Patents by Inventor Rudolf Kral

Rudolf Kral 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: 11791633
    Abstract: Various enhancements to grid-interactive inverters in accordance with embodiments of the invention are disclosed. One embodiment includes input terminals configured to receive a direct current, output terminals configured to provide an alternating output current to the utility grid, a controller, an output current sensor, and a DC-AC inverter stage comprising a plurality of switches controlled by control signals generated by the controller. In addition, the controller is configured to: generate control signals that cause the switches in the DC-AC inverter stage to switch a direct current in a bidirectional manner; measure the alternating output current; perform frequency decomposition of the output current; and generate control signals that cause the switches in the DC-AC inverter stage to switch current in a way that the magnitude of a plurality of unwanted current components is subtracted from the resulting output current.
    Type: Grant
    Filed: December 8, 2020
    Date of Patent: October 17, 2023
    Assignee: Generac Power Systems, Inc.
    Inventors: Christopher Richard Jones, Alexandre Rudolf Kral
  • Publication number: 20210194347
    Abstract: Various enhancements to grid-interactive inverters in accordance with embodiments of the invention are disclosed. One embodiment includes input terminals configured to receive a direct current, output terminals configured to provide an alternating output current to the utility grid, a controller, an output current sensor, and a DC-AC inverter stage comprising a plurality of switches controlled by control signals generated by the controller. In addition, the controller is configured to: generate control signals that cause the switches in the DC-AC inverter stage to switch a direct current in a bidirectional manner; measure the alternating output current; perform frequency decomposition of the output current; and generate control signals that cause the switches in the DC-AC inverter stage to switch current in a way that the magnitude of a plurality of unwanted current components is subtracted from the resulting output current.
    Type: Application
    Filed: December 8, 2020
    Publication date: June 24, 2021
    Applicant: Chilicon Power, LLC
    Inventors: Christopher Richard Jones, Alexandre Rudolf Kral
  • Patent number: 9810101
    Abstract: A method for starting a continuous steam generator is provided. The steam generator includes a combustion chamber provided with a plurality of burners, a water-steam separation device that is mounted downstream of evaporator tubes of the water-steam separation device on a flow-medium side. The amount of water flowing into the water-steam separation device during a starting process is kept to a minimum. The firing power of at least one of the burners is adjusted in accordance with a filling level characteristic value of the water-steam separation device.
    Type: Grant
    Filed: February 10, 2009
    Date of Patent: November 7, 2017
    Assignee: SIEMENS AKTIENGESELLSCHAFT
    Inventors: Rudolf Kral, Frank Thomas
  • Patent number: 8780592
    Abstract: Various enhancements to grid-interactive inverters in accordance with embodiments of the invention are disclosed. One embodiment includes input terminals configured to receive a direct current, output terminals configured to provide an alternating output current to the utility grid, a controller, an output current sensor, and a DC-AC inverter stage comprising a plurality of switches controlled by control signals generated by the controller. In addition, the controller is configured to: generate control signals that cause the switches in the DC-AC inverter stage to switch a direct current in a bidirectional manner; measure the alternating output current; perform frequency decomposition of the output current; and generate control signals that cause the switches in the DC-AC inverter stage to switch current in a way that the magnitude of a plurality of unwanted current components is subtracted from the resulting output current.
    Type: Grant
    Filed: July 11, 2012
    Date of Patent: July 15, 2014
    Assignee: Chilicon Power, LLC
    Inventors: Christopher Richard Jones, Alexandre Rudolf Kral
  • Patent number: 8297236
    Abstract: The invention relates to a steam generator wherein a continuous heating panel of a generator, which is formed from a number of evaporator tubes, and an overheating panel, which is formed from a number of over-heating tubes which are arranged downstream from the evaporator tubes and on the flow side, are arranged in a heating gas channel. According to the invention, a water separating element is integrated into a number of over-flow tubes which are connected on the flow side of one of several evaporator tubes to one or several overheating tubes.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: October 30, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventors: Joachim Franke, Rudolf Kral
  • Patent number: 8146540
    Abstract: The invention relates to a continuous steam generator comprising a surrounding wall which forms a gas draught and whose lower section is configured from gas-tight evaporator tubes that are welded together and whose upper section is configured from gas-tight superheater tubes that are welded together. According to the invention, superheater tubes are connected downstream of the evaporator tubes on the flow medium side by means of a water separator system. The aim of the invention is to provide a system with particularly high degree of operational flexibility even in the start-up and off-peak periods, while keeping the production and installation expenditure relatively low. To achieve this, the water separator system comprises a large number of water separator elements, each of which is connected downstream or upstream of less than ten evaporator tubes, preferably one tube and/or less than ten superheater tubes, preferably one tube on the flow medium side.
