Patents by Inventor Kenji Nanataki

Kenji Nanataki 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: 11203983
    Abstract: A gas turbine includes a compressor, a combustor, a turbine, a generator, and a control apparatus, the compressor being provided with an air extraction valves, a plurality of inlet guide vanes, and a plurality of casing air extraction valves at its last stage, in which the control is carried out on at least one of the opening of the air extraction valve, the opening of the inlet guide vanes, and the number of openings of the casing air extraction valves which are defined as control parameters taking blade vibration stress values as indexes based on a compressor metal temperature included in behavior parameters of the gas turbine.
    Type: Grant
    Filed: December 12, 2019
    Date of Patent: December 21, 2021
    Assignee: Mitsubishi Power, Ltd.
    Inventors: Hiroki Takeda, Takashi Yokoyama, Kenji Nanataki, Tomoyuki Matsui
  • Publication number: 20200277902
    Abstract: A gas turbine includes a compressor, a combustor, a turbine, a generator, and a control apparatus, the compressor being provided with an air extraction valves, a plurality of inlet guide vanes, and a plurality of casing air extraction valves at its last stage, in which the control is carried out on at least one of the opening of the air extraction valve, the opening of the inlet guide vanes, and the number of openings of the casing air extraction valves which are defined as control parameters taking blade vibration stress values as indexes based on a compressor metal temperature included in behavior parameters of the gas turbine.
    Type: Application
    Filed: December 12, 2019
    Publication date: September 3, 2020
    Inventors: Hiroki TAKEDA, Takashi YOKOYAMA, Kenji NANATAKI, Tomoyuki MATSUI
  • Patent number: 10422249
    Abstract: An exhaust frame includes: an inner casing; an inner diffuser which defines, between the inner diffuser and the inner casing, an annular inner cooling passage connected to a final-stage wheel space; an outer diffuser which defines an exhaust passage between the outer diffuser and the inner diffuser; an outer casing which defines an annular outer cooling passage between the outer casing and the outer diffuser; a strut which connects the inner casing and the outer casing to each other while crossing the exhaust passage; a strut cover which connects the inner diffuser and the outer diffuser to each other, and defines, between the strut cover and the strut, an annular connection passage connecting the inner cooling passage and the outer cooling passage to each other; and a communication hole provided in a wall of the outer cooling passage at a position on the downstream side of a center line of the strut in the flow direction of a combustion gas.
    Type: Grant
    Filed: January 18, 2017
    Date of Patent: September 24, 2019
    Assignee: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Takuya Takeda, Tetsuya Nakamura, Ryo Kawai, Kenji Nanataki
  • Patent number: 10323570
    Abstract: A two-shaft gas turbine of the present invention, in which a mass flow of an air into a compressor is regulated by controlling a set angle of an inlet guide vane (IGV) on an air intake side of the compressor, comprises, as a device to control the set angle of the IGV, a first controller to control the set angle of the IGV based on a corrected speed of the gas generator shaft during low speed rotation of the gas generator shaft, the corrected speed having been corrected according to an ambient temperature; a second controller to control the set angle of the IGV to maintain a constant actual speed of the gas generator shaft during high speed rotation of the gas generator shaft; and an ambient temperature correction part to increase the actual speed maintained constant by the second controller if the ambient temperature is equal to or more than a threshold value.
    Type: Grant
    Filed: February 22, 2016
    Date of Patent: June 18, 2019
    Assignee: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Chihiro Myoren, Kenji Nanataki, Yasuo Takahashi, Kota Kawamura
  • Patent number: 10247109
    Abstract: A 2-shaft gas turbine has a controller which controls the opening degree of an air inlet guide vane to adjust the inlet mass flow rate to a compressor. The air inlet guide vane control unit includes a first control unit that adjusts the opening degree of the inlet guide vane to keep the speed of a high pressure turbine shaft constant; a control status confirmation unit that confirms the actual speed and the opening degree of the inlet guide vane; and a low ambient temperature correction unit that reduces the actual speed in a case where the actual speed is equal to or greater than a predetermined threshold value, the opening degree of the inlet guide vane is equal to or greater than a predetermined threshold value, and the ambient temperature is equal to or less than a predetermined threshold value.
    Type: Grant
    Filed: January 27, 2017
    Date of Patent: April 2, 2019
    Assignee: MITSUBISHI HITACHI POWER SYSTEMS, LTD.
