A core fuel assembly transfer device and method for a nuclear reactor

Abstract

A core fuel assembly transfer device and method of a nuclear reactor, the device comprising a driving mechanism, a transfer track, a transfer trolley and a carrier, the transfer track comprising a KX side transfer track, a transfer channel and an RX side transfer track, the transfer channel being provided with an inner track, two ends of the inner track corresponding to the KX side straight track and the RX side straight track, and a track changing mechanism being installed at the bottom of the RX side straight track corresponding to the RX side turnover track, used for realizing the height switching of the RX side turnover track entrance position; wherein the driving mechanism is a push-pull driving mechanism, the driving mechanism drives the transfer trolley to walk along the KX side straight track, the inner track and the RX side straight track; the carrier is hinged with the transfer trolley, the transfer trolley drives the carrier to realize the turnover switching between the horizontal position and the vertical position through the KX side turnover track and the RX side turnover track respectively in the fuel factory and the reactor factory, and the transfer of the fuel assembly is completed. The application also provides a core fuel assembly transfer method of a nuclear reactor.

Description

Technical Field

[0001] This invention relates to the refueling technology of core fuel assemblies in nuclear power plant reactors, and in particular to a core fuel assembly transfer device and method suitable for pressurized water reactor nuclear power plants. Background Technology

[0002] Nuclear power generation, as a clean energy source that does not produce greenhouse gases, is receiving increasing attention. Pressurized water reactor nuclear power plants, as a typical representative of nuclear power generation technology, have high power generation efficiency and fuel utilization rate, reducing energy waste, and are therefore widely used.

[0003] During the operation of a pressurized water reactor nuclear power plant, the fuel assemblies in the reactor core continuously burn and are converted into spent fuel assemblies. To ensure the normal operation of the nuclear power plant, it is necessary to periodically shut down the reactor and replace the fuel assemblies in the core. The reactor core is located in the reactor building (RX side), while the fuel assemblies to be installed and the spent fuel assemblies removed from the core are stored in the fuel building (KX side). The reactor building and the fuel building are isolated by a thick containment wall. In most pressurized water reactor nuclear power plants, the fuel assembly transfer device operates via a transport trolley running on the RX-side track, KX-side track, and transfer channel. A drive mechanism is installed on both the reactor building side and the fuel building side. Gears on these two drive mechanisms relay the rack on the transport trolley, completing the task of transporting fuel assemblies from the reactor building to the fuel building via the transfer channel. One tilting frame is located in both the reactor building and the fuel building, respectively bolted to the RX-side track and the KX-side track. Once the carrier is in place with the transport trolley, the tilting frame tilts the carrier, causing it to flip. The carrier flips to a vertical position, allowing fuel assemblies to be vertically loaded or removed from the top of the carrier.

[0004] Existing fuel assembly transfer devices mainly suffer from the following problems:

[0005] 1) The gears on the transport trolley are driven by the gears on the two sets of drive mechanisms installed in the reactor building and the fuel building to complete the transfer of fuel assemblies between the reactor building (RX side) and the fuel building (KX side). This transmission method has high requirements for the machining and assembly accuracy of the guide rails and racks, resulting in high cost of the transfer device, complex control program, risk of jamming of the transport trolley and low reliability.

[0006] 2) Two sets of tilting frames need to be installed in the reactor building and the fuel building respectively, and equipped with corresponding motors and transmission mechanisms to drive steel cables to complete the tilting operation of the carrier. This results in a high cost of the transfer device. In addition, due to the need for coordination of multiple control units, the control program is complex and the system is difficult to maintain and operate.

[0007] 3) The flipping of the carrier is achieved by pulling with a single-axis steel cable, which has low reliability. If the steel cable is accidentally damaged, the fuel assembly is prone to falling.

[0008] 4) The gap between the side wall of the carrier and the fuel assembly is only 5mm. The fuel assembly, which is more than 4 meters long, is vertically installed and removed from the top of the carrier. Due to the narrow gap, the fuel assembly is easily scratched during the operation. In order to reduce the risk of damage to the fuel assembly caused by scratching, the speed of the fuel assembly being installed into and removed from the carrier is usually limited, resulting in low efficiency of fuel assembly installation and removal. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a reactor core fuel assembly transfer device and method to address the above-mentioned deficiencies of the prior art.

[0010] To achieve the above objectives, the present invention provides a reactor core fuel assembly transfer device, comprising a drive mechanism, a transfer track, a transfer trolley, and a carrier, wherein the transfer track includes:

[0011] The KX-side transfer track includes a KX-side straight track and a KX-side tilting track. The KX-side straight track is located in the spent fuel pool of the fuel plant. The KX-side tilting track is set above the KX-side straight track and is used to cooperate with the transfer trolley to achieve the tilting of the carrier in the vertical and horizontal positions.

[0012] The RX-side transfer track includes an RX-side straight track and an RX-side tilting track. The RX-side straight track is located in the refueling pool of the reactor building. The RX-side tilting track is located above the RX-side straight track and is used to cooperate with the transfer trolley to achieve the tilting of the carrier in the vertical and horizontal positions.

[0013] A transfer channel runs through the containment wall between the fuel building and the reactor building. An inner track is installed within the transfer channel, with its two ends corresponding to the KX-side straight track and the RX-side straight track, respectively, to allow the transfer trolley to move smoothly across the track.

[0014] The track-changing mechanism is installed at the bottom of the RX-side straight track, corresponding to the RX-side flip track, and is used to switch the height of the RX-side flip track inlet position.

[0015] The driving mechanism is a push-pull driving mechanism, which is connected to the transfer trolley and drives the transfer trolley to travel along the KX side straight track, the inner track, and the RX side straight track. One end of the carrier is hinged to the transfer trolley and rotates around the hinge axis. The transfer trolley drives the carrier to switch between horizontal and vertical positions in the fuel plant and reactor plant via the KX side rotating track and the RX side rotating track, respectively, to complete the transfer of fuel assemblies.

[0016] The aforementioned nuclear reactor core fuel assembly transfer device includes a KX-side flipping track comprising a KX-side fixed frame and a KX-side arc-shaped track. The KX-side fixed frame is symmetrically installed on both sides of the KX-side straight track via adjustable feet. The KX-side arc-shaped tracks on both sides are respectively connected to the KX-side fixed frame on the same side. The spacing between the two KX-side arc-shaped tracks is adapted to the carrier. The guide wheels on both sides of the carrier run along the tracks of the KX-side arc-shaped tracks to achieve the flipping of the carrier in vertical and horizontal positions.

[0017] The aforementioned nuclear reactor core fuel assembly transfer device includes an RX-side flipping track comprising an RX-side fixed frame and an RX-side arc-shaped rail. The RX-side fixed frame is symmetrically installed on both sides of the RX-side straight track via adjustable feet, and the spacing between the two RX-side arc-shaped rails is adapted to the carrier. The RX-side arc-shaped rail comprises a fixed rail and a swing rail. The fixed rail is installed on the RX-side fixed frame. The end of the fixed rail is connected to the top of the swing rail, and a support positioning block is installed at the bottom of the end of the swing rail. A support positioning part is provided on the RX-side straight track corresponding to the support positioning block. The track-changing mechanism is installed at the bottom of the RX-side straight track corresponding to the support positioning block. The track-changing mechanism adjusts the swing rail to switch between a descending position and a rising position. When the swing rail is in the descending position, the guide wheels on both sides of the carrier run along the track of the RX-side arc-shaped rail through the guide opening of the swing rail to achieve the flipping of the carrier between the vertical and horizontal positions.

[0018] The aforementioned reactor core fuel assembly transfer device includes, respectively, the KX-side straight track and the RX-side straight track comprising: a straight track, multiple supports and adjustable feet; the straight track is mounted and supported on the multiple supports, and the adjustable feet are respectively provided at the bottom end of each support; a guide port is provided at the connection between the straight track and the inner track; a limit baffle is provided at the end of the KX-side straight track, and a connecting plate is provided at the end of the RX-side straight track.

[0019] The aforementioned reactor core fuel assembly transfer device, wherein the carrier comprises:

[0020] The carrier includes a left side plate, a right side plate, a rear side plate, a front side plate, and a carrier bottom plate. The left side plate, right side plate, rear side plate, and front side plate are respectively connected to the carrier bottom plate and form a rectangular box with an opening at the top and front. The rectangular box is used to accommodate the fuel assembly to be transferred.

[0021] Guide wheels are symmetrically installed at the top ends of the left and right side plates;

[0022] A hinge shaft is symmetrically mounted on one end of the left and right side plates near the bottom; the carrier is mounted on a transfer trolley via the hinge shaft and rotates around the axis of the hinge shaft to achieve conversion between a vertical and a horizontal position; and

[0023] An anti-tipping mechanism is installed on the side of the left and / or right side plates near the front opening and at the top end, to prevent the fuel assembly to be transferred from falling out of the front opening together with the front side plates.

[0024] The aforementioned reactor core fuel assembly transfer device, wherein the anti-tipping mechanism includes:

[0025] The limiting plates are symmetrically installed on the left and right side plates respectively by fixing blocks, and the limiting plates have an open position and a retracted position relative to the fixing blocks;

[0026] A transmission mechanism includes an upper pull rod, a lower pull rod, and a pull rod reset component. The two ends of the upper pull rod are respectively connected to the limiting plate and the lower pull rod, and the pull rod reset component is connected to both the upper pull rod and the lower pull rod.

