Patents by Inventor Kiyoshi Suenaga

Kiyoshi Suenaga 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: 6186740
    Abstract: In a gas turbine cooling blade, cooling passages are defined by ribs formed therein. The cooling blade comprises an insert fitted in one of the cooling passages at the front edge of the blade, a plurality of nozzles formed in the front face of the insert and used to spray an impact jet of a refrigerant against the inner surface of the front edge of the blade, thereby cooling the inner surface, and a passage formed between the rear face of the insert and the rib and communicating with a rear-side flow.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: February 13, 2001
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kenichiro Takeishi, Kiyoshi Suenaga, Kazuo Uematsu
  • Patent number: 6152695
    Abstract: In a gas turbine moving blade 1, the convection of cooling air is promoted to enhance the heat transfer rate, the cooling effect of a shroud 2 is enhanced and the entire cooling effect of the blade is enhanced. An inner cavity 10 is formed in the blade over the entire length thereof. A multiplicity of pin fins 5 are provided in the inner cavity, being fixed to wall thereof. An enlarged cavity 6 is formed in the shroud 2 of a terminal end of the blade 1. Cooling air entering the inner cavity 10 of the blade 1 flows into the enlarged cavity 6 and flows out of the shroud 2 downwardly through holes 7 of a peripheral portion of the enlarged cavity 6. The entire portion of the shroud 2 is cooled uniformly, and the cooling effect of the entire blade is enhanced by an enhanced heat transfer rate in the blade and by uniform cooling of the entire shroud.
    Type: Grant
    Filed: February 3, 1999
    Date of Patent: November 28, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Ichiro Fukue, Eiji Akita, Kiyoshi Suenaga, Yasuoki Tomita
  • Patent number: 6151881
    Abstract: An air separator for a gas turbine, in which cracks are prevented from occurring at a flange portion of the air separator due to fretting fatigue. The air separator (20) has a cylindrical split structure formed by two separator members (20-1 and 20-2), of which one of the separators (20-1) is mounted on a rotor (1) whereas the other separator member (20-2) is mounted on a disc portion (7) on a side of a moving blade (2) by bolts (28) extending through bolt holes (23) formed in a flange portion (22). Cooling air from a compressor enters a space (6) from a duct (5) and passes to a passage (32) from a clearance (33) so that it is fed to air feed holes (43) and radial holes (44) of the disc portion (7). Alternatively, air holes (50) are provided in the flange portion (22) in the form of circumferential slots for covering a plurality of radial holes to feed the cooling air homogeneously so that a prior art air separator of an existing plant can be replaced.
    Type: Grant
    Filed: February 11, 1999
    Date of Patent: November 28, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Toshishige Ai, Yoichi Iwasaki, Sunao Aoki, Yukihiro Hashimoto, Kiyoshi Suenaga
  • Patent number: 6146091
    Abstract: A gas turbine having cooling structure disposed on an outside peripheral side in a radial direction of a movable vane in which the cooling efficiency is further improved and sealing structure disposed on an inner peripheral side to suppress leakage of sealing air and prevent invasion of combustion gas into the turbine disc and enlargement of sealing air clearance is prevented. Outwardly in the radial direction, a gap between ring segment (90) and impingement cooling plate (92) disposed on the outer periphery thereof, is divided in the axial direction by a pressure partition plate (97) extending in a circumferential direction so as to provide plural cavities adjusted to different pressures, thereby forming a cooling structure in the ring segment (90). Inside in the radial direction, a static vane inside diameter side cavity (53) and downstream cavity (31) are formed by a box (57) for sealing the static vane inside diameter side cavity (53).
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: November 14, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Koji Watanabe, Akiko Aizawa, Rintaro Chikami, Kiyoshi Suenaga
  • Patent number: 6142730
    Abstract: In a cooled gas turbine stationary blade, both steam cooling and air cooling are utilized to reduce the amount of cooling air. In the stationary blade having outer and inner shrouds 1, 21 and steam passages 10A, 10B, 10C, 10D and 10E which are communicated with each other and in which a sealing air feed tube 2 passes through a central portion thereof, steam covers 3, 4 are provided in the outer shroud 1, and steam S is introduced from a steam feed port 5. The steam S passes through serpentine passages 10A to 10E and is recovered from the steam outlet 12 after cooling the central portion of the outer shroud 1 by means of an impingement plate 8. A portion of the steam of the passage 10A is introduced from the impingement plate 25 to a steam sump 24 to cool the central portion of the inner shroud 21 and pass through the passage 10D to be recovered from the steam outlet port 12.
