Abstract: A solar thermal power system includes a solar receiver, and a thermal energy storage arrangement having thermal energy storage fluid to be circulated through the solar receiver to store thermal energy. The system includes a multistage steam turbine operable on variable pressure steam generated by a steam generator arrangement, by utilizing the thermal energy storage fluid. The arrangement includes an economizer section, an evaporator section, and a superheater section communicably configured to utilize the heat of the hot thermal energy storage fluid to generate and supply the variable pressure steam to the turbine. The system includes a recirculation line configured around the economizer section to recirculate the heated water to an inlet of the economizer section, increasing pressure range of the variable pressure steam in the arrangement.

Abstract: A solar thermal power system includes a solar receiver, and a thermal energy storage arrangement having thermal energy storage fluid to be circulated through the solar receiver to store thermal energy. The system includes a multistage steam turbine operable on variable pressure steam generated by a steam generator arrangement, by utilizing the thermal energy storage fluid. The arrangement includes an economizer section, an evaporator section, and a superheater section communicably configured to utilize the heat of the hot thermal energy storage fluid to generate and supply the variable pressure steam to the turbine. The system includes a recirculation line configured around the economizer section to recirculate the heated water to an inlet of the economizer section, increasing pressure range of the variable pressure steam in the arrangement.

Abstract: A solar thermal power system can include a solar receiver steam generator, a thermal energy storage arrangement utilizing a thermal energy storage fluid, and a multistage steam turbine for driving an electrical generator to produce electrical power. The solar thermal power system has a first operating mode in which steam is generated by the solar receiver steam generator and is supplied both to the thermal energy storage arrangement and to a high pressure turbine inlet of the multistage steam turbine. In a second operating mode, steam is generated by recovering stored thermal energy from the thermal energy storage fluid of the thermal energy storage arrangement for injection into the multistage steam turbine at a location or turbine stage downstream of the high pressure turbine inlet.

Abstract: A method of controlling a steam turbine, having a controller controlling at least the position of a steam inlet valve located in a steam conduit between a steam generator and the turbine to control mass flow into the turbine, includes selecting, before beginning startup, a predefined set of startup sequences of setpoints based on a turbine status at the beginning of startup and/or a startup mode chosen by the operator, the set of startup sequences of setpoints includes parameters controlled and not controlled by the controller; using the controller to control the parameters controlled by the controller so as to progress the turbine from setpoint to setpoint in accordance with predefined set of startup sequences until reaching a release point; and at the release point, delaying moving to the next setpoint until actual setpoint values agree with predefined release point setpoint values for parameters not controlled by the controller.

Abstract: A solar thermal power system includes a solar receiver, and a thermal energy storage arrangement having thermal energy storage fluid to be circulated through the solar receiver to store thermal energy. The system includes a multistage steam turbine operable on variable pressure steam generated by a steam generator arrangement, by utilizing the thermal energy storage fluid. The arrangement includes an economizer section, an evaporator section, and a superheater section communicably configured to utilize the heat of the hot thermal energy storage fluid to generate and supply the variable pressure steam to the turbine. The system includes a recirculation line configured around the economizer section to recirculate the heated water to an inlet of the economizer section, increasing pressure range of the variable pressure steam in the arrangement.

Abstract: A method for starting a combined cycle power plant (1) includes loading the gas turbine unit (2), providing a starting temperature (Tstart) for the steam supplied to the steam turbine (5), while the control valve (7) is regulated controlling the temperature of the steam at a temperature substantially equal to the starting temperature (Tstart) at a position (P2) downstream of the control valve (7) and upstream of the rotor (8), when the control valve (7) is substantially fully open, supplying steam to the steam turbine (5) at the starting temperature (Tstart). The steam temperature is controlled by controlling the steam temperature upstream of the control valve (7) in accordance with the temperature drop caused by the control valve (7) when the steam passes through it.