    Inventors: Chihiro Myoren, Kenji Nanataki, Yasuo Takahashi, Kota Kawamura
  • Patent number: 9951696
    Abstract: A twin-shaft gas turbine can be used for 50 and 60 Hz power generation without using a reducer. A gas generator includes a compressor that generates compressed air, a burner that burns a fuel mixed with the compressed air received from the compressor so as to generate combustion gas, and a high-pressure turbine that is rotationally driven by the combustion gas received from the burner and generates driving force for the compressor. An output turbine includes a low-pressure turbine that is driven by exhaust gas received from the high-pressure turbine and a power generator that is driven by the low-pressure turbine. A control device reduces opening degree of IGV of the compressor and thereby reduces power of the compressor, and the rotational frequency of the gas generator is increased in a full-speed no-load operating state of the power generator.
    Type: Grant
    Filed: November 13, 2012
    Date of Patent: April 24, 2018
    Assignee: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Kenji Nanataki, Hidetaro Murata, Hidetoshi Kuroki
  • Publication number: 20170284308
    Abstract: A 2-shaft gas turbine has a controller which controls the opening degree of an air inlet guide vane to adjust the inlet mass flow rate to a compressor. The air inlet guide vane control unit includes a first control unit that adjusts the opening degree of the inlet guide vane to keep the speed of a high pressure turbine shaft constant; a control status confirmation unit that confirms the actual speed and the opening degree of the inlet guide vane; and a low ambient temperature correction unit that reduces the actual speed in a case where the actual speed is equal to or greater than a predetermined threshold value, the opening degree of the inlet guide vane is equal to or greater than a predetermined threshold value, and the ambient temperature is equal to or less than a predetermined threshold value.
    Type: Application
    Filed: January 27, 2017
    Publication date: October 5, 2017
    Applicant: MITSUBISHI HITACHI POWER SYSTEMS, LTD.
    Inventors: Chihiro MYOREN, Kenji NANATAKI, Yasuo TAKAHASHI, Kota KAWAMURA
  • Publication number: 20170211424
    Abstract: An exhaust frame includes: an inner casing; an inner diffuser which defines, between the inner diffuser and the inner casing, an annular inner cooling passage connected to a final-stage wheel space; an outer diffuser which defines an exhaust passage between the outer diffuser and the inner diffuser; an outer casing which defines an annular outer cooling passage between the outer casing and the outer diffuser; a strut which connects the inner casing and the outer casing to each other while crossing the exhaust passage; a strut cover which connects the inner diffuser and the outer diffuser to each other, and defines, between the strut cover and the strut, an annular connection passage connecting the inner cooling passage and the outer cooling passage to each other; and a communication hole provided in a wall of the outer cooling passage at a position on the downstream side of a center line of the strut in the flow direction of a combustion gas.
    Type: Application
    Filed: January 18, 2017
    Publication date: July 27, 2017
    Inventors: Takuya TAKEDA, Tetsuya NAKAMURA, Ryo KAWAI, Kenji NANATAKI
  • Patent number: 9617867
    Abstract: A gas turbine includes a disk wheel forming a rotor; a rotor blade including a shank mounted on the outer circumference of the disk wheel and a rotor blade profile portion; a stator blade including a stator blade profile portion and an inner circumferential end wall provided on the inner circumferential side of the stator blade profile portion; and a seal fin provided on the shank of the rotor blade so as to face an inside-diameter surface of the inner circumferential end wall of the stator blade. An abradable coating is applied to such a portion of the inside-diameter surface of the inner circumferential end wall of the stator blade that faces the seal fin.
    Type: Grant
    Filed: November 13, 2013
    Date of Patent: April 11, 2017
    Assignee: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Hayato Maekawa, Kenji Nanataki
  • Publication number: 20160245172
    Abstract: A two-shaft gas turbine of the present invention, in which a mass flow of an air into a compressor is regulated by controlling a set angle of an inlet guide vane (IGV) on an air intake side of the compressor, comprises, as a device to control the set angle of the IGV, a first controller to control the set angle of the IGV based on a corrected speed of the gas generator shaft during low speed rotation of the gas generator shaft, the corrected speed having been corrected according to an ambient temperature; a second controller to control the set angle of the IGV to maintain a constant actual speed of the gas generator shaft during high speed rotation of the gas generator shaft; and an ambient temperature correction part to increase the actual speed maintained constant by the second controller if the ambient temperature is equal to or more than a threshold value.