    Type: Grant
    Filed: December 21, 1998
    Date of Patent: November 7, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Kenichi Arase, Hiroki Fukuno, Hideki Murata, Kiyoshi Suenaga, Tsuyoshi Kitamura
  • Patent number: 6099253
    Abstract: A gas turbine rotor blade has a plurality of first cooling holes for the flow of a cooling gas bored in a blade portion along its lengthwise direction and a plurality of second cooling holes for flow of the cooling gas bored in a shroud along its plane direction so as to communicate with the first cooling holes, and is constructed such that the cooling gas can flow in a uniform distribution. The plurality of the first cooling holes 3 for flow of the cooling gas are bored in the blade portion 2 and the plurality of the second cooling holes 5 for flow of the cooling gas are bored in the shroud 1 along its plane direction. The second cooling holes 5 communicate with the first cooling holes 3, hole to hole, via two-step holes 4, and the second cooling holes 5 are bored alternately on the dorsal side and the ventral side of the rotor blade.
    Type: Grant
    Filed: December 1, 1998
    Date of Patent: August 8, 2000
    Assignee: Mitsubishi Heavy Industries, Inc.
    Inventors: Ichiro Fukue, Eiji Akita, Kiyoshi Suenaga, Yasuoki Tomita
  • Patent number: 6099244
    Abstract: In the present invention, seal air passes through a tube extending in a stationary blade from an outside shroud to an inside shroud, flows into a cavity to keep the pressure in the cavity high so as to seal the high-temperature combustion gas, and is discharged to a passage. Part of cooling air flows into an air passage to cool the leading edge portion, passes through the peripheral portion of the inside shroud to cool the same, and is discharged to a passage. The remaining cooling air flows into a passage, passes through a serpentine cooling flow path consisting of air passages having turbulators, and is discharged through air cooling holes formed at the trailing edge. The cooling air passing through the passage at the leading edge portion cools the peripheral portion of the inside shroud as well as the leading edge portion of blade, by which the cooling efficiency is increased.
    Type: Grant
    Filed: March 11, 1998
    Date of Patent: August 8, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Hiroki Fukuno, Kiyoshi Suenaga
  • Patent number: 6092991
    Abstract: A gas turbine blade having a platform and a turbine wheel plate, in which cooling passages are arranged in a plurality of rows and connected to one another in a blade trunk section of a moving blade and a supply-side passage and a discharge-side passage are formed in a blade root section. The gas turbine blade comprises a pocket having an inlet and an outlet formed in the blade root section. The supply-side passage is connected to one of the cooling passages and the inlet of the pocket, the outlet of the pocket is connected to another of the cooling passages, and the discharge-side passage is connected to one of the cooling passages other than the ones connected individually to the supply-side passage and the pocket.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: July 25, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Taku Ichiryu, Kiyoshi Suenaga
  • Patent number: 6092983
    Abstract: In a cooled stationary blade assembly for a gas turbine, an interior of a blade and an inner shroud are cooled by steam to eliminate the use of air cooling. Steam passages 33A, 33B, 33C, 33D, 33E and 33F are provided in the stationary blade 30. The cooling steam 39 is introduced from the steam passage 33A on the front edge side through an outer shroud and passes, in order, through the steam passages 33B, 33C, 33D, and 33E to flow into the steam passage 33F at the rear edge side to cool the interior of the blade, and is recovered through the outer shroud from the upper portion of the steam passage 33F. A portion of the steam from the steam passage 33A is introduced into the inner shroud 31, enters to steam passages 20 from a steam introduction passage 22, branches to the right and left through both end portions, and flows out into the steam passage 33F at the rear edge from a steam discharge passage 21.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: July 25, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Sunao Aoki, Kiyoshi Suenaga, Tatsuo Ishiguro
  • Patent number: 6089826
    Abstract: A gas turbine cooled blade has leading edge turbulators. A rounded tip portion of the leading edge portion cooling passage (3) is approximated by a triangular cooling passage (1) having orthogonal turbulators (11, 12) and a smoothly curved rear portion thereof of the leading edge portion cooling passage (3) is approximated by a square cooling passage 2 having oblique turbulators (13, 14).
