Patent ID: 7874162

Claim:
A supercritical steam combined cycle system comprising: a gas turbine; a supercritical steam turbine system including a supercritical section, a high pressure section, an intermediate pressure section and at least one low pressure section; and a supercritical steam heat recovery steam generator for receiving exhaust gas from the gas turbine for heating fluid from the steam turbine system, said gas turbine exhaust gas flowing along an exhaust gas flow path from an entry end to an exit end of the heat recovery steam generator, wherein said heat recovery steam generator includes a supercritical evaporator arranged to supply supercritical steam to a superheater between the supercritical evaporator and the entry end of the heat recovery steam generator, steam exiting said superheater being returned to the supercritical section of the steam turbine, and a reheater disposed along said exhaust gas flow path, said reheater receiving cold reheat steam from the steam turbine system and returning reheated steam to the steam turbine system, wherein the reheater includes at least first and second sections, said first reheater section being disposed downstream of said second reheater section along said exhaust gas flow path through said heat recovery steam generator, wherein said first section of said reheater is disposed downstream of said supercritical evaporator along said exhaust gas flow path and said second section of said reheater is disposed upstream of said supercritical evaporator along said exhaust gas flow path, and wherein said first and second sections of said reheater are disposed in series flow such that cool reheat steam from the steam turbine system is received by said first section of said reheater and steam leaving the first section of the reheater is supplied to said second section of said reheater.