초록 ▼

In a method of operating a combined cycle system including a gas turbine, a steam turbine and a multi-pressure heat recovery steam generator, an improvement includes supplying gas turbine cooling duty steam from a high pressure section of the steam turbine and from an intermediate pressure evaporato

In a method of operating a combined cycle system including a gas turbine, a steam turbine and a multi-pressure heat recovery steam generator, an improvement includes supplying gas turbine cooling duty steam from a high pressure section of the steam turbine and from an intermediate pressure evaporator in the multi-pressure heat recovery steam generator, conducting the gas turbine cooling duty steam to the gas turbine for cooling hot gas turbine parts, and then returning the gas turbine cooling duty steam to an intermediate pressure section of the steam turbine. In a start-up procedure, steam is extracted from a first pass of a high pressure superheater in the multi-pressure heat recovery steam generator, mixed with steam discharged from the high pressure superheater and then supplied to the gas turbine cooling duty system. In this same start-up procedure, the gas turbine cooling duty steam is returned to the system condenser, bypassing the intermediate pressure section of the steam turbine. Related apparatus is also disclosed.

대표청구항 ▼

[ What is claimed is:] [13.] In a method of operating a combined cycle system including a gas turbine combined with a steam cycle incorporating a steam turbine and a multi-pressure heat recovery steam generator, wherein gas turbine exhaust is used in the heat recovery steam generator for reheating s

[ What is claimed is:] [13.] In a method of operating a combined cycle system including a gas turbine combined with a steam cycle incorporating a steam turbine and a multi-pressure heat recovery steam generator, wherein gas turbine exhaust is used in the heat recovery steam generator for reheating steam from the steam turbine, the improvement comprising supplying gas turbine cooling duty steam from a high pressure section of the steam turbine and from an intermediate pressure evaporator in the multi-pressure heat recovery steam generator, conducting the gas turbine cooling duty steam to the gas turbine for cooling hot gas turbine parts, and then returning the gas turbine cooling duty steam to the steam cycle; and wherein, early in start-up, prior to the availability of any cooling steam, the gas turbine hot stationary and rotating parts are cooled with filtered compressor discharge air, which, after cooling the gas turbine hot stationary and rotating parts, is discharged to the gas turbine exhaust. .Iaddend..Iadd.14. In a method of operating a combined cycle system including a gas turbine combined with a steam cycle incorporating a steam turbine and a multi-pressure heat recovery steam generator, wherein gas turbine exhaust is used in the heat recovery steam generator for reheating steam from the steam turbine, the improvement comprising supplying gas turbine cooling duty steam from a high pressure section of the steam turbine and from an intermediate pressure evaporator in the multi-pressure heat recovery steam generator, conducting the gas turbine cooling duty steam to the gas turbine for cooling hot gas turbine parts, and then returning the gas turbine cooling duty steam to the steam cycle; and wherein, during start-up, as start-up cooling steam is being established, the start-up cooling steam is bypassed around an intermediate pressure section of the steam turbine to warm the piping and valves. ddend..Iadd.5. In a method of operating a combined cycle system including a gas turbine combined with a steam cycle incorporating a steam turbine and a multi-pressure heat recovery steam generator, wherein gas turbine exhaust is used in the heat recovery steam generator for reheating steam from the steam turbine, the improvement comprising supplying gas turbine cooling duty steam from a high pressure section of the steam turbine and from an intermediate pressure evaporator in the multi-pressure heat recovery steam generator, conducting the gas turbine cooling duty steam to the gas turbine for cooling hot gas turbine parts, and then returning the gas turbine cooling duty steam to the steam cycle; and wherein, during start-up, steam is extracted from a first pass of a high pressure superheater in the multi-pressure heat recovery steam generator, mixed with steam discharged from the high pressure superheater and then supplied to the gas turbine cooling duty system. .Iaddend.