Heat transfer to a spray droplet in a PWR pressurizer

Heat transfer rates to spray droplets under conditions corresponding to those of spray transients in a PWR pressurizer have been predicted by three different simple droplet models: the complete mixing model, the partial mixing model and the no-mixing model. In those processes, the transient responses of the partial mixing and no-mixing models have been analyzed by using the integral method, and the physical properties of the saturated steam-hydrogen gas mixture surrounding the droplets are estimated applying the concept of compressibility factor and using appropriate correlations. Typical results have been provided for the temporal variations of total heat flux with its convection and condensation heat transfer components, dimensionless droplet bulk temperature and droplet flight distance. The effects of ambient pressure, initial droplet size, concentration of hydrogen gas in the mixture, initial injection velocity, and spray angle on the heat transfer of spray droplets have been discussed. (author)