Dimensionless Analysis of Single-Phase Natural Circulation Characteristics for PWR under Ocean Condition

The dimensionless equation for a single-phase natural circulation loop has been established with the Boussinesq approximation.Through the deduction of single-phase momentum and energy equations,influencing parameter of natural circulation flow in different outside conditions has been obtained.The effect of heeling,heaving and rolling on flow variation of natural circulation has been discussed and the conservation criteria of single-phase natural circulation flow constraint have been given.This study showed that the single-phase natural circulation flow rate decreased as the heeling angle increasing.The heaving impact on the natural circulation flow rate is small as the heaving acceleration is much smaller than the gravity acceleration.In different rolling conditions,the maximum rolling angular acceleration are the same for identical flow rate oscillating amplitude.The constraint criteria of single-phase natural circulation flow can be obtained through the subcooling of heat source.