STEADY STATE MODELING OF WET STEAM IN A PIPING SYSTEM

Abstract

Current designs for steam piping systems are predicated on conservative deterministic design approaches to prevent the admission of moisture. This design approach may result in excess conservatism and larger, more inefficient components. During normal steady-state operations, the steam system operates with high-quality saturated steam, and moisture admission is not a concern. However, implementing design parameters for possible transient conditions can lead to components whose potential may never be fully utilized, adding inefficiencies. This effort seeks to identify features and physics of the piping system that can be used to challenge previous design criteria and show that off-design conditions for short durations can be mitigated. These types of features include the locations of piping bends and steam traps. This effort focuses on a steady state analysis of a wet saturated steam piping system and develops and implements a computational fluid dynamics (CFD) model for qualitatively evaluating the effect of droplet size and inlet quality on the behavior of a two-phase saturated steam flow. Additional modeling using TRAC/RELAP Advanced Computational Engine (TRACE) was performed to determine the code’s suitability for modeling a saturated steam system. The models developed in this effort will be used as the foundation for follow-on research of transient conditions.