A waterwheel chain box type fuel vertical conveying device

Abstract

The present invention provides a waterwheel chain box type fuel vertical conveying device, the mechanical transmission component of the device is placed inside the enclosure, the driving assembly is placed outside the enclosure, and the upper and lower ends of the enclosure are respectively connected to the slotted rolling track. The mechanical transmission component includes a driving wheel and a driven wheel, a driving chain, and a plurality of chain boxes fixed on the driving chain for accommodating spherical nuclear fuel elements; the driving wheel is driven by the driving assembly and drives the driven ratchet to rotate through the driving chain; each chain box is a box with an open end, and a centering guide plate for ensuring that the spherical nuclear fuel element is located at the center of the chain box is provided in the box, and the side wall of the box opening end in contact with the driving chain extends outward to form a guide plate for guiding the spherical nuclear fuel element into the chain box or providing a rolling distance for the spherical nuclear fuel element to enter the slotted rolling track; the meshing between the driving chain and the transmission ratchet is ensured by a deviation correction piece fixed to the inner wall of the enclosure. The device is reliable in operation, simple in structure, and highly economical.

Description

Technical Field

[0001] The present invention is a waterwheel chain box type fuel vertical conveying device, which is used in the spherical nuclear fuel element loading and unloading circulation system, spent fuel unloading system and new fuel injection system of high-temperature gas-cooled reactor nuclear power plants, or similar application fields such as petrochemical and electric power, and belongs to the field of transmission technology. Background Art

[0002] For the loading and unloading circulation of spherical nuclear fuel elements in high-temperature gas-cooled reactor nuclear power plants, a helium compressor is required to provide the pneumatic conveying power source for lifting the spherical nuclear fuel elements. Under normal operating conditions, the spherical nuclear fuel elements are subjected to the main circulation in the reactor core, spent fuel unloading and new fuel injection through helium pneumatic conveying. During the pneumatic circulation transmission process, the spherical nuclear fuel elements continuously rub and collide with the inner wall of the pipeline and equipment such as the unloading device, broken ball separation equipment, burnup measurement equipment, and bridge connector.

[0003] At present, the devices for realizing the loading and unloading circulation transmission of spherical nuclear fuel elements through the above pneumatic conveying power source mainly have the following deficiencies:

[0004] Deficiency 1: The loading and unloading circulation of spherical nuclear fuel elements adopts helium pneumatic conveying. Under normal operating conditions, during the pneumatic circulation transmission process of spherical nuclear fuel elements, a helium compressor is required to provide the pneumatic conveying power source for lifting. Insufficient reliability of the helium compressor leads to the loss of the power source for the spherical nuclear fuel element circulation, resulting in the passive shutdown of the reactor; at the same time, during the pneumatic circulation transmission process, high requirements are imposed on the inner diameter of the pneumatic transmission pipeline, the protrusions and depressions on the inner wall of the pipeline welds. The spherical nuclear fuel elements continuously rub and collide with the pipe wall, and the generated fuel dust and debris often cause jamming accidents of the spherical nuclear fuel elements, so that the spherical nuclear fuel elements cannot be transmitted and circulated, resulting in the passive shutdown of the reactor; the number of spherical nuclear fuel elements and the deviation of the size of burned fuel balls in the pneumatic conveying pipeline require different pneumatic conveying pressure parameters, which exacerbates the retention and oscillation of the spherical nuclear fuel elements in the pipeline, leading to jamming of the spherical nuclear fuel elements and unstable system operation.

[0005] Deficiency 2: Under the conditions of a spherical nuclear fuel element jamming accident, in a high-temperature, high-pressure and highly radioactive environment and a complex pipeline environment, it is difficult to detect and check the jamming points of the spherical nuclear fuel elements. Some jamming points are inaccessible to maintenance personnel and maintenance tools and equipment, and eliminating the jamming accident of the spherical nuclear fuel elements is likely to cause radioactive leakage.

