Duct fired combined cycle system

摘要

The present application provides a combined cycle system. The combined cycle system may include a heat recovery steam generator with a first low pressure section and a second low pressure section, a steam turbine with a low pressure steam section in communication with the second low pressure section of the heat recovery steam generator, and a duct burner positioned upstream of the heat recovery steam generator.

主权项

1. A heat recovery steam generator for a combined cycle system, comprising:
a high pressure section comprising a first high pressure superheater and a second high pressure superheater; an intermediate pressure section comprising a reheater; a duct burner; a steam conduit in communication with the first high pressure superheater and the second high pressure superheater; and a first set of valves and a second set of valves disposed on the steam conduit, wherein when the duct burner is unfired the first set of valves are open and the second set of valves are closed such that a flow of steam in the steam conduit is directed to the first high pressure superheater and then to the second high pressure superheater, and wherein when the duct burner is fired the second set of valves are open and the first set of valves are closed such that the flow of steam is directed to the second high pressure superheater and then to the first high pressure superheater; wherein the first high pressure superheater is positioned upstream of the duct burner, wherein the second high pressure superheater is positioned immediately downstream of the duct burner, wherein the reheater is positioned immediately downstream of the second high pressure superheater.