Double-layer water rod assembly structure for supercritical water cooled reactor

Abstract

The invention discloses a double-layer water rod assembly structure for a supercritical water cooled reactor, belonging to the field of parts and components of reactors. The double-layer water rod assembly structure is characterized in that a double-layer water rod structure is adopted in the supercritical water cooled reactor, and a layer of water rod wall is added, that is to say, two ends of a channel between a hanging basket and the outer wall of the assembly are communicated with an upper chamber and a lower chamber respectively; the lower end of the water rod inner pipe wall of the double-layer water rod is communicated with the lower chamber, and the upper end of the water rod outer pipe wall of the double-layer water rod is communicated with the upper chamber; a fuel channel is formed among the water rod outer pipe wall, the assembly outer wall and surfaces of fuel rods; and the fuel rods are vertically arranged in the fuel channel. Therefore, axial temperature distribution which is more uniform that that of a mode of adopting a single-layer water rod is obtained by changing the flowing mode of a working medium, and further, the axial power of the double-layer water rod assembly is distributed more uniformly. Therefore, the maximum fuel canning temperature under the same average heat-flow density condition can be reduced; and according to the double-layer water rod assembly structure, the safety of the reactor can be improved, and a space of promoting the total power of the reactor can be enlarged at the same time. The double-layer water rod assembly structure disclosed by the invention has the characteristics of simple structure and little improvement on original design.

Description

technical field [0001] The invention belongs to the field of reactor components, in particular to a double-layer water rod component structure used in a supercritical water-cooled reactor. Specifically, in the supercritical water-cooled reactor, a layer of water rod wall is added to the water rod assembly to change the flow mode of the working fluid, so as to obtain a more uniform axial temperature distribution than that of a single layer of water rod, and then make the assembly axial The power distribution is more even. Therefore, the maximum fuel cladding temperature under the same average heat flux condition can be reduced, and there can also be enough margin to increase the average heat flux. The supercritical water-cooled reactor adopts a double-layer water rod structure design, which can improve the safety of the reactor, and at the same time increase the space for increasing the total power of the reactor. It has the characteristics of simple structure and little impro...

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Problems solved by technology

[0003] The axial temperature distribution will greatly affect the neutron moderation performance in the core, and then affect the axial power distribution of the components

At present, most of the components using the water rod structure use single-layer water rods. Although materials with low thermal conductivity are used as the material of the water rod wall in this design, due to material technology and cost issues, the moderator in the water rod There will still be a large degree of temperature rise

In the 1990s, Japanese researchers proposed the design of a double-layer circular tube water rod, but it was not applied to the design of various forms of supercritical components.

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