[0006] In order to overcome the deficiencies of the above-mentioned conveying device, the present applicant has proposed an escalator-type fuel transfer device (application number 201910471958.1). According to the requirements of nuclear power plant radiation zoning and fire prevention zoning, this solution uses multiple sections of escalator-type fuel transfer devices connected to grooved runways to achieve the loading and unloading cycle of spherical nuclear fuel elements, the discharge of spent fuel, and the injection of new spherical nuclear fuel elements. The mechanical transmission components therein include a driving ratchet, a driving chain fixed to the driving ratchet, and a plurality of steps fixed to the driving chain. However, during the engineering implementation process, the escalator-type fuel transfer device needs to maintain a certain angle with the horizontal plane (generally less than 45°), which requires a large building area and space, and the construction cost is high; the spherical nuclear fuel elements use multiple sections of escalator-type fuel transfer devices and grooved runways to achieve continuous transmission, with high equipment manufacturing and installation accuracy and high costs; the escalator-type fuel transfer device is complex in equipment and there are certain difficulties in maintenance. Summary of the Invention

[0007] The present invention aims to solve the above various problems and proposes a waterwheel chain box-type fuel vertical conveying device with a simple structure, unlimited vertical lifting height, wider application range, better economy, and higher reliability.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A waterwheel chain box-type fuel vertical conveying device, comprising a sealed containment containing helium, a mechanical transmission component located inside the containment, and a driving component located outside the containment; the upper and lower ends of the containment are respectively connected to a gravity-driven non-active grooved runway to form a loop, and a dust conveying pipe for collecting dust and debris falling through the grooved runway is provided at the bottom of the grooved runway, and the end of the dust conveying pipe is connected to a dust collection device; characterized in that

[0010] The mechanical transmission components include a driving wheel and a driven wheel located at the top and bottom of the containment body, a driving chain fixed between the driving wheel and the driven wheel, and a plurality of chain boxes fixed at equal intervals on the driving chain for accommodating spherical nuclear fuel elements; the driving wheel is sleeved on a first transmission shaft, one end of the transmission shaft is located inside the containment body and is fixed to the inner side wall of the containment body through a first bearing and a bearing end cover, the other end of the transmission shaft is located outside the containment body and is connected to the output end of the driving assembly, the driven wheel is sleeved on a second transmission shaft, and both ends of the transmission shaft are fixed to the inner side wall of the containment body through matching bearings and bearing end covers; each of the chain boxes has the same structure and is a box body with an open end, and a centering guide plate for ensuring that the spherical nuclear fuel element is located at the center position of the chain box is arranged in the box body, and a diversion plate for guiding the spherical nuclear fuel element into the chain box or providing a rolling distance for the spherical nuclear fuel element to enter the grooved raceway extends outward from the side wall of the open end of the box body in contact with the driving chain; the engagement between the driving chain and the transmission wheel is ensured by a deviation correction member fixed to the inner side wall of the containment body.

[0011] Further, the deviation correction member is a U-shaped block body that envelopes the driving chain, and can be in an integral or segmented form; a plurality of balls with solid lubrication functions are evenly arranged on the inner side wall of the deviation correction member and are in contact with the driving chain.

[0012] Further, the surfaces of the centering guide plate and the diversion plate in the chain box in contact with the spherical nuclear fuel element are both arc-shaped surfaces with a diversion direction.

[0013] Further, an automatic tensioning member (21) is arranged between the bearing end covers at both ends of the second transmission shaft and the inner side wall of the containment body for ensuring that the driving chain is always in a tensioned state; the automatic tensioning member includes a support frame fixed to the inner side wall of the containment body, and a plurality of foldable limit bodies parallel to the axial direction of the driving chain are fixed on the side wall of the support frame opposite to the bearing end cover of the second transmission shaft for preventing the bearing end cover of the second transmission shaft from moving in the direction that makes the driving chain tend to be loose, the limit bodies blocked by the bearing end cover of the second transmission shaft are in a folded state, and the limit bodies not blocked by the bearing end cover are in an open state; a bolt fixedly connected to the bottom of the bearing end cover of the second transmission shaft is arranged at the bottom of the support frame, and a limit spring is sleeved on the bolt.

