Patents by Inventor Stefan Rofka

Stefan Rofka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10724382
    Abstract: A gas turbine having a compressor, a combustor downstream from the compressor in a gas flow direction, and a turbine downstream from the combustor in the gas flow direction is described herein. The turbine includes a rotating part and a stationary part arranged around the rotating part. A gap between the rotating part and the stationary part, extends in a substantially radial direction relative to the rotation axis of the rotating part. A cooling fluid flows from the compressor to the gap, wherein at least a part of the cooling path extends in the stationary part, and wherein a pre-swirl nozzle is arranged adjacent to the gap and within the cooling path in the stationary part.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: July 28, 2020
    Assignee: ANSALDO ENERGIA SWITZERLAND AG
    Inventors: Sergei Riazantsev, Stefan Rofka, Robert Marmilic, Hanspeter Knopfel, Sergey Shchukin
  • Patent number: 10100728
    Abstract: A method and system are disclosed for operating a gas turbine power plant with flue gas recirculation, in which variable compressor inlet guide vanes are controlled as a function of flue gas recirculation ratio and/or as a function of a process parameter which is indicative for the flue gas recirculation. A controller setpoint position of the variable compressor inlet guide vanes can be controlled as a function of a position of a control element for controlling flue gas recirculation flow.
    Type: Grant
    Filed: October 5, 2012
    Date of Patent: October 16, 2018
    Assignee: ANSALDO ENERGIA SWITZERLAND AG
    Inventors: Frank Sander, Stefan Rofka, Eribert Benz
  • Patent number: 10066513
    Abstract: 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.
    Type: Grant
    Filed: December 3, 2014
    Date of Patent: September 4, 2018
    Assignee: General Electric Technology GmbH
    Inventors: Francois Droux, Dario Ugo Breschi, Karl Reyser, Stefan Rofka, Johannes Wick
  • Publication number: 20170044909
    Abstract: A gas turbine having a compressor, a combustor downstream from the compressor in a gas flow direction, and a turbine downstream from the combustor in the gas flow direction is described herein. The turbine includes a rotating part and a stationary part arranged around the rotating part. A gap between the rotating part and the stationary part, extends in a substantially radial direction relative to the rotation axis of the rotating part. A cooling fluid flows from the compressor to the gap, wherein at least a part of the cooling path extends in the stationary part, and wherein a pre-swirl nozzle is arranged adjacent to the gap and within the cooling path in the stationary part.
    Type: Application
    Filed: August 12, 2016
    Publication date: February 16, 2017
    Applicant: ANSALDO ENERGIA SWITZERLAND AG
    Inventors: Sergei RIAZANTSEV, Stefan ROFKA, Robert MARMILIC, Hanspeter KNÖPFEL, Sergey SHCHUKIN
  • Patent number: 9500127
    Abstract: The power plant includes a gas turbine unit adapted to feed flue gases into a diverter where they are divided into a recirculated flow and a discharged flow. The recirculated flow is fed into a mixer together with fresh air to form a mixture that is fed to the gas turbine unit. The gas turbine unit includes a combustion chamber where a fuel is burnt together with the mixture. A control unit is provided, that is supplied with information regarding the fuel C2+ and/or H2 content and is connected to at least the diverter to drive it and online regulate the recirculated flow mass flow rate in relation to the fuel C2+ and/or H2 content.
    Type: Grant
    Filed: October 13, 2011
    Date of Patent: November 22, 2016
    Assignee: GENERAL ELECTRIC TECHNOLOGY GMBH
    Inventors: Stefan Rofka, Frank Sander, Eribert Benz, Felix Güthe, Dragan Stankovic
  • Patent number: 9297311
    Abstract: A method is disclosed for operating a gas turbine power plant having a gas turbine, a heat recovery steam generator and an flue gas splitter which splits flue gases into a first flue gas flow for recirculation into an inlet flow of the gas turbine and into a second flue gas flow for discharge to an environment. An oxygen-depleted gas can be used in an open cooling system for cooling hot gas parts of the gas turbine. A split compressor intake can be provided for separate feed of recirculated flue gas and fresh air into a compressor intake. Compressor blades can include a separating band which blocks intermixing of recirculated flue gas and fresh air during compression.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: March 29, 2016
    Assignee: ALSTOM TECHNOLOGY LTD
    Inventors: Jaan Hellat, Stefan Rofka, Michael Hoevel, Eribert Benz, Andre Burdet, Frank Sander, Felix Guethe
  • Patent number: 9200540
    Abstract: A power plant includes a gas turbine unit adapted to feed flue gases into a diverter where they are divided into a recirculated flow that is fed into a mixer together with fresh air to form a mixture that is fed to a gas turbine unit compressor inlet, and a discharged flow, that is fed into a CO2 capture unit. A monitoring system for the mixture oxygen content at the compressor inlet is provided. The monitoring system includes a recirculated flow mass flow rate sensor, a recirculated flow oxygen concentration sensor, mixture mass flow rate sensors, a control unit arranged to process information detected by the recirculated flow mass flow rate sensor, recirculated flow oxygen concentration sensor and mixture mass flow rate sensor, to determine an oxygen concentration upstream of the compressor inlet.