[0027] A control mechanism is disposed on the bearing base plate and connected to the transmission mechanism, and is used to control the limiting plate to switch between the open position and the retracted position.

[0028] The aforementioned nuclear reactor core fuel assembly transfer device includes a control mechanism comprising a base, a support block, and a base reset component. The rear end of the base is hinged to the supporting base plate. The support block is mounted on the supporting base plate corresponding to the front end of the base. The base reset component is located between the base and the supporting base plate. The lower end of the pull rod is connected to the base and, together with the base reset component, drives the base to swing up and down around the hinge point. The base has a pressed position and a released position relative to the supporting base plate. When the base is in the pressed position, the limiting plate switches to the open position; when the base is in the released position, the limiting plate switches to the retracted position.

[0029] The aforementioned reactor core fuel assembly transfer device includes a transfer trolley comprising a trolley body and traveling wheels and guide wheels mounted on the trolley body. The trolley body includes a base plate, a rear side wall, a front side wall, a left side wall, and a right side wall. One end of the trolley body is connected to a drive mechanism. The end of the base plate away from the drive mechanism has a hole for the carrier to flip and pass through. The traveling wheels and guide wheels are respectively mounted on the left side wall and the right side wall. The transfer trolley travels across the transfer track via the traveling wheels and guide wheels. The left side wall and the right side wall are respectively provided with concentric hinge holes for connecting the carrier.

[0030] To better achieve the above objectives, the present invention also provides a method for transferring core fuel assemblies in a nuclear reactor, comprising the following steps:

[0031] S100, the unloading procedure further includes:

[0032] S110. The transfer trolley with the load-bearing device is located in the fuel plant, and the load-bearing device is hinged to the transfer trolley and located in a vertical position;

[0033] S120. The transfer trolley moves toward the reactor building, the guide wheel of the carrier moves downward along the KX side arc rail, the carrier flips to a horizontal position with the hinge shaft as the center, and the guide wheel of the carrier disengages from the KX side arc rail.

[0034] S130, The transfer trolley carrying the carrier passes through the transfer channel to the reactor building, the track changing mechanism causes the swing rail of the RX side flip track to descend, and the transfer trolley stops after it reaches its position;

[0035] S140, the transfer trolley moves toward the fuel plant, the guide wheel of the carrier enters the swing rail of the RX side flipping track and moves upward along the swing rail until the carrier flips to a vertical position; at the same time, the transfer trolley stops moving;

[0036] S150, The loading and unloading machine uses an offset method to load the fuel assembly into the carrier;

[0037] S160. The transfer trolley moves toward the reactor building, and the guide wheel of the carrier moves downward along the swing rail of the RX side flip track until the carrier flips to a horizontal position and the guide wheel of the carrier disengages from the swing rail of the RX side flip track; the track changing mechanism causes the swing rail of the RX side flip track to rise, and the transfer trolley stops after it reaches its position.

[0038] S170, The transfer trolley carrying the carrier loaded with fuel components moves toward the fuel plant, passes through the transfer channel and arrives at the fuel plant;

[0039] S180, the guide wheel of the carrier enters the arc-shaped rail on the KX side and moves upward along the arc-shaped rail on the KX side until the carrier flips to a vertical position and the transfer trolley stops moving; and

[0040] S190, the waste pool manipulator uses an offset method to remove the fuel assembly from the carrier;

[0041] S200, the loading process, further includes:

[0042] S210, The carrier is in a vertical position, and the spent pool manipulator uses the offset method to load the fuel assembly to be installed into the carrier;

[0043] S220, the transfer trolley moves toward the reactor building, and the guide wheel of the carrier moves downward along the KX side arc rail until the carrier flips to a horizontal position and the guide wheel of the carrier disengages from the KX side arc rail;

[0044] S230, The transfer trolley carrying the carrier loaded with fuel assemblies passes through the transfer channel to the reactor building, the track changing mechanism causes the swing rail of the RX side tilting track to descend, and the transfer trolley stops after it reaches its position;

[0045] S240, the transfer trolley moves towards the fuel plant, the guide wheel of the carrier enters the swing rail of the RX side flipping track and moves upward along the swing rail until the carrier flips to a vertical position; at the same time, the transfer trolley stops moving;

[0046] S250, The loading and unloading machine uses an offset method to remove the fuel assembly to be loaded from the carrier;

[0047] S260. The transfer trolley moves toward the reactor building, and the guide wheel of the carrier moves downward along the RX-side arc-shaped rail until the carrier flips to a horizontal position, at which point the guide wheel of the carrier disengages from the RX-side arc-shaped rail; the track-changing mechanism causes the swing rail of the RX-side flipping track to rise; the transfer trolley stops after it reaches its position.

[0048] S270, The transfer trolley carrying the carrier passes through the transfer channel to the fuel plant. The guide wheel of the carrier enters the KX side arc rail and moves upward along the KX side arc rail until the carrier flips to a vertical position, and the transfer trolley stops moving.

[0049] The above-mentioned method for transferring core fuel assemblies in a nuclear reactor, wherein the offset method includes the following steps:

[0050] In the loading step, the carrier is in a vertical position. A lifting device is used to lift the fuel assembly and quickly lower it to near the upper edge of the front side plate of the carrier. The fuel assembly is then moved horizontally into the carrier through the opening in the front side plate and slowly lowered. When the fuel assembly reaches its lowered position, the limiting plate of the anti-tipping mechanism is triggered and swings out. The limiting plate and the front side plate work together to prevent the fuel assembly from falling out of the front opening. The lifting device releases the fuel assembly and moves away, completing the loading process.

[0051] In the material handling process, the carrier is positioned vertically, the lifting device grabs the fuel assembly and slowly lifts it above the upper edge of the front side plate, while the limit plate of the anti-tipping mechanism retracts; the fuel assembly is moved horizontally out from the front opening; the lifting device quickly lifts the fuel assembly away, and the material handling is completed.

[0052] The technical effects of this invention are as follows:

[0053] The fuel assembly transfer device of this invention is suitable for pressurized water reactor nuclear power plants, solving the problems of high cost and complex control procedures caused by the need to install tilting frames in the fuel building and reactor building separately in existing fuel assembly transfer devices; low reliability of the carrier's tilting method, with fuel assemblies falling after accidental damage to the steel cable; and long loading and unloading times and low efficiency of fuel assemblies. This invention uses a rigid push-pull mechanism to drive the transfer trolley to achieve horizontal transfer and tilting of the carrier, reducing the control difficulty of the fuel assembly transfer device, lowering costs, and improving reliability; its carrier tilting is a simply supported structure with strong constraints, which is more reliable than single-axis tilting, and there is no risk of fuel assemblies falling; the carrier uses an offset method to load and unload fuel assemblies, significantly improving transfer efficiency.

[0054] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of a fuel assembly transfer device according to an embodiment of the present invention;

[0056] Figure 2A This is a schematic diagram of the KX side straight track structure according to an embodiment of the present invention;

[0057] Figure 2B This is a side view of the straight track on the KX side according to an embodiment of the present invention;

[0058] Figure 3 This is a schematic diagram of the RX-side straight track structure according to an embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram of the KX side-flipping track structure according to an embodiment of the present invention;

[0060] Figure 5A This is a schematic diagram of an RX-side flip track structure according to an embodiment of the present invention;

[0061] Figure 5B This is a schematic diagram of the installation position of the track-changing mechanism according to an embodiment of the present invention;

[0062] Figure 5C for Figure 5B A magnified view of a portion of the image;

[0063] Figure 6 This is a schematic diagram of a push-pull drive mechanism according to an embodiment of the present invention;

[0064] Figure 7 This is a schematic diagram of the installation of the carrier and the transfer trolley according to an embodiment of the present invention;

[0065] Figure 8A This is a schematic diagram of the structure of a transfer trolley according to an embodiment of the present invention;

[0066] Figure 8B for Figure 8A Top view;

[0067] Figure 9A This is a schematic diagram of a carrier structure according to an embodiment of the present invention;

[0068] Figure 9B This is a schematic diagram of a carrier structure according to an embodiment of the present invention;

[0069] Figure 9C This is a schematic diagram of an anti-tipping mechanism according to an embodiment of the present invention;

[0070] Figure 9D for Figure 9C A magnified view of a portion of the image;

[0071] Figure 10 This is a schematic diagram of a fuel assembly according to an embodiment of the present invention;

[0072] Figure 11 This is a schematic diagram of the offset method for loading a fuel assembly according to an embodiment of the present invention;

[0073] Figure 12 This is a schematic diagram of a fuel assembly removal method according to an embodiment of the present invention.