[0014] Features and beneficial effects of the present invention:

[0015] A waterwheel chain box type fuel vertical conveying device proposed by the present invention has a transmission principle similar to that of the ancient agricultural irrigation tool - waterwheel in our country. The mechanical transmission components of this conveying device are built into a high-temperature, high-pressure and highly radioactive containment helium atmosphere, while the drive motor and the permanent magnet coupling are placed outside the containment. The torque of the drive motor is input to the transmission ratchet through the permanent magnet coupling and drives the drive chain to circulate and transmit. The transmission wheel is fixed on the inner wall of the containment through an oil-free lubricating bearing and a bearing housing. The torque of the drive wheel depends on the permanent magnet input, avoiding the opening of the containment caused by torque input, preventing the leakage of primary loop helium and the escape of radioactivity. The inlet end and the outlet end of the fuel vertical transmission device are connected to the grooved track, and fuel dust and debris flow into the dust collection device through the grooved track. The centering guide plate in the chain box of the waterwheel chain box type fuel vertical conveying device ensures that the spherical fuel element is in the central position of the chain box, preventing the deviation of the drive chain due to the offset of the center of the chain box. The guide plate on the chain box can prevent the spherical fuel element from getting stuck between the drive chains and prevent the spherical fuel element from hitting the drive chain, avoiding the deviation of the drive chain caused by the impact force of the spherical fuel element on the drive chain, and preventing the spherical fuel element from being damaged due to the generation of debris by impact. At the same time, the guide plate on the chain box can provide enough rolling distance for the spherical fuel element, so that the spherical fuel element can be discharged by diversion after obtaining a certain speed. After the spherical fuel element is discharged from the fuel vertical conveying device, it is continuously transmitted through the gravity type grooved track, thus realizing the cyclic conveying, injection and discharge of the spherical fuel element. The drive chain of the fuel vertical conveying device realizes the reliable transmission of the driving force between the drive chain and the ratchet through the deviation correction part, ensuring that the drive chain does not deviate, and the theoretical lifting height is unlimited. The automatic tensioning part can realize the fastening when the drive chain is loose, ensuring the stable transmission of the torque between the transmission wheel and the drive chain.

[0016] In summary, compared with the pneumatic conveying device and the escalator type fuel transmission device, the waterwheel chain box type fuel vertical conveying device of the present invention has a small floor area, no fault points, reliable operation, simple system equipment and pipeline layout, flexible and convenient combination with other functional equipment (unloading device, broken ball separation device, burnup measurement device, feeding device), and high economy. Brief Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the overall structure of a waterwheel chain box type fuel vertical conveying device according to an embodiment of the present invention.

[0018] Figure 2 is Figure 1 the schematic diagram of the A-A section in

[0019] Figure 3 (a) to (c) are respectively Figure 1 the front view, left view and top view of the chain box structure shown in

[0020] Figure 4 (a) to (d) are respectivelyFigure 1 The front view, top view, left view, and C-C sectional view of the deviation rectifying part structure shown in

[0021] Figure 5 For Figure 1 The partial enlarged view of the tensioning part shown in

[0022] Figure 6 (a) - (c) are respectively Figure 5 The front view, left view, and top view of the tensioning part structure shown in

[0023] Figure 7 For Figure 1 The structural schematic diagram of the grooved raceway and the slit thereon shown in

[0024] Figure 8 For Figure 1 The application example diagram of the device shown in Specific implementation manners

