Investigation of containment spraying characteristics based on the correction of droplet evaporation shielding effects

Abstract

Historically, the spray models in the accident analysis program are mostly based on the isolated droplet and ignore the shielding effects among droplets, which theoretically introduces some errors. This paper investigates the effect of multi-droplet shielding on spray evaporation by taking the containment spray systems as the research object. By discussing the correction factors, the law of droplet group shielding effects can be studied, and then the correction of the spray package can be realized by the self-programming. After that, the transient response characteristics of temperature and pressure in the containment before and after the model correction are studied by modeling the loss of coolant accident and main steam line break accident, respectively. And, this research tries to analyze the influence of the cell normalization model as well as spray parameters on the calculation results. The results reveal that the program can achieve more accurate prediction after being modified by the shielding effects, and the multi-cell model can capture the temperature stratification effects more accurately under accident conditions. Additionally, the spray temperature and spray sizes have an insignificant effect on the in-shell thermal hydraulics response characteristics, but the increase of the spray flow rate has a better effect on the mitigation of the temperature stratification effects and the suppression of the in-shell pressure. The research in this paper can provide some reference or research ideas for accurate modeling and safety analysis of accidents.