[0074] Among them, the attached reference numerals

[0075] 1 transfer cart

[0076] 11 car bodies

[0077] 111 base plate

[0078] 1111 holes

[0079] 112 Rear Side Wall

[0080] 113 Anterior sidewall

[0081] 114 Left side wall

[0082] 115 right side wall

[0083] 12 wheels

[0084] 13 guide wheels

[0085] 14 hinge holes 2 bearings

[0086] 21 carriers

[0087] 211 Left Side Panel

[0088] 212 right side panel

[0089] 213 rear side panel

[0090] 214 front side panel

[0091] 215 bearing base plate

[0092] 216 guide angle

[0093] 22 Anti-tipping mechanism

[0094] 221 Limit Plate

[0095] 222 fixing block

[0096] 223 upper pull rod

[0097] 224 Pull rod reset component 225 Pull rod

[0098] 226 hinge block

[0099] 227 support blocks

[0100] 228 base

[0101] 229 Base reset component 23 Guide wheel

[0102] 24 reinforcing ribs

[0103] 25-inch hinge shaft 3-inch push-pull drive mechanism

[0104] 31 Drive Components

[0105] 311 motor

[0106] 312 reducer

[0107] 313 First drive shaft; 314 Emergency handwheel

[0108] 32 Transmission Components

[0109] 321 Chain Library

[0110] 322 rigid chain

[0111] 323 Second drive shaft

[0112] 33 Quick Connector

[0113] 34 Quick Installation Structure

[0114] 4 transfer tracks

[0115] 41KX side transfer track

[0116] 411KX Side Straight Rail

[0117] 4111KX Side Straight Rail

[0118] 41111 Bottom

[0119] 41112 Side View

[0120] 41113 Top surface

[0121] 41114 Rigid Chain Guide Groove; 4112KX Side Bracket

[0122] 4113KX Side Adjustable Feet

[0123] 4114 Limiting baffle

[0124] 412KX Side-Tilting Track

[0125] 4121KX Side Curved Rail

[0126] 4122 Fixture

[0127] 4123 connecting column

[0128] 4124 reinforced leg

[0129] 4125 connecting beam

[0130] 4126KX Side-tilt Adjustable Feet 42 Transfer Channel

[0131] 421 Inner Track

[0132] 43RX side transfer track

[0133] 431RX Side Straight Rail

[0134] 4311RX Side Straight Rail

[0135] 4312 connecting board

[0136] 4313 Support Positioning Unit

[0137] 4314RX Side Adjustable Feet

[0138] 4315RX Side Bracket

[0139] 432RX Side-flipping Rail

[0140] 4321RX Side Curved Rail

[0141] 43211 Fixed Rail

[0142] 43212 Swing Rail

[0143] 4322 Support Positioning Block

[0144] 4323RX Side Mount

[0145] 43231 Upper limit beam

[0146] 43232 Lower limit beam

[0147] 4324RX Side-flipping feet

[0148] 4325RX side connecting column

[0149] 4326RX Side Reinforced Legs

[0150] 4327RX side connecting beam

[0151] 44 Track Changing Mechanism

[0152] 5 blind flange

[0153] 6 manual gate valves

[0154] 7 lifting tools

[0155] 8 fuel assemblies

[0156] 81 Upper tube seat

[0157] 82 lower tube seat Detailed Implementation

[0158] The structural and working principles of the present invention will be described in detail below with reference to the accompanying drawings:

[0159] The reactor core fuel assembly transfer device of the present invention is a key piece of equipment for replacing fuel assembly 8 during the shutdown of a nuclear power plant. It is mainly used to transfer fuel assembly 8 between the reactor building and the fuel building, and plays an important role in the shutdown and refueling process of pressurized water reactor nuclear power plants.

[0160] See Figure 1 , Figure 1This is a schematic diagram of a fuel assembly transfer device according to an embodiment of the present invention. The fuel assembly transfer device of the present invention is suitable for transferring fuel assemblies 8 in pressurized water reactor nuclear power plants, and includes a transfer trolley 1, a carrier 2, a push-pull drive mechanism 3, a KX-side transfer track 41 (including a KX-side straight track 411 and a KX-side flip track 412), a transfer channel 42, and an inner track 421, an RX-side transfer track 43 (including an RX-side straight track 431 and an RX-side flip track 432), and a track-changing mechanism 44. The push-pull drive mechanism 3, the KX-side straight track 411, and the KX-side tilting track 412 are installed in the spent fuel pool of the fuel building, while the RX-side straight track 431 and the RX-side tilting track 432 are installed in the refueling pool of the reactor building. The transfer channel 42 is installed through the containment wall between the fuel building and the reactor building. The inner track 421 is installed inside the transfer channel 42. In this embodiment, the cross-sectional structure of the inner track 421 is consistent with that of the KX-side straight track 411, and both ends are provided with easily guided flared openings to prevent the transfer trolley 1 from getting stuck when crossing tracks. A track-changing mechanism is also included. 44 is installed at the bottom of the RX side straight track 431; the transfer trolley 1 travels back and forth on the KX side straight track 411, the RX side straight track 431 and the inner track 421 to complete the transfer of fuel assembly 8; the push-pull drive mechanism 3 provides power to the transfer trolley 1; the carrier 2 is hinged on the transfer trolley 1 and can be rotated around the hinge shaft 25; the KX side flip track 412 enables the carrier 2 to be rotated in the horizontal and vertical states in the fuel building; the RX side flip track 432 enables the carrier 2 to be rotated in the horizontal and vertical states in the reactor building.

[0161] This embodiment may also include a blind flange 5 and a manual gate valve 6. The blind flange 5 is installed at the port of the transfer channel 42 on the reactor building refueling pool side, and the manual gate valve 6 is installed at the other port of the transfer channel 42 on the spent fuel pool side. After the core fuel assembly 8 is replaced, the manual gate valve 6 is closed to drain the water from the reactor building refueling pool, and the blind flange 5 is installed to seal the transfer channel 42.

[0162] In this embodiment, the transfer track 4 includes: a KX-side transfer track 41, comprising a KX-side straight track 411 and a KX-side flipping track 412, wherein the KX-side straight track 411 is located in the spent fuel pool of the fuel building; the KX-side flipping track 412 is disposed above the KX-side straight track 411 and is used to cooperate with the transfer trolley 1 to achieve the vertical and horizontal flipping of the carrier 2; an RX-side transfer track 43, comprising an RX-side straight track 431 and an RX-side flipping track 432, wherein the RX-side straight track 431 is located in the refueling pool of the reactor building; the RX-side flipping track 432 is disposed above the RX-side straight track 431 and is used to cooperate with the transfer trolley 1 to achieve the vertical and horizontal flipping of the carrier 2; and a transfer channel 42, which is installed through the containment wall between the fuel building and the reactor building, wherein an inner track 421 is installed inside the transfer channel 42, and the two ends of the inner track 421 correspond to the KX-side straight track 41 respectively. The system includes a straight track 431 on the RX side to enable the transfer trolley 1 to move smoothly across the track; a track-changing mechanism 44, corresponding to the RX side flip track 432, is installed at the bottom of the RX side straight track 431 and is used to cooperate with the transfer trolley 1 or the carrier 2 to switch the height of the entrance position of the RX side flip track 432; the bottom of the transfer trolley 1 is provided with a contact block for driving the track-changing mechanism 44; wherein, the driving mechanism is a push-pull driving mechanism 3, which is connected to the transfer trolley 1 and drives the transfer trolley 1 to move along the straight track 411 on the KX side, the inner track 421 and the straight track 431 on the RX side; one end of the carrier 2 is hinged to the transfer trolley 1 and flips with the hinge shaft 25 as the center; the transfer trolley 1 drives the carrier 2 to switch between horizontal and vertical positions in the fuel plant and the reactor plant respectively through the KX side flip track 412 and the RX side flip track 432 to complete the transfer of fuel assembly 8.

[0163] See Figures 2A-3 , Figure 2A This is a schematic diagram of the KX side straight track 411 structure according to an embodiment of the present invention. Figure 2B This is a side view of the KX-side straight track 411 according to an embodiment of the present invention. Figure 3This is a schematic diagram of the RX-side straight track 431 according to an embodiment of the present invention. The KX-side straight track 411 of the present invention is located in the spent fuel pool of the fuel building and is used for the storage and movement guidance of the transfer trolley 1; the RX-side straight track 431 is located in the refueling pool of the reactor building and is used to support the transfer trolley 1 and serve as the running track of the transfer trolley 1. The KX-side straight track 411 and RX-side straight track 431 in this embodiment each include: a straight track, multiple supports (including KX-side support 4112 and RX-side support 4315), and adjustable feet (including KX-side adjustable feet 4113 and RX-side adjustable feet 4314). The straight track is mounted and supported on the multiple supports to ensure the stability and load-bearing capacity of the track. The adjustable feet are symmetrically arranged at the bottom of each support. The adjustable feet are welded and fixed to the stainless steel bottom surface of the spent fuel water tank. The adjustable feet are used to adjust the height and level of the straight track. By adjusting the adjustable feet, the KX-side straight track 411 and the inner track 421 are kept within a specified height deviation range, so that the transfer trolley 1 can travel smoothly across the two tracks, that is, to ensure that the transfer trolley 1 can travel smoothly across the KX-side straight track 411, the inner track 421, and the RX-side straight track 431. The connection between the straight rail and the inner rail 421 is provided with a flared guide opening to effectively prevent the transfer trolley 1 from getting stuck when it crosses the rail; a limit baffle 4114 is provided at the end of the straight rail 4111 on the KX side, and a connecting plate 4312 is provided at the end of the straight rail 4311 on the RX side.

[0164] The RX-side straight track 431 in this embodiment is similar in structure to the KX-side straight track 411. The difference is that one end of the RX-side straight track 431 is a funnel shape that is easy to guide, and the other end is connected by a connecting plate 4312. The connecting plate 4312 can prevent the transfer trolley 1 from accidentally leaving the track. The RX-side adjusting foot 4314 is welded and fixed to the stainless steel bottom surface of the reactor building refueling pool.

