Patents by Inventor Yoshitomo Asai

Yoshitomo Asai 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: 10497955
    Abstract: A fuel cell system includes a supply valve for supplying an anode gas into an anode system, a purge valve for discharging an off-gas from the anode system, a pressure detecting portion configured to estimate or measures a pressure inside the anode system, a supply valve control portion configured to control an open/close operation of the supply valve based on a load of the fuel cell, a purge flow rate estimating portion configured to estimate a purge flow rate of the off-gas discharged from the anode system through the purge valve based on a pressure decrease inside the anode system in a supply valve close state, and a purge valve control portion configured to open the purge valve in synchronization with the supply valve close state.
    Type: Grant
    Filed: September 16, 2015
    Date of Patent: December 3, 2019
    Assignee: NISSAN MOTOR CO., LTD.
    Inventor: Yoshitomo Asai
  • Patent number: 10388972
    Abstract: In order to improve estimation accuracy of a purging amount, a fuel cell system comprises a supply valve that controls a supply of an anode gas into an anode system, a purge valve that discharges an off-gas from the anode system, a pressure detecting unit configured to estimate or measures a pressure inside the anode system, and a purging amount estimating unit configured to estimate a purging amount of the off-gas discharged from the anode system through the purge valve based on a pressure change inside the anode system during a purge valve close duration in a supply valve open state and a pressure change inside the anode system during a purge valve close duration in a supply valve close state.
    Type: Grant
    Filed: September 17, 2015
    Date of Patent: August 20, 2019
    Assignee: NISSAN MOTOR CO., LTD.
    Inventor: Yoshitomo Asai
  • Patent number: 10340540
    Abstract: A fuel cell system comprising: a supply valve for supplying the anode gas into an anode system of the fuel cell system; a purge valve for discharging an off-gas from the anode system; a pressure detecting portion that estimates or measures a pressure inside the anode system; and a hydrogen concentration estimating portion that estimates a hydrogen concentration inside the anode system based on a pressure decrease during a purge valve open duration in a supply valve close state.
    Type: Grant
    Filed: September 17, 2015
    Date of Patent: July 2, 2019
    Assignee: NISSAN MOTOR CO., LTD.
    Inventor: Yoshitomo Asai
  • Patent number: 10141587
    Abstract: A fuel cell system includes a supply unit configured to supply cathode gas to a fuel cell, a bypass valve configured to bypass the cathode gas to be supplied to the fuel cell by the supply unit, a detection unit configured to detect a state of the cathode gas to be supplied to the fuel cell without being bypassed by the bypass valve, a pressure adjusting unit configured to adjust a pressure of the cathode gas to be supplied to the fuel cell, a calculation unit configured to calculate a target flow rate and a target pressure of the cathode gas to be supplied to the fuel cell according to an operating state of the fuel cell, an operating state control unit configured to control an operation amount of at least one of the pressure adjusting unit and the supply unit on the basis of a flow rate and the pressure of the cathode gas detected by the detection unit and the target flow rate and the target pressure calculated by the calculation unit, a bypass valve control unit configured to open and close the bypass valv
    Type: Grant
    Filed: August 20, 2014
    Date of Patent: November 27, 2018
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Yoshitomo Asai, Hiroshi Takeda
  • Patent number: 10141590
    Abstract: A fuel cell system includes a compressor, a relief valve that adjusts a pressure of a cathode gas, a pulsation operation unit that pulsates an anode gas pressure, a target flow rate setting unit that sets a target flow rate of the cathode gas, a first target pressure setting unit that sets a first target pressure of the cathode gas, a second target pressure setting unit that sets a second target pressure of the cathode gas for maintaining a pressure difference between an anode and a cathode within a predetermined allowable range, a target pressure setting unit that sets the higher one of the first and second target pressures as a target pressure, and a control unit that controls the compressor on the basis of the target flow rate and a limitative pressure obtained by limiting pulsation of the target pressure.
