Patent ID: 11879364
Assignee: POWERPHASE INTERNATIONAL, LLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 6:
7. A system for preheating a power augmentation system comprising:
a gas turbine engine comprising a compressor coupled to a turbine by a shaft, the compressor and the turbine in fluid communication with one or more combustors;
a heat recovery steam generator in selective fluid communication with the gas turbine engine;
a steam turbine in fluid communication with the gas turbine engine;
steam injection piping connecting the gas turbine engine to the heat recovery steam generator, the steam injection piping comprising a steam injection valve, a steam vent valve, a steam vent for venting steam from the steam vent valve to atmosphere, and an isolation valve;
an air vent and an air vent valve in communication with the steam injection piping; and,
an auxiliary source of compressed air comprising:
a fueled engine coupled to a multi-stage compressor, the fueled engine configured to produce exhaust heat;
a recuperator receiving compressed air from the multi-stage compressor and configured to heat the compressed air with the exhaust heat; and,
an air injection valve located between the recuperator and the steam injection piping;

a steam injection mode wherein the air injection valve is closed and each of the steam injection valve and the steam vent valve are opened upon the steam injection piping reaching a predetermined temperature to permit a first flow of steam from the heat recovery steam generator to flow into the gas turbine; and,
a steam-air injection mode wherein the air injection valve remains open and each of the steam injection valve and the steam vent valve are opened upon the steam injection piping reaching a predetermined temperature to permit both a second flow of steam from the steam turbine and the compressed air from the multi-stage compressor to form a mixed flow and flow into the gas turbine;
wherein injection of the mixed flow in the steam-air injection mode is a more efficient use of steam than injection of the first flow in the steam injection mode.