[0025] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0026] Refer to Figure 1 , which is the overall structural schematic diagram of a waterwheel chain box type fuel vertical conveying device according to an embodiment of the present invention, for a high-temperature gas-cooled reactor nuclear power plant. The fuel vertical conveying device of this embodiment includes a sealed containment 7 containing helium, a mechanical transmission component 5 located inside the containment 7, and a driving assembly located outside the containment 7; the upper and lower ends of the containment 7 are respectively connected to the gravity-driven non-active grooved raceways 11 and 2 to form a loop, and dust conveying pipes 3 for collecting dust and debris falling through the grooved raceways are provided at the bottoms of the grooved raceways 2 and 11, and the end of the dust conveying pipe 3 is connected to a dust collection device 4; the mechanical transmission component 5 includes a driving wheel 101 and a driven wheel 102 located at the top and bottom of the containment 7, a driving chain 9 fixed between the driving wheel 101 and the driven wheel 102, and a plurality of chain boxes 6 fixed on the driving chain 9 at equal intervals for accommodating spherical nuclear fuel elements 1; refer to Figure 2 , the driving wheel 101 is sleeved on the first transmission shaft 16, one end of the transmission shaft 16 is located inside the containment 7 and is fixed to the inner side wall of the containment 7 through a first bearing 19 and a bearing end cover 20, the other end of the transmission shaft 16 is located outside the containment 7 and is connected to the output end of the driving assembly, the driven wheel 102 is sleeved on the second transmission shaft 23, and both ends of the transmission shaft 23 are fixed to the inner side wall of the containment 7 through matching bearings 24 and bearing end covers 23; refer to Figure 3In FIGS. (a)-(c), the structures of the respective chain boxes 6 are the same, each being a box body with an open end. Inside the box body, there is a centering guide plate 25 for ensuring that the spherical nuclear fuel element 1 is located at the center of the chain box 6. The side wall of the open end of the box body in contact with the drive chain 9 extends outward to form a diversion plate 26 for diverting the spherical nuclear fuel element 1 into the chain box 6 or providing a rolling distance for the spherical nuclear fuel element 1 to enter the slotted raceway 11. The meshing between the drive chain 9 and the transmission wheels (101, 102) is ensured by a deviation correcting member 8 fixed to the inner side wall of the containment 7.

[0027] The specific implementation manners and functions of the respective components in this embodiment are as follows:

[0028] The containment 7 is made of a material capable of containing high temperature, high pressure, and high radioactivity, including ceramics, carbon fiber, steel, or other composite materials, and the inside of the containment contains a helium atmosphere. An inlet end and an outlet end communicating with the gravity-driven passive slotted raceways 2 and 11 are respectively provided at the lower and upper parts of the containment 7 for feeding and discharging the spherical nuclear fuel element 1. When installing the containment, it forms an arbitrary angle between 0 and 90° (inclusive) with the installation reference plane. In this embodiment, a 90° vertical installation is adopted. It should be noted that for scenarios where the installation area is not limited, non-vertical installation can be selected. Especially when the axis of the containment is parallel to the installation reference plane (i.e., the angle between the two is 0°), a limiting groove needs to be provided in the middle of the diversion plate 26 of each chain box 6 to prevent the spherical nuclear fuel element 1 from rolling out of the chain box when it is located between the inlet end and the outlet end of the containment 7.

[0029] See Figure 2, the mechanical transmission component 5 is used to achieve the cyclic transmission of the spherical nuclear fuel element 1. The central connection line of the driving wheel 101 and the driven wheel 102 coincides with the central axis of the inclusion body 7. The driving wheel 101 and the driven wheel 102 can adopt ratchets or gears to drive the driving chain 9. In this embodiment, the driving wheel 101 and the driven wheel 102 adopt ratchet drive. The driving wheel 101 is provided with torque by a driving component located outside the inclusion body 7. The driving component in this embodiment includes a driving motor 12, a coupling, and a magnetic drive in sequence. The magnetic drive adopts a cylindrical magnetic drive, including an outer magnetic rotor 13, an inner magnetic rotor 15, and a non-magnetic isolation sleeve 14. Torque transmission without contact and leakage can be achieved through the magnetic drive. Among them, the outer magnetic rotor 13 is connected to the output shaft of the driving motor 12 through a coupling. The end parts of the outer magnetic rotor 13 and the inner magnetic rotor 15 are respectively connected to the outer side wall of the inclusion body 7 through oil-free lubrication bearings 18 and 17. The inner magnetic rotor 15 is connected to one end of the first transmission shaft 16 through an oil-free lubrication bearing. The other end of the first transmission shaft 16 is fixed to the inner side wall of the inclusion body 7 through an oil-free lubrication bearing 19 and a supporting bearing end cover 20. The driving wheel 101 is sleeved on the first transmission shaft 16, so as to achieve the rotation of the driving wheel 101 driven by the driving component through the first transmission shaft 16. The isolation sleeve 14 is located between the inner and outer magnetic rotors and is welded to the flange of the inclusion body 7. The driving wheel 101 drives the rotation of the driven wheel 102 through the driving chain 9. In addition, the torque of the driving ratchet 101 can also be input through a transmission shaft in occasions where there is no radioactive medium and mechanical sealing can be achieved. The driving chain 9 located between the driving wheel 101 and the driven wheel 102 can adopt a ring chain, a plate chain (the number of ring chains and plate chains used can be single, double, or multiple), or a driving belt. In this embodiment, a plate chain structure is adopted.

