Simulation Research on Combustion of Liquid Sodium Droplet

Abstract

Since sodium leak and sodium fire belongs to incidental accident in fast reactor. This paper made the simulation research on sodium droplet combustion, which was the most fundamental one of the analysis on sodium spray fire. Referencing to the sodium droplet combustion experiment, this paper made improvement in the traditional model of the sodium droplet and researched on the initial temperature and oxygen fraction on oxidation behavior of sodium droplet. This paper used the new spherical model with cones on the sodium droplet surface and improved the spherical model used in the traditional calculation of sodium droplet. This made the simulation was closer with the actual combustion situation. According to the characteristics of the reaction between the sodium and oxygen, this paper modeled sodium droplet combustion process, which was divided into three stages, namely the surface oxidation stage, pre-combustion stage and combustion stage, set up the mathematical model, compiled the calculation program and got the regulation of the sodium droplet temperature changed with time under different initial temperatures (200–500 °C) and different oxygen fractions (4–20%). This program was validated with the sodium droplet combustion experiment. Through using the proportion γ of the sodium mass participated in the oxidation reaction to vaporizing reaction in the unit time, under the different conditions of sodium droplet combustion, this paper used different γ in different reaction stage, got the simulation results, which were consistent with the experimental data and analyzed the changing regularity of γ.