A steam turbine of an opposed-current single-casing type has a high pressure turbine part and an intermediate-pressure turbine part housed in a single casing. A dummy ring partitions the high-pressure turbine part and the intermediate-pressure part, and a cooling steam supply path and a cooling steam discharge path are formed in the dummy ring in the radial direction. Extraction steam or discharge steam of the high-pressure turbine part, whose temperature is not less than that of the steam having passed through a first-stage stator blade, is supplied to the cooling steam supply path. The cooling steam is fed throughout the clearance to improve the cooling effect of the dummy ring and a turbine rotor. The cooling steam is then discharged through a cooling steam discharge path to a discharge steam pipe which supplies the steam to a subsequent steam turbine.

A steam turbine of an opposed-current single-casing type has a high pressure turbine part and an intermediate-pressure turbine part housed in a single casing. A dummy ring partitions the high-pressure turbine part and the intermediate-pressure part, and a cooling steam supply path and a cooling steam discharge path are formed in the dummy ring in the radial direction. Extraction steam or discharge steam of the high-pressure turbine part, whose temperature is not less than that of the steam having passed through a first-stage stator blade, is supplied to the cooling steam supply path. The cooling steam is fed throughout the clearance to improve the cooling effect of the dummy ring and a turbine rotor. The cooling steam is then discharged through a cooling steam discharge path to a discharge steam pipe which supplies the steam to a subsequent steam turbine.

Device for expanding a fluid, which device (1) comprises an inlet (2) for a high pressure fluid, an outlet (3) for a low pressure fluid, and a control valve (4) between the aforementioned inlet (2) and outlet (3) for expanding the fluid to a predefined pressure level, characterized in that the device (1) is further provided with one or more expanders (5) for expanding the fluid, of which one or more expanders (5) are connected in parallel with the control valve (4), whereby the device (1) is provided with a controller (8) configured to control the expanders (5) based on a flow rate (Qklep) of the fluid through the control valve (4).

Device for expanding a fluid, which device (1) comprises an inlet (2) for a high pressure fluid, an outlet (3) for a low pressure fluid, and a control valve (4) between the aforementioned inlet (2) and outlet (3) for expanding the fluid to a predefined pressure level, characterized in that the device (1) is further provided with one or more expanders (5) for expanding the fluid, of which one or more expanders (5) are connected in parallel with the control valve (4), whereby the device (1) is provided with a controller (8) configured to control the expanders (5) based on a flow rate (Qklep) of the fluid through the control valve (4).

In some aspects, a steam turbine system includes a high-pressure turbine section; a low-pressure turbine section; a high-pressure control valve operable to provide an adjustable flow of steam into the high-pressure turbine section; a low-pressure control valve operable to provide an adjustable flow of steam into the low-pressure turbine section; a controller associated with the high-pressure control valve and the low-pressure control valve. The controller is operable to: receive measurements of three or more different operating points of the steam turbine system, the measurements of each of the three or more different operating points including a position of the high-pressure control valve, a position of the low-pressure control valve, and two of process variables of the steam turbine system; calculate coefficients of a steam performance map of the steam turbine system based on the measurements; and generate the steam performance map based on the coefficients.

In some aspects, a steam turbine system includes a high-pressure turbine section; a low-pressure turbine section; a high-pressure control valve operable to provide an adjustable flow of steam into the high-pressure turbine section; a low-pressure control valve operable to provide an adjustable flow of steam into the low-pressure turbine section; a controller associated with the high-pressure control valve and the low-pressure control valve. The controller is operable to: receive measurements of three or more different operating points of the steam turbine system, the measurements of each of the three or more different operating points including a position of the high-pressure control valve, a position of the low-pressure control valve, and two of process variables of the steam turbine system; calculate coefficients of a steam performance map of the steam turbine system based on the measurements; and generate the steam performance map based on the coefficients.

A system includes an HRSG that includes a plurality of heat exchanger sections 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 system includes an HRSG that includes a plurality of heat exchanger sections 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 steam turbine having a plurality of stages comprising a plurality of points of admission connected to a plurality of admission lines, a feed line connected to the plurality of admission lines and at least one extraction line, extending from an intermediate stage of the steam turbine, for extracting steam from the steam turbine. The at least one capacity line fluidly connects an admission lines and at least one extraction line so as to bypass the steam turbine, and is further configured to increase a swallowing capacity of the steam turbine as measured from the feed line upstream of the capacity line compared to the plurality of points of admission.

Device for expanding a fluid, which device (1) comprises an inlet (2) for a high pressure fluid, an outlet (3) for a low pressure fluid, and a control valve (4) between the aforementioned inlet (2) and outlet (3) for expanding the fluid to a predefined pressure level, characterized in that the device (1) is further provided with one or more expanders (5) for expanding the fluid, of which one or more expanders (5) are connected in parallel with the control valve (4), whereby the device (1) is provided with a controller (8) configured to control the expanders (5) based on a flow rate (Qklep) of the fluid through the control valve (4).