Patents by Inventor Keigo Ikezoe

Keigo Ikezoe 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: 10651486
    Abstract: A fuel cell system includes a fuel cell stack configured to generate power according to a load, a fuel tank configured to store fuel gas, a pressure regulating valve configured to regulate a pressure of the fuel gas supplied from the fuel tank to the fuel cell stack, a purge valve configured to purge the fuel gas discharged from the fuel cell stack and a controller for controlling the system. The controller includes a pulsating unit configured to cause a fuel gas pressure of the fuel cell stack to pulsate, and a pressure increasing rate setting unit configured to set a pressure increasing rate of the pulsation of the fuel gas pressure according to an operating state.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: May 12, 2020
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Susumu Maeshima, Keigo Ikezoe, Yasushi Ichikawa, Takahiro Fujii, Takashi Naka, Daigo Iwasaki
  • Patent number: 10193177
    Abstract: A fuel cell system and method that enables warm-up power generation corresponding to the residual water volume in the fuel cell stack without using auxiliary devices for measuring the residual water volume in the fuel cell stack. A controller computes total generated electrical energy Q by integrating of the generated current detected by current sensor during the period from start-up to shutting down of the fuel cell system, and stores the result in total generated electrical energy storage part. Also, controller measures fuel cell temperature Ts at the last shutting down cycle with temperature sensor, and stores it in power generation shutting down temperature storage part.
    Type: Grant
    Filed: June 9, 2014
    Date of Patent: January 29, 2019
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Takahiro Kaito, Keigo Ikezoe
  • Patent number: 9786931
    Abstract: A fuel cell system 100 includes: a fuel cell 1 for generating a power by causing an electrochemical reaction between an oxidant gas supplied to an oxidant electrode 34 and a fuel gas supplied to a fuel electrode 67; a fuel gas supplier HS for supplying the fuel gas to the fuel electrode 67; and a controller 40 for controlling the fuel gas supplier HS to thereby supply the fuel gas to the fuel electrode 67, the controller 40 being configured to implement a pressure change when an outlet of the fuel electrode 67 side is closed, wherein based on a first pressure change pattern for implementing the pressure change at a first pressure width ?P1, the controller 40 periodically changes a pressure of the fuel gas at the fuel electrode 67.
    Type: Grant
    Filed: November 16, 2009
    Date of Patent: October 10, 2017
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Yasushi Ichikawa, Keigo Ikezoe, Kenichi Goto, Ken Nakayama, Mitsunori Kumada, Yousuke Tomita
  • Patent number: 9350033
    Abstract: A fuel cell system includes a cathode gas supply unit, a cathode pressure detection unit, a fuel cell temperature detection unit configured to detect a temperature of the fuel cell, an internal resistance detection unit configured to detect an internal resistance of the fuel cell, a target cathode flow rate calculation unit configured to calculate a target cathode flow rate necessary for supply to the fuel cell based on an operating state of the fuel cell system, a cathode flow rate estimation unit configured to estimate a flow rate of the cathode gas according to the pressure of the cathode gas, the temperature of the fuel cell and the internal resistance of the fuel cell, and a cathode flow rate control unit configured to control the cathode gas supply unit based on the target cathode flow rate and the estimated flow rate of the cathode gas.
    Type: Grant
    Filed: January 10, 2013
    Date of Patent: May 24, 2016
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Yousuke Tomita, Keigo Ikezoe, Fumio Kagami
  • Patent number: 9269973
    Abstract: Conventional fuel cell systems had the problem of impurity gases flowing back from a buffer tank and a reduction in the voltages of unit cells when the supply pressure of an anode gas is caused to pulsate at startup. An operating method include setting any one of the amplitude and cycle of the pulsation of the supply pressure of the anode gas to a fuel cell stack (FS) in accordance with the permeability of a nitrogen gas from a cathode side to an anode side. The method makes it possible to suppress unnecessary pulsation of the supply pressure of the anode gas at startup, and thus to maintain the concentration of a hydrogen gas in the fuel cell stack (FS) at an optimum level while preventing degradation in the mechanical strength of a membrane electrode structure that constitutes each unit cell (FC) of the fuel cell stack (FS).
