Adjustable loop rotor air cooler and fuel gas heater

A cooling system for rotor assembly cooling air, comprising:

• a housing including a support structure and a main plenum with at least a first inlet opening at a first end and a first exhaust opening at a second end;
• a rotor air cooler positioned at least partially in the main plenum between the first and second ends such that cooling fluids may be directed to flow through the plenum and contact the rotor air cooler;
• a fuel gas heater positioned at least partially in the main plenum downstream from the rotor air cooler;
• a by-pass plenum having a by-pass inlet opening in the main plenum downstream from the rotor air cooler and a by-pass outlet opening upstream of the rotor air cooler;
• an exhaust fluid control device that controls fluid flow out of the first exhaust opening at the second end of the main plenum;
• a by-pass fluid control device that controls fluid flow into the by-pass inlet opening of the by-pass plenum;
• and
• a fan for circulating cooling fluids through the main plenum.

A method of controlling cooling of rotor cooling air and heating of fuel gas, comprising:

• passing a cooling fluid through a cooling system, wherein the cooling system comprises:
• a housing including a support structure and a main plenum with at least a first inlet opening at a first end and a first exhaust opening at a second end;
• a rotor air cooler positioned at least partially in the main plenum between the first and second ends such that cooling fluids may be directed to flow through the plenum and contact the rotor air cooler;
• a fuel gas heater positioned at least partially in the main plenum downstream from the rotor air cooler;
• a by-pass plenum having a by-pass inlet opening in the main plenum downstream from the rotor air cooler and a by-pass outlet opening upstream of the rotor air cooler;
• an exhaust fluid control device that controls fluid flow out of the first exhaust opening at the second end of the main plenum;
• a by-pass fluid control device that controls fluid flow into the by-pass inlet opening of the by-pass plenum;
• and
• a fan for circulating cooling fluids through the main plenum passing rotor cooling air through the rotor air cooler;
• passing fuel gas through the fuel gas heater;
• and
• controlling the exhaust fluid control device and the by-pass fluid control device, thereby controlling heating of the fuel gas flowing through the fuel gas heater.