Fuel assembly mixing grid with rectified mixing blades

Abstract

A fuel component stirring-mixing lattice provided with fairing-type stirring-mixing vanes, comprising an outer band (10) and multiple inner bands (11). The multiple inner bands (11) intersect each other to form a grating structure. The grating structure is provided with multiple hollow grating units (110). The outer band (10) encloses the periphery of the grating structure and is fixed with the inner bands (11). The grating structure is provided with multiple stirring-mixing vanes (12). The stirring-mixing vanes (12) are extended into the grating units (110) and a surface of each of the stirring-mixing vanes (12) facing the interior of the grating units (110) is provided with a diversion groove (120). The fuel component stirring-mixing lattice is capable of reducing diversion of a coolant towards the left and right of the stirring-mixing vanes, thus restricting unordered fluid flow, providing a fairing effect, and ensuring an effect in which the stirring-mixing vanes increase the thermal headroom of a fuel component.

Description

technical field [0001] The invention relates to a reactor component, in particular to a fuel assembly mixing grid with rectification-type mixing wings. Background technique [0002] A certain number of fuel rods are arranged at certain intervals (such as: 15×15 or 17×17, etc.) and fixed into a bundle, which is called a reactor fuel assembly. The reactor fuel assembly is mainly composed of an upper nozzle, a lower nozzle, and a mixing grid ( Also known as positioning grid), control rod guide tube and fuel rods. Wherein, the stirring grid is used for loading fuel rods and is composed of a plurality of inner strips and outer strips surrounding the inner strips. A plurality of inner strips intersect each other (generally orthogonal) to form a grid-like grid structure with a plurality of grid units. [0003] As we all know, the chain reaction in the nuclear reactor will produce a large amount of radioactive substances harmful to human body, such as iodine 131, cesium 137, etc. ...

AI Technical Summary

Problems solved by technology

[0005] However, there are certain limitations in the structure of the mixing blades used in the prior art, which greatly reduces the effect of improving the thermal margin

like image 3 As shown, the existing mixing blade is a triangular flat plate structure. When the coolant fluid F flows upward, it will directly hit the flat surface of the mixing blade, thereby generating a split flow. It is what we need, but the coolant fluid L and R diffused to the left and right along the surface of the stirring wing weakens the upward coolant flow, which is why the effect of the stirring wing on improving the thermal margin is reduced

In addition, the coolant fluid diffused left and right will disturb the surrounding flow field, increasing the invalid kinetic energy dissipation

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