Development of a seven-region lumped parameter nonlinear dynamic model for U-tube recirculation nuclear steam generator

A lumped parameter nonlinear dynamic model for U-tube recirculation steam generator (UTSG) transient analysis is developed based on the conservation laws of mass, momentum and energy. UTSG is modeled by being divided into seven regions (control volumes), namely, primary-side region, steam region, waterdowncomer region, subcooled region of heated rising channel, boiling region of heated rising channel, unheated rising section and water-steam separator region, and heat transfer tube region. The model is verified with the published models. The comparison results show that the accuracy of the steady-state simulation, the trend and most amplitudes of the transient response of this model are consistent with those of the published models, which supports the reliability of this model. This model can be used for the development of the steam dump and bypass control system and as a simulation module for coupling with the primary loop system. (c) 2022 Elsevier Ltd. All rights reserved.