Deformable-volume-based thermal-hydraulic model for a tanks-in-series water–gas system in a vertically stratified flow. Part II: Under non-adiabatic conditions

In this paper, heat and mass transfers in a high-pressure water–gas system with a clear water–gas interface are modeled, and the concept of a pseudo-deformable heat structure is described. The model of the pseudo-deformable heat structure and water vapor bulk condensation under nearly saturated conditions has two distinguishing features. First, the heat structure contacting a deformable fluid volume is modeled as if it deforms along with the deformable fluid; due to this feature, the exact average temperature of the heat structure can be predicted. Second, the rate of change of water vapor mass in the gas dome under nearly saturated conditions is determined by a differential equation derived from the Gibbs free energy function. Then, the rate of bulk condensation is determined from the water vapor mass conservation in the gas dome. The proposed model was partially validated by comparison with the results of the MARS3.1 accumulator model at low temperature conditions.