143 results about "Spacer grid" patented technology

A fuel assembly spacer grid including swirl deflectors respectively arranged at interconnections between interconnecting longitudinally and laterally-extending straps on upper ends of the interconnecting straps adapted to support fuel elements of a nuclear fuel assembly. Each of the swirl deflectors has four vanes bent to have an air vane shape. By virtue of this configuration, an improvement in the efficiency of the spacer grid cooling the fuel elements. The spacer grid also includes springs each configured to generate not only a main spring force caused by a displacement of the spring occurring when the spring comes into contact with a fuel element placed in a reactor core, but also an additional spring force caused by hydraulic pressure applied to the spring. Each spring, which is in a fixed state at one end thereof, has a free bent portion at the other end. By virtue of such a spring configuration, it is possible to compensate for a reduction in the initial spring force of the spring resulting from a change in the property of the spring material. The spring has a curved contact portion configured in such a manner that it is in conformal surface contact with a circumferential surface of the fuel element, thereby enhancing vibration suppressing and abrasion resistance forces.

A nuclear fuel assembly having improved dimensional stability to support aggressive fuel management wherein the fuel skeleton lateral stiffness is enhanced by the addition of a second joint attachment between the control rod guide thimble and spacer grid support sleeve.

A spacer grid used for placing and supporting fuel rods in nuclear reactor fuel assemblies is disclosed. The spacer grid of this invention has a plurality of inner strips intersecting each other to form a plurality of guide tube cells and a plurality of fuel rod cells, with a plurality of mixing blades projecting upward from the inner strips at intersections of the inner strips. The spacer grid further includes a plurality of perimeter strips to encircle the intersecting inner strips. Each of the perimeter strips is fabricated with a plurality of unit intermediate strips and a plurality of unit corner strips, with a grid spring provided on each of the unit strips. The grid spring includes a vertical opening formed at a central area of each of the unit strips, a vertical support part extending vertically between the central portions of top and bottom edges of the vertical opening, and a fuel rod support part provided at a central portion of the vertical support part while being bent to have an outward rounded cross-section. The vertical support part is bent at two steps, and the fuel rod support part is bent to be in equiangular contact with each of the fuel rods, thus accomplishing a uniform contact pressure distribution when the fuel rod support part is in contact with each of the fuel rods.

A four point contact grid for a nuclear fuel assembly, that is structured to engage at least one generally cylindrical fuel rod. The four point contact grid includes a plurality of elongated, generally flat straps including a first set of straps and a second set of straps, each strap having a plurality of cell portions. The straps are divided into a first set and a second set. The first set of straps are disposed in a spaced parallel relation to each other. The second set of straps are also disposed in a spaced parallel relation to each other and are generally perpendicular to the first set of straps. The first set of straps and second set of straps are coupled to each other thereby forming a plurality of generally square cells. Each strap cell portion has at least one protrusion. Each the strap cell portion further has only a single protrusion extending into each cell. Each the protrusion is either an elongated spring or an elongated dimple. Thus, each the fuel rod is contacted by only four protrusions in each cell.

A spacer grid for a fuel assembly in a light-water-cooled nuclear reactor, for providing the transverse retention of a bundle of fuel rods in mutually parallel arrangements, having an array of cells juxtaposed and placed in a regular lattice, each bounded and separated from neighboring cells by at least one peripheral wall which is open at two opposed ends, along the direction of an axis of the cell, so as to receive a fuel rod of cylindrical general shape passing along the cell along its axis parallel to the peripheral wall.

A spacer grid having tunable mixing vanes for optimizing coolant flow is provided for a nuclear fuel assembly. The mixing vanes include an upper piece and a lower piece, which are coupled to a middle ligament that is coupled to the top or downstream portion of one or more of the grid straps forming the spacer grid. The upper piece, lower piece, and middle ligament are bent, rotated, and / or twisted into various positions to more effectively mix the coolant and affect the coolant's flow as it moves upwards through the fuel assembly. For example, in one embodiment, the mixing vane has an “S” shape wherein the middle ligament is positioned parallel to the longitudinal axes of the fuel rods of the fuel assembly, the upper piece bends towards one of the fuel rods, and the lower piece bends away from the fuel rod. In this manner, optimized even and sustained mixing of the coolant is provided.

