Device and method for gas turbine unlocking

A method for unlocking a rotor in an aeroderivative gas turbine following shut-down of the aeroderivative gas turbine, the method comprising:

• providing an air intake plenum of the aeroderivative gas turbine,
• providing a compressor of the aeroderivative gas turbine, the compressor comprising a compressor air intake,
• providing a combustor of the aeroderivative gas turbine,
• providing a high pressure turbine of the aeroderivative gas turbine,
• providing a power turbine of the aeroderivative gas turbine, and
• providing a forced air-stream generator,
• wherein the air intake plenum is in fluid communication with a combustion-air flow path of the aeroderivative gas turbine, the compressor air intake, and the forced air-stream generator;
• providing a shutter arrangement, arranged and controlled to selectively open and close the combustion-air flow path, wherein the shutter arrangement is provided in the combustion-air flow path through which air enters the air intake plenum;
• providing a silencer arrangement, wherein the silencer arrangement comprises a plurality of parallel arranged silencer panels, the silencer arrangement defining a plurality of air passageways such that a respective air passageway is defined between respective pairs of adjacent parallel arranged silencer panels, each air passageway having an air outlet aperture, and a respective shutter provided by the shutter arrangement is movably arranged at each air outlet aperture to selectively open and close the respective air passageway;
• and
• cooling the rotor, when the rotor is locked following shut down of the aeroderivative gas turbine, by closing the shutters of the shutter arrangement and generating an overpressure in the air intake plenum using the forced air-stream generator, the overpressure being sufficient to force pressurized air through the locked rotor of the aeroderivative gas turbine.