    Type: Grant
    Filed: June 5, 2014
    Date of Patent: November 27, 2018
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Yoshitomo Asai, Hiroshi Takeda
  • Publication number: 20180294497
    Abstract: A fuel cell system comprising: a supply valve for supplying the anode gas into an anode system of the fuel cell system; a purge valve for discharging an off-gas from the anode system; a pressure detecting portion that estimates or measures a pressure inside the anode system; and a hydrogen concentration estimating portion that estimates a hydrogen concentration inside the anode system based on a pressure decrease during a purge valve open duration in a supply valve close state.
    Type: Application
    Filed: September 17, 2015
    Publication date: October 11, 2018
    Applicant: Nissan Motor Co., Ltd.
    Inventor: Yoshitomo ASAI
  • Patent number: 9960440
    Abstract: A fuel cell system includes a compressor for supplying the cathode gas to the fuel cell, an anode gas discharge system for discharging anode off-gas discharged from the fuel cell into a cathode gas flow passage, a pulsating operation control unit for causing a pressure of the anode gas to pulsate based on an operating state of the fuel cell, a purge control unit for purging the anode off-gas into the cathode gas flow passage based on an impurity concentration of an anode of the fuel cell and a pressure of the anode, and a compressor control unit for controlling the compressor based on a purge flow rate controlled by the purge control unit, and the purge control unit for setting the pressure of the anode to a predetermined value determined according to a pulsating state of the anode gas.
    Type: Grant
    Filed: July 16, 2014
    Date of Patent: May 1, 2018
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Yoshitomo Asai, Yousuke Tomita
  • Patent number: 9905867
    Abstract: A fuel cell system sets the larger one of a stack request compressor supply flow rate calculated based on a request of a fuel cell stack and a system request compressor supply flow rate calculated based on a request by the fuel cell system as a target compressor supply flow rate and controls a compressor according to the target compressor supply flow rate. The fuel cell system also controls a bypass valve based on a stack supply flow rate and a target stack supply flow rate to be supplied to the fuel cell stack. The fuel cell system fixes the bypass valve or limits the drive of the bypass valve when the system request compressor supply flow rate is set as the target compressor supply flow rate and the stack supply flow rate becomes smaller than the target stack supply flow rate.
    Type: Grant
    Filed: November 13, 2013
    Date of Patent: February 27, 2018
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Yoshitomo Asai, Hiroshi Takeda
  • Patent number: 9876242
    Abstract: A fuel cell system (100) includes a hydrogen supply valve (33) that controls a supply of the anode gas into an anode system, a purge valve (36) that discharges an off-gas from the anode system, a pressure detecting unit (34) configured to measure a pressure inside the anode system, and a purge flow rate estimating unit (4) configured to estimate a purge flow rate of the off-gas discharged from the anode system through the purge valve (36) based on a pressure decrease in a purge valve open state and a pressure decrease in a purge valve close state when an anode gas supply into the anode system stops.
    Type: Grant
    Filed: September 16, 2015
    Date of Patent: January 23, 2018
    Assignee: NISSAN MOTOR CO., LTD.
    Inventor: Yoshitomo Asai
  • Publication number: 20180006319
    Abstract: In order to improve estimation accuracy of a purging amount, a fuel cell system comprises a supply valve that controls a supply of an anode gas into an anode system, a purge valve that discharges an off-gas from the anode system, a pressure detecting unit configured to estimate or measures a pressure inside the anode system, and a purging amount estimating unit configured to estimate a purging amount of the off-gas discharged from the anode system through the purge valve based on a pressure change inside the anode system during a purge valve close duration in a supply valve open state and a pressure change inside the anode system during a purge valve close duration in a supply valve close state.
    Type: Application
    Filed: September 17, 2015
    Publication date: January 4, 2018
    Applicant: NISSAN MOTOR CO., LTD.
    Inventor: Yoshitomo ASAI
  • Publication number: 20170373334
    Abstract: A fuel cell system includes a supply valve for supplying an anode gas into an anode system, a purge valve for discharging an off-gas from the anode system, a pressure detecting portion configured to estimate or measures a pressure inside the anode system, a supply valve control portion configured to control an open/close operation of the supply valve based on a load of the fuel cell, a purge flow rate estimating portion configured to estimate a purge flow rate of the off-gas discharged from the anode system through the purge valve based on a pressure decrease inside the anode system in a supply valve close state, and a purge valve control portion configured to open the purge valve in synchronization with the supply valve close state.