    Type: Grant
    Filed: November 9, 1998
    Date of Patent: July 18, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Sunao Aoki, Hiroki Fukuno, Kiyoshi Suenaga
  • Patent number: 6079946
    Abstract: In the cooling system for the gas turbine blade, the apparatus of the present disclosure ensures cooling of the trailing edge part of the blade for which machining is difficult, while aiming at improvement of the thermal efficiency. The steam cooling structure for carrying out heat recovery-type steam cooling is employed to the leading edge part and the central part of the blade where machining is easy because of its large thickness, and the convection cooling end film cooling are employed for the trailing edge part of the blade where the thickness is small, using steam cooling and air cooling at the same time.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: June 27, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kiyoshi Suenaga, Sunao Aoki, Kazuo Uematsu
  • Patent number: 6077034
    Abstract: In the present disclosure, an air pipe extends through a stationary blade between outer and inner shrouds. Further, an air passage is directed to a lower portion of the stationary blade and is communicated with the air pipe so that a serpentine cooling passage is formed. The air enters a cavity from the air passage and is discharged to a gas passage through an air hole, a passage and a seal. Thus, the cavity is sealed at a high pressure. Cooling air is supplied from the air passage to a rotating blade through a cooling air hole, a cooling air chamber, a radial hole and a lower portion of a platform. The stationary blade is cooled by the air through the air passage. The cooling air can be supplied to the rotating blade at a low temperature and a high pressure as they are. Accordingly, the air can be also supplied to the rotating blade when a rotor is cooled by vapor.
    Type: Grant
    Filed: March 11, 1998
    Date of Patent: June 20, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Hiroki Fukuno, Yukihiro Hashimoto, Kiyoshi Suenaga
  • Patent number: 6065931
    Abstract: A gas turbine moving blade, which has a blade root section, a wing section, and a platform section, comprises a refrigerant supply port provided in the blade root section, a refrigerant recovery port provided in the blade root section, a serpentine passage provided in the wing section and communicating with the refrigerant supply port and the refrigerant recovery port, and a convection-cooling passage provided in the platform section and allowing sealing air and a refrigerant for cooling the platform section by convection to pass therein.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: May 23, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kiyoshi Suenaga, Yoshikuni Kasai, Kazuo Uematsu
  • Patent number: 6039531
    Abstract: The present disclosure provides a gas turbine blade in which the tip end thereof is cooled effectively to decrease the metal temperature for the prevention of burning and the temperature gradient of blade metal is decreased to prevent the occurrence of cracking. In the gas turbine blade provided with a cooling passage therein, a protrusion is provided inwardly of the peripheral walls of the blade, which define the blade profile and the protrusion is positioned on the outer surface of blade tip end wall directly above a cooling passage within the blade.
    Type: Grant
    Filed: March 3, 1998
    Date of Patent: March 21, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kiyoshi Suenaga, Yasuoki Tomita, Hiroki Fukuno
  • Patent number: 6036436
    Abstract: There is provided a cooled stationary blade of a gas turbine in which the portions which can be cooled sufficiently by air are air-cooled, and the portions which are difficult to cool by air are steam-cooled, by which high temperatures can be overcome. In a stationary blade 1, there is formed a serpentine passage 3 in which cooling steam flows and an air passage 10 adjacent to the trailing edge portion and separated from the serpentine passage 3. Also, an outside shroud 4 is formed with an air cooling passage 16 at the outer edge portion and a steam impingement cooling portion 17 and an air impingement cooling portion 18 on the inside of the air cooling passage 16. An inside shroud 11 is provided with an air cooling passage 19 at the outer edge portion and shaped holes 20 formed on the inside of the air cooling passage 19. The air flowing out through the shaped holes 20 performs film cooling.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: March 14, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Hiroki Fukuno, Yasuoki Tomita, Kiyoshi Suenaga
  • Patent number: 6036440
    Abstract: The present invention relates to a gas turbine cooled moving blade in order to cool the gas turbine using steam alone. In the moving blade, two cavities are installed in the lower part of the moving blade root section of the moving blade, a steam inlet is located in one cavity, and a steam outlet is installed in the other cavity. Steam is charged from the steam inlet and passes through a serpentine cooling passage consisting of a plurality of steam passages, and discharged to the steam outlet and collected. Bypasses are located near the base of the moving blade in the middle of each steam passage, so that cold steam on the leading edge side can be led into the bypass, mixed with the hot steam which comes from the tip section side and goes into the next downstream section of the steam passage, and flows to an upstream portion of the steam passage, thereby equalizing the steam temperature and cooling the steam over the entire range from the upstream to downstream of the steam flow.