    Type: Application
    Filed: February 22, 2016
    Publication date: August 25, 2016
    Inventors: Chihiro MYOREN, Kenji NANATAKI, Yasuo TAKAHASHI, Kota KAWAMURA
  • Publication number: 20140352320
    Abstract: A two-shaft gas turbine is provided that can raise an inlet temperature of a high-pressure turbine and the air quantity of a compressor to respective rated values at any atmospheric temperature without using a variable stator vane in the initial stage of a low-pressure turbine. The two-shaft gas turbine includes a power generator 21 having a compressor 11, a combustor 12 and a high-pressure turbine 13; a low-pressure turbine 14 driven by exhaust gas from the high-pressure turbine 13; a generator motor 23 connected to the gas generator 21; and a control unit 24. When either one of a value of the inlet temperature of the high-pressure turbine 13 and a value of the air quantity of the compressor 11 reaches a rated value before the other value reaches a rated value, the control unit 24 drives the generator motor 23 to bring the other value close to the rated value.
    Type: Application
    Filed: May 27, 2014
    Publication date: December 4, 2014
    Applicant: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Kenji NANATAKI, Hidetoshi KUROKI
  • Publication number: 20140205445
    Abstract: A gas turbine includes a disk wheel forming a rotor; a rotor blade including a shank mounted on the outer circumference of the disk wheel and a rotor blade profile portion; a stator blade including a stator blade profile portion and an inner circumferential end wall provided on the inner circumferential side of the stator blade profile portion; and a seal fin provided on the shank of the rotor blade so as to face an inside-diameter surface of the inner circumferential end wall of the stator blade. An abradable coating is applied to such a portion of the inside-diameter surface of the inner circumferential end wall of the stator blade that faces the seal fin.
    Type: Application
    Filed: November 13, 2013
    Publication date: July 24, 2014
    Applicant: Hitachi, Ltd.
    Inventors: Hayato MAEKAWA, Kenji NANATAKI
  • Patent number: 8499541
    Abstract: A two-shaft gas turbine is capable of starting premixed combustion without extinguishing a flame. The two-shaft gas turbine includes a combustor and a gas generator controller. The combustor has a premix burner that includes combustion regions in which premixed combustion is to be carried out individually. The gas generator controller controls the combustor. In a method for starting the premixed combustion in the combustor, the gas generator controller selects at least one of the combustion regions in which the premixed combustion is to be carried out, on the basis of a fuel-air ratio, and starts premix combustion in the selected combustion region or separately in each of the selected combustion regions. Further, as the fuel-air ratio is increased, the controller increases the number of the selected region in which the premixed combustion is carried out.
    Type: Grant
    Filed: March 22, 2011
    Date of Patent: August 6, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Ryo Kawai, Hidetaro Murata, Takeo Saito, Nobuaki Kizuka, Kenji Nanataki
  • Publication number: 20130064670
    Abstract: An airfoil profile is formed such that a passage width ratio, represented in a dimensionless manner, of an inter-blade passage width of vane root cross-section to an outlet throat width substantially monotonously decreases from a blade inlet toward a blade outlet. The blade has a blade airfoil profile shape in an envelope within a range of ±2.0 mm in a direction normal to any surface location of an airfoil profile portion. The airfoil profile portion has a reference airfoil contour represented in Cartesian coordinates, wherein Z is a distance representing a sectional height from a root of the airfoil profile portion. The contours represented by X and Y at each section Z are joined smoothly with one another in a blade height direction to form a complete shape of the airfoil profile portion.
    Type: Application
    Filed: August 31, 2012
    Publication date: March 14, 2013
    Inventors: Nobuaki KIZUKA, Hidetaro MURATA, Hidetoshi KUROKI, Kenji NANATAKI
  • Publication number: 20130000316
    Abstract: A twin-shaft gas turbine, which has a gas generator including a compressor, a combustor, and a high-pressure turbine, is configured to make a first control mode and a second control mode selectively useable for control of the gas generator. In addition, in the first control mode, an IGV angle in the compressor is controlled in accordance with a corrected shaft rotation speed of the gas generator, and in the second control mode, the IGV angle is controlled to maintain a constant gas generator shaft rotation speed. Furthermore, the first control mode is used to start, to stop, and to operate the turbine under fixed or lower load conditions, and that the second control mode is used under operational states other than those to which the first control mode is applied.
