Method of starting combined gas-and-steam power plant when the mains fails

摘要

The method involves first bringing an emergency power supply into operation and using its electrical output to supply a fresh air supply, fuel supply (37), auxiliary ignition (36) for a boiler (24), an auxiliary system and pumps. Water in the boiler is boiled and superheated, the steam drives the steam turbine (28) and the steam turbine generator (30) is switched on when a defined steam turbine speed is reached and takes over supplying power to the start-up system (22,23). The starting system powers the gas turbine (20) until its speed exceeds its ignition speed. The gas turbine generator (22) is synchronised with the steam turbine generator and the steam turbine is finally operated with the normal load gradient.