    Type: Grant
    Filed: April 1, 1998
    Date of Patent: March 14, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Hiroki Fukuno, Kiyoshi Suenaga
  • Patent number: 6019579
    Abstract: A gas turbine rotating blade comprises a serpentine passage provided in the blade width direction in plural rows in a blade profile portion except the portion near the trailing edge having a small blade thickness, a steam cooling passage provided around the outer periphery of a platform, an air passage provided in the blade width direction in the vicinity of the trailing edge of blade profile portion, an impingement plate provided under the platform on the inside of the steam cooling passage, slot holes formed so as to branch off from the air passage and be directed to the trailing edge, and slits formed in the platform above the impingement plate. Therefore, the blade profile portion is cooled by the steam passing through the serpentine passage and the air passing through the air passage, so that the cooling construction is not complicated, and cooling is performed effectively. For the platform, the outer periphery thereof is cooled by steam and the inside thereof by air effectively.
    Type: Grant
    Filed: March 9, 1998
    Date of Patent: February 1, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Hiroki Fukuno, Yasuoki Tomita, Kiyoshi Suenaga
  • Patent number: 6019573
    Abstract: In a steam cooled type gas turbine, taking the effect of efficiency and power output into consideration, a rear stage is sufficiently cooled by air in place of cooling all of the stages by steam. In a rotor of the gas turbine having a steam cooled moving blade, a moving blade disposed in a front stage is cooled by steam, and a moving blade disposed at the rear stage is cooled by cooling air through a stationary blade disposed in front of the moving blade at the rear stage.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: February 1, 2000
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kazuo Uematsu, Kiyoshi Suenaga
  • Patent number: 5997245
    Abstract: The invention relates to a cooled shroud in a gas turbine stationary blade which is able to flow a cooling air in the entire area of an inner shroud for cooling thereof. Three stationary blades are fixed to the inner shroud 2, a cover 13, 14 is provided to form a space 21 and space 22a, 22b and 22c, respectively. The cooling air is introduced through an independent air passage 3A of a leading edge of each stationary blade into the spaces 22a, 22b and 22c and is flown therefrom through a tunnel 18 and air reservoirs 19-2, 19-3 and 19-4 to be blown out of a trailing edge while cooling surfaces of the shrouds and the trailing edges. Also, a portion of the cooling air from the space 22b is flown into the space 21 through a tunnel 11, a leading edge side passage 12 and an endmost tunnel 11 and is then blown out of the trailing edge through a tunnel 18 and an air reservoir 19-1, so that the leading edge portion, the endmost portion and the endmost trailing edge portion are cooled.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: December 7, 1999
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Hiroki Fukuno, Hideki Murata, Kiyoshi Suenaga
  • Patent number: 5980202
    Abstract: A gas turbine stationary blade having a cooling medium passage and outer and inner shrouds in a blade section, comprising a hollow portion in the blade section, the hollow portion including a plurality of chambers divided in the chord direction, the cooling medium passage being formed by connecting the divided chambers in series, one of the chambers located in the center with respect to the chord direction being formed as a sealing air passage in order to allow a cooling medium to flow from the outside of the outer shroud to the bore of the inner shroud.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: November 9, 1999
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yasuoki Tomita, Kiyoshi Suenaga, Taku Ichiryu