An improved nuclear fuel assembly having elongated grid straps curved in a substantially undulating wave pattern along their axial length and interleaved together to form an egg-crate configuration having a plurality of roughly square cells that support fuel rods and guide tube thimbles. The cells that support fuel rods have their outer walls curved outward to increase the contact area around the fuel rod cladding The interior straps are on a diagonal with regard to a peripheral strap and at least one cell adjacent each fuel rod cell is left empty for the unobstructed flow of coolant. Additional coolant mixing devices can be added to the empty cells. The walls of each fuel rod cell are devoid of dimples and, in one embodiment, springs.

A high Fe-containing zirconium composition having excellent corrosion resistance and a preparation method thereof. Specifically, disclosed are a high Fe-containing zirconium composition having excellent corrosion resistance and a preparation method thereof, the composition comprising: 0.5-1.0 wt % iron; 0.25-0.5 wt % chromium; 0.06-0.18 wt % oxygen; at least one element selected from the group consisting of 0.2-0.5 wt % tin, 0.1-0.3 wt % niobium and 0.05-0.3 wt % copper; and the balance of zirconium. The zirconium alloy has excellent corrosion resistance, and thus can be used as a material for nuclear fuel claddings, spacer grids and nuclear reactor core structures in light water reactor and heavy water reactor nuclear power plants.

An improved grid for a nuclear reactor fuel assembly that has an egg-crate base grid as the primary support structure with each support cell of the base grid that supports a fuel rod having a lock-support sleeve that is rotatable within the support cell between a first and second orientation. In the first orientation the lock-support sleeve fits loosely within the support cell of the base grid and respectively, loosely receives the fuel rods that are loaded therein. The lock-support sleeves are then rotated to a second orientation that locks the fuel rods axially within the support cells.

The automatic robot spot welding apparatus includes a welding bench including clamping frames, which are uniformly arrayed and have receiving portions for the sparer grids, and have, at both ends of the welding bench, fixing plates for the guide tubes and the instrumentation tube which are inserted into the spacer grids; a robot moving on a running rail, which is arranged in parallel to the welding bench, and having a welding gun for welding the spacer grids with the guide and instrumentation tubes; guide tube electrodes for being inserted into the guide tubes for the spot welding; an instrumentation tube electrode for being inserted into the instrumentation tube; and a controller having an apparatus control block and a robot control block for controlling components based on a program stored therein.

The diameter of a segment of a peripheral rod in a fuel assembly is measured between two successive spacer grids. A measuring tool is positioned at a level situated between the two successive spacer grids, the tool comprising two measuring fingers that are free to move relative to each other in a first horizontal direction and that are urged towards each other by a resilient return arrangement, and that extend in a second horizontal direction perpendicular to the first horizontal direction. The measuring fingers are moved in the second horizontal direction towards a rod so as to put two contact pieces of the measuring fingers into contact with two zones of the rod segment. The measuring fingers are moved in the vertical axial direction of the rod along its segment situated between the two spacer grids and an electromagnetic sensor is used to measure the distance between the measuring fingers in the first horizontal direction while the measuring fingers are being moved axially.

Disclosed herein are a zirconium alloy composition, which exhibits excellent corrosion resistance by varying the kinds of metal oxides and controlling the size of precipitates of the composition, including: 1.05˜1.45 wt % of Nb; one or more selected from the group consisting of 0.1˜0.7 wt % of Fe and 0.05˜0.6 wt % of Cr; and residual Zr, and a method of preparing the same. The zirconium alloy composition exhibits excellent corrosion resistance by controlling the kinds and amounts of the elements included in the zirconium alloy composition and the heat-treatment temperature and thus varying the kinds of metal oxides formed during an oxidation process and controlling the size of precipitates of the zirconium alloy, so that it can be usefully used as a raw material for nuclear fuel cladding tubes, spacer grids, nuclear reactor internals and the like of a light-water reactor or a heavy-water reactor in a nuclear power plant.

The invention discloses a tubular positioning grid frame for double-sided cooling of fuel rods in a pressurized water reactor. The positioning grid frame is formed by welding quasi-square grid units. The convex surface of the center is in contact with the outer circle of the fuel rod to form support and positioning for the fuel rod, and the grid unit is stamped or drawn from a circular tube. The invention provides a tubular positioning grid for double-sided cooling of fuel rods of a pressurized water reactor, which has simple structure, low manufacturing process technical difficulty, better economy and better safety, and is easy to install.

