GAS TURBINE ASSEMBLY FOR POWER PLANT APPLICATION FED BY AT LEAST TWO DIFFERENT FUELS (FUEL-GAS OR FUEL-OIL) AND A METHOD FOR OPERATING THIS ASSEMBLY WHEN SWITCHING FUELS OR WHEN OPERATING THIS ASSEMBLY WITH FUEL-OIL

摘要

A gas turbine for power plant fed by a dual-fuel source; the gas turbine comprising: a compressor configured for compressing incoming air; a dual fuel source configured for selectively delivering gas fuel or oil fuel depending on different operating conditions; a combustor assembly comprising fuel gas nozzles and fuel oil nozzles configured for feeding fuel gas and fuel oil in the main flow; a fuel distribution system comprising an fuel oil line for feeding fuel oil to the fuel oil nozzles and a fuel gas line for feeding fuel gas to the fuel gas nozzles; at least the fuel gas line being provided with at least a valve configured to be closed during oil fuel only operation and a first duct between the last downstream valve and the fuel gas nozzles; a turbine configured to be driven by the hot gas for performing work on a rotor; wherein the gas turbine moreover comprises a second duct configured for feeding cooled air into the first duct during fuel oil operation wherein the cooled air has a temperature lower than the auto ignition temperature of the fuel gas.