Abstract: A system is disclosed for adjusting a gas turbine firing temperature control algorithm and combustion reference temperature algorithms based on exhaust gas temperature, turbine pressure ratio and compressor discharge temperature for water content in the air entering the compressor differing from the design water content of ambient air. The water content in the ambient air is calculated by the control system from measured data from a dry bulb temperature sensor and a wet bulb temperature or humidity sensor.

Abstract: A system is disclosed for adjusting a gas turbine firing temperature control algorithm and combustion reference temperature algorithms based on exhaust gas temperature, turbine pressure ratio and compressor discharge temperature for water content in the air entering the compressor differing from the design water content of ambient air. The water content in the ambient air is calculated by the control system from measured data from a dry bulb temperature sensor and a wet bulb temperature or humidity sensor.

Abstract: A system is disclosed for adjusting a gas turbine firing temperature control algorithm and combustion reference temperature algorithms based on exhaust gas temperature, turbine pressure ratio and compressor discharge temperature for water content in the air entering the compressor differing from the design water content of ambient air. The water content in the ambient air is calculated by the control system from measured data from a dry bulb temperature sensor and a wet bulb temperature or humidity sensor.

Abstract: A system is disclosed for adjusting a gas turbine firing temperature control algorithm and combustion reference temperature algorithms based on exhaust gas temperature, turbine pressure ratio and compressor discharge temperature for water content in the air entering the compressor differing from the design water content of ambient air. The water content in the ambient air is calculated by the control system from measured data from a dry bulb temperature sensor and a wet bulb temperature or humidity sensor.

Abstract: In a combined cycle system having a multi-pressure heat recovery steam generator, a gas turbine and steam turbine, steam for cooling gas turbine components is supplied from the intermediate pressure section of the heat recovery steam generator supplemented by a portion of the steam exhausting from the HP section of the steam turbine, steam from the gas turbine cooling cycle and the exhaust from the HP section of the steam turbine are combined for flow through a reheat section of the HRSG. The reheated steam is supplied to the IP section inlet of the steam turbine. Thus, where gas turbine cooling steam temperature is lower than optimum, a net improvement in performance is achieved by flowing the cooling steam exhausting from the gas turbine and the exhaust steam from the high pressure section of the steam turbine in series through the reheater of the HRSG for applying steam at optimum temperature to the IP section of the steam turbine.

Abstract: In a combined cycle system including a gas turbine, a steam turbine and a heat recovery steam generator (HRSG), wherein gas turbine exhaust gas is used in the heat recovery steam generator for heating steam for the steam turbine, the gas turbine exhaust gas flowing from an entry end to an exit end of the HRSG, and wherein the HRSG includes at least one high pressure evaporator arranged to supply steam to a superheater including multiple passes including a first pass at one end thereof adjacent the evaporator, and a final pass adjacent an opposite end thereof and adjacent the entry end of the heat recovery steam generator, and one or more intermediate passes between the first and final passes, the improvement comprising an attemperating conduit not exposed to the gas turbine exhaust gas, connecting the one end and the opposite end of the superheater, bypassing the intermediate passes to thereby introduce cooler superheated steam from the one end into the superheater at the opposite end.

Abstract: 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.

Abstract: In a combined cycle system (10) which includes a gas turbine (12), a steam turbine (20); and at least one heat recovery steam generator (34) including evaporator(s) (38, 42, 46) operating at one or more pressures, and where condensate from the steam turbine (20) is evaporated by exhaust gas from the gas turbine (12) and returned to the steam turbine (20), the improvement comprising a closed loop cooling air circuit arranged such that hot cooling air from the gas turbine (12) is passed in heat exchange relationship with water from that one or more of the evaporators (46) in the heat recovery steam generator (34).

Abstract: In a combined cycle system including a gas turbine (412), a steam turbine (420) and a heat recovery steam generator (436), wherein gas turbine exhaust is used in the heat recovery steam generator (436) for reheating steam for the steam turbine (420), an improvement wherein steam is extracted from the high pressure section (422) of the steam turbine 420), conducted to the gas turbine (412) for cooling hot gas turbine parts, and returned to the intermediate pressure section (424) of the steam turbine (420).

Abstract: In a combined cycle power generation system which includes a gas turbine; a steam turbine; and a heat recovery steam generator which includes a superheater section and an evaporator section, and wherein condensate from the steam turbine is reheated in the heat recovery steam generator by exhaust gas from the gas turbine and returned via a main steam outlet to the steam turbine, a method of effecting start-up of the steam turbine comprising the steps of:a) dumping a portion of the gas turbine exhaust gas to atmosphere, while simultaneously introducing a remaining portion of the gas turbine exhaust gas to the heat recovery steam generator;b) with the main steam outlet from the heat recovery steam generator closed, extracting steam from an intermediate location in the superheater and supplying the extracted steam to the steam turbine at a temperature between about 550-1000.degree. F.

Abstract: In a combined cycle system including a gas turbine (12), a steam turbine (20) and a heat recovery steam generator (32), wherein gas turbine exhaust is used in the heat recovery steam generator (32) for reheating steam for the steam turbine (20), an improvement wherein steam is extracted from the heat recovery steam generator (32) at a location where steam pressure is highest, conducted to the gas turbine (12) for cooling hot gas turbine parts, and returned to the steam turbine (20) at the point of highest pressure admission.

Abstract: A combined cycle power system is disclosed in which condensate from a steam turbine is reheated in at least one heat recovery steam generator by exhaust gas from at least one gas turbine, and wherein at east one heat recovery steam generator includes at least one superheater and at least one reheater. In a preferred arrangement, the high temperature section of the superheater is located within the heat recovery steam generator so as to present first heat exchange surfaces to exhaust gas entering the heat recovery steam generator from at least one gas turbine, to thereby lower the exhaust gas temperature at the inlet to the reheater.

Abstract: This disclosure is directed toward combined cycle power plants which include at least one gas turbine and one steam turbine thermally coupled through a heat recovery steam generator (HRSG). Exhaust gas from the gas turbine is used to heat feedwater into steam for the steam turbine. One optimum criterion is to design the HRSG so that the exit temperature of the exhaust gas is at a minimum without the occurrence of sulfur condensation on the economizer tube bundles. The allowable minimum temperature varies with the sulfur content of the fuel and, hence, it would be desirable to be able to adjust the tube surface temperature as necessary in accordance with the sulfur content of the gas turbine fuel.

Abstract: A power plant arrangement having a gas turbine, a heat recovery steam generator, a steam turbine and means for controlling steam flow from the heat recovery steam generator to the steam turbine so that steam conditions are maintained generally constant and variations in power plant loading are carried by the steam turbine while operating the gas turbine at a generally constant fuel flow.

Abstract: 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.

Abstract: In a combined cycle system including a gas turbine, a steam turbine and a heat recovery steam generator (HRSG), wherein gas turbine exhaust gas is used in the heat recovery steam generator for heating steam for the steam turbine, the gas turbine exhaust gas flowing from an entry end to an exit end of the HRSG, and wherein the HRSG includes at least one high pressure evaporator arranged to supply steam to a superheater including multiple passes including a first pass at one end thereof adjacent the evaporator, and a final pass adjacent an opposite end thereof and adjacent the entry end of the heat recovery steam generator, and one or more intermediate passes between the first and final passes, the improvement comprising an attemperating conduit not exposed to the gas turbine exhaust gas, connecting the one end and the opposite end of the superheater, bypassing the intermediate passes to thereby introduce cooler superheated steam from the one end into the superheater at the opposite end.