METHOD FOR OPERATING A GAS TURBINE AND GAS TURBINE FOR PERFORMING THE METHOD

摘要

#CMT# #/CMT# The method involves maintaining the nitrous oxide content of the exhaust gas at a constant level via a regulated return of a portion of the exhaust gas in varying operating conditions of the gas turbine (11). The addition of the ammonia in the selective catalysis device (14) is adjusted to the constant nitrous oxide level. The exhaust gases are directed prior to the selective catalytic reduction in the selective catalytic device by a cooling device (13). #CMT# : #/CMT# An independent claim is included for gas turbine. #CMT#USE : #/CMT# Method for operating gas turbine used in combination power plant (all claimed). #CMT#ADVANTAGE : #/CMT# The combination of selective catalytic reduction (SCR) and exhaust gas recirculation (FGR) can be used effectively. The costly contamination of the exhaust gas with ammonia is reduced or avoided. The exhaust gas recirculation is controlled so that the constant nitrous oxide content in the exhaust gas is maintained at different operating conditions of the gas turbine. The addition of ammonia to the selective catalytic reduction is tailored to the held constant nitrous oxide content in the exhaust gas. The ratio of nitrous oxide to nitrogen dioxide is monitored for the selective catalytic reduction. The washing effect in direct contact cooler can increase efficiency of nitrous oxide removal depending on the ratio of nitrous oxide to nitrogen dioxide with respect to pH and oxidant additive is 10-30% and the operation of the direct contact condenser. The direct-contact condenser is arranged upstream of the separation of the exhaust gases, such that the total exhaust gas mass flow can be handled effectively. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a schematic view of the combination power plant. 10 : Combination power plant 11 : Gas turbine 13 : Cooling device 14 : Selective catalysis device 15 : Compressor.