Multi Fuel Concept of the Siemens 3A – Gas Turbine Series

To provide maximum fuel flexibility, Siemens has developed a liquid-fuel supply system for its 3A-Series gas turbines, which in addition to customary distillate can also accommodate special fuels such as naphtha and condensates, and which also enables fuel changeover during gas turbine operation. The high vapor pressure and correspondingly low flash point of naphtha and condensates necessitate a complex fuel system safety concept as well as special flushing procedures when the gas turbine is started up and shut down. The addition of water to the fuel has been shown to be an efficient method of reducing NOx emissions. This addition of water, coupled with the highly variable fuel density, places increased demands on the gas turbine control system. Moreover, it is possible to switch from natural-gas operation to fuel-oil operation and back again when the turbine is operated in the output range near base load.Copyright © 2001 by ASME