    Type: Grant
    Filed: October 11, 2011
    Date of Patent: December 1, 2015
    Assignee: ALSTOM TECHNOLOGY LTD
    Inventors: Stefan Rofka, Frank Sander, Eribert Benz
  • Patent number: 9097187
    Abstract: An exemplary method is disclosed for operating a gas turbine power plant with exhaust gas recirculation, in which the exhaust gas recirculation is, for example, disengaged during starting and shutting down of the gas turbine, and in which the engaging or disengaging of the exhaust gas recirculation can be carried out in dependence upon an operating state of the gas turbine. An exemplary gas turbine power plant with exhaust gas recirculation is also disclosed which can include a control element, the closing speed of which is such that the control element can be closed within a time which is less than a time for exhaust gases to flow from the turbine through an HRSG.
    Type: Grant
    Filed: April 30, 2012
    Date of Patent: August 4, 2015
    Assignee: ALSTOM TECHNOLOGY LTD.
    Inventors: Stefan Rofka, Jürgen Hoffmann, Eribert Benz, Frank Sander, Martin Nicklas
  • Publication number: 20150082803
    Abstract: 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.
    Type: Application
    Filed: December 3, 2014
    Publication date: March 26, 2015
    Applicant: ALSTOM Technology Ltd
    Inventors: Francois DROUX, Dario Ugo BRESCHI, Karl REYSER, Stefan ROFKA, Johannes WICK
  • Patent number: 8984894
    Abstract: 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, is compressed and is supplied to at least one combustion chamber for combustion of a fuel, and the resultant exhaust gas is expanded in at least one turbine, producing work, and in which method the exhaust gas emerging from the at least one turbine is passed through a heat recovery steam generator in order to generate steam, which generator is part of a water-steam circuit with at least one steam turbine, a condenser, a feedwater tank and a feedwater pump, wherein heat is provided by extracting steam from the at least one steam turbine.
    Type: Grant
    Filed: April 16, 2013
    Date of Patent: March 24, 2015
    Assignee: ALSTOM Technology Ltd
    Inventors: Francois Droux, Dario Ugo Breschi, Karl Reyser, Stefan Rofka, Johannes Wick
  • Publication number: 20150016964
    Abstract: An improved gas turbine engine is adapted to include an inlet flow control arrangement disposed in an inlet passage at least between a filter member and a row of Variable Inlet Guide Vanes (VIGV), and adjacent the filter member, to enable pressure loss in the inlet passage and supply reduced amount of inlet air to a compressor to enable the reduction of power output of the gas turbine engine at a low load condition.
    Type: Application
    Filed: June 27, 2014
    Publication date: January 15, 2015
    Inventors: Wilhelm REITER, Stefan Rofka, Michael Hoevel
  • Patent number: 8843293
    Abstract: With a method for controlling a gas turbine in a power plant, a multiplicity of operating lines for the gas turbine for different gas turbine inlet temperatures TIT or gas turbine exhaust temperatures TAT and positions of the compressor inlet guide vane cascade VIGV are specified as a function of the load. For minimizing the electricity production costs during operation switching can be optionally carried out between different operating lines during constant or varying power output of the power plant.
    Type: Grant
    Filed: December 8, 2008
    Date of Patent: September 23, 2014
    Assignee: Alstom Technology Ltd.
    Inventors: Stefan Rofka, Andreas Rueter, Klaus Doebbeling, Martin Nicklas
  • Publication number: 20140193237
    Abstract: The disclosure relates to a turbo-machine comprising a stator and a rotor arranged rotatable inside the stator as well as at least one electric heating device which is arranged on the surface of at least part of the stator for active clearance control. Besides the turbo-machine, a method for operating the active clearance control comprising electric heating devices is disclosed.
    Type: Application
    Filed: January 10, 2014
    Publication date: July 10, 2014
    Applicant: ALSTOM Technology Ltd
    Inventors: Wilhelm REITER, Stefan ROFKA, Giovanni CATALDI, Thomas Peter SOMMER
  • Publication number: 20130227957
    Abstract: 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, is compressed and is supplied to at least one combustion chamber for combustion of a fuel, and the resultant exhaust gas is expanded in at least one turbine, producing work, and in which method the exhaust gas emerging from the at least one turbine is passed through a heat recovery steam generator in order to generate steam, which generator is part of a water-steam circuit with at least one steam turbine, a condenser, a feedwater tank and a feedwater pump, wherein heat is provided by extracting steam from the at least one steam turbine.
    Type: Application
    Filed: April 16, 2013
    Publication date: September 5, 2013
    Applicant: ALSTOM Technology Ltd.
    Inventors: Francois Droux, Dario Ugo Breschi, Karl Reyser, Stefan Rofka, Johannes Wick
  • Publication number: 20130227958
    Abstract: The invention relates to a method for operating a combined-cycle power plant with cogeneration, in which method combustion air is inducted in at least one gas turbine, is compressed and is fed to at least one combustion chamber for combustion of a fuel, and the resultant exhaust gas is expanded in at least one turbine producing work, and in which method the exhaust gas which emerges from the at least one turbine is fed through a heat recovery steam generator in order to generate steam, which heat recovery steam generator is part of a water-steam circuit with at least one steam turbine, a condenser, a feedwater tank and a feedwater pump, wherein heat is produced by extraction of steam from the at least one steam turbine.
