Abstract: The gas turbine system comprises an aeroderivative gas turbine engine and a load having a shaft line drivingly coupled to the gas turbine engine. The gas turbine engine comprises a high-pressure turbine section and a high-pressure compressor section, drivingly coupled to one another by a first turbine shaft. The gas turbine engine further comprises an intermediate-pressure turbine section and a low-pressure compressor section, drivingly coupled to one another by a second turbine shaft, coaxial to the first turbine shaft (91). Furthermore, a combustor section is provided, fluidly coupled to the high-pressure compressor section and to the high-pressure turbine section. A free power turbine, supported by a third turbine shaft which is mechanically uncoupled from the first turbine shaft and the second turbine shaft, and is directly coupled to the shaft line, such that the shaft line and the third turbine shaft rotate at the same rotational speed.

Abstract: An operation method for a gas turbine is provided which includes compressing a working fluid by a compressor, feeding this compressed working fluid into at least one combustion chamber where it is overheated, expanding this overheated working fluid in at least one expansion turbine to produce energy, carrying out a first tapping of the compressed work fluid from the compressor to feed it into a first cavity of the turbine for cooling, carrying out a second tapping of the working fluid downstream from the first tapping to feed it into a second cavity of the turbine upstream from the first cavity, for cooling, and fluidly connecting the first tapping to the second tapping to selectively feed the first tapping by a part of the second tapping during partial load operation conditions to keep the temperature of the first cavity within the acceptable limits for the resistance of the materials.

Abstract: An operation method for a gas turbine including: compressing a working fluid by means of a compressor; feeding this compressed working fluid into at least one combustion chamber where it is overheated; expanding this overheated working fluid in at least one expansion turbine to produce energy; carrying out a first tapping of the compressed work fluid from the compressor to feed it into a first cavity of the turbine for cooling; carrying out a second tapping of the working fluid downstream from the first tapping to feed it into a second cavity of the turbine upstream from the first cavity, for cooling; and fluidly connecting the first tapping to the second tapping to selectively feed the first tapping by means of a part of the second tapping during partial load operation conditions to keep the temperature of the first cavity within the acceptable limits for the resistance of the materials.