[0165] The straight rail has the same structure as the inner rail 421. Taking the KX side straight rail 4111 as an example, both include a bottom surface 41111, a side surface 41112, and an open top surface 41113. The bottom surface 41111 has a rigid chain guide groove 41114 along its length for auxiliary guidance of the rigid chain 322. The bottom surface 41111 is a shared support surface for the transfer trolley 1 and the rigid chain 322. The side surface 41112 is a guide surface for the transfer trolley 1. The top surface 41113 is used to prevent the transfer trolley 1 from accidentally derailing. The KX side straight rail 4111 achieves a shared rail for the transfer trolley 1 and the rigid chain 322, simplifying the rail structure and reducing manufacturing costs.

[0166] See Figure 4 , Figure 4This is a schematic diagram of a KX-side tilting track structure according to an embodiment of the present invention. In this embodiment, the KX-side tilting track 412 includes a KX-side fixing frame 4122 and a KX-side arc-shaped track 4121. The KX-side fixing frame 4122 is symmetrically installed on both sides of the KX-side straight track 411 by adjusting feet. The KX-side arc-shaped tracks 4121 on both sides are respectively connected to the KX-side fixing frame 4122 on the same side. The two symmetrically arranged KX-side arc-shaped tracks 4121 are connected to each other by connecting beams 4125 to enhance the overall rigidity of the KX-side tilting track 412. The spacing between the KX-side arc-shaped tracks 4121 on both sides is adapted to the carrier 2. The traveling guide wheels 13 on both sides of the carrier 2 run along the tracks of the KX-side arc-shaped tracks 4121 to realize the tilting of the carrier 2 in vertical and horizontal positions. A flared guide structure is provided at one end of the KX-side curved rail 4121 adjacent to the KX-side straight rail 411 to guide the guide wheel 23 of the carrier 2 to smoothly switch between the KX-side curved rail 4121 and the KX-side straight rail 411. The KX-side fixing frame 4122 can be a triangular fixing frame, a rectangular fixing frame, an L-shaped fixing frame, or a groove-shaped fixing frame, preferably a triangular fixing frame, which can be adjusted according to actual needs to adapt to different working environments. The KX-side curved rail 4121 is connected to the two KX-side fixing frames 4122 through the connecting column 4123, increasing the distance between the two KX-side fixing frames 4122 and providing sufficient space for the offset loading of the fuel assembly 8. The KX side mounting bracket 4122 is connected to the side wall of the spent fuel water tank using reinforcing legs 4124. The reinforcing legs 4124 are welded and fixed to the stainless steel side wall of the spent fuel water tank. The reinforcing legs 4124 have an adjustable length, allowing them to be adjusted to suit different installation requirements. The KX side mounting bracket 4122 is connected to the bottom surface of the spent fuel water tank using KX side tilting adjustable feet 4126. The KX side tilting adjustable feet 4126 are welded and fixed to the stainless steel bottom surface of the spent fuel water tank. The KX side tilting adjustable feet 4126 have a height adjustable function, allowing the height of the KX side tilting track 412 to be adjusted.

[0167] See Figures 5A-5C , Figure 5A This is a schematic diagram of an RX side flip rail structure according to an embodiment of the present invention. Figure 5B This is a schematic diagram of the installation position of the track-changing mechanism 44 according to an embodiment of the present invention. Figure 5C for Figure 5BA partial enlarged view. The RX-side tilting track 432 is located on the reactor building side. In this embodiment, the RX-side tilting track 432 includes an RX-side fixing frame 4323 and an RX-side arc-shaped rail 4321. The RX-side fixing frame 4323 is symmetrically installed on both sides of the RX-side straight rail 431 via RX-side tilting feet 4324. The spacing between the two sides of the RX-side arc-shaped rails 4321 is adapted to the carrier 2. An upper limit beam 43231 and a lower limit beam 43232 are provided on the side of the RX-side fixing frame 4323 closest to the KX-side building to achieve mechanical positioning of the carrier in the vertical state of the RX-side building. The two ends of the upper limit beam 43231 and the lower limit beam 43232 are respectively connected to the corresponding side of the RX-side fixing frame 4323, and can be arranged parallel to the lower part of the RX-side fixing frame 4323, spanning the RX-side straight rail 431 and located above the RX-side straight rail 431. In this embodiment, the RX-side fixing bracket 4323 is preferably a right-angled triangular bracket structure. The upper limit beam 43231 and the lower limit beam 43232 are arranged parallel to each other on the lower part of one side of the vertical right angle of the triangular bracket. Alternatively, only the upper limit beam 43231 or the lower limit beam 43232 can be provided, and they are located above the RX-side straight track 431. The RX-side arc-shaped track 4321 includes a fixed track 43211 and a swing track 43212. The fixed track 43211 is installed on the RX-side fixing bracket 4323. The two symmetrically arranged fixed tracks 43211 are connected to each other by the RX-side connecting beam 4327 to enhance the overall rigidity of the RX-side flip track 432. The RX-side arc-shaped track 4321 is connected to the two RX-side fixing brackets 4323 by the RX-side connecting column 4325, which increases the distance between the two RX-side fixing brackets 4323 and provides sufficient space for the offset loading of the fuel assembly 8. The RX-side fixing bracket 4323 is connected to the side wall of the refill tank using RX-side reinforcing legs 4326. The RX-side reinforcing legs 4326 are welded and fixed to the stainless steel side wall of the refill tank. The RX-side reinforcing legs 4326 have an adjustable length, allowing them to be adjusted to suit different installation requirements. The RX-side fixing bracket 4323 is connected to the bottom surface of the refill tank using RX-side tilting feet 4324. The RX-side tilting feet 4324 are welded and fixed to the stainless steel bottom surface of the refill tank. The RX-side tilting feet 4324 have an adjustable height, allowing the height of the RX-side tilting track 432 to be adjusted.The end of the fixed rail 43211 is hinged to the upper end of the swing rail 43212, which can swing around the hinge axis. The interface between the fixed rail 43211 and the swing rail 43212 is far from the position where the guide wheel 23 bears the maximum pressure during the flipping of the carrier 2. A support positioning block 4322 is installed at the bottom of the end of the swing rail 43212, and a support positioning part 4313 is provided on the RX side straight rail 4311 corresponding to the support positioning block 4322. The track changing mechanism 44 is installed at the bottom of the RX side straight rail 4311 corresponding to the support positioning block 4322, and the swing rail 43212 can be raised and lowered through the track changing mechanism 44. The lower end of the swing rail 43212 is a funnel shape that is easy to guide, allowing the guide wheel 23 on the carrier 2 to pass smoothly.

[0168] The track-changing mechanism 44 is installed at the bottom of the straight track 431 on the RX side and is mainly used for switching the height of the swing track 43212. The track-changing mechanism 44 is preferably a purely mechanical structure, without an independent power source and control system. This eliminates the possibility of incorrect positioning of the swing track 43212, resulting in fewer potential failure points, higher reliability, and lower cost. Furthermore, it eliminates the risk of contaminating the reactor pool by eliminating pollutants. In this embodiment, the track-changing mechanism 44 can be triggered by contact blocks at corresponding positions on the transfer trolley 1 to control the switching of the swing track 43212 between the lowering and raising positions. When the swing track 43212 is in the lowering position, the guide wheels 23 on both sides of the carrier 2 run along the track of the arc-shaped track 4321 on the RX side through the guide openings of the swing track 43212, thereby achieving the flipping of the carrier 2 between the vertical and horizontal positions. When the swing track 43212 is in the raising position, the transfer trolley 1 can carry the carrier 2 under the swing track 43212. When the swing rail 43212 is in the descending position, the support positioning block 4322 at the bottom of the swing rail 43212 is inserted into the groove of the support positioning part 4313, which can effectively prevent the swing rail 43212 from swinging left and right and improve the left and right rigidity of the swing rail 43212. The bottom surface of the swing rail 43212 contacts the top surface of the support positioning part 4313, and the guide wheel 23 of the carrier 2 can enter the RX side arc rail 4321. When the carrier 2 passes the swing rail 43212, part of its weight is transferred to the RX side straight rail 431 through the support positioning part 4313, and is not borne by the track changing mechanism 44. The track-changing mechanism 44 can adopt various structures to adjust the swing rail 43212, as long as it can switch between the lowering position and the raising position. When the track-changing mechanism 44 is a purely mechanical structure, it can be triggered by setting a corresponding component on the transfer trolley 1 or by setting a corresponding component on the carrier 2. The track-changing mechanism 44 can also be an electromagnetic or electric structure. Its specific structure and corresponding triggering method can adopt relatively mature existing technologies. This invention does not limit its structure or the triggering component adapted to its structure.

[0169] The RX-side tilting track 432 is structurally similar to the KX-side tilting track 412, but the RX-side arc-shaped track 4321 can swing, and the height of the flared end of the RX-side arc-shaped track 4321 can be changed by the track-changing mechanism 44. The swing of the RX-side arc-shaped track 4321 can be achieved through the hinge point or by relying on the elastic deformation of the arc-shaped track itself. The hinge point can be located at the upper or lower part of the RX-side arc-shaped track 4321.

