Closed thermodynamic cycle systems, such as closed Brayton cycle systems, with regenerative heat exchangers are disclosed. Embodiments include dual regenerators and regenerators with buffer tank systems. Regenerators may be used instead of or in addition to one or more recuperators within the systems, and may be used as a means of gas-gas heat exchange for different streams of a working fluid.

A system includes an HRSG that includes a plurality of heat exchanger section fluidly coupled to each other. The plurality of heat exchanger sections comprises at least one economizer, at least one evaporator, at least one reheater, and at least one superheater. In addition, the HRSG includes an additional heat exchanger section coupled to two different heat exchanger sections of the plurality of heat exchanger sections. Further, the HRSG includes a controller programmed to selectively fluidly couple the additional heat exchanger section to one of the two different heat exchanger sections to alter a heat duty for the selected heat exchanger section fluidly coupled to the additional heat exchanger.

The invention relates to a method for operation of a combined-cycle power plant with cogeneration, in which method combustion air is inducted in at least one gas turbine, and in which method the exhaust gas emerging from the at least one turbine is passed through a heat recovery steam generator (HRSG) in order to generate steam. The electricity production can be decoupled from the steam production in order to restrict the electricity production while the heat provided by steam extraction remains at a constant level. A portion of the inducted combustion air can be passed through at least one turbine to the HRSG without being involved in the combustion of the fuel in the gas turbine. This portion of the combustion air can be used to operate at least one supplementary firing in the heat recovery steam generator.

A valve control system for a steam turbine that decrease in effective power as well as secure control stability in the event of an electric power system accident is provided. A valve control system for a steam turbine includes an accident detection unit 44 which detects an occurrence of an electric power system accident, a first selection unit 45 which selects, from a plurality of control valves 13 (13a13d) which adjust a volume of steam flowing into a steam turbine, control valves 13 to be rapidly closed according to a scale of the accident detected, and a normal control circuit 11 which continues normal pressure or speed control by the control valves 13 which are not selected.

A valve assembly for use to regulate a flow of steam in a flowpath of a turbine. The valve assembly can be configured with a body that circumscribes a rotor. The body is disposed upstream of the rotor blades. In one implementation, the body forms an annular ring with a plurality of arcuate segments, each being configured to move independently of the other segments in the ring to change the size of an annular gap between the arcuate segments and the rotor. The size of the annular gap corresponds with flow parameters for working fluid that flows across the rotor and that exits the turbine for use in pre-heaters and like collateral equipment.

In the context of electric power generation facilities, a system and method that enable control of maximum sustained rate of change in output to accommodate changing load conditions and to facilitate efficient use of system resources are disclosed. In accordance with aspects of the disclosed subject matter, a ramp rate for an electric generator source may be set, operating parameters may be monitored, rates of change or discrepancies of the operating parameters over time may be computed; and output signals may then be used selectively to control certain system components.

A dual trip manifold assembly (TMA) includes an isolation valve assembly having a first valve configured to receive a flow of fluid from a hydraulic system fluid supply. The first valve is configured to channel the flow of fluid to at least one hydraulic circuit. The isolation valve assembly also includes a second valve configured to receive the flow of fluid from the at least one hydraulic circuit. The second valve is further configured to channel the fluid flow to a trip header. The first valve and the second valve are synchronized to each other such that rotation of one valve causes a substantially similar rotation in the other valve.

Closed thermodynamic cycle systems, such as closed Brayton cycle systems, with regenerative heat exchangers are disclosed. Embodiments include dual regenerators and regenerators with buffer tank systems. Regenerators may be used instead of or in addition to one or more recuperators within the systems, and may be used as a means of gas-gas heat exchange for different streams of a working fluid.

A system includes an HRSG that includes a plurality of heat exchanger section fluidly coupled to each other. The plurality of heat exchanger sections comprises at least one economizer, at least one evaporator, at least one reheater, and at least one superheater. In addition, the HRSG includes an additional heat exchanger section coupled to two different heat exchanger sections of the plurality of heat exchanger sections. Further, the HRSG includes a controller programmed to selectively fluidly couple the additional heat exchanger section to one of the two different heat exchanger sections to alter a heat duty for the selected heat exchanger section fluidly coupled to the additional heat exchanger.

A dual trip manifold assembly (TMA) includes an isolation valve assembly having a first valve configured to receive a flow of fluid from a hydraulic system fluid supply. The first valve is configured to channel the flow of fluid to at least one hydraulic circuit. The isolation valve assembly also includes a second valve configured to receive the flow of fluid from the at least one hydraulic circuit of the at least two hydraulic circuits. The second valve is further configured to channel the fluid flow to a trip header and to receive the fluid flow from the trip header. The first valve and the second valve are synchronized to each other such that rotation of one of said first and second valves causes a substantially similar rotation in the other of said first and second valves header.