Coupling analysis method of rod cluster subchannel and critical heat flux mechanism model

Abstract

The invention relates to a coupling analysis method of a rod cluster subchannel and a critical heat flux mechanism model. The coupling analysis method comprises the following steps: firstly, setting the average heat flux qo of rod cluster channels, and calculating thermo-hydraulic parameters in the channels by adopting a subchannel analysis method; secondly, when the thermo-hydraulic parameters obtained through calculation in the step 1 reach a stable state, correcting and converting the obtained subchannel thermo-hydraulic parameters into a control volume of the critical heat flux mechanism model, judging a critical heat flux occurrence type, calling a departure nucleate boiling type or dry type critical heat flux mechanism model, and solving critical heat flux qCHF; and thirdly, judgingwhether critical heat flux can occur in the hottest channel, if conditions are not met, returning to the step 1 and modifying the preset average heat flux qo of the channels, and repeating the step 1and the step 2 until the conditions are met. The coupling analysis method provided by the invention has the advantages that the critical heat flux in the rod cluster subchannel can be effectively predicted, data dependency is reduced, application range is widened, and the coupling analysis method provided by the invention is significant on design and safety analysis of a reactor.

Description

technical field [0001] The invention belongs to the technical field of reactor safety analysis, and in particular relates to a coupling analysis method of a reactor rod bundle subchannel and a critical heat flux mechanism model. Background technique [0002] In the design and safety analysis of nuclear reactors, critical heat flux is an important restrictive thermal parameter, and its size directly affects the safety and economy of nuclear reactors. The critical heat flux is the heat generated per unit area of ​​the surface of the heating element when the heat transfer mechanism of the nuclear fuel element changes due to the change of the boiling heat transfer mechanism. If the surface of the reactor fuel element boils critically, the surface temperature of the fuel element will be too high and cause heating. The wall is burnt, the radioactive material leaks, and then causes serious reactor operation accidents. Therefore, accurate prediction of critical heat flux is of great...

AI Technical Summary

Problems solved by technology

The empirical relational formula is to obtain the relationship between various parameters that affect the critical heat flux through the collation and analysis of the obtained experimental data, but most of the empirical relational formulas are developed based on a small database, for specific thermal engineering Geometric conditions, flow patterns and geometric dimensions cannot be easily extended to working conditions beyond the scope of application

The critical heat flux lookup table can directly look up the table in a wide range of parameters and obtain the critical heat flux under the corresponding parameters by interpolation, but it is only applicable to a single fluid, and extrapolated to outside the range of parameters provided by the lookup table (such as high flow rate and high supercooling degree) the prediction accuracy decreases, and the form of the data table makes it difficult to update

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