143 results about "Spacer grid" patented technology

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.

A grid strap includes a spacer grid spring that increases the conformal contact area with a fuel rod of a nuclear fuel rod assembly. The shape of the spacer grid spring of the grid strap which is in contact with the fuel rod is optimized, thereby the elasticity of the spacer grid spring contacting the fuel rod is increased, the conformal contact area with a contact portion of the spacer grid spring contacting the fuel rod when the fuel rod is inserted into each cell of a spacer grid is expanded to obtain uniform stress distribution, and excessive plastic deformation of the spacer grid spring can be reduced. Further, magnitude and distribution of contact pressure between the fuel rod and the spacer grid spring are improved, thereby reducing the possibility of fretting wear caused by contact between the fuel rod and the spacer grid spring. The elastic behavior region of the spacer grid spring is expanded, so that the fuel rod can be reliably supported until the lifetime of the fuel rod expires despite changes in the supporting conditions of the fuel rod.

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.

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.

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.

Disclosed are a bottom spacer grid with a louver on a spring that can filter debris flowed through a channel of a lower end fitting with coolant on the lower end fitting of a nuclear fuel assembly, and can prevent uplift of fuel rods due to coolant, simultaneously.The bottom spacer grid for debris filtering with the louver for preventing uplift of the fuel rods, in the spacer grid equipped with a strip dividing a plurality of unit grid cells and a plurality of springs, protruded in uniform directions of each of vertical and horizontal directions on a grid surface of the strip, having uniform elasticity and supporting a lower end cap of a nuclear fuel rod, which includes: a spring having a plane portion with a predetermined size to contact to an outer circumference of the bottom end cap of the nuclear fuel rod; a louver protruded downward the spacer grid at a predetermined angle from the plane portion of the spring; and a debris filtering member bent and protruded to the bottom of the grid surface of the spacer grid.

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.

The invention relates to a clamping jig and a system for inspecting spacer grids for a nuclear fuel assembly. The jig firmly and precisely clamps a variety of spacer grids on a measurement stage moving at high speed using a non-contact measurer. The clamping jig includes a frame having a plurality of holding recesses into which the corresponding spacer grids are inserted, supporting means mounted in each holding recess of the frame to allow each spacer grid to be adjusted from below so it can be maintained in a horizontal state, clamping means installed around each holding recess to clamp two adjacent sides of each spacer grid to a corner of the respective holding recess, and resilient means installed on the sides opposite the clamping means and resiliently supporting the other two sides of each spacer grid. According to the present invention, the variety of spacer grids having flexible shape or size can be held by the clamping jig of the invention, so that a plurality of spacer grids can be inspected at a time. As a result, it is possible to improve work efficiency.