Patent ID: 8483929

Claim:
A method of controlling a gas turbine operation, the method comprising: receiving an inlet-air in a compressor of a gas turbine, wherein the gas turbine produces an exhaust-gas; providing an air preheating system comprising at least one heat exchanging section, wherein the air preheating system heats the inlet-air before the inlet-air flows to the compressor; receiving an operating target range, wherein the operating target range comprises at least one of: an extended turndown range, a gas turbine efficiency, an output, a heatrate and an emissions target; utilizing a fluid to heat the inlet-air; wherein the fluid flows through at least a portion of the at least one heat exchanging section, and wherein the fluid flows from a source external to the gas turbine, the source external to the gas turbine comprising at least one of a heat recovery steam generator (HRSG), a wind turbine, a boiler, an additional gas turbine, a solar energy source, a geothermal energy source, a fuel-cell chemical reaction and a nuclear process and/or reaction; and determining whether the gas turbine is operating within the operating target range.