Abstract: A method of operating a gas turbine in which variations in power requirements are accomplished by varying the rate of steam injection into the combustor while maintaining the temperature of the fluid flowing to the turbine at a constant value. The steam injection flow rate is varied by varying the pressure in the evaporator of a HRSG that receives exhaust gas from the turbine. Preferably, the flow area of the turbine is increased so as to allow the use of especially high rates of steam injection.

Abstract: A combustor in which fuel is introduced into a combustion zone at a first acute angle with respect to the radially outward direction so as to swirl the fuel about the combustor axis, thereby improving the stability of the combustion process. Combustion air is introduced into the combustion zone at a second acute angle with respect to the radially inward direction so as to swirl the air about the combustor axis in the same circumferential direction that the fuel is swirled, with the first and second acute angles being approximately equal. By swirling the combustion air in a manner that is compatible with the swirling of the fuel, noise associated with the combustion process is reduced.