A method for coupling lower head internal molten pool stratified heat transfer and external pressure vessel cooling
By coupling calculations using a multidimensional moving particle semi-implicit program and a one-dimensional system program, the coupling problem of stratified heat transfer in the molten pool inside the lower head and the external cooling system of the pressure vessel was solved. This enabled accurate prediction of the wall temperature and heat flux density of the lower head, improving the accuracy and efficiency of severe accident analysis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NUCLEAR POWER INSTITUTE OF CHINA
- Filing Date
- 2026-03-13
- Publication Date
- 2026-07-17
AI Technical Summary
The existing technology lacks a coupled calculation method for the layered heat transfer process of the molten pool inside the lower head and the operation process of the external cooling system of the pressure vessel, resulting in insufficient accuracy in simulating the heat transfer from the molten pool to the lower head and making it difficult to accurately predict the risk of the lower head melting through.
A multidimensional moving particle semi-implicit program is used to simulate the stratified heat transfer of the molten pool inside the lower head, combined with a one-dimensional system program to simulate the external cooling system of the pressure vessel. The heat flux density and cooling amount of the lower head wall are calculated through multiple iterations until a critical value or a specified time is reached.
It achieves accurate coupled calculation of stratified heat transfer in the molten pool inside the lower head and the external cooling system of the pressure vessel, and can predict the temperature distribution and heat flux density of the lower head wall, providing accurate input parameters for the external cooling system of the pressure vessel, thus improving the accuracy and efficiency of severe accident analysis.
Smart Images
Figure CN122414014A_ABST