[0170] See Figure 6 , Figure 6 This is a schematic diagram of the push-pull drive mechanism 3 according to an embodiment of the present invention. The push-pull drive mechanism 3 in this embodiment can be a rigid push chain structure, a steel cable structure, or a gear and rack structure, etc., as long as it can realize the pushing and pulling action of the transfer trolley 1; its specific form is not limited. Preferably, it is a rigid push chain structure, which can be installed and fixed on the side wall of the spent fuel pool to provide power to the transfer trolley 1. It adopts a modular structure, including a drive component 31 and a transmission component 32, divided into upper and lower parts. After the upper and lower parts are separated, both can be lifted out of the spent fuel pool as a whole, facilitating maintenance. The upper drive component 31 includes a motor 311, a reducer 312, and a first drive shaft 313. The reducer 312 is connected to both the motor 311 and the first drive shaft 313. The motor 311 and the reducer 312 are bolted together and installed on the side of the spent fuel pool. The lower transmission component 32 is installed on the side wall of the spent fuel pool via a quick-installation structure 34. The transmission component 32 includes a chain magazine 321, a rigid chain 322, and a second drive shaft 323. The rigid chain 322 is installed inside the chain magazine 321. One end of the second drive shaft 323 is connected to the first drive shaft 313 via a quick connector 33, and the other end of the second drive shaft 323 is connected to the rigid chain 322 via a steering mechanism. The rigid chain 322 inside the chain magazine 321 can be a single chain with a central arrangement or a double chain arrangement with both sides. A single chain arrangement in the middle is preferred due to its simplicity and avoidance of cumulative error issues associated with double chains. The rigid chain 322 is connected to the transfer trolley 1 via a quick-release structure and can be disassembled and reassembled remotely using a long-handled tool. The drive component 31 may also include an emergency handwheel 314 connected to the first drive shaft 313. In the event of a failure in the motor 311 or control system, the emergency handwheel 314 can be used to pull the transfer trolley 1 back to the spent fuel pool for reset. The drive component 31 is installed above the water surface of the spent fuel pool, while the underwater component 32 is a purely mechanical transmission component, ensuring high reliability.

[0171] The transfer trolley 1 of this invention can travel on the transfer track 4 (including the KX side straight track 411, the RX side straight track 431, and the inner track 421) to complete the transfer task of the fuel assembly 8. In this embodiment, the transfer track 4 includes a bottom surface, side surfaces, and an open top surface. The traveling wheels 12 are supported on the bottom surface, providing support for the transfer trolley 1 and enabling the transfer trolley 1 to travel on the transfer track 4 (including the KX side straight track 411, the RX side straight track 431, and the inner track 421). The traveling guide wheels 13 contact the side surfaces and roll along them, providing left-right guidance for the transfer trolley 1. The transfer trolley 1 is engaged within the top surface to prevent accidental derailment. The rigid chain 322 provides power to the transfer trolley 1. The rigid chain 322 drive structure has low requirements for track machining and debugging precision, thereby effectively reducing manufacturing costs, assembly and debugging costs, and maintenance costs. Furthermore, the rigid chain 322 drive system operates without power alternation, eliminating the risk of jamming and power failure.

[0172] See Figures 7-8B , Figure 7 This is a schematic diagram of the installation of the carrier 2 and the transfer trolley 1 according to an embodiment of the present invention. Figure 8A This is a schematic diagram of the structure of the transfer trolley 1 according to an embodiment of the present invention. Figure 8B for Figure 8A A top view. The transfer trolley 1 of this embodiment includes a body 11 and traveling wheels 12 and traveling guide wheels 13 mounted on the body 11. The body 11 is a rectangular cavity structure with an open upper section, including a base plate 111, a rear side wall 112, a front side wall 113, a left side wall 114, and a right side wall 115. One end of the body 11 is connected to a push-pull drive mechanism 3. The end of the base plate 111 away from the push-pull drive mechanism 3 has a hole 1111 for the carrier 2 to flip and pass through. Multiple traveling wheels 12 and traveling guide wheels 13 are respectively mounted on the left side wall 114. On the left and right side walls 115, the transfer trolley 1 travels across the discontinuous transfer track 4 via the traveling wheels 12 and the traveling guide wheels 13. The number of traveling wheels 12 and traveling guide wheels 13 installed on the left and right side walls 115 can be adjusted according to actual needs to adapt to different working environments and track configurations. The left and right side walls 114 and 115 of the vehicle body 11 are respectively provided with concentric hinge holes 14 for connecting the carrier 2. The hinge shaft 25 of the carrier 2 passes through the hinge hole 14, and the carrier 2 can rotate around the hinge shaft 25. The hinge hole 14 is located at the front of the vehicle body 11.

[0173] See Figure 9A and Figure 9B , Figure 9A This is a schematic diagram of the carrier 2 structure according to an embodiment of the present invention. Figure 9BThis is a schematic diagram of the structure of the carrier 21 according to an embodiment of the present invention. The carrier 2 of this embodiment includes a carrier 21, comprising a left side plate 211, a right side plate 212, a rear side plate 213, a front side plate 214, and a base plate 215. The left side plate 211, right side plate 212, rear side plate 213, and front side plate 214 are respectively connected to the base plate 215 and form a rectangular box with an opening at the top and front. The rectangular box is used to accommodate the fuel assembly 8 to be transferred. Guide angles 216 are provided at the top and front opening of the carrier 21 to facilitate the entry of the fuel assembly 8. The left side plate 211, right side plate 212, and rear side plate 213 are of equal height, and the height of the front side plate 214 is preferably 3% to 5% of the height of the rear side plate 213. The height of the front side plate 214 is twice the height of the lower tube seat 82 of the fuel assembly 8; guide wheels 23 are symmetrically installed on the left side plate 211 and the right side plate 212 near the top; hinge shafts 25 are symmetrically installed on the left side plate 211 and the right side plate 212 near the bottom; the carrier 21 is mounted on the transfer trolley 1 via the hinge shaft 25 and rotates around the axis of the hinge shaft 25 to achieve conversion between vertical and horizontal positions; and an anti-tipping mechanism 22 is installed on the side of the left side plate 211 and / or the right side plate 212 near the front opening and located near the top, for use together with the front side plate 214 to prevent the fuel assembly 8 to be transferred from falling out of the front opening.

[0174] This embodiment also includes multiple reinforcing ribs 24, which are arranged parallel to each other on the outer surfaces of the left side plate 211, the rear side plate 213, and the right side plate 212. These ribs prevent expansion and deformation at the front opening of the carrier 21, improve the rigidity of the carrier 2, and effectively protect the fuel assembly 8 during transport. The reinforcing ribs 24 are preferably U-shaped integral structural components. The distribution of the reinforcing ribs 24 can be determined based on the degree of deformation at the opening of the carrier 21 during the carrier 2's flipping process. The reinforcing ribs 24 are more densely distributed in the upper and middle regions of the carrier 21, while their distribution in other areas is sparser. That is, the distribution density of the reinforcing ribs 24 is adapted to the degree of deformation at the opening of the carrier 21 during the carrier 2's flipping process. The spacing between adjacent reinforcing ribs 24 in the upper and middle parts of the carrier 21 is smaller than the spacing in the lower part of the carrier 21. When the carrier 2 is in a horizontal state, the U-shaped bottom of the reinforcing rib 24 contacts the bottom plate 111 of the vehicle body 11. The weight of the carrier 2 and the internal fuel assembly 8 is directly applied to the transfer trolley 1. The rear side wall 112 of the transfer trolley 1 can prevent the fuel assembly 8 from escaping from the carrier 2 when the carrier 2 is in a horizontal state.

[0175] See Figure 9C and Figure 9D , Figure 9C This is a schematic diagram of the installation of the anti-tipping mechanism 22 according to an embodiment of the present invention. Figure 9D for Figure 9C A partial enlarged view. The anti-tipping mechanism 22 of this embodiment includes: a limiting plate 221, symmetrically mounted on the left side plate 211 and the right side plate 212 respectively via fixing blocks 222. The fixing blocks 222 are symmetrically arranged and mounted on the left side plate 211 and the right side plate 212. Preferably, the limiting plate 221 and the fixing blocks 222 are close to the guide wheel 23 and located above the guide wheel 23, or located at the middle position between the guide wheel 23 and the top of the support body 21. The limiting plate 221 is provided with two holes, one hole is hinged to the fixing block 222, and the other hole is hinged to the upper pull rod 223. The limiting plate 221 has an open position and a retracted position relative to the fixing block 222. The distance from the limiting plate 221 to the top of the support body 21 is a certain percentage of the height of the support body 21. 3% to 4%, preferably, the limiting plate 221 is located at the middle position of the upper pipe seat 81 of the corresponding fuel assembly 8; the transmission mechanism includes an upper pull rod 223, a lower pull rod 225 and a pull rod reset member 224, the two ends of the upper pull rod 223 are respectively connected to the limiting plate 221 and the lower pull rod 225, the pull rod reset member 224 is respectively connected to the upper pull rod 223 and the lower pull rod 225, the pull rod reset member 224 is preferably a pull rod spring, the lower pull rod 225 passes through the holes on the pull rod spring and the reinforcing rib 24, one end is hinged to the upper pull rod 223 and the other end is hinged to the base 228; and a control mechanism is set on the bearing base plate 215 and connected to the transmission mechanism, used to control the limiting plate 221 to switch between the open position and the retracted position.