[0030] See Figure 3, the chain box 6 spaced on the drive chain 9 is used to accommodate the spherical nuclear fuel element 1. The interval between two adjacent chain boxes 6 should be greater than the diameter of a spherical nuclear fuel element 1 to ensure that the spherical nuclear fuel element 1 will not be stuck by the adjacent chain box 6 when entering the containment 7. The overall shape of the chain box 6 can be a cube, a cuboid or other irregular geometric shapes whose outer contour complies with JB / T 3926-2014 "Vertical Bucket Elevator" (P17-23) (a cube is adopted in this embodiment), and it has an open end. The opening directions of the chain boxes 6 on the same side of the drive chain 9 are the same. The distance between the inner side wall of the containment 7 and the side wall of the chain box 6 should meet the requirements of the maximum turning radius and installation distance of the chain box at the drive wheel 101 and the driven wheel 102. Connecting lugs 27 are provided on the side wall of the chain box 6 in contact with the drive chain 9, and the chain box 6 is fixed to the drive chain 9 through the connecting lugs 27. The surfaces of the centering guide plate 25 and the flow guide plate 26 in the chain box 6 in contact with the spherical nuclear fuel element 1 are both set as arc surfaces with a flow guide direction. Among them, the centering guide plate 25 ensures that the spherical nuclear fuel element 1 is at the center position of the chain box 6 to prevent the center of the chain box 6 from shifting and causing the drive chain 9 to deviate from the track. The flow guide plate 26 can prevent the spherical nuclear fuel element 1 from being stuck between the drive chains 9 and prevent the spherical nuclear fuel element 1 from hitting the drive chain 9, avoiding the impact force of the spherical nuclear fuel element 1 on the drive chain 9 from causing the drive chain 9 to deviate from the track, and preventing the spherical nuclear fuel element 1 from being damaged due to impact and generating debris. When the chain box 6 loaded with the spherical nuclear fuel element 1 is transported to the highest potential energy point and starts to be transported downward, the flow guide plate 26 on the chain box 6 can provide enough rolling distance for the spherical nuclear fuel element 1, so that the spherical nuclear fuel element 1 can obtain a certain speed and then be discharged by guiding.

[0031] See Figure 4 (a)-(d), the deviation correction member 8 is in an integral or segmented form, which is used to realize the reliable transmission of the driving force of the drive 9 and the transmission wheels (101, 102), ensure that the drive chain 9 does not deviate from the transmission wheels, and the theoretical lifting height is not limited. The deviation correction member 8 in this embodiment is in a segmented form, including a plurality of U-shaped blocks arranged at equal intervals and enclosing the drive chain 9; a plurality of balls 30 with a solid lubricating effect are evenly arranged on the inner side wall of each U-shaped block and are in contact with the drive chain 9. The arranged balls 30 can reduce the friction between the U-shaped block and the drive chain 9, ensure the service life of the drive chain 9 and the efficient meshing of the drive chain 9 and the transmission ratchets (101, 102), without deviation, with high reliability. The rollers of the drive chain 9 and the balls 30 on the deviation correction member 8 can be made of oil-free lubricating ceramics or alloy steel with high temperature resistance and radiation resistance to ensure the purity of the primary circuit pressure boundary of the nuclear reactor.

