A power plant having a gas turbine and having a heat recovery steam generator installed downstream of the gas turbine in the direction of flow of an exhaust gas, wherein the heat recovery steam generator includes heating surfaces of a high pressure section, of an intermediate pressure section and of a low pressure section, wherein an exhaust gas recirculation line branches from the heat recovery steam generator downstream of an evaporator in the flow direction of an exhaust gas in the high pressure section and opens again into the heat recovery steam generator upstream of the heating surfaces. A blower is arranged in the exhaust gas recirculation line, with a steam feed opening into the exhaust gas recirculation line downstream of the blower in the direction of flow of a recirculated exhaust gas. A method operates a power plant of this kind.

A fast HRSG starting method and apparatus for combined cycles requiring frequent cycling, baseload and backup power; preventing grid failure from variables of wind and solar power. A once-through HRSG, eliminating all except two hot thick wall components: the high pressure superheater and reheater headers. The method fills the high pressure superheater with boilerwater; whereby steam is generated in starting as thick header's and tube's ramp-up together at saturation temperatures as the gas turbine attains synchronous speed No-Load; reducing conventional thermal stress failures loss of availability and costly repairs. At gas turbine full power dry steam is generated by the high pressure superheater at low allowable temperature start and load the steam turbine and protect the reheater. The dryout zone in the high pressure superheater is controlled loading the steam turbine faster than conventional without problematic attemperators, thereby decreasing: thermal stresses, fuel, emissions and possible ingestion of spray-water.

Various embodiments include a system having: at least one computing device configured to perform actions including: measuring at least one of the following parameters: a steam pressure within a steam drum, a load on a GT, a position of a bypass valve bypassing an HRSG, and a steam flow rate through the steam drum; defining a threshold range for each of: a steam pressure within the steam drum, a load on the GT, a position of the bypass valve bypassing the HRSG and a steam flow rate through the steam drum based upon the measured data and a target steam level; and adjusting the steam flow rate through the steam drum in response to at least one of the measured parameters deviating from the corresponding threshold range.

A power plant having a gas turbine and having a heat recovery steam generator installed downstream of the gas turbine in the direction of flow of an exhaust gas, wherein the heat recovery steam generator includes heating surfaces of a high pressure section, of an intermediate pressure section and of a low pressure section, wherein an exhaust gas recirculation line branches from the heat recovery steam generator downstream of an evaporator in the flow direction of an exhaust gas in the high pressure section and opens again into the heat recovery steam generator upstream of the heating surfaces. A blower is arranged in the exhaust gas recirculation line, with a steam feed opening into the exhaust gas recirculation line downstream of the blower in the direction of flow of a recirculated exhaust gas. A method operates a power plant of this kind.

A steam turbine plant and an operating method thereof, and a combined cycle plant and an operating method thereof, include: a turbine; steam supply lines that supply main steam to the turbine; a steam control valve and an intercept valve provided to the steam supply lines; and a first auxiliary steam supply line that supplies auxiliary steam to the turbine via the steam supply lines which are located farther downstream than the steam control valve and the intercept valve.

In a combined cycle plant and a method for operating the same, the combined cycle plant is provided with a gas turbine, a waste heat recovery boiler, and a steam turbine, and is also provided with a low-pressure gland steam line for supplying steam to a low-pressure gland portion of a low-pressure turbine, and a first heat exchanging unit which performs heat exchange between gland steam flowing through the low-pressure gland steam line, and fuel gas to be supplied to a combustor.

A combined power generation system includes a gas turbine, a heat recovery steam generator (HRSG) configured to heat feedwater using combustion gases discharged from the gas turbine and having a high-pressure section, a medium-pressure section, and a low-pressure section having different pressure levels, an ammonia decomposer decomposing ammonia with the combustion gases discharged from the gas turbine, a first exhaust gas line through which the exhaust gases discharged from the gas turbine are transferred to the HRSG, a second exhaust gas line through which the exhaust gases discharged from the gas turbine are transferred to the ammonia decomposer, a third exhaust gas line through which the exhaust gases discharged from the ammonia decomposer are transferred to the HRSG, and a decomposed gas transfer tube connecting the ammonia decomposer and the combustor to transfer decomposed gases generated with the decomposition of ammonia to the combustor.

A heat exchange system includes: a gas line through which a gas to be cooled flows; a first heat exchanger disposed in the gas line and configured to cool the gas through heat exchange with a refrigerant; a refrigerant introduction line for introducing the refrigerant into the first heat exchanger; a refrigerant discharge line for discharging the refrigerant after cooling the gas from the first heat exchanger; a recirculation line for recirculating at least a part of the refrigerant flowing through the refrigerant discharge line into the refrigerant introduction line; and a flow-rate adjustment unit for adjusting a flow rate of the refrigerant flowing through the recirculation line so that a temperature of the refrigerant introduced into the first heat exchanger from the refrigerant introduction line is not lower than a threshold.

In a combined cycle plant and a method for operating the same, the combined cycle plant is provided with a gas turbine, a waste heat recovery boiler, and a steam turbine, and is also provided with a low-pressure gland steam line for supplying steam to a low-pressure gland portion of a low-pressure turbine, and a first heat exchanging unit which performs heat exchange between gland steam flowing through the low-pressure gland steam line, and fuel gas to be supplied to a combustor.

Provided is a solar thermal power generation facility that includes: a compressor; a medium heating heat receiver that receives sunlight and heats a compressed medium from the compressor; a turbine that is driven by the compressed medium heated by the medium heating heat receiver; a power generator that generates electric power by driving of the turbine; and a tower that supports these components. The compressor, the turbine, and the power generator are formed as arranged devices. A plurality of the arranged devices are aligned in a vertical direction.