[0176] In this embodiment, the control mechanism includes a base 228, a support block 227, and a base reset component 229. The rear end of the base 228 is hinged to the bearing base plate 215 via a hinge block 226. The hinge block 226 is mounted on the bearing base plate 215, and the base 228 is hinged to the hinge block 226, allowing the base 228 to rotate around the hinge point. The support block 227 is mounted on the bearing base plate 215 corresponding to the front end of the base 228. Preferably, there are two hinge blocks 226 and two support blocks 227, respectively mounted at the four corners of the bearing base plate 215. The base reset component 229 is located between the base 228 and the bearing base plate 215. 229 is preferably a base spring, located at the midpoint of the base 228 and the supporting base plate 215 near the front. Under the action of the base spring, the base 228 can swing up and down around the hinge point. The lower end of the pull rod 225 is connected to the base 228 and, together with the base reset member 229, drives the base 228 to swing up and down around the hinge point. The base 228 has a pressed position and a released position relative to the supporting base plate 215. When the base 228 is in the pressed position, the limiting plate 221 switches to the open position; when the base 228 is in the released position, the limiting plate 221 switches to the retracted position. The fuel assembly 8 is placed on the base 228, and the limiting plate 221 swings out to the open position to prevent it from tipping over. When the fuel assembly 8 is lifted, the limiting plate 221 automatically resets to the retracted position under the action of the control mechanism. The swinging out and retraction of the limiting plate 221 are achieved passively through a mechanical structure, which is simple, safe, and reliable.

[0177] During operation, the KX-side tilting track 412 enables the carrier 2 to switch between horizontal and vertical positions within the fuel building. The RX-side tilting track 432 enables the carrier 2 to switch between horizontal and vertical positions within the reactor building. When the carrier 2 tilts to the vertical position, it comes into contact with the RX-side upper limit beam 43231 and the RX-side lower limit beam 43232, thus mechanically stopping the transfer trolley 1. The transfer trolley 1, through mechanical limiting, is sensorless, low-cost, and highly reliable, while effectively preventing the risk of the transfer trolley 1 exceeding its limits and damaging the fuel assembly 8. The carrier 2's tilting mechanism is a simply supported structure with strong constraints, making it more reliable than a single-axis tilting structure, and preventing the fuel assembly 8 from falling.

[0178] See Figures 10-12 , Figure 10 This is a schematic diagram of a fuel assembly 8 according to an embodiment of the present invention. Figure 11 This is a schematic diagram of the offset method for loading fuel assembly 8 according to an embodiment of the present invention. Figure 12This is a schematic diagram of the offset method for removing fuel assembly 8 according to an embodiment of the present invention. During the unloading process, fuel assembly 8 is transported from the RX side to the KX side. The transfer trolley 1 and the carrier 2 are stored in the fuel building, with the carrier 2 in a vertical position. As the transfer trolley 1 moves towards the reactor building, the guide wheel 23 of the carrier 2 moves downward along the arc-shaped rail 4121 on the KX side. The carrier 2 rotates around the hinge shaft 25 until it reaches a horizontal position. At this point, the guide wheel 23 of the carrier 2 disengages from the arc-shaped rail 4121 on the KX side. Subsequently, the transfer trolley 1, carrying the carrier 2, continues to pass through the transfer channel 42 to reach the reactor building. The track-changing mechanism 44 is triggered, and the swing rail 43212 of the RX side flipping track 432 descends. The transfer trolley 1 stops after reaching its position.

[0179] The transfer trolley 1 carries the carrier 2 towards the fuel plant. The guide wheel 23 of the carrier 2 enters the RX-side arc-shaped rail 4321 and moves upward along the arc-shaped rail. The carrier 2 rotates around the hinge shaft 25 until it rotates to a vertical position. The carrier 2 comes into contact with the RX-side upper limit beam 43231 and the RX-side lower limit beam 43232 and stops. At the same time, the transfer trolley 1 stops moving in place.

[0180] The loading and unloading machine uses an offset method to load fuel assemblies 8 into the carrier 2. The transfer trolley 1 moves towards the reactor building, and the guide wheels 23 of the carrier 2 move downward along the RX-side arc-shaped rail 4321. The carrier 2 rotates around the hinge shaft 25 until it reaches a horizontal position, at which point the guide wheels 23 of the carrier 2 disengage from the RX-side arc-shaped rail 4321. The track-changing mechanism 44 is triggered, and the swing rail 43212 of the RX-side tilting track 432 rises. The transfer trolley 1 stops after reaching its position.

[0181] The transfer trolley 1, carrying the carrier 2 and fuel assembly 8, moves towards the fuel plant, passing through the transfer channel 42 to reach the fuel plant. The guide wheel 23 of the carrier 2 enters the KX-side arc rail 4121 and moves upward along the KX-side arc rail 4121. The carrier 2 rotates around the hinge shaft 25 until it reaches a vertical position, at which point the transfer trolley 1 contacts the limit baffle 4114, and the transfer trolley 1 stops moving. The spent fuel pool manipulator uses an offset method to remove the fuel assembly 8 from the carrier 2 and hoist it to the storage compartment of the spent fuel pool for storage.

[0182] During the loading process, fuel assembly 8 is transported from the KX side to the RX side. After the unloading process is completed, the carrier 2 is in a vertical position. The spent pool manipulator uses an offset method to load the fuel assembly 8 into the carrier 2. The transfer trolley 1 moves towards the reactor building, and the guide wheel 23 of the carrier 2 moves downward along the arc-shaped rail 4121 on the KX side. The carrier 2 rotates around the hinge shaft 25 until it is reversed to a horizontal position, and the guide wheel 23 of the carrier 2 disengages from the arc-shaped rail 4121 on the KX side. Subsequently, the transfer trolley 1, carrying the carrier 2, continues to rotate through the transfer channel 42 to reach the reactor building. The track-changing mechanism 44 is triggered, and the swing rail 43212 of the RX side tilting rail 432 descends. The transfer trolley 1 stops after reaching its position.

[0183] The transfer trolley 1 carries the carrier 2 towards the fuel plant. The guide wheels 23 of the carrier 2 enter the RX-side arc-shaped rail 4321 and move upward along the RX-side arc-shaped rail 4321. The carrier 2 rotates around the hinge shaft 25 until it rotates to a vertical position. The carrier 2 comes into contact with the RX-side upper limit beam 43231 and the RX-side lower limit beam 43232 and stops. At the same time, the transfer trolley 1 stops moving in place.

[0184] The loading and unloading machine uses an offset method to remove the fuel assembly 8 to be loaded from the carrier 2 and hoist it to the pressure vessel. The transfer trolley 1 moves towards the reactor building, the guide wheel 23 of the carrier 2 moves downward along the RX side arc rail 4321, the carrier 2 rotates around the hinge shaft 25 until it rotates to a horizontal state, the guide wheel 23 of the carrier 2 disengages from the RX side arc rail 4321, the track changing mechanism 44 is triggered, the swing rail 43212 of the RX side flipping track 432 rises, and the transfer trolley 1 stops after it reaches its position.

[0185] The transfer trolley 1, carrying the carrier 2, moves towards the fuel plant, passing through the transfer channel 42 to reach the fuel plant. The guide wheel 23 of the carrier 2 enters the KX side arc rail 4121 and moves upward along the KX side arc rail 4121. The carrier 2 rotates around the hinge shaft 25 until it rotates to a vertical position, at which point the transfer trolley 1 contacts the limit baffle 4114, and the transfer trolley 1 stops moving.

[0186] This embodiment uses the aforementioned carrier 2 and employs an offset method to load and unload the fuel assembly 8, including the following steps:

[0187] like Figure 11As shown, in the loading step, the carrier 2 is positioned vertically, and the lifting device 7 is used to lift the fuel assembly 8 and quickly lower it to near the upper edge of the front side plate 214 of the carrier 2. The fuel assembly 8 is then moved horizontally into the carrier 2 through the opening of the front side plate 214 and slowly lowered. When the fuel assembly 8 is in place, the limiting plate 221 of the anti-tipping mechanism 22 is triggered to swing out to the open position. The limiting plate 221 and the front side plate 214 work together to prevent the fuel assembly 8 from falling out of the front opening. After the fuel assembly 8 is loaded, the lifting device 7 releases the fuel assembly 8 and leaves. In this embodiment, when the fuel assembly 8 descends to its position, the pull rod spring and the base 228 spring are compressed, the base 228 is flattened and contacts the support block 227, and at the same time the base 228 drives the pull rod 225 to pull the upper pull rod 223 downward. The upper pull rod 223 drives the limiting plate 221 to swing out to the open position. The limiting plate 221 and the front side plate 214 work together to prevent the fuel assembly 8 from falling out of the front opening of the carrier 2. After the fuel assembly 8 is loaded, the lifting device 7 releases the fuel assembly 8 and resets to the initial state.

[0188] like Figure 12 As shown, in the material handling step, the carrier 2 is positioned vertically, the lifting device 7 grabs the fuel assembly 8 and slowly lifts it above the upper edge of the front side plate 214, while the limiting plate 221 of the anti-tipping mechanism 22 returns to the retracted position; the fuel assembly 8 moves horizontally out from the front opening; the lifting device 7 quickly lifts the fuel assembly 8 away, and the material handling of the fuel assembly 8 is completed. In this embodiment, the base 228 is lifted under the action of the base 228 spring, and the pull rod 225 is lifted at the same time. The pull rod spring returns to its original position, the limiting plate 221 retracts under the action of the pull rod spring, and after the fuel assembly 8 moves horizontally out from the front opening of the carrier 2, it is quickly lifted away by the lifting device 7.

