Patents by Inventor Rene Waelchli

Rene Waelchli 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: 10151250
    Abstract: The invention relates to a method of operating a gas turbine assembly, which includes a compressor, a combustor and a gas turbine. The method includes operating the gas turbine assembly at a partial load with respect to a base load of the gas turbine assembly; bypassing a portion of blow-off air from the compressor; and introducing the portion of blow-off air into an exhaust gas duct after the gas turbine. The gas turbine assembly, when operating at partial load, can maintain the air-to-fuel ratio approximately constant and hence to control the combustion flame temperature at a level where emissions are kept below the permission limit.
    Type: Grant
    Filed: January 20, 2015
    Date of Patent: December 11, 2018
    Assignee: ANSALDO ENERGIA SWITZERLAND AG
    Inventors: Klaus Doebbeling, Anton Nemet, Martin Zajadatz, Rene Waelchli
  • Publication number: 20170030268
    Abstract: The invention relates to a surge control method for a gas turbine engine. The method includes providing a gas turbine engine having a compressor, a combustor, downstream of the compressor, with a hot gas path, a turbine downstream of the combustor, with a hot gas path. The method further includes monitoring the gas turbine engine for a potential surge condition, controlling a blow-off flow from the compressor, based on the monitoring for the control purpose of avoiding the surge condition, and directing the blow-off flow to at least one of the hot gas paths so as to bypass at least a portion of the combustor.
    Type: Application
    Filed: October 13, 2016
    Publication date: February 2, 2017
    Applicant: GENERAL ELECTRIC TECHNOLOGY GMBH
    Inventors: Adrien Franz STUDERUS, Ulrich Robert STEIGER, Ralf JAKOBY, René WÄLCHLI
  • Publication number: 20150204247
    Abstract: The invention relates to a method of operating a gas turbine assembly, which includes a compressor, a combustor and a gas turbine. The method includes operating the gas turbine assembly at a partial load with respect to a base load of the gas turbine assembly; bypassing a portion of blow-off air from the compressor; and introducing the portion of blow-off air into an exhaust gas duct after the gas turbine. The gas turbine assembly, when operating at partial load, can maintain the air-to-fuel ratio approximately constant and hence to control the combustion flame temperature at a level where emissions are kept below the permission limit.
    Type: Application
    Filed: January 20, 2015
    Publication date: July 23, 2015
    Inventors: Klaus DOEBBELING, Anton Nemet, Martin Zajadatz, Rene Waelchli
  • Publication number: 20140013765
    Abstract: The invention relates to a surge control method for a gas turbine engine. The method includes providing a gas turbine engine having a compressor, a combustor, downstream of the compressor, with a hot gas path, a turbine downstream of the combustor, with a hot gas path. The method further includes monitoring the gas turbine engine for a potential surge condition, controlling a blow-off flow from the compressor, based on the monitoring for the control purpose of avoiding the surge condition, and directing the blow-off flow to at least one of the hot gas paths so as to bypass at least a portion of the combustor.
    Type: Application
    Filed: July 11, 2013
    Publication date: January 16, 2014
    Applicant: ALSTOM Technology Ltd
    Inventors: Adrien Franz Studerus, Ulrich Robert Steiger, Ralf Jakoby, René Wälchli
  • Patent number: 8092150
    Abstract: A method for axial thrust control of a gas turbine, and a gas turbine with a device for controlling axial thrust are provided. A gas turbine, with regard to aerodynamic forces and pressure forces, which exert an axial force upon the rotor, is configured such that at no-load and low partial load it has a negative thrust, and at high load it has a positive thrust. In order to ensure a resulting positive thrust upon the thrust bearing within the entire load range of the gas turbine, an additional thrust is applied in a controlled manner. The additional thrust for example can be controlled in dependence upon the gas turbine load. The resulting thrust force at full load is consequently less than in the case of a conventionally designed gas turbine without thrust balance.
    Type: Grant
    Filed: July 3, 2008
    Date of Patent: January 10, 2012
    Assignee: Alstom Technology Ltd.
    Inventors: Stefan Rofka, Rene Waelchli, Sven Olmes, Thomas Zierer
  • Publication number: 20090067984
    Abstract: A method for axial thrust control of a gas turbine, and a gas turbine with a device for controlling axial thrust are provided. A gas turbine, with regard to aerodynamic forces and pressure forces, which exert an axial force upon the rotor, is configured such that at no-load and low partial load it has a negative thrust, and at high load it has a positive thrust. In order to ensure a resulting positive thrust upon the thrust bearing within the entire load range of the gas turbine, an additional thrust is applied in a controlled manner. The additional thrust for example can be controlled in dependence upon the gas turbine load. The resulting thrust force at full load is consequently less than in the case of a conventionally designed gas turbine without thrust balance.
    Type: Application
    Filed: July 3, 2008
    Publication date: March 12, 2009
    Applicant: ALSTOM TECHNOLOGY LTD.
    Inventors: Stefan Rofka, Rene Waelchli, Sven Olmes, Thomas Zierer
  • Patent number: 7237386
    Abstract: A process is provided for the control of the amount of cooling air of a gas turbine set. Suitable means are provided in the cooling system to enable the amount of cooling air to be varied. The control of this means takes place in dependence on an operating parameter (X). This operating parameter is made dependent on the fuel type used.
