Fuel Flexibility of the Alstom GT13E2 Medium Sized Gas Turbine

Abstract

Today’s power generation markets require considerable flexibility in terms of type and quality of fuels. However, this must be with low emissions, high reliability and high efficiency. In more than 100 installations worldwide the Alstom GT13E2 is in use with a wide variety of fuels. Fuel flexibility is the ability to burn natural gas fuels with a wide Wobbe index range which also allows the use of fuel preheaters (to increase efficiency) as well as the ability to use fuel oil as back up or main fuel. The paper will show the allowable Wobbe index range and higher hydrocarbon effects on gas turbine combustion and the field experience gained. Specific design features implemented in the GT13E2 ensure reliable and environmental friendly operation with varying fuels. Those are: 1.) an almost entirely convectively cooled combustor with only a small amount of film cooling. 2.) the use of premix burners which are stabilized by an aerodynamically induced recirculation at the centerline and a separately controlled pilot fuel injection. 3.) an adaptive fuel staging that monitors the flame stability by pulsation measurements and adjusts the fuel staging in the combustor such that the flame is always stable but not overly rich. This results in better NOx control under varying operating conditions due to the closed-loop controlled flame stability.