[0189] This fuel assembly loading and unloading offset method solves the problem of low efficiency in loading and unloading fuel assemblies 8 into and out of the carrier 2. The fuel assembly 8 descends or rises from an open position on the outside of the carrier 2, with no objects around it causing friction. Therefore, the fuel assembly 8 can descend and rise rapidly. Only after entering the carrier 2 does the speed of the fuel assembly 8 need to be controlled to avoid friction with the sides of the carrier 21; that is, only 3% to 5% of its total length requires a slow descent, thus greatly shortening the time for descent and lifting. Simultaneously, the fuel assembly 8 enters and exits the carrier 2 using a translational method, resulting in short distances and less time spent, effectively improving the loading and unloading efficiency of the fuel assembly 8.

[0190] The method for transferring the core fuel assembly 8 of a nuclear reactor according to the present invention is implemented using the aforementioned transfer device for the core fuel assembly 8 of a nuclear reactor, and includes the following steps:

[0191] Step S100, the unloading step, further includes:

[0192] Step S110: The transfer trolley 1 with the carrier 2 installed is located in the fuel plant, and the carrier 2 is hinged to the transfer trolley 1 and located in a vertical position;

[0193] Step S120: The transfer trolley 1 moves toward the reactor building, the guide wheel 23 of the carrier 2 moves downward along the KX side arc track 4121, the carrier 2 flips to a horizontal position with the hinge shaft 25 as the center, and the guide wheel 23 of the carrier 2 disengages from the KX side arc track 4121.

[0194] Step S130: The transfer trolley 1 carrying the carrier 2 passes through the transfer channel 42 to the reactor building. The track changing mechanism 44 is triggered, causing the swing rail 43212 of the RX side flip track 432 to descend, and the transfer trolley 1 stops after it reaches its position.

[0195] Step S140: The transfer trolley 1 moves toward the fuel plant, and the guide wheel 23 of the carrier 2 enters the swing rail 43212 of the RX side flipping track 432 and moves upward along the swing rail 43212 until the carrier 2 flips to the vertical position and comes into contact with the RX side upper limit beam 43231 and the RX side lower limit beam 43231 and stops. At the same time, the transfer trolley 1 stops moving.

[0196] Step S150: The loading and unloading machine uses an offset method to load the fuel assembly 8 into the carrier 2;

[0197] Step S160: The transfer trolley 1 moves toward the reactor building, and the guide wheel 23 of the carrier 2 moves downward along the swing rail 43212 of the RX side flip track 432 until the carrier 2 flips to a horizontal position. The guide wheel 23 of the carrier 2 disengages from the swing rail 43212 of the RX side flip track 432. The track changing mechanism 44 is triggered, causing the swing rail 43212 of the RX side flip track 432 to rise, and the transfer trolley 1 stops after it reaches its position.

[0198] Step S170: The transfer trolley 1, carrying the carrier 2 loaded with fuel assembly 8, moves toward the fuel plant and passes through the transfer channel 42 to reach the fuel plant.

[0199] Step S180: The guide wheel 23 of the carrier 2 enters the KX side arc-shaped rail 4121 and moves upward along the KX side arc-shaped rail 4121 until the carrier 2 flips to a vertical position and the transfer trolley 1 stops moving; and

[0200] Step S190: The spent fuel tank manipulator uses an offset method to remove the fuel assembly 8 from the carrier 2 and hoist it to the storage compartment of the spent fuel water tank for storage.

[0201] Step S200, the loading step, further includes:

[0202] Step S210: The carrier 2 is in a vertical position, and the spent pool manipulator uses the offset method to load the fuel assembly 8 to be installed into the carrier 2;

[0203] Step S220: The transfer trolley 1 moves toward the reactor building, and the guide wheel 23 of the carrier 2 moves downward along the KX side arc track 4121 until the carrier 2 flips to a horizontal position and the guide wheel 23 of the carrier 2 disengages from the KX side arc track 4121.

[0204] Step S230: The transfer trolley 1 carrying the carrier 2 loaded with fuel assembly 8 passes through the transfer channel 42 to the reactor building. The track changing mechanism 44 is triggered, causing the swing rail 43212 of the RX side flip track 432 to descend, and the transfer trolley 1 stops after it reaches its position.

[0205] Step S240: The transfer trolley 1 moves toward the fuel plant, and the guide wheel 23 of the carrier 2 enters the swing rail 43212 of the RX side flipping track 432 and moves upward along the swing rail 43212 until the carrier 2 flips to the vertical position and comes into contact with the RX side upper limit beam 43231 and the RX side lower limit beam 43231 and stops. At the same time, the transfer trolley 1 stops moving.

[0206] Step S250: The loading and unloading machine uses the offset method to remove the fuel assembly 8 to be loaded from the carrier 2 and hoist it into the reactor pressure vessel;

[0207] Step S260: The transfer trolley 1 moves toward the reactor building, and the guide wheel 23 of the carrier 2 moves downward along the RX-side arc-shaped rail 4321 until the carrier 2 flips to a horizontal position and the guide wheel 23 of the carrier 2 disengages from the RX-side arc-shaped rail 4321; the track-changing mechanism 44 is triggered, causing the swing rail 43212 of the RX-side flipping track 432 to rise; the transfer trolley 1 stops after reaching its position.

[0208] Step S270: The transfer trolley 1 carries the carrier 2 through the transfer channel 42 to the fuel plant. The guide wheel 23 of the carrier 2 enters the KX side arc track 4121 and moves upward along the KX side arc track 4121 until the carrier 2 flips to a vertical position, and the transfer trolley 1 stops moving.

[0209] The carrier 2 of this invention adopts a simply supported structure to achieve flipping, which provides strong constraint and is more reliable than single-axis flipping structures. A push-pull drive mechanism 3 drives the horizontal transport and flipping of the carrier 2, reducing the number of control points in the entire device, effectively lowering costs and increasing reliability. The rigid push-pull drive mechanism 3 has lower requirements for the machining and debugging accuracy of the track, thus significantly reducing manufacturing, assembly, debugging, and maintenance costs. Furthermore, its operation is free from power alternation, eliminating the risk of jamming and power failure. The transfer trolley 1 uses mechanical limit stops, eliminating sensors, resulting in low cost and high reliability, while effectively preventing the risk of the transfer trolley 1 exceeding its limit and damaging the fuel assembly 8. The offset method for loading and unloading the fuel assembly 8 solves the problem of low efficiency in loading and unloading the fuel assembly 8 from the carrier 2. During loading, the spreader 7, carrying the fuel assembly 8, rapidly descends from the outside of the front opening of the carrier 2 to a predetermined height. The fuel assembly 8 then moves horizontally into the carrier 2. When the fuel assembly 8 reaches its final position, the pull rod spring and the base spring are compressed, the base 228 is flattened and contacts the support block 227, and simultaneously the limiting plate 221 swings out, allowing the spreader 7 to release the fuel assembly 8 and move away. During unloading, the spreader 7 grabs the fuel assembly 8, lifting it to a certain height. The base 228 is lifted by the base spring, while the limiting plate 221 retracts under the action of the pull rod spring. The fuel assembly 8 moves horizontally out of the front opening of the carrier 2, and finally, the fuel assembly 8 is quickly lifted away. The limiting plate 221 and the front side plate 214 work together to prevent the fuel assembly 8 from falling out of the front opening of the carrier 2. The swinging out and retraction of the limiting plate 221 are achieved by a passive method, which is simple and safe and reliable. The push-pull drive mechanism 3 is installed and fixed on the side wall of the spent fuel pool, which can provide power for the transfer trolley 1. Its upper drive component 31 is installed on the bank of the spent fuel pool by bolting. The lower transmission component is installed on the side wall of the spent fuel pool using a quick-installation structure 34. The upper and lower parts are connected by a quick connector 33. The drive component 31 is installed above the water surface of the spent fuel pool. The underwater part is a purely mechanical transmission component 32, which has no risk of failure and high reliability. It is connected to the transfer trolley 1 by a quick-installation method. It can be disassembled and assembled remotely with the help of long pole tools. After the upper and lower parts are separated, they can be lifted out of the spent fuel pool as a whole, which is convenient for maintenance.

