An experimental device for measuring heat transfer characteristics of a three-dimensional ellipsoidal melting pool

Abstract

The invention provides an experimental device for measuring a thermal exchanging feature of a three-dimensional ellipsoidal melting pool. The experimental device mainly comprises an ellipsoidal lowersealing head, an upper cylindrical connecting cylinder, an external cooling channel, an upper cover plate, a volume heating assembly and a temperature measuring assembly. The ellipsoidal lower sealinghead and the upper cylindrical connecting cylinder are welded to form the outer wall face of the melting pool, the external cooling channel is welded to the outer side of the wall face of the meltingpool, and external forced cooling is provided through cooling water. The upper cover plate is fixed to the upper part of the melting pool, and can provide adiabatic boundary conditions. The volume heating assembly fixed into the melting pool simulates a volumetric heat release source. Temperature field distribution and wall face heat flux density distribution conditions in the melting pool can beobtained through thermocouples arranged in the melting pool and on the arc wall face, and the distribution characteristics of hard shells in the melting pool can be obtained through multi-point thermocouples arranged in the arc wall face of the melting pool. The experimental device for measuring the thermal exchanging feature of the three-dimensional ellipsoidal melting pool provides an effectiveresearch method and an important basis for serious accident safety research of an ellipsoidal pressure vessel lower sealing head type reactor.

Description

Technical field [0001] The invention relates to the technical field of research on the heat exchange characteristics of a melting pool of a head under a severe accident in a nuclear power plant, and in particular to an experimental device for measuring the heat exchange characteristics of a three-dimensional ellipsoidal melting pool. Background technique [0002] When a serious accident occurs in a nuclear power plant pressurized water reactor, if the core cannot be effectively cooled, a large number of fuel assemblies and structural materials may melt to form a melt and migrate to the bottom of the pressure vessel to form a fragment bed or the lower head of the melting pool. The melting pool transfers the decay heat to the wall of the lower head. When the decay heat cannot be fully discharged, the melting pool will melt through the wall of the lower head, seriously threatening the integrity of the pressure vessel. The flow and heat transfer characteristics of the melting pool in...

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Problems solved by technology

However, due to the limited volume of the experimental section, the experimental Rayleigh number is still relatively small compared to the reactor level. In addition, the shape of the experimental device is not ellipsoidal, which is insufficient in the applicability of the marine small reactor with the lower head of the ellipsoidal pressure vessel.

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