    Type: Grant
    Filed: September 27, 2011
    Date of Patent: February 23, 2016
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Hidetaka Nishimura, Keigo Ikezoe, Masashi Sato
  • Patent number: 9166233
    Abstract: An anode gas non-recirculation type fuel cell system includes a fuel cell, a buffer tank for purging impurity gas included in anode off-gas from the fuel cell stack, an impurity gas concentration detector for detecting impurity gas concentration in the buffer tank, and an anode gas supply unit for supplying anode gas to the fuel cell stack. When pressure-supplying impurity gas in the fuel cell stack to the buffer tank while pulsating a supply pressure by the anode gas supply unit, an activation control is executed by changing, by the anode gas supply unit, at least one of a pulsative pressure and a pulsative cycle of anode gas supply according to impurity gas concentration in the buffer tank. According to the system, it is possible to get adequate hydrogen gas concentration in a fuel cell stack and to remove impurity at its activation.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: October 20, 2015
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Hidetaka Nishimura, Keigo Ikezoe, Masashi Sato
  • Publication number: 20150288008
    Abstract: A fuel cell system 100 includes: a fuel cell 1 for generating a power by causing an electrochemical reaction between an oxidant gas supplied to an oxidant electrode 34 and a fuel gas supplied to a fuel electrode 67; a fuel gas supplier HS for supplying the fuel gas to the fuel electrode 67; and a controller 40 for controlling the fuel gas supplier HS to thereby supply the fuel gas to the fuel electrode 67, the controller 40 being configured to implement a pressure change when an outlet of the fuel electrode 67 side is closed, wherein based on a first pressure change pattern for implementing the pressure change at a first pressure width ?P1, the controller 40 periodically changes a pressure of the fuel gas at the fuel electrode 67.
    Type: Application
    Filed: June 17, 2015
    Publication date: October 8, 2015
    Applicant: NISSAN MOTOR CO , LTD.
    Inventors: Yasushi ICHIKAWA, Keigo IKEZOE, Kenichi GOTO, Ken NAKAYAMA, Mitsunori KUMADA, Yousuke TOMITA
  • Patent number: 9147896
    Abstract: A fuel cell system is basically provided with a fuel cell, a pressure adjusting valve, a purge valve and an anode pressure controller. The fuel cell includes an anode that receives an anode gas and a cathode that receives a cathode gas to generate electric power corresponding to a load. The pressure adjusting valve is disposed in a supply path to adjust anode gas pressure to the anode. The purge valve is disposed in a discharging flow path to discharge an anode-off gas containing impurities from the fuel cell. The anode pressure controller is configured to control the pressure adjusting valve to perform a pulsation operation that pulsates the anode gas pressure of the fuel cell. The anode pressure controller decreases a median pressure of the pulsation operation as a wetness level of an electrolyte membrane of the fuel cell stack is determined to become higher.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: September 29, 2015
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Susumu Maeshima, Keigo Ikezoe, Yasushi Ichikawa, Takahiro Fujii, Ryoichi Shimoi, Taiji Nishiyama, Yusuke Ito
  • Patent number: 8999597
    Abstract: Disclosed is a fuel cell provided with a membrane electrode structure having a frame, two separators that sandwich the membrane electrode structure therebetween, and gas seals between the end portion of the frame and the end portions of respective separators, and diffuser sections for distributing a reacting gas to between the frame and respective separators. In the diffuser section on the cathode side, the frame is provided with a protruding section in contact with the separator, and in the diffuser section on the anode side, the frame and the separator are disposed by being spaced apart from each other, thereby excellently maintaining contact surface pressure between the membrane electrode structure and the separators, and preventing contact resistance from being increased.
    Type: Grant
    Filed: April 19, 2011
    Date of Patent: April 7, 2015
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Keigo Ikezoe, Mitsutaka Abe, Takanori Oku, Yasuhiro Numao
  • Publication number: 20150056531
    Abstract: A fuel cell system includes a fuel cell stack configured to generate power according to a load, a fuel tank configured to store fuel gas, a pressure regulating valve configured to regulate a pressure of the fuel gas supplied from the fuel tank to the fuel cell stack, a purge valve configured to purge the fuel gas discharged from the fuel cell stack and a controller for controlling the system. The controller includes a pulsating unit configured to cause a fuel gas pressure of the fuel cell stack to pulsate, and a pressure increasing rate setting unit configured to set a pressure increasing rate of the pulsation of the fuel gas pressure according to an operating state.