A spacer grid with hybrid flow-mixing devices for nuclear fuel bundle is made up of an intersection of a plurality of thin straps at right angles to form a plurality of cells for receiving and supporting fuel rods. Each strap is composed of two types of strap units, called a primary strap unit and a secondary strap unit, which are alternately arranged along the strap. The primary strap unit is a strap section having a primary vane set, and a secondary strap unit is a strap section having a secondary vane set. The straps intersect such that, by primary and secondary strap units, each intersection forms a hybrid flow-mixing device around the top of each junction. The primary vane set, consisting of a trapezoidal primary vane stand and two bent primary mixing vanes on both sides, protrudes upwardly from the strap and is primarily for generating cross flow between channels. Meanwhile, the secondary vane set, consisting of a trapezoidal secondary vane stand and two bent primary mixing vanes on both sides, also protrudes upwardly from the strap, but is primarily for swirl flow generation within the channels. The hybrid flow-mixing device induces a complex but effective flow pattern in flow channels for fuel rod cooling.

A spacer grid for dual-cooling nuclear fuel rods arranged at a narrow interval. The spacer grid solves the problem in which, since the dual-cooling nuclear fuel rods are used to improve the cooling performance and stability of nuclear fuel and obtain high burnup and output, the outer diameter of each dual-cooling nuclear fuel rod is increased, and thus the gap between each dual-cooling nuclear fuel rod and the grid strap is decreased. The spacer grid includes first grid straps and second grid straps, which are crossed and arranged in transverse and longitudinal directions at regular intervals and have the shape of a flat strip, and support structures, which are fitted into the first and second grid straps around intersections of the first and second grid straps so as to support the dual-cooling nuclear fuel rods.

An assembly device for a power supply is composed of a rectangular case which is provided with a transversal spacer grid in a horizontal direction, with an upper spacer grid and a lower spacer grid being vertically installed above and below the transversal spacer grid, to divide the rectangular case into four rectangular positioning holes; and four rectangular power supplies which are inserted and fitted into the four rectangular positioning holes respectively, such that when the four power supplies start, four fans at their front parts can be activated, thereby allowing air inside and outside the rectangular case to be able to flow uniformly.

The present invention relates to an anti-fretting wear spacer grid having a plurality of canoe-shaped springs formed thereon, wherein each of the canoe-shaped springs includes: a fuel rod-contacting part having a flat surface having a predetermined longitudinal length so as to have linear contact with the fuel rod; a curved face-connecting part formed on the upper and lower portions of the fuel rod-contacting part; a leg-connecting part formed on the end portion of the curved face-connecting part; and legs each being formed of a plate shape having a predetermined length and connecting the both sides of the leg-connecting part with one unit grid cell surface.

The invention discloses a shockproof logistics box for long-distance fruit transportation, which comprises a logistics box body, four corners of the bottom of the logistics box body are welded with connecting bases, and four corners of the top of the logistics box body are welded There are connecting grooves, and spring shock absorbers are embedded inside the connecting grooves, connecting bayonets and connecting bays are respectively welded on the shells on both sides of the logistics box body, and isolation nets are embedded alternately inside the logistics box body The grid frame and the middle partition, the top casing and the bottom casing of the middle partition are respectively equidistantly provided with a first shock-absorbing air cushion and a second shock-absorbing air cushion. In the present invention, firstly, through the isolation grid frame and the intermediate partition, the fruits placed inside the logistics box body can be separated one by one, and at the same time, the fruits on each layer can be separated to fully protect the fruits, effectively To prevent the collision of the fruit inside the logistics box body during the transportation project, resulting in damage and rot of the fruit.

The invention discloses an energy-saving and heat-dissipating photovoltaic combined switchgear, which includes a cabinet body, the cabinet body is hinged with a cabinet door, and a plurality of grid plates are fixedly connected to the inner cavity of the cabinet body, and the grid plate separates the cabinet body from top to bottom with bus bars Room, switch room and installation room, the top of the busbar room is provided with a cover plate, both sides of the cover plate are provided with exhaust ports, the top of the cover plate is provided with a trumpet-shaped air inlet, the bottom of the air inlet is provided with a water pipe, and the air inlet is close to the end of the cover plate A first ventilation pipe is fixedly connected, and the first ventilation pipe penetrates through the cover plate and the grid plate and enters the bottom of the installation room. Several first air outlets are opened on the outer wall of the first ventilation pipe, and the first ventilation pipe is fixedly connected with a second ventilation pipe. The side of the outer wall of the second ventilation pipe close to the top of the installation room is provided with a number of second air outlets, a water tank is provided at the bottom of the inner cavity of the cabinet, and ammonium nitrate particles are provided above the water tank. The invention has the beneficial effects of reducing power energy consumption and better effectively cooling the cabinet.

