Studies on geometrical effect on sodium aerosol characteristics in cover gas region

Abstract

Sodium aerosol characteristics in the cover gas region of sodium cooled fast reactor is important for determining the heat and mass transfer phenomena from the hot sodium pool surface to the roof slab of the reactor vessel. In this study, experiments are carried out in the Test Pot-3 (TP-3) of SILVERINA loop and sodium aerosol characteristics are compared with that of Test Pot-1 (TP-1) carried out in our earlier work and with previous similar type of work available in the literature to understand the geometrical effect of sodium aerosol characteristics. The bulk cover gas temperature and sodium aerosol diameter are required as input parameters for the theoretical simulation of sodium aerosol mass concentration. An empirical relation for bulk cover gas temperature is derived and validated with our experimental results and used for other geometries. Similarly, an empirical relation for sodium aerosol diameter is arrived based on our experimental results and available published works. The theoretical model developed earlier for the prediction of sodium aerosol mass concentration is used for calculating the aerosol mass concentration for various geometries, by incorporating new relation for particle diameter and bulk cover gas temperature. The simulated mass concentration of sodium aerosol in cover gas region of various studies showed good agreement with the experimental results. The sodium aerosol mass concentration and Mass Median Diameter (MMD) increases with increase of sodium pool temperature. However, the values are strongly dependent on the aspect ratio (L/D) of cover gas geometry. It is also observed that MMD of sodium aerosols increases with increase of aspect ratio (L/D) while mass concentration increases with decrease of aspect ratio of the cover gas region. The modeling is found useful in predicting the sodium aerosol mass concentration for similar type of geometries and pool temperature.