[0032] See Figure 5 、 6In Figures (a) to (c), under the operating conditions of this conveying device, the drive chain 9 may become slack due to wear. In order to prevent the drive chain 9 from being in a slack state and ensure the stable transmission of torque between the transmission wheel and the drive chain 9, this fuel vertical conveying device includes an automatic tensioning member 21 fixed between the bearing end cover 22 fixed to the bearing end of the second transmission shaft 23 and the inner side wall of the housing 7. The automatic tensioning member 21 includes a support frame 211 fixed to the inner side wall of the housing 7. On the side wall of the support frame opposite to the bearing end cover 22, a plurality of foldable limit bodies 32 parallel to the axial direction of the drive chain 9 are fixed. The limit bodies blocked by the bearing end cover 22 are in a folded state, and the limit bodies not blocked by the bearing end cover 22 are in an open state; when the drive chain 9 is tensioned and the top of the bearing end cover 22 passes through the foldable limit body 32, the foldable limit body 32 opens to prevent the bearing end cover 22 from moving in the direction that makes the drive chain 9 tend to be slack (upward when the housing is in a vertical state), and the foldable limit body 32 not exceeding the top of the bearing housing is in a semi-closed state; at the bottom of the support frame 211, there is a bolt fixedly connected to the bottom of the bearing end cover 22. A limit spring 33 is sleeved on this bolt. The diameter of the limit spring 33 is larger than the diameter of the bolt hole provided at the bottom of the support frame 211, so that the limit spring 33 is always located between the bottom of the support frame 211 and the gasket of the bolt. By tightening the bolt to compress the limit spring 33, the elastic force of the limit spring 33 will tension the drive chain 9.

[0033] See Figure 7 , slits are provided at the bottom of each grooved raceway. Taking the grooved raceway 2 as an example, the dust and debris generated when the spherical nuclear fuel element 1 rolls in the grooved raceway 2 fall into the dust conveying pipe 3 below it through the slit 34 of the grooved raceway 2 and finally converge in the dust collection device 4 for collection and removal, avoiding the accumulation of dust and debris from affecting the rolling of the spherical nuclear fuel element 1 in the grooved raceway 2. Among them, the grooved raceway 2 can adopt any one or a combination of linear, spiral, curved, and annular forms, and the grooved raceway 2 is installed at any inclination angle between horizontal and vertical. The angle between the axis of the slit 34 and the axis of the grooved raceway 2 is any angle from 0 to 90°.

[0034] In practical applications, the waterwheel chain box type fuel vertical conveying device of the present invention can be flexibly combined with existing equipment in nuclear power plants such as nuclear fuel unloading devices, ball-breaking separation devices, burnup measurement devices, and feeding devices to realize the function of loading and unloading the spherical nuclear fuel elements in the nuclear reactor of the nuclear power plant, with high transmission efficiency and strong reliability. For application examples, see Figure 8 .

[0035] In this application embodiment,

[0036] The nuclear reactor pressure vessel 39 containing the spherical nuclear fuel element 1 is connected to the inlet end of the gravity-driven passive slotted raceway 2 through the discharging device 40. At the same time, a broken ball separation device 41 is provided at the inlet end of the slotted raceway 2. The outlet end of the slotted raceway 2 is connected to the inlet end of the present waterwheel chain box type fuel vertical conveying device. The outlet end of the present waterwheel chain box type fuel vertical conveying device is connected to the inlet end of the slotted raceway 11. A nuclear burnup measurement and distribution device 36 is provided on the slotted pipeline 11. The nuclear fuel ball element 1 that meets the measurement requirements continues to be transported in the slotted pipeline 11, while the nuclear fuel ball element 1 that does not meet the measurement requirements is discharged from the slotted pipeline 11 and enters the spent fuel discharging device 35. The slotted pipeline 11 is also connected to the new fuel injection device 37.

