A device for increasing the heat flux density at the boundary of the outer wall of a pressure vessel

Abstract

The invention discloses a device for increasing the critical heat flux density of an outer wall surface of a pressure vessel, comprises a reactor pressure vessel and a heat-insulating layer coated outside the reactor pressure vessel. A flow passage is formed between the outer wall surface and the heat-insulating layer of the reactor pressure vessel, a plurality of protrusions which are fixed on the inner wall surface of the heat-insulating layer are arranged in the flow passage, and the plurality of protrusions are out of contact and arranged in a circumferential or staggered manner. According to the invention, the staggered arrangement of the protrusions enhances the turbid effect of a fluid during the flowing process, changes the phenomenon of vapor bubble accumulation in the outer wall surface of the pressure vessel, improves the heat transfer capability of the fluid, and increases the critical heat flux density of the fluid in the corresponding position of the outer wall surface of the pressure vessel, so as to facilitate the implementation of melt retention measures in a nuclear power plant and improve the security of the nuclear power plant under accident conditions. The device disclosed in the invention has a simple structure, low manufacturing cost, low introduction resistance and high system reliability.

Description

technical field [0001] The invention relates to measures for retention of molten matter in a nuclear power plant, in particular to a device for increasing the critical heat flux outside a pressure vessel. Background technique [0002] The WASH-1400 report published in 1975 pointed out after the PRA analysis of nuclear power plants that the risks of nuclear power plants do not mainly come from design basis accidents, but from core melting accidents. For this reason, major nuclear power countries in the world require the industry to carry out severe accident research and seek countermeasures for severe accidents, so as to improve the ability of nuclear power plants to deal with severe accidents. [0003] At present, according to the characteristics of the development process of severe accidents, many strategies to deal with severe accidents have been proposed in the world. Among them, the collapse of the core melt to the lower head in a severe accident of a nuclear power plan...

AI Technical Summary

Problems solved by technology

Among them, the collapse of the core melt to the lower head in a severe accident of a nuclear power plant may cause the failure of the pressure vessel, threaten the integrity of the containment, and lead to serious consequences of leakage of radioactive materials. Therefore, maintaining the integrity of the pressure vessel and keeping the core Keeping the molten product in the pressure vessel is one of the key points in the research of mitigation measures for severe accidents

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