Method For Controlling Gas Turbine Rotor Temperature During Periods Of Extended Downtime

A method for warming the rotor of a gas turbine during extended periods of downtime comprising feeding ambient air to an air blower; extracting compressed air from the air blower (103); feeding a portion of the compressed air (104) to one side of a heat exchanger (105) and feeding steam (114) (typically saturated) from e.g. a gas turbine heat recovery steam generator, to the other side of the heat exchanger; passing the resulting heated air stream (108) from the exchanger into and through into defined flow channels formed within the rotor; continuously monitoring the air temperature inside the rotor; and controlling (109) the amount of air and steam fed to the heat exchanger (105) using a feedback control loop (113) that controls the amount of air and steam feeds to the exchanger and/or adjusts the flow rate of heated air stream into the rotor.