Abstract
Ultra Supercritical (USC) power plants operate at extremely high pressures (typically above 250 bar) and temperatures exceeding 600°C to achieve maximum thermal efficiency. During boiler startup, water must be gradually introduced into the system to control thermal stress and prepare for steam generation. This process requires precise regulation of water flow under severe transient conditions. The water control valve used in this application is normally closed when the boiler is offline. Once opened, it operates continuously for approximately four hours during startup to manage controlled heating and pressure buildup. During this period, the valve experiences extreme operating conditions, including: • High Differential Pressure: Upstream pressure is very high while downstream pressure is relatively low, creating a large pressure drop across the valve. • Flashing and Two-Phase Flow: As water passes through the valve and pressure falls below its vapor pressure, part of the liquid flashes into steam. This results in two-phase flow, high-velocity jets, and turbulence inside the valve. • Severe Erosion: The combination of flashing and turbulence causes significant erosion of the valve seat and plug, especially near throttling positions, leading to premature wear and compromised sealing integrity. These challenges make conventional valve designs inadequate for USC boiler startup applications, necessitating innovative solutions to protect critical components and ensure reliable operation.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Telungupalayam Ramakrishnan, Iniyankarthik; Ramasamy, Senthil; and Shahda, Joseph G., "Sacrificial integral liner Plug seating with Pressure Drop offsetting for Flashing in Globe Valves", Technical Disclosure Commons, (March 19, 2026)
https://www.tdcommons.org/dpubs_series/9560