    Type: Grant
    Filed: February 6, 2006
    Date of Patent: April 3, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventors: Martin Effert, Joachim Franke, Rudolf Kral
  • Patent number: 7878157
    Abstract: The invention relates to a fossil-energy heated continuous steam generator, whereby the at least one combustion chamber, viewed in the flow direction of the hot gases, is divided into at least two throughflow segments, formed by evaporator heating surfaces, whereby the evaporator heating surfaces each comprise steam generation tubes welded to each other in a gastight manner and pressurized in parallel with a flow medium. According to the invention, said generator is suitable for operation with high fresh steam parameters, such as for example, steam temperatures of approximately 700° C., with a simple construction and particularly simple assembly, whereby a throughflow segment, arranged after the first through flow segment, viewed in the direction of flow of the hot gases, forms the first evaporator stage for the flow medium, such that the injection of particularly cold flow medium can occur in the region of maximum heating.
    Type: Grant
    Filed: July 22, 2005
    Date of Patent: February 1, 2011
    Assignee: Siemens Aktiengesellschaft
    Inventors: Martin Effert, Joachim Franke, Rudolf Kral
  • Publication number: 20110011090
    Abstract: A method for starting a continuous steam generator is provided. The steam generator includes a combustion chamber provided with a plurality of burners, a water-steam separation device that is mounted downstream of evaporator tubes of the water-steam separation device on a flow-medium side. The amount of water flowing into the water-steam separation device during a starting process is kept to a minimum. The firing power of at least one of the burners is adjusted in accordance with a filling level characteristic value of the water-steam separation device.
    Type: Application
    Filed: February 10, 2009
    Publication date: January 20, 2011
    Inventors: Rudolf Kral, Frank Thomas
  • Patent number: 7628124
    Abstract: The invention relates to a steam generator whose continuously heating evaporator surface is arranged in a hot gas channel for a hot gas passage in a substantially horizontal direction and which comprises a plurality of steam generating pipes passed through by flowing medium, wherein a plurality of output collectors which are mounted downstream of certain steam generating pipes, on the side of flowing medium, are oriented in the longitudinal direction thereof substantially parallel to the hot gas direction. The invention improves the steam generator such that it is possible to attain a high operational flexibility, a particularly reduced start- and load-alternation time, including starting operation or light load phases and to maintain a low-cost production. Each output collector comprises an integrated water separating element by means of which said collector is connected, on the side of flowing medium, to a plurality of downstream arranged overheating pipes of an overheating surface.
    Type: Grant
    Filed: February 10, 2006
    Date of Patent: December 8, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jan Brückner, Joachim Franke, Rudolf Kral
  • Patent number: 7624708
    Abstract: The invention relates to a process for operating a continuous steam generator. The aim of the invention is to provide, with little technical complexity and for any operating state, a synchronous variation of the feed-water mass flow passing through the evaporator heating surface and of the heat input into the evaporator heating surface. To this end, a regulating device for the discharge of feed-water is allocated to a device for adjusting the feed-water mass flow. The control variable of said regulating device is the feed-water mass flow, while its set-point value in relation to the feed-water mass flow depends on the set-point value associated to the power of the steam generator. The actual value of the feed-water density at the entry of the pre-heater is fed to the regulating device for the discharge of feed-water as one of the input values.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: December 1, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Axel Butterlin, Rudolf Kral, Frank Thomas
  • Patent number: 7587133
    Abstract: The invention relates to a continuous steam generator provided with an evaporator through flow heating surface which is disposed in a heating gas channel which can be cross flown in an approximately vertical manner in a heating gas device, said evaporator through flow heating surface comprising a plurality of parallel connected steam generating pipes enabling a flow medium to flow through, and an overheating heating surface which is arranged downstream from the evaporator through flow heating surface comprising a plurality of parallel connected overheating pipes enabling the evaporated flow medium to flow through, also enabling production and operational costs to be reduced and enabling the temperature of the steam on the outlet of the overheating heating surface to be controlled in a comparatively simple and flexible manner. The steam end-point of the flow medium is displaced to the overheating pipe, if required.