[0037] The transmission process of the spherical nuclear fuel element 1 in the above application example is as follows:

[0038] After the spherical nuclear fuel element 1 is discharged from the nuclear reactor pressure vessel 39 through the discharging device 40, under the action of gravity, it rolls through the slotted raceway 2 into the chain box 6 at the lower end of the mechanical transmission component 5 in the enclosure 7 of the chain box type vertical transmission device. The spherical nuclear fuel element 1 rolls to the center position at the bottom of the chain box through the centering guide plate 25 provided on the chain box 6. The dust and debris generated when the spherical nuclear fuel element 1 rolls in the slotted raceway 2 fall into the dust conveying pipe 3 through the slit 34 of the slotted raceway 2 and finally converge into the dust collection device 4 for collection and removal, avoiding the accumulation of dust and debris from affecting the rolling of the spherical nuclear fuel element 1 in the slotted raceway 2. The spherical nuclear fuel element 1 is injected into the chain box 6 in a single row (one by one, connected in a row) through continuous transmission in the slotted raceway. The chain box 6 on the mechanical transmission component 5 in the chain box type vertical transmission device is transmitted to the upper end of the slotted raceway 11 along with the driving chain 9 through the transmission of the transmission wheels (101, 102). When the spherical nuclear fuel element 1 rolls in the slotted raceway 11 under the action of gravity, the burnup of the spherical nuclear fuel element 1 is measured by the nuclear burnup measurement and distribution device 36. For the spherical nuclear fuel element 1 with a burnup greater than the predetermined burnup measurement value, it continues to roll in the slotted raceway 11 and enters the nuclear reactor pressure vessel 39. For the spherical nuclear fuel element 1 with a deep burnup, it is sent to the spent fuel discharging device 35. At the same time, new fuel is injected by the new fuel injection device 37 and sent into the nuclear reactor pressure vessel 39 through the slotted raceway 11, realizing the cyclic transmission of the fuel.

[0039] The transmission process of the spherical nuclear fuel element 1 in the enclosure 7:

[0040] When the spherical nuclear fuel element 1 rolls to the lower end of the mechanical transmission component 5 through the grooved raceway 2 and continues to be transported, the spherical nuclear fuel element 1 obtains a certain speed and impacts the chain box 6 or the gap between two adjacent chain boxes 6. When the spherical nuclear fuel element 1 impacts the outer wall of the chain box 6, the speed of the spherical nuclear fuel element 1 is zero. The chain box 6 continues to circulate upward under the drive of the drive chain 9, but the spherical nuclear fuel element 1 rolls under the action of gravity and rolls into the chain box 6 through the centering guide plate 25; when the spherical nuclear fuel element 1 impacts the gap between two adjacent chain boxes 6 at a certain speed, the deflector 26 installed on the chain box 6 blocks the spherical nuclear fuel element 1 from impacting on the drive chain 9, and the spherical nuclear fuel element 1 is deflected into the chain box 6 through the deflector 26. When the spherical nuclear fuel element 1 is transported to the highest gravitational potential energy end of the mechanical transmission component 5 through the chain box 6, the chain box 6 is still circulating under the drive of the drive chain 9. The spherical nuclear fuel element 1 rolls in the chain box 6 at the highest gravitational potential energy end and obtains a relatively greater rolling speed through the deflector 26 and rolls to the upper end (goal end) of the grooved raceway 11.

[0041] The above embodiments are only used to illustrate the present invention, rather than limiting the present invention. According to the technical principle of the present invention, those of ordinary skill in the art can have various deformation designs for the design scheme of a waterwheel chain box type fuel vertical conveying device. The patent protection scope of the present invention shall be defined by the claims.

