).

6. The pebble bed type high temperature gas-cooled reactor internals top assembly device according to claim 5, characterized in that: The connecting plate (3) is formed by stacking bricks, and four flow channels (31) are provided inside the connecting plate (3) for allowing coolant to flow to the ball bed (6).

7. The pebble bed type high temperature gas-cooled reactor internals top assembly device according to claim 6, characterized in that: A support plate (41) is axially fixedly provided on the outer side of the shell (4) for fixing the device above the ball bed (6).

8. The pebble bed type high temperature gas-cooled reactor internals top assembly device according to claim 7, characterized in that: The channel on the top of the shell (4) is used to connect with the fuel loading and unloading system, and the length of the shell (4) covers the height of the cavity area to suppress coolant bypass flow.

9. The pebble bed type high temperature gas-cooled reactor internals top assembly device according to claim 8, characterized in that: The shell (4) is cylindrical and made of steel.

10. A pebble bed type high temperature gas cooled reactor internals and top composite system, characterized by: It comprises the pebble bed type high temperature gas-cooled reactor internal component top composite device as described in any one of claims 1 to 9.

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