    Type: Grant
    Filed: August 2, 2004
    Date of Patent: September 8, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Joachim Franke, Rudolf Kral, Dieter Schiesser
  • Patent number: 7516719
    Abstract: A steam generator comprising a combustion chamber having funnel-shaped side walls in the bottom area thereof and an encircling wall formed from a plurality of steam generator pipes through which a flow medium can flow, wherein there area as little temperature differences as possible in the flow medium at the output of the steam generator pies. The steam generator pipes are, more particularly, arranged in the lower section forming the funnel-shaped side walls such that they are exposed to heat in as homongenous a manner as possible. According to the invention, the diameter of a number of steam generator pipes in the region of the funnel shaped side walls is different from that in the region of the encircling wall.
    Type: Grant
    Filed: October 26, 2004
    Date of Patent: April 14, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Rudolf Kral, Andre Schrief, Frank Thomas
  • Publication number: 20090071419
    Abstract: The invention relates to a steam generator wherein a continuous heating panel of a generator, which is formed from a number of evaporator tubes, and an overheating panel, which is formed from a number of over-heating tubes which are arranged downstream from the evaporator tubes and on the flow side, are arranged in a heating gas channel. According to the invention, a water separating element is integrated into a number of over-flow tubes which are connected on the flow side of one of several evaporator tubes to one or several overheating tubes.
    Type: Application
    Filed: March 31, 2006
    Publication date: March 19, 2009
    Inventors: Joachim Franke, Rudolf Kral
  • Publication number: 20080257282
    Abstract: The invention relates to a fossil-energy heated continuous steam generator, whereby the at least one combustion chamber, viewed in the flow direction of the hot gases, is divided into at least two throughflow segments, formed by evaporator heating surfaces, whereby the evaporator heating surfaces each comprise steam generation tubes welded to each other in a gastight manner and pressurized in parallel with a flow medium. According to the invention, said generator is suitable for operation with high fresh steam parameters, such as for example, steam temperatures of approximately 700° C., with a simple construction and particularly simple assembly, whereby a throughflow segment, arranged after the first through flow segment, viewed in the direction of flow of the hot gases, forms the first evaporator stage for the flow medium, such that the injection of particularly cold flow medium can occur in the region of maximum heating.
    Type: Application
    Filed: July 22, 2005
    Publication date: October 23, 2008
    Inventors: Martin Effert, Joachim Franke, Rudolf Kral
  • Patent number: 7428374
    Abstract: Disclosed is a steam generator in which a continuous evaporating heating area is disposed within a heating gas duct that is penetrated in a nearly horizontal direction by a heating gas. Said continuous evaporating heating area comprises a number of steam-generating pipes that are connected in parallel and are penetrated by a flowing medium and is configured such that a steam-generating pipe which is heated more than another steam-generating pipe of the same continuous evaporating heating area has a higher throughput of the flowing medium than said other steam-generating pipe. The aim of the invention is to create a steam generator which provides a particularly high degree of stability of flow during operation of the continuous evaporating heating area while keeping the structural complexity and design comparatively simple.