    Type: Application
    Filed: April 16, 2013
    Publication date: September 5, 2013
    Applicant: ALSTOM Technology Ltd
    Inventors: Francois Droux, Dario Ugo Breschi, Karl Reyser, Stefan Rofka, Johannes Wick
  • Publication number: 20120291445
    Abstract: An exemplary method is disclosed for operating a gas turbine power plant with exhaust gas recirculation, in which the exhaust gas recirculation is, for example, disengaged during starting and shutting down of the gas turbine, and in which the engaging or disengaging of the exhaust gas recirculation can be carried out in dependence upon an operating state of the gas turbine. An exemplary gas turbine power plant with exhaust gas recirculation is also disclosed which can include a control element, the closing speed of which is such that the control element can be closed within a time which is less than a time for exhaust gases to flow from the turbine through an HRSG.
    Type: Application
    Filed: April 30, 2012
    Publication date: November 22, 2012
    Applicant: ALSTOM Technology Ltd.
    Inventors: Stefan Rofka, Jürgen Hoffmann, Eribert Benz, Frank Sander, Martin Nicklas
  • Publication number: 20120240590
    Abstract: A method is disclosed for operating a gas turbine power plant having a gas turbine, a heat recovery steam generator and an flue gas splitter which splits flue gases into a first flue gas flow for recirculation into an inlet flow of the gas turbine and into a second flue gas flow for discharge to an environment. An oxygen-depleted gas can be used in an open cooling system for cooling hot gas parts of the gas turbine. A split compressor intake can be provided for separate feed of recirculated flue gas and fresh air into a compressor intake. Compressor blades can include a separating band which blocks intermixing of recirculated flue gas and fresh air during compression.
    Type: Application
    Filed: March 21, 2012
    Publication date: September 27, 2012
    Applicant: ALSTOM Technology Ltd
    Inventors: Jaan HELLAT, Stefan Rofka, Michael Hoevel, Eribert Benz, Andre Burdet, Frank Sander, Felix Guethe
  • Publication number: 20120186268
    Abstract: A method is provided for operating a gas turbine power plant with exhaust gas recirculation, in which, based upon the operating state of the gas turbine a setpoint concentration of at least one constituent in an exhaust gas flow and/or in the intake flow of the gas turbine after adding the recirculated exhaust gases is determined. The actual concentration of the at least one constituent in the exhaust gas flow and/or in the intake flow is measured and a control element for controlling the recirculation flow is controlled based upon the setpoint/actual deviation. Also provided is a gas turbine power plant with exhaust gas recirculation and includes a controller, in which a setpoint concentration of at least one constituent in an exhaust gas flow or in the intake flow of the gas turbine is determined, and a measuring instrument for measuring the actual concentration of the at least one constituent.
    Type: Application
    Filed: January 21, 2012
    Publication date: July 26, 2012
    Applicant: ALSTOM TECHNOLOGY LTD
    Inventors: Stefan ROFKA, Juergen HOFFMANN, Eribert BENZ, Frank SANDER, Martin NICKLAS
  • Publication number: 20120090326
    Abstract: A power plant includes a gas turbine unit adapted to feed flue gases into a diverter where they are divided into a recirculated flow that is fed into a mixer together with fresh air to form a mixture that is fed to a gas turbine unit compressor inlet, and a discharged flow, that is fed into a CO2 capture unit. A monitoring system for the mixture oxygen content at the compressor inlet is provided. The monitoring system includes a recirculated flow mass flow rate sensor, a recirculated flow oxygen concentration sensor, mixture mass flow rate sensors, a control unit arranged to process information detected by the recirculated flow mass flow rate sensor, recirculated flow oxygen concentration sensor and mixture mass flow rate sensor, to determine an oxygen concentration upstream of the compressor inlet.
    Type: Application
    Filed: October 11, 2011
    Publication date: April 19, 2012
    Applicant: ALSTOM TECHNOLOGY LTD
    Inventors: Stefan ROFKA, Frank SANDER, Eribert BENZ
  • Publication number: 20120090327
    Abstract: The power plant includes a gas turbine unit adapted to feed flue gases into a diverter where they are divided into a recirculated flow and a discharged flow. The recirculated flow is fed into a mixer together with fresh air to form a mixture that is fed to the gas turbine unit. The gas turbine unit includes a combustion chamber where a fuel is burnt together with the mixture. A control unit is provided, that is supplied with information regarding the fuel C2+ and/or H2 content and is connected to at least the diverter to drive it and online regulate the recirculated flow mass flow rate in relation to the fuel C2+ and/or H2 content.
    Type: Application
    Filed: October 13, 2011
    Publication date: April 19, 2012
    Applicant: ALSTOM TECHNOLOGY LTD
    Inventors: Stefan ROFKA, Frank SANER, Eribert BENZ, Felix GÜTHE, Dragan STANKOVIC