HRSG Floor Pressure Control for Faster Startup

The patent applies partial action by pressurizing the HRSG to a sub-floor pressure level (lower than the required floor pressure) during the initial startup phase. This partial pressurization allows steam bypass valves to open earlier and establish steam flow through the piping system. The remaining pressure deficit is made up later by the gas turbine exhaust, achieving the required floor pressure without the time penalty of sealing to full floor pressure from the start.

The patent implements preliminary action by establishing steam flow through the bypass valves before the HRSG reaches full floor pressure. This preliminary steam flow initiates pipe warming earlier in the startup sequence, preventing the delay that would occur if the system waited until floor pressure was fully established before allowing any steam flow.

The patent applies self-service by using the gas turbine exhaust itself to make up the pressure difference after sub-floor pressurization. Instead of requiring external pressurization equipment or mechanical means, the system utilizes its own exhaust gas to reach the required floor pressure level, eliminating the need for additional capital equipment while maintaining fast startup performance.

The patent changes the pressure parameter dynamically during startup by first operating at a sub-floor pressure level to enable early steam flow, then allowing the exhaust gas to naturally raise the pressure to the required floor level. This parameter change approach replaces expensive mechanical pressurization systems with a controlled pressure transition strategy.