    Type: Grant
    Filed: August 28, 2003
    Date of Patent: September 23, 2008
    Assignee: Siemens Aktiengesellschaft
    Inventors: Joachim Franke, Rudolf Kral, Eberhard Wittchow
  • Publication number: 20080190382
    Abstract: The invention relates to a steam generator whose continuously heating evaporator surface is arranged in a hot gas channel for a hot gas passage in a substantially horizontal direction and which comprises a plurality of steam generating pipes passed through by flowing medium, wherein a plurality of output collectors which are mounted downstream of certain steam generating pipes, on the side of flowing medium, are oriented in the longitudinal direction thereof substantially parallel to the hot gas direction. The invention improves the steam generator such that it is possible to attain a high operational flexibility, a particularly reduced start- and load-alternation time, including starting operation or light load phases and to maintain a low-cost production. Each output collector comprises an integrated water separating element by means of which said collector is connected, on the side of flowing medium, to a plurality of downstream arranged overheating pipes of an overheating surface.
    Type: Application
    Filed: February 10, 2006
    Publication date: August 14, 2008
    Inventors: Jan Bruckner, Joachim Franke, Rudolf Kral
  • Patent number: 7406928
    Abstract: The invention relates to a continuous steam generator provided, in a duct for hot gas circulating in a substantially horizontal direction, with a continuous heating surface of an evaporator comprising a plurality of steam generator tubes which are mounted in parallel for circulating a fluid flow. The inventive device requires exceptionally low construction expenditures and ensures a high degree of safety and a high efficiency. For this purpose, the continuous heating surface of the evaporator is characterized in that it comprises a segment of the heating surface through which a moving fluid flows in an opposite direction with respect to the heated gas direction is positioned in such a way that a saturated steam temperature which is adjusted during operation at the exit from the continuous heating surface deviates from the predetermined maximum value of the temperature of the gas prevailing during operation at the outlet of the segment of the heating surface.
    Type: Grant
    Filed: August 2, 2004
    Date of Patent: August 5, 2008
    Assignee: Siemens Aktiengesellschaft
    Inventors: Joachim Franke, Rudolf Kral
  • Patent number: 7383791
    Abstract: The invention relates to a continuous steam generator wherein an evaporator throughflow heating surface is disposed in a gas duct which can be cross flown in an approximately vertical manner in a heating gas device, said evaporator throughflow heating surface comprising a plurality of parallel connected steam generating pipes enabling a flow medium to flow through, also enabling particularly high operating stability and security during the supply of the flow medium having a comparatively high mass flow density.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: June 10, 2008
    Assignee: Siemens Aktiengesellschaft
    Inventors: Joachim Franke, Rudolf Kral
  • Publication number: 20080115743
    Abstract: The invention relates to a continuous steam generator comprising a surrounding wall which forms a gas draught and whose lower section is configured from gas-tight evaporator tubes that are welded together and whose upper section is configured from gas-tight superheater tubes that are welded together. According to the invention, superheater tubes are connected downstream of the evaporator tubes on the flow medium side by means of a water separator system. The aim of the invention is to provide a system with particularly high degree of operational flexibility even in the start-up and off-peak periods, whilst keeping the production and installation expenditure relatively low. To achieve this, the water separator system comprises a large number of water separator elements, each of which is connected downstream or upstream of less than ten evaporator tubes, preferably one tube and/or less than ten superheater tubes, preferably one tube on the flow medium side.
    Type: Application
    Filed: February 6, 2006
    Publication date: May 22, 2008
    Applicant: SIEMENS AKTIENGESELLSCHAFT
    Inventors: Martin Effert, Joachim Franke, Rudolf Kral
  • Publication number: 20080066695
    Abstract: The invention relates to a process for operating a continuous steam generator. The aim of the invention is to provide, with little technical complexity and for any operating state, a synchronous variation of the feed-water mass flow passing through the evaporator heating surface and of the heat input into the evaporator heating surface. To this end, a regulating device for the discharge of feed-water is allocated to a device for adjusting the feed-water mass flow. The control variable of said regulating device is the feed-water mass flow, while its set-point value in relation to the feed-water mass flow depends on the set-point value associated to the power of the steam generator. The actual value of the feed-water density at the entry of the pre-heater is fed to the regulating device for the discharge of feed-water as one of the input values.
    Type: Application
    Filed: July 6, 2005
    Publication date: March 20, 2008
    Inventors: Axel Butterlin, Rudolf Kral, Frank Thomas