Patent ID: 8984892
Filing Date: 2015-03-24
Classification: F01D,F01K,F02C,Y02E

Abstract:
1. A combined cycle power plant comprising: a gas turbomachine; a steam turbomachine operatively coupled to the gas turbomachine; a heat recovery steam generator (HRSG) operatively coupled to the gas turbomachine and the steam turbomachine, the heat recovery steam generator including a high pressure reheat section provided with at least one high pressure superheater and at least one reheater; and a controller operatively connected to the gas turbomachine, the steam turbomachine and the heat recovery steam generator, the controller being configured to selectively initiate a flow of steam through the heat recovery steam generator following shutdown of the gas turbomachine responsive to calculating a difference between a sensed temperature and pressure of a fluid in the at least one high pressure superheater and a superheater discharge steam temperature and determining that the calculated difference is less than a threshold value to lower a temperature of the at least one high pressure superheater and the at least one reheater and reduce development of condensate quench effects during HRSG purge of a combined cycle power plant shutdown.