Method and apparatus for warming a steam turbine in a combined cycle power plant

Abstract

A combined cycle gas turbine power plant uses compressed air bleed from the gas turbine compressor discharge air as a source of warming air for the steam turbine at start-up by incorporating a bypass line from the compressor discharge to the steam chest. During this time period, the steam produced by the heat recovery steam generator is dumped to the condenser. After warming the steam turbine, the compressed air is directed to the heat recovery steam generator for discharge to atmosphere. Once the heat recovery steam generator is capable of generating steam at sufficient temperature and pressure for introduction into the steam turbine, a control valve in the bypass line is closed, thereby eliminating the warming air, and a control valve in the steam supply line from the heat recovery steam generator to the steam turbine is opened so that the steam turbine can be brought on line.

Dependencies are inferred from the claim text.