    Type: Grant
    Filed: April 23, 2004
    Date of Patent: July 3, 2007
    Assignee: ALSTOM Technology Ltd
    Inventors: Jürgen Hoffmann, Stefan Rofka, René Wälchli
  • Patent number: 7143573
    Abstract: A gas turbine set, with a cooling air system through which at least one cooling air mass flow flows from a compressor to thermally highly loaded components of the gas turbine set. Pressure increasing ejectors are arranged in a cooling air duct of the cooling air system for increasing the pressure of flowing cooling air. The ejectors are operable with a working fluid. The working fluid mass flow is less than twenty percent of a driven cooling air mass flow.
    Type: Grant
    Filed: August 7, 2003
    Date of Patent: December 5, 2006
    Assignee: Alstom Switzerland Ltd
    Inventors: Juergen Hoffmann, Stefan Rofka, René Waelchli, Rolf Dittmann
  • Publication number: 20040025491
    Abstract: For supporting the cooling of an air-cooled gas turbine set, it is proposed to arrange, in the cooling air ducts of the cooling system, means for increasing the pressure of the flowing cooling air. In an embodiment, the cooling system (17) is supplied with high pressure compressor air from the end stages of the compressor (1) of a gas turbine set (1, 2, 3, 4). This cooling system branches into a first branch (18), by means of which the combustor (2) and the first stages, particularly the first guide blade row of the turbine (3), are cooled. A second branch (19) conducts cooling air to the further turbine stages. An ejector (20) is provided for increasing, as needed, the pressure drop available by means of the first branch (18) of the cooling system. Its ejector nozzle (22) is supplied with live steam (9) taken from a waste heat steam generator (51), the live steam supply being adjustable by means of an adjusting member (21).
    Type: Application
    Filed: August 7, 2003
    Publication date: February 12, 2004
    Inventors: Juergen Hoffmann, Stefan Rofka, Rene Waelchli, Rolf Dittmann
  • Patent number: 6644012
    Abstract: For supporting the cooling of an air-cooled gas turbine set, it is proposed to arrange, in the cooling air ducts of the cooling system, means for increasing the pressure of the flowing cooling air. In an embodiment, the cooling system (17) is supplied with high pressure compressor air from the end stages of the compressor (1) of a gas turbine set (1, 2, 3, 4). This cooling system branches into a first branch (18), by means of which the combustor (2) and the first stages, particularly the first guide blade row of the turbine (3), are cooled. A second branch (19) conducts cooling air to the further turbine stages. An ejector (20) is provided for increasing, as needed, the pressure drop available by means of the first branch (18) of the cooling system. Its ejector nozzle (22) is supplied with live steam (9) taken from a waste heat steam generator (51), the live steam supply being adjustable by means of an adjusting member (21).
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: November 11, 2003
    Assignee: Alston (Switzerland) Ltd
    Inventors: Juergen Hoffmann, Stefan Rofka, René Waelchli, Rolf Dittmann
  • Patent number: 6640550
    Abstract: A gas turbo set (1, 2, 3) is equipped with at least a cooling air system (20,21). Throttle points (22, 23) are arranged as throttling points in the cooling air flowpath, for the purpose of defining the cooling air mass flow. Said manifolds are bypassed by bypass lines (24). Means (25) are arranged in said bypass lines for adjusting the bypass mass flow. Thus, the cooling air mass flow can be varied without acting on the main cooling air flow as such.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: November 4, 2003
    Assignee: Alstom (Switzerland) Ltd
    Inventors: Juergen Hoffmann, Stefan Rofka, René Waelchli, Rolf Dittmann
  • Publication number: 20030106322
    Abstract: A gas turbo set (1, 2, 3) is equipped with at least a cooling air system (20,21). Manifolds (22,23) are arranged as throttling points in the cooling air flowpath, for the purpose of defining the cooling air mass flow. Said manifolds are bypassed by bypass lines (24). Means (25) are arranged in said bypass lines for adjusting the bypass mass flow. Thus, the cooling air mass flow can be varied without acting on the main cooling air flow as such.
    Type: Application
    Filed: November 21, 2001
    Publication date: June 12, 2003
    Inventors: Juergen Hoffmann, Stefan Rofka, Rene Waelchli, Rolf Dittmann
  • Publication number: 20030084656
    Abstract: For supporting the cooling of an air-cooled gas turbine set, it is proposed to arrange, in the cooling air ducts of the cooling system, means for increasing the pressure of the flowing cooling air. In an embodiment, the cooling system (17) is supplied with high pressure compressor air from the end stages of the compressor (1) of a gas turbine set (1, 2, 3, 4). This cooling system branches into a first branch (18), by means of which the combustor (2) and the first stages, particularly the first guide blade row of the turbine (3), are cooled. A second branch (19) conducts cooling air to the further turbine stages. An ejector (20) is provided for increasing, as needed, the pressure drop available by means of the first branch (18) of the cooling system. Its ejector nozzle (22) is supplied with live steam (9) taken from a waste heat steam generator (51), the live steam supply being adjustable by means of an adjusting member (21).
    Type: Application
    Filed: November 27, 2001
    Publication date: May 8, 2003
    Inventors: Juergen Hoffmann, Stefan Rofka, Rene Waelchli, Rolf Dittmann
  • Patent number: 6523346
    Abstract: The invention gives a process for the control of the amount of cooling air of a gas turbine set (1, 2, 3). Suitable means (32, 33) are provided in the cooling system (26, 27) to enable the amount of cooling air to be varied. The control of this means takes place in dependence on an operating parameter (X). This is determined in a computer unit (22) by suitable combination of measured machine data (p1, p2).
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: February 25, 2003
    Assignee: Alstom (Switzerland) Ltd
    Inventors: Juergen Hoffmann, Stefan Rofka, René Waelchli