Abstract: A steam turbine is provided having a relief groove which is arranged in the region of the equalizing piston and extends in the circumferential direction of the rotor. The relief groove, with regard to an inlet passage, is arranged in the axial upstream direction so that it is arranged on the rotor outside a region in which the steam flow enters the bladed flow path via the inlet passage. The relief groove, with regard to the first blade row, is arranged in a region in which the greatest thermal stresses can arise in the rotor. As an option, the relief groove has a cover for reducing vortex flows, and also devices for reducing heating of the groove or devices for active cooling. The steam turbine allows an increased number of risk-free running up and running down operations of the steam turbine with minimum detriment to the turbine performance.

Abstract: A solar thermal power system can include a solar receiver steam generator, a thermal energy storage arrangement utilising a thermal energy storage fluid, and a multistage steam turbine for driving an electrical generator to produce electrical power. The solar thermal power system has a first operating mode in which steam is generated by the solar receiver steam generator and is supplied both to the thermal energy storage arrangement and to a high pressure turbine inlet of the multistage steam turbine. In a second operating mode, steam is generated by recovering stored thermal energy from the thermal energy storage fluid of the thermal energy storage arrangement for injection into the multistage steam turbine at a location or turbine stage downstream of the high pressure turbine inlet.

Abstract: A method of controlling a steam turbine, having a controller controlling at least the position of a steam inlet valve located in a steam conduit between a steam generator and the turbine to control mass flow into the turbine, includes selecting, before beginning startup, a predefined set of startup sequences of setpoints based on a turbine status at the beginning of startup and/or a startup mode chosen by the operator, the set of startup sequences of setpoints includes parameters controlled and not controlled by the controller; using the controller to control the parameters controlled by the controller so as to progress the turbine from setpoint to setpoint in accordance with predefined set of startup sequences until reaching a release point; and at the release point, delaying moving to the next setpoint until actual setpoint values agree with predefined release point setpoint values for parameters not controlled by the controller.

Abstract: A method for determining the remaining service life of a rotor of a thermally loaded turboengine in which a temperature on the rotor is determined. Thermal stress on the rotor is calculated from the determined temperature, and the remaining service life of the rotor is calculated from the derived thermal stress. The temperature is measured directly at a predetermined point of the rotor, and the thermal stress on the rotor is derived from the measured temperature.

Abstract: A method for starting a combined cycle power plant (1) includes loading the gas turbine unit (2), providing a starting temperature (Tsrart) for the steam supplied to the steam turbine (5), while the control valve (7) is regulated controlling the temperature of the steam at a temperature substantially equal to the starting temperature (Tstart) at a position (P2) downstream of the control valve (7) and upstream of the rotor (8), when the control valve (7) is substantially fully open, supplying steam to the steam turbine (5) at the starting temperature (Tstart). The steam temperature is controlled by controlling the steam temperature upstream of the control valve (7) in accordance with the temperature drop caused by the control valve (7) when the steam passes through it.

Abstract: A steam turbine is provided having a relief groove which is arranged in the region of the equalizing piston and extends in the circumferential direction of the rotor. The relief groove, with regard to an inlet passage, is arranged in the axial upstream direction so that it is arranged on the rotor outside a region in which the steam flow enters the bladed flow path via the inlet passage. The relief groove, with regard to the first blade row, is arranged in a region in which the greatest thermal stresses can arise in the rotor. As an option, the relief groove has a cover for reducing vortex flows, and also devices for reducing heating of the groove or devices for active cooling. The steam turbine allows an increased number of risk-free running up and running down operations of the steam turbine with minimum detriment to the turbine performance.

Abstract: A method is provided for determining the remaining service life of a rotor of a thermally loaded turboengine. In the method, a temperature on the rotor is determined, the thermal stress on the rotor is derived from the determined temperature, and the remaining service life of the rotor is deduced from the derived thermal stress. A simple, exact and flexible determination of the remaining service life is achieved in that the temperature is measured directly at a predetermined point of the rotor, and in that the thermal stress on the rotor is derived from the measured temperature.