Abstract: A system for use in a combined cycle power plant including gas and steam turbines includes a single kettle boiler and a valve system. The valve system is operated such that feedwater from a first source passes into the kettle boiler during certain operating conditions, whereas feedwater from a second source passes into the kettle boiler during other operating conditions, wherein the first and second sources have feedwater under different pressures. Rotor cooling air extracted from a compressor section of the gas turbine is cooled with the feedwater in the kettle boiler, wherein at least a portion of the feedwater is evaporated in the kettle boiler by heat transferred to the feedwater from the rotor cooling air to create steam, wherein the valve system is operated to selectively deliver the steam to a first or second steam receiving unit depending on the operating conditions.

Abstract: A system for use in a combined cycle power plant including gas and steam turbines includes a single kettle boiler and a valve system. The valve system is operated such that feedwater from a first source passes into the kettle boiler during certain operating conditions, whereas feedwater from a second source passes into the kettle boiler during other operating conditions, wherein the first and second sources have feedwater under different pressures. Rotor cooling air extracted from a compressor section of the gas turbine is cooled with the feedwater in the kettle boiler, wherein at least a portion of the feedwater is evaporated in the kettle boiler by heat transferred to the feedwater from the rotor cooling air to create steam, wherein the valve system is operated to selectively deliver the steam to a first or second steam receiving unit depending on the operating conditions.