    Type: Application
    Filed: March 15, 2013
    Publication date: February 26, 2015
    Inventors: Susumu Maeshima, Keigo Ikezoe, Yasushi Ichikawa, Takahiro Fujii, Takashi Naka, Daigo Iwasaki
  • Publication number: 20150050528
    Abstract: A fuel cell system includes a control valve configured to control a pressure of the anode gas supplied to the fuel cell, the power controller electrically connected to the fuel cell and configured to control an output of the fuel cell based on a power generation required amount for the fuel cell, a pulsation operation control unit configured to increase a pressure of the anode gas downstream of the control valve in accordance with the power generation required amount for the fuel cell and to increase and decrease the pressure of the anode gas periodically, and an output limiting unit configured to limit an output of the fuel cell set by the power controller when the power generation required amount for the fuel cell decreases.
    Type: Application
    Filed: March 12, 2013
    Publication date: February 19, 2015
    Inventors: Takahiro Fujii, Tatsuro Ishikawa, Yasushi Ichikawa, Keigo Ikezoe
  • Publication number: 20150037700
    Abstract: A fuel cell system includes a pressure regulating valve configured to control a pressure of an anode gas to be supplied to a fuel cell, a pulsation operation control means configured to control such that the anode gas pressure becomes higher as a load becomes larger, and the anode gas pressure is pulsated at the same load, and an anode gas pressure limiting means configured to limit the anode gas pressure by a pressure higher than the anode gas pressure according to the load when the load lowers.
    Type: Application
    Filed: February 28, 2013
    Publication date: February 5, 2015
    Inventors: Yasushi Ichikawa, Takahiro Fujii, Keigo Ikezoe, Atsushi Fukunaka, Tatsuro Ishikawa
  • Publication number: 20150030948
    Abstract: A fuel cell system includes a pressure regulating valve for controlling a pressure of an anode gas, a purge valve for controlling a discharge amount of an anode off-gas, the purge valve being configured to change an opening area thereof at least on two stages, a pulsation operation control means configured to control the pressure regulating valve so that the pressure of the anode gas in a fuel cell when a load is high becomes higher than when the load is low, and so that the pressure of the anode gas is periodically increased and decreased at a predetermined load, and a purge valve control means configured to increase the opening area of the purge valve used during a descending transition operation so that the opening area becomes larger than the opening area used during other operations.
    Type: Application
    Filed: March 1, 2013
    Publication date: January 29, 2015
    Inventors: Keigo Ikezoe, Hayato Chikugo, Yasushi Ichikawa
  • Publication number: 20150017562
    Abstract: A fuel cell system includes a pressure regulating valve configured to control a pressure of an anode gas to be supplied to a fuel cell, a buffer unit configured to store an anode off-gas discharged from the fuel cell, and a purge valve configured to control an amount to be discharged to an outside of the anode off-gas stored in the buffer unit. The pressure of the anode gas periodically increases/decreases by periodically opening/closing the pressure regulating valve. The purge valve is controlled so that a purge flow rate increases more during pressure reduction of the pulsation operation than during pressure increase in pulsation operation control.
    Type: Application
    Filed: February 27, 2013
    Publication date: January 15, 2015
    Applicant: Nissan Motor Co., Ltd
    Inventors: Yasushi Ichikawa, Keigo Ikezoe
  • Publication number: 20150004512
    Abstract: A fuel cell system configured to generate power by supplying anode gas and cathode gas to a fuel cell includes a control valve for controlling a pressure of the anode gas to be supplied to the fuel cell, a buffer unit configured to store anode off-gas to be discharged from the fuel cell, a purge valve configured to adjust a flow rate of the anode off-gas discharged from the buffer unit, a pulsating operation unit configured to increase and vary the pressure of the anode gas downstream of the control valve according to a load of the fuel cell, and a purge unit configured to control an opening of the purge valve according to the load of the fuel cell. The purge unit increases the opening of the purge valve controlled according to the load of the fuel cell during a down transient operation in which the load of the fuel cell decreases.
