Patent ID: 9328668
Filing Date: 2016-05-03
CPC Classification: F01K,F02C,F22B,Y02E

Claim Text:
1. A method for operating a combined cycle power plant during a black start, the combined cycle power plant comprising a gas turbine and a steam turbine that generate alternating voltage of an assigned frequency and deliver the alternating voltage to an AC network via an electric generator connected to the gas turbine and an electric generator connected to the steam turbine, wherein flue gas of the gas turbine is used for producing steam for the steam turbine for network restoration, the method comprising: a) supplying internal consumers by the gas turbine in island mode, an operating point of the gas turbine being set for such supplying such that a minimum steam temperature is achieved for the steam turbine; b) synchronizing and ramping up the steam turbine in island mode to an operating point at which a maximum power increase is achievable, a load change of the steam turbine created from the internal consumers being compensated for by the gas turbine such that a network-side power consumption corresponds to zero MW; c) connecting consumer loads block by block; d) providing power for an increase in demanded load from the connected consumer loads via the steam turbine; e) reducing a load of the steam turbine gradually while increasing a load on the gas turbine to maintain power output from the combined cycle power plant such that load-increasing capacity of the steam turbine is increased such that a subsequent change to steam turbine operations is actuatable to accommodate an increase in load at a later time; and f) repeating steps c) to e) until a base load of the combined cycle power plant is achieved.