    Type: Application
    Filed: September 11, 2012
    Publication date: January 3, 2013
    Applicant: HITACHI, LTD.
    Inventors: Kenji NANATAKI, Nozomi SAITO, Hidetaro MURATA
  • Patent number: 8277192
    Abstract: An airfoil profile is formed such that a passage width ratio, represented in a dimensionless manner, of an inter-blade passage width of vane root cross-section to an outlet throat width substantially monotonously decreases from a blade inlet toward a blade outlet. The blade has a blade airfoil profile shape in an envelope within a range of .+?.2.0 mm in a direction normal to any surface location of an airfoil profile portion. The airfoil profile portion has a reference airfoil contour represented in Cartesian coordinates wherein Z is a distance representing a sectional height from a root of the airfoil profile portion. The contours represented by X and Y at each section Z are joined smoothly with one another in a blade height direction to form a complete shape of the airfoil profile portion.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: October 2, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Nobuaki Kizuka, Hidetaro Murata, Hidetoshi Kuroki, Kenji Nanataki
  • Patent number: 8272223
    Abstract: A twin-shaft gas turbine 1, which has a gas generator 2 including a compressor 7, a combustor 8, and a high-pressure turbine 9, is configured to make a first control mode and a second control mode selectively useable for control of the gas generator. In addition, in the first control mode, an IGV angle in the compressor is controlled in accordance with a corrected shaft rotation speed of the gas generator, and in the second control mode, the IGV angle is controlled to maintain a constant gas generator shaft rotation speed. Furthermore, the first control mode is used to start, to stop, and to operate the turbine under fixed or lower load conditions, and that the second control mode is used under operational states other than those to which the first control mode is applied.
    Type: Grant
    Filed: December 28, 2010
    Date of Patent: September 25, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Nanataki, Nozomi Saito, Hidetaro Murata
  • Patent number: 8196414
    Abstract: A twin-shaft gas turbine 1, which has a gas generator 2 including a compressor 7, a combustor 8, and a high-pressure turbine 9, is configured to make a first control mode and a second control mode selectively usable for control of the gas generator. In addition, in the first control mode, an IGV angle in the compressor is controlled in accordance with a corrected shaft rotation speed of the gas generator, and in the second control mode, the IGV angle is controlled to maintain a constant gas generator shaft rotation speed. Furthermore, the first control mode is used to start, to stop, and to operate the turbine under fixed or lower load conditions, and that the second control mode is used under operational states other than those to which the first control mode is applied.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: June 12, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Nanataki, Nozomi Saito, Hidetaro Murata
  • Patent number: 8191374
    Abstract: The temperature rise of a wheel space between a high-pressure turbine and a low-pressure turbine is suppressed. Cooling air is led from outside a casing 17 to a wheel space via a low-pressure turbine initial stage stator blade 5 and a diaphragm 11. An upstream side space seal portion 41 is adapted to restrict and divide the upstream side space into an outer circumferential portion 25 and an inner circumferential portion 27 and to allow cooling air to the upstream side space outer circumferential portion 27 to blow out into the upstream side space outer circumferential portion 25. Also, a downstream side space seal portion 42 is adapted to restrict and divide the downstream side space into an outer circumferential portion 26 and an inner circumferential portion 28 and to allow cooling air to blow out into the downstream side space outer circumferential portion 26.
    Type: Grant
    Filed: February 13, 2009
    Date of Patent: June 5, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Nanataki, Hidetaro Murata, Nobuaki Kizuka
  • Publication number: 20120017600
    Abstract: Provided are a combustor control method and a combustor controller capable of calculating the combustion air flow and the fuel flow in multi-shafts gas turbine with high precision and without the need of performing complicated calculations and thereby calculating a fuel-air ratio necessary for stable combustion control. The multi-shaft gas turbine is made up of a gas generator turbine and a power turbine. Combustors includes a diffusive combustion units and a plurality of premixed combustion units.
    Type: Application
    Filed: July 20, 2011
    Publication date: January 26, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Nozomi SAITO, Takeo Saito, Kenji Nanataki