[0210] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A reactor core fuel assembly transfer device, comprising a drive mechanism, a transfer track, a transfer trolley, and a carrier, characterized in that, The transfer track includes: The KX-side transfer track includes a KX-side straight track and a KX-side tilting track. The KX-side straight track is located inside the spent fuel pool of the fuel plant. The KX-side tilting track is located above the KX-side straight track and is used to cooperate with the transfer trolley to achieve the tilting of the carrier in both vertical and horizontal positions. The KX side is the fuel plant. The RX-side transfer track includes an RX-side straight track and an RX-side tilting track. The RX-side straight track is located in the refueling pool of the reactor building. The RX-side tilting track is located above the RX-side straight track and is used to cooperate with the transfer trolley to achieve the tilting of the carrier in vertical and horizontal positions. The RX side is the reactor building. A transfer channel runs through the containment wall between the fuel building and the reactor building. An inner track is installed within the transfer channel, with its two ends corresponding to the KX-side straight track and the RX-side straight track, respectively, to allow the transfer trolley to move smoothly across the track. The track-changing mechanism is installed at the bottom of the RX-side straight track, corresponding to the RX-side flip track, and is used to switch the height of the RX-side flip track inlet position. The driving mechanism is a push-pull driving mechanism, which is connected to the transfer trolley and drives the transfer trolley to travel along the KX side straight track, the inner track, and the RX side straight track. One end of the carrier is hinged to the transfer trolley and rotates around the hinge axis. The transfer trolley drives the carrier to switch between horizontal and vertical positions in the fuel plant and reactor plant via the KX side rotating track and the RX side rotating track, respectively, to complete the transfer of fuel assemblies. The carrier includes: The carrier includes a left side plate, a right side plate, a rear side plate, a front side plate, and a carrier bottom plate. The left side plate, right side plate, rear side plate, and front side plate are respectively connected to the carrier bottom plate and form a rectangular box with an opening at the top and front. The rectangular box is used to accommodate the fuel assembly to be transferred. Guide wheels are symmetrically installed at one end of the left and right side plates near the top; A hinge shaft is symmetrically mounted on one end of the left and right side plates near the bottom; the carrier is mounted on a transfer trolley via the hinge shaft and rotates around the axis of the hinge shaft to achieve conversion between a vertical and a horizontal position; and An anti-tipping mechanism is installed on the side of the left and / or right side plates near the front opening and at the top end, to prevent the fuel assembly to be transferred from falling out of the front opening together with the front side plates. The anti-tipping mechanism includes: The limiting plates are symmetrically installed on the left and right side plates respectively by fixing blocks, and the limiting plates have an open position and a retracted position relative to the fixing blocks; A transmission mechanism includes an upper pull rod, a lower pull rod, and a pull rod reset component. The two ends of the upper pull rod are respectively connected to the limiting plate and the lower pull rod, and the pull rod reset component is connected to both the upper pull rod and the lower pull rod. A control mechanism is disposed on the bearing base plate and connected to the transmission mechanism, and is used to control the limiting plate to switch between the open position and the retracted position.

2. The reactor core fuel assembly transfer device as described in claim 1, characterized in that, The KX-side flipping track includes a KX-side fixed frame and a KX-side arc-shaped rail. The KX-side fixed frame is symmetrically installed on both sides of the KX-side straight rail by adjusting the feet. The KX-side arc-shaped rails on both sides are respectively connected to the KX-side fixed frame on the same side. The spacing between the KX-side arc-shaped rails on both sides is adapted to the carrier. The guide wheels on both sides of the carrier run along the KX-side arc-shaped rail to realize the flipping of the carrier in vertical and horizontal positions.

3. The reactor core fuel assembly transfer device as described in claim 2, characterized in that, The RX-side flipping track includes an RX-side fixed frame and an RX-side arc-shaped rail. The RX-side fixed frame is symmetrically installed on both sides of the RX-side straight rail via adjustable feet. The spacing between the two sides of the RX-side arc-shaped rail is adapted to the carrier. The RX-side arc-shaped rail includes a fixed rail and a swing rail. The fixed rail is installed on the RX-side fixed frame. The end of the fixed rail is connected to the top of the swing rail. A support positioning block is installed at the bottom of the end of the swing rail. A support positioning part is provided on the RX-side straight rail corresponding to the support positioning block. The track-changing mechanism is installed at the bottom of the RX-side straight rail corresponding to the support positioning block. The track-changing mechanism adjusts the swing rail to switch between a descending position and a rising position. When the swing rail is in the descending position, the guide wheels on both sides of the carrier run along the track of the RX-side arc-shaped rail through the guide opening of the swing rail to realize the flipping of the carrier in the vertical and horizontal positions.

4. The reactor core fuel assembly transfer device as described in claim 3, characterized in that, The KX side straight track and the RX side straight track each include: a straight track, multiple brackets and adjustable feet. The straight track is mounted and supported on the multiple brackets, and the adjustable feet are respectively provided at the bottom of each bracket. A guide port is provided at the connection between the straight track and the inner track. A limit baffle is provided at the end of the KX side straight track, and a connecting plate is provided at the end of the RX side straight track.

5. The reactor core fuel assembly transfer device as described in claim 1, characterized in that, The control mechanism includes a base, a support block, and a base reset component. The rear end of the base is hinged to the supporting base plate. The support block is mounted on the supporting base plate corresponding to the front end of the base. The base reset component is located between the base and the supporting base plate. The lower end of the pull rod is connected to the base and, together with the base reset component, drives the base to swing up and down around the hinge point. The base has a pressed position and a released position relative to the supporting base plate. When the base is in the pressed position, the limiting plate switches to the open position, and when the base is in the released position, the limiting plate switches to the retracted position.

6. The reactor core fuel assembly transfer device as described in claim 1, characterized in that, The transfer trolley includes a body and traveling wheels and guide wheels mounted on the body. The body includes a base plate, a rear side wall, a front side wall, a left side wall, and a right side wall. The body is connected to the drive mechanism. The end of the base plate away from the drive mechanism has a hole for the carrier to flip and pass through. The traveling wheels and guide wheels are respectively mounted on the left side wall and the right side wall. The transfer trolley travels across the transfer track by means of the traveling wheels and guide wheels. The left side wall and the right side wall are respectively provided with concentric hinge holes for connecting the carrier.

7. A method for transferring core fuel assemblies in a nuclear reactor, characterized in that, The process is achieved using the reactor core fuel assembly transfer device of any one of claims 3-6, comprising the following steps: S100, the unloading procedure further includes: S110. The transfer trolley with the load-bearing device is located in the fuel plant, and the load-bearing device is hinged to the transfer trolley and located in a vertical position; S120. The transfer trolley moves toward the reactor building, the guide wheel of the carrier moves downward along the KX side arc rail, the carrier flips to a horizontal position with the hinge shaft as the center, and the guide wheel of the carrier disengages from the KX side arc rail. S130, The transfer trolley carrying the carrier passes through the transfer channel to the reactor building, the track changing mechanism causes the swing rail of the RX side flip track to descend, and the transfer trolley stops after it reaches its position; S140, the transfer trolley moves toward the fuel plant, the guide wheel of the carrier enters the swing rail of the RX side flipping track and moves upward along the swing rail until the carrier flips to a vertical position; at the same time, the transfer trolley stops moving; S150, The loading and unloading machine uses an offset method to load the fuel assembly into the carrier; S160. The transfer trolley moves toward the reactor building, and the guide wheel of the carrier moves downward along the swing rail of the RX side flip track until the carrier flips to a horizontal position and the guide wheel of the carrier disengages from the swing rail of the RX side flip track; the track changing mechanism causes the swing rail of the RX side flip track to rise, and the transfer trolley stops after it reaches its position. S170, The transfer trolley carrying the carrier loaded with fuel components moves toward the fuel plant, passes through the transfer channel and arrives at the fuel plant; S180, the guide wheel of the carrier enters the arc-shaped rail on the KX side and moves upward along the arc-shaped rail on the KX side until the carrier flips to a vertical position and the transfer trolley stops moving; and S190, the waste pool manipulator uses an offset method to remove the fuel assembly from the carrier; S200, the loading process, further includes: S210, The carrier is in a vertical position, and the spent pool manipulator uses the offset method to load the fuel assembly to be installed into the carrier; S220, the transfer trolley moves toward the reactor building, and the guide wheel of the carrier moves downward along the KX side arc rail until the carrier flips to a horizontal position and the guide wheel of the carrier disengages from the KX side arc rail; S230, The transfer trolley carrying the carrier loaded with fuel assemblies passes through the transfer channel to the reactor building, the track changing mechanism causes the swing rail of the RX side tilting track to descend, and the transfer trolley stops after it reaches its position; S240, the transfer trolley moves towards the fuel plant, the guide wheel of the carrier enters the swing rail of the RX side flipping track and moves upward along the swing rail until the carrier flips to a vertical position; at the same time, the transfer trolley stops moving; S250, The loading and unloading machine uses an offset method to remove the fuel assembly to be loaded from the carrier; S260. The transfer trolley moves toward the reactor building, and the guide wheel of the carrier moves downward along the RX-side arc-shaped rail until the carrier flips to a horizontal position, at which point the guide wheel of the carrier disengages from the RX-side arc-shaped rail; the track-changing mechanism causes the swing rail of the RX-side flipping track to rise; the transfer trolley stops after it reaches its position. S270, The transfer trolley carries the carrier through the transfer channel to the fuel plant. The guide wheel of the carrier enters the KX side arc rail and moves upward along the KX side arc rail until the carrier flips to a vertical position, and the transfer trolley stops moving.

8. The method for transferring core fuel assemblies in a nuclear reactor as described in claim 7, characterized in that, The offset method includes the following steps: In the loading step, the carrier is in a vertical position. A lifting device is used to lift the fuel assembly and quickly lower it to near the upper edge of the front side plate of the carrier. The fuel assembly is then moved horizontally into the carrier through the opening in the front side plate and slowly lowered. When the fuel assembly reaches its lowered position, the limiting plate of the anti-tipping mechanism is triggered and swings out. The limiting plate and the front side plate work together to prevent the fuel assembly from falling out of the front opening. The lifting device releases the fuel assembly and moves away, completing the loading process. In the material handling process, the carrier is positioned vertically, the lifting device grabs the fuel assembly and slowly lifts it above the upper edge of the front side plate, while the limit plate of the anti-tipping mechanism retracts; the fuel assembly is moved horizontally out from the front opening; the lifting device quickly lifts the fuel assembly away, and the material handling is completed.

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