Alstom Technology Limited

General Electric Technology Gmbh

Thomas Schreier

Andreas Ehrsam

Gregoire Etienne Witz

Ingo Kuehn

Mageshwaran Ramesh

Martin Reigl

Maurus Herzog

Thomas Mokulys

Davor Kriz

Philipp Brunner

Martin Schoenenberger

Luca Marie Ripamonti

Giorgio Zanazzi

Jozo Drmic

Jian Chen

Rolf Döbler

Rabiye Bekyigit

The invention relates to a steam turbine rotor wherein the inter blade region rotor surface, the feed region rotor surface, the piston region rotor surface and the stress relief groove rotor surface of the rotor are configured and arranged as steam exposed surfaces during normal operation of the steam turbine rotor. The steam turbine rotor has a thermal barrier coating on at least the piston region rotor surface.

Steam turbine rotor

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.

Startup method for large steam turbines

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

Method for starting a combined cycle power plant

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.

Steam turbine with relief groove on the rotor

Growing community of inventors

Neuenhof, Switzerland

Thomas Schreier