    Type: Application
    Filed: November 21, 2012
    Publication date: January 1, 2015
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Keigo Ikezoe, Hayato Chikugo, Yousuke Tomita, Yasushi Ichikawa
  • Publication number: 20150004506
    Abstract: A fuel cell system includes a cathode gas supply unit, a cathode pressure detection unit, a fuel cell temperature detection unit configured to detect a temperature of the fuel cell, an internal resistance detection unit configured to detect an internal resistance of the fuel cell, a target cathode flow rate calculation unit configured to calculate a target cathode flow rate necessary for supply to the fuel cell based on an operating state of the fuel cell system, a cathode flow rate estimation unit configured to estimate a flow rate of the cathode gas according to the pressure of the cathode gas, the temperature of the fuel cell and the internal resistance of the fuel cell, and a cathode flow rate control unit configured to control the cathode gas supply unit based on the target cathode flow rate and the estimated flow rate of the cathode gas.
    Type: Application
    Filed: January 10, 2013
    Publication date: January 1, 2015
    Inventors: Yousuke Tomita, Keigo Ikezoe, Fumio Kagami
  • Publication number: 20150004513
    Abstract: A fuel cell system that generates power by supplying anode gas and cathode gas to a fuel cell has a control valve that controls pressure of the anode gas supplied to the fuel cell, a pulsation operation unit that causes pulsation of pressure of anode gas in the fuel cell in accordance with a predetermined pressure by controlling an opening degree of the control valve based on an operating condition of the fuel cell system, and a stagnation point determination unit that determines, based on a change in the pressure of the anode gas in the fuel cell, whether or not a stagnation point exists where an anode gas concentration is locally low in the fuel cell. When the stagnation determining unit determines that the stagnation point exists in the fuel cell, the pulsation operation unit increases the predetermined pressure in execution of a pulsation operation.
    Type: Application
    Filed: December 28, 2012
    Publication date: January 1, 2015
    Applicant: Nissan Motor Company, Ltd.
    Inventors: Keigo Ikezoe, Hayato Chikugo, Shinichi Makino
  • Patent number: 8900770
    Abstract: A fuel cell system and a method for controlling the same. The system and method employ a fuel cell stack that generates electrical power by electrochemical reaction of a fuel gas and an oxidant gas, a total generated electrical energy computation device that computes a value pertaining to the total generated electrical energy as the sum of the electrical energy generated by said fuel cell stack from start-up of the fuel cell system, and a residual water volume estimation device that estimates the residual water volume left in the fuel cell stack based on said value pertaining to said total generated electrical energy computed by said total generated electrical energy computation device.
    Type: Grant
    Filed: June 18, 2008
    Date of Patent: December 2, 2014
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Takahiro Kaito, Keigo Ikezoe
  • Publication number: 20140349208
    Abstract: In a fuel cell system including a load and a fuel cell stack connected to the load and supplying an anode gas and a cathode gas to the fuel cell stack to generate power according to the load, the fuel cell system includes, a pressure setting unit configured to set a pressure of the anode gas higher when the load is high as compared with when the load is low, a stagnation point determination unit configured to determine, according to a state of power generation of the fuel cell stack, whether or not a nitrogen stagnation point is left in a reaction flow path within the fuel cell stack, and an operation control unit configured to performs an operation while preventing the pressure of the anode gas from being lowered when a required load is lowered in a state where the nitrogen stagnation point is left.
    Type: Application
    Filed: November 16, 2012
    Publication date: November 27, 2014
    Inventors: Keigo Ikezoe, Hayato Chikugo, Yasushi Ichikawa
  • Publication number: 20140335430
    Abstract: A fuel cell system and method that enables warm-up power generation corresponding to the residual water volume in the fuel cell stack without using auxiliary devices for measuring the residual water volume in the fuel cell stack. A controller computes total generated electrical energy Q by integrating of the generated current detected by current sensor during the period from start-up to shutting down of the fuel cell system, and stores the result in total generated electrical energy storage part. Also, controller measures fuel cell temperature Ts at the last shutting down cycle with temperature sensor, and stores it in power generation shutting down temperature storage part.
    Type: Application
    Filed: June 9, 2014
    Publication date: November 13, 2014
    Inventors: Takahiro KAITO, Keigo IKEZOE