Method for operating a gas turbine power plant with exhaust gas recirculation

摘要

An exemplary method is disclosed for operating a gas turbine power plant with exhaust gas recirculation, in which the exhaust gas recirculation is, for example, disengaged during starting and shutting down of the gas turbine, and in which the engaging or disengaging of the exhaust gas recirculation can be carried out in dependence upon an operating state of the gas turbine. An exemplary gas turbine power plant with exhaust gas recirculation is also disclosed which can include a control element, the closing speed of which is such that the control element can be closed within a time which is less than a time for exhaust gases to flow from the turbine through an HRSG.

主权项

1. A method for operating a gas turbine power plant having exhaust gas recirculation, a gas turbine, a heat recovery steam generator (HRSG) and an exhaust gas splitter which divides exhaust gases of the gas turbine power plant into a first exhaust gas flow, for recirculation into an intake flow of the gas turbine, and into a second exhaust gas flow, for discharge to an environment outside of the gas turbine, and also having a control element for controlling the first exhaust gas flow, the method comprising:
closing the control element until achieving a permissive condition in which an entire exhaust gas flow of the gas turbine power plant is discharged as the second exhaust gas flow to the environment; opening the control element only after achieving the permissive condition in order to recirculate a portion of the exhaust gas as the first exhaust gas flow into the intake flow; and wherein the permissive condition depends on an operating state of the gas turbine, and wherein the permissive condition is an exceeding of an engagement load (Pon) of the gas turbine; and opening the control element for controlling the first exhaust gas flow only after exceeding of the engagement load (Pon) in order to recirculate the portion of the exhaust gas as the first exhaust gas flow into the intake flow.