Numerical study on annular tube once-through steam generator using compressible flow model

The once-through steam generator is an essential component of the integrated nuclear power system. A compressible model with fixed boundaries was applied to study the thermo-hydraulic characteristics of an annular tube once-through steam generator. The present model follows the three fundamental conservation principles in the lumped parameters form, and adopts special method for the primary flow distribution in the annular tube. The Gear algorithm is adopted to solve the differential equations. The steady-state and transient results show that the proposed model can successfully simulate the transient processes with large disturbances in the steam generator. Comparisons between the compressible and incompressible flow models indicate that the compressible flow model is necessary to the steam generator transient simulation.

► Compressible model with fixed boundaries for the OTSG study.
► Total heat transfer rate is approximately linear to the steam mass flow rate.
► Compressible model is necessary to the steam generator transient simulation.
► Model proposed can successfully simulate the large disturbance transient of OTSG.