Claims

1. A waterwheel chain box type fuel vertical conveying device, comprising a sealed containment body (7) containing helium, a mechanical transmission component (5) located inside the containment body (7), and a driving assembly located outside the containment body (7); the upper and lower ends of the containment body (7) are respectively connected to gravity-driven passive slotted raceways to form a loop, a dust conveying pipe (3) for collecting dust and debris falling through the slotted raceway is provided at the bottom of the slotted raceway, and the end of the dust conveying pipe is connected to a dust collection device (4); characterized in that, The mechanical transmission component (5) includes a driving wheel (101) and a driven wheel (102) located at the top and bottom of the containment body (7), a driving chain (9) fixed between the driving wheel (101) and the driven wheel (102), and a plurality of chain boxes (6) fixed on the driving chain (9) at equal intervals for accommodating spherical nuclear fuel elements (1); the driving wheel (101) is sleeved on a first transmission shaft (16), one end of the first transmission shaft (16) is located inside the containment body (7) and is fixed to the inner side wall of the containment body (7) through a first bearing (19) and a bearing end cover (20), the other end of the first transmission shaft (16) is located outside the containment body (7) and is connected to the output end of the driving assembly, the driven wheel (102) is sleeved on a second transmission shaft (23), and both ends of the second transmission shaft (23) are fixed to the inner side wall of the containment body (7) through matching bearings and bearing end covers; each of the chain boxes (6) has the same structure and is a box body with an open end, and a centering guide plate (25) for ensuring that the spherical nuclear fuel element (1) is located at the center position of the chain box (6) is arranged inside the box body, and a diversion plate (26) for diverting the spherical nuclear fuel element (1) into the chain box (6) or providing a rolling distance for the spherical nuclear fuel element (1) to enter the grooved raceway (11) extends outward from the side wall of the open end of the box body in contact with the driving chain (9); the deviation rectifying member (8) fixed to the inner side wall of the containment body (7) ensures the meshing between the driving chain (9) and the transmission wheel.

2. The fuel vertical conveying device according to claim 1, characterized in that, The deviation rectifying member (8) is a U-shaped block that forms an envelope around the driving chain (9), and can be of an integral or segmented type; a plurality of balls (30) with solid lubrication functions are evenly arranged on the inner side wall of the deviation rectifying member (8) and are in contact with the driving chain (9).

3. The fuel vertical conveying device according to claim 1, characterized in that, The surfaces of the centering guide plate (25) and the diversion plate (26) in the chain box (6) that are in contact with the spherical nuclear fuel element (1) are both arc-shaped surfaces with a diversion direction.

4. The fuel vertical conveying device according to claim 1, characterized in that, The driving chain (9) is a ring chain, a plate chain or a driving belt.

5. The fuel vertical conveying device according to claim 1, characterized in that, The driving wheel (101) and the driven wheel (102) are ratchets or gears.

6. The fuel vertical conveying device according to claim 1, characterized in that, The torque provided by the driving assembly for the driving wheel (101) is input in the form of permanent magnetic force or a transmission shaft.

7. The fuel vertical conveying device according to claim 1, characterized in that, Each of the bearings is an oil-free lubrication bearing.

8. The fuel vertical conveying device according to any one of claims 1 to 7, characterized in that, An automatic tensioning member (21) is provided between the bearing end covers at both ends of the second transmission shaft (23) and the inner side wall of the inclusion body (7) to ensure that the drive chain (9) is always in a tensioned state; the automatic tensioning member (21) includes a support frame (211) fixed to the inner side wall of the inclusion body (7), and a plurality of foldable limit bodies (32) parallel to the axis of the drive chain (9) are fixed on the side wall of the support frame opposite to the bearing end cover of the second transmission shaft (23) to prevent the bearing end cover of the second transmission shaft (23) from moving in the direction that makes the drive chain (9) tend to be loose. The limit bodies blocked by the bearing end cover of the second transmission shaft (23) are in a folded state, and the limit bodies not blocked by the bearing end cover are in an open state; a bolt fixedly connected to the bottom of the bearing end cover of the second transmission shaft (23) is provided at the bottom of the support frame (211), and a limit spring (33) is sleeved on the bolt.

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