Locating grid

Abstract

The invention provides a locating grid suitable for locating fuel rods. The locating grid comprises a grid unit with a hollow structure, wherein a fuel rod penetrates through the grid unit; an inner side wall of the grid unit is in point contact or line contact with a wall surface of the fuel rod. Therefore, the locating grid has a locating function of well fixing the fuel rod, and fluid disturbance near the locating grid is enhanced; according to the structure that the inner side wall of the grid unit is in point contact or line contact with the wall surface of the fuel rod, fluid heat transfer in an area near the locating grid is intensified, so that temperature distribution on the wall surface of the fuel rod is regular, and a phenomenon that the temperature on the wall surface of the fuel rod is greatly increased is avoided. Compared with a traditional locating grid, contact between the locating grid and the fuel rod is improved from surface contact to point contact or line contact, the influence on heat transfer of the wall surface of the fuel rod is greatly reduced, and the fuel rod is flexibly fixed. Moreover, compared with a wire winding locating mode with low heat transfer influence, the fixing effect is better.

Description

technical field [0001] The invention relates to the technical field of nuclear reactor thermal hydraulic rod bundle experiments, in particular to a positioning grid suitable for positioning fuel rods. Background technique [0002] In the experimental research on the bundle of nuclear reactors, it is necessary to locate the fuel rods such as the bundle components, and the existing common methods for positioning the bundle components are: using the traditional positioning grid to locate the rod bundle components and positioning by winding wires. [0003] Among them, using the traditional positioning grid to locate the rod bundle components is a common positioning method for nuclear reactors at present. However, the traditional positioning grid is positioned by surface contact with the rod bundle components. Because of the surface contact method, it is impossible To avoid the impact on the heat transfer of the fluid; and because the flow and heat transfer process of the rod bun...

AI Technical Summary

Problems solved by technology

[0003] Among them, using the traditional positioning grid to locate the rod bundle components is a common positioning method for nuclear reactors at present. However, the traditional positioning grid is positioned by surface contact with the rod bundle components. Because of the surface contact method, it is impossible To avoid the impact on the heat transfer of the fluid; and because the flow and heat transfer process of the rod bundle elements is much more complicated under the supercritical condition than that under the subcritical pressure, the heat transfer deterioration generally occurs in the vicinity of the traditional spacer grid, and the obtained The heat transfer data are messy (such as figure 1 shown), and the temperature of the wall surface of the rod bundle element is too high, the result is not ideal

Moreover, the fixation of the fuel rods by the traditional positioning grid is relatively rigid and inflexible, and it is easy to get stuck with the fuel rods under high temperature and high pressure conditions

[0004] Furthermore, the wire-wrapping positioning method is currently the most widely used positioning method in fast reactors. The biggest advantage is that it has less impact on heat transfer, but the wire-wrapping positioning method has the disadvantages of weak fixation and instability

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