Patent ID: 8899008

Claim:
A system, comprising: a gas turbine engine; and an anti-icing heat recovery system, comprising: a first heat exchanger configured to receive a working fluid from an exhaust section of the gas turbine engine and to transfer heat from the working fluid to a cooled intermediate heat transfer medium to generate a heated intermediate heat transfer medium; a second heat exchanger configured to receive the heated intermediate heat transfer medium from the first heat exchanger and to transfer heat from the heated intermediate heat transfer medium to air entering the gas turbine engine; a variable speed fan configured to urge the working fluid from the exhaust section of the gas turbine engine through the first heat exchanger and to return the working fluid to the exhaust section; and a controller configured to control a fan speed of the variable speed fan based on sensor feedback indicative of an inlet temperature of the air entering the gas turbine engine and an exhaust temperature of the working fluid, wherein the controller is configured to reduce the fan speed of the variable speed fan when the exhaust temperature of the working fluid is less than or equal to a threshold acid dew point temperature, and to modulate the fan speed of the variable speed fan when the exhaust temperature of the working fluid is above the threshold acid dew point temperature and the inlet temperature of the air entering the gas turbine engine is within an anti-icing range, wherein the controller is configured to modulate the fan speed of the variable speed fan to provide anti-icing to the gas turbine engine only when the exhaust temperature of the working fluid is above the threshold acid dew point temperature.