Fuel assemblies for light water reactors

Abstract

The invention provides a fuel assembly of a light-water reactor. The fuel assembly comprises a plurality of fuel rods and a grid rack, wherein the grid rack is separated into a plurality of grid elements which are arrayed in a rectangular array; the fuel rods are respectively inserted into the corresponding grid elements and form a plurality of rows and a plurality of arrays in parallel; and at least parts of the fuel rods are arranged in a manner of being deviated from the centers of the corresponding grid elements, so that the distance between the centers of the two adjacent fuel rods in parts of the arrays of the fuel rods is greater than the distance between the centers of the two adjacent grid elements corresponding to the two adjacent fuel rods. According to the fuel assembly of the light-water reactor disclosed by the invention, the distance between the two adjacent fuel rods can be increased after the fuel rods are eccentric and the fuel rods have a trend to be crossly arrayed; the transverse flowing resistance is reduced and the transverse flow is enhanced and a disturbance effect of the transverse flow can be sufficiently expressed; and the heat exchanging capability of fluid is enhanced and the thermo-technical residual amount is increased.

Description

technical field [0001] The present invention relates to a light water reactor, and more particularly, to a fuel assembly of a light water reactor. Background technique [0002] At present, the fuel assembly of a light water reactor is usually distributed with several grids at intervals along its length direction, and each grid includes several vertically intersecting strips and is divided into several cells by the strips, and fuel rods are inserted into these grids. Yuan Zhong. The fuel assembly also includes several conduits and upper and lower nozzles. These conduits replace the fuel rods and are inserted into some cells of the grid to ensure that the grid is fixed at positions distributed along the length of the conduits of the fuel assembly. These fuel rods and tubes are densely arrayed together with the grid and upper and lower nozzles to form a fuel assembly. [0003] like Figure 1a Shown is the arrangement of fuel rods 11 in the grid 12 in the fuel assembly of an e...

AI Technical Summary

Problems solved by technology

like Figure 1b As shown, the fluid flows through Figure 1a The velocity (Velocity) field diagram of the fuel assembly shown, from Figure 1b It can be seen that when the fluid flows through the fuel rod 11 and the grid 12, the fluid loses energy due to the wall shear stress of the viscous fluid, which will generate frictional resistance on the surface of the strip 121 and the fuel rod 11, and will form a low velocity near the surface. area, especially at low flow rates near the surface of the fuel rods 11, which deteriorates heat transfer

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