The nuclear fuel assembly having nuclear fuel rods and a support skeleton having two nozzles, guide tubes interconnecting the nozzles, and spacer grids for holding the rods, the grids being secured to the guide tubes. The assembly further has at least one lattice reinforcing device for reinforcing the support skeleton. The reinforcing device is placed between two spacer grids and is secured to the guide tubes. The invention is applicable to fuel assemblies for pressurized water reactors.

The invention discloses a control rod guide tube, which is inserted in a spacer grid, the control rod guide tube has a hollow tubular structure, and several flow-disturbing openings through the sidewall of the control rod guide tube are provided with the control rod guide tube. According to the flow-disturbing openings on the sidewall of the control rod guide tube, fully mixing of cryogenic fluid on a cold wall surface and hot fluid on a hot wall surface in a cold wall lattice cell occupied by the control rod guide tube can be realized, fluid on the cold wall surface in the cold wall lattice cell can participate in channel heat exchange, thereby CHF performance of the control rod guide tube can be enhanced. The flow-disturbing opening can adjust the fluid resistance when the control rod drops, further the rod-dropping performance of the control rod under accident can be improved. Correspondingly, the invention also provides a fuel assembly possessing the control rod guide tube.

The present invention relates to an apparatus and method for capturing an image of a welding spot during a welding task and determining an accurate position of the welding spot based on the captured image in order to perform an accurate welding task. A beam splitter splits a path of light reflected from a welding section of a spacer grid from a path of a laser beam generated from a laser generator. An image sensor receives light reflected from a welding spot of the spacer grid, and senses and stores an image of the spacer grid. Welding control means controls the image sensor to capture the image of the spacer grid, receives the image of the spacer grind from the image sensor, calculates an accurate position of the welding spot based on the received image, corrects position information of the welding spot based on the calculated position, and controls a servo motor so that the laser generator can accurately collimate the welding spot based on the corrected position value.

An assembly device for a power supply is composed of a rectangular case which is provided with a transversal spacer grid in a horizontal direction, with an upper spacer grid and a lower spacer grid being vertically installed above and below the transversal spacer grid, to divide the rectangular case into four rectangular positioning holes; and four rectangular power supplies which are inserted and fitted into the four rectangular positioning holes respectively, such that when the four power supplies start, four fans at their front parts can be activated, thereby allowing air inside and outside the rectangular case to be able to flow uniformly.

A bi-alloy spacer grid (BASG) is provided with grid straps and springs made using different zirconium alloys. The grid straps are made from a relatively low growth zirconium alloy, and the springs are made from a relatively high growth zirconium alloy. The springs are coupled to the grid straps by welding, mechanical interference, or secondary forming in place. When subjected to irradiation, the springs grow relative to the grid straps thereby maintaining contact with the fuel rod cladding, while the grid straps resist growth to maintain structural stability of the entire fuel assembly. The optimized balance of the high growth springs and low growth grid straps mitigates the formation of gaps between the fuel rods and grid support structures). The growth properties of the grid straps and springs may be further controlled through optional different fabrication processes.

A charging device of a welding fixture of spacer grid comprises a base frame; a conveyor for conveying a welding fixture horizontally over the base frame; and a gripper located over the base frame for gripping a welding fixture conveyed along the conveyor to charge a welding fixture into a welding chamber, wherein the gripper comprises a gripper body; and a gripping part installed horizontal to the end of the gripper body for gripping a welding fixture and capable of tilting in vertical direction to the gripper body in case more than a predetermined load is applied as a vertical load.

An apparatus and method for welding strap connections between inner grid straps of a spacer grid using a laser tool, and a spacer grid manufactured by the same, in which the strap connections between the inner grid straps of the spacer grid are seam-welded continuously or intermittently using the laser tool, so that the structural strength of the spacer grid is increased, a spattering phenomenon, in which a welded material is spattered during welding, is reduced, and thermal deformation is reduced. Further, fine welding is possible, and thus the welded bead of each strap connection between the inner grid straps can have a small size, and the number of welding defects can be reduced. In addition, the flow resistance of a coolant is reduced, and thereby the pressure drop of the coolant can be reduced As a result, the load on a flow pump for the coolant can be reduced, and economic efficiency and safety can be improved.