Initiation of convection flows in the wall granular layer in the problem of boiling of subcooled coolant

Abstract

A computational model of boiling of a subcooled liquid in the wall granular layer has been developed on the basis of new experimental data on initiation and evolution of convective flows during nonstationary heating of the wall. The influence of the thermophysical properties of the batch elements on the temperature distribution in the wall region has been studied. The characteristic features of initiation of microconvection in a model cell have been revealed, and the impact of microconvection on the conditions of vapor bubble nucleation depending on the initial subcooling and the extent of the delivered heat flux has been established. New experimental data on limiting heat fluxes that cause microconvection have been obtained with the help of a gradient heat flux sensor for different combinations of the properties of the liquid and the particles of the granular layer model.