    Type: Application
    Filed: September 16, 2016
    Publication date: December 28, 2017
    Applicant: NISSAN MOTOR CO., LTD.
    Inventor: Yoshitomo ASAI
  • Patent number: 9853316
    Abstract: A fuel cell system includes a target pressure setting unit configured to periodically and repeatedly set a target upper limit pressure and a target lower limit pressure as a target pressure of anode gas. An upper limit pressure setting unit is configured to set the smaller one of an upper limit value based on durability performance and an upper limit value based on output performance as an upper limit pressure of the anode gas. The target pressure setting unit sets a value smaller than the upper limit value as the target upper limit pressure when the upper limit value based on the durability performance of the fuel cell is selected as the upper limit pressure of the anode gas, and sets a pressure higher than the upper limit value as the target upper limit pressure when the upper limit value based on the output performance is selected.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: December 26, 2017
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Takeaki Obata, Yoshitomo Asai, Hayato Chikugo
  • Patent number: 9853304
    Abstract: A fuel cell system includes a fuel cell, an air supplier, an air passage connected to the fuel cell, air supplied from the air supplier flowing in the air passage, a bleed passage branched off from the air passage on a side upstream of the fuel cell and joining the air passage on a side downstream of the fuel cell, part of the air supplied by the air supplier flowing in the bleed passage in such a manner as to circumvent the fuel cell, a bleed valve provided in the bleed passage, the bleed valve regulating the amount of air flowing in the bleed passage, an air supplier control unit which controls the air supplier to supply a predetermined amount of air, a wetness reduction determination unit which determines whether or not it is necessary to reduce a degree of wetness of the fuel cell, and a bleed amount control unit which reduces an opening of the bleed valve when the degree of wetness of the fuel cell needs to be reduced.
    Type: Grant
    Filed: November 26, 2013
    Date of Patent: December 26, 2017
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Hiroshi Takeda, Yoshitomo Asai
  • Patent number: 9843057
    Abstract: A fuel cell system for generating power by supplying anode gas and cathode gas to a fuel cell, comprising a compressor for supplying the cathode gas to the fuel cell, a pulsating operation unit causing a pressure of the anode gas to pulsate based on an operation state of the fuel cell system, a first target pressure setting unit setting a first target pressure of the cathode gas based on a request of the fuel cell, a second target pressure setting unit setting a second target pressure of the cathode gas for keeping a differential pressure in the fuel cell to be within a permissible differential pressure range according to the pressure of the anode gas in the fuel cell, and a compressor control unit controlling the compressor based on the first target pressure and the second target pressure. The second target pressure setting unit sets the second target pressure based on an upper limit target pressure in pulsation on the pulsation of the pressure of the anode gas.
    Type: Grant
    Filed: July 3, 2014
    Date of Patent: December 12, 2017
    Assignee: NISSAN MOTOR CO., LTD.
    Inventor: Yoshitomo Asai
  • Publication number: 20170352899
    Abstract: A fuel cell system includes a supply unit configured to supply cathode gas to a fuel cell, a bypass valve configured to bypass the cathode gas to be supplied to the fuel cell by the supply unit, a detection unit configured to detect a state of the cathode gas to be supplied to the fuel cell without being bypassed by the bypass valve, a pressure adjusting unit configured to adjust a pressure of the cathode gas to be supplied to the fuel cell, a calculation unit configured to calculate a target flow rate and a target pressure of the cathode gas to be supplied to the fuel cell according to an operating state of the fuel cell, an operating state control unit configured to control an operation amount of at least one of the pressure adjusting unit and the supply unit on the basis of a flow rate and the pressure of the cathode gas detected by the detection unit and the target flow rate and the target pressure calculated by the calculation unit, a bypass valve control unit configured to open and close the bypass valv
    Type: Application
    Filed: August 20, 2014
    Publication date: December 7, 2017
    Applicant: NISSAN MOTOR CO., LTD
    Inventors: Yoshitomo ASAI, Hiroshi TAKEDA
  • Publication number: 20170331129
    Abstract: A fuel cell system (100) includes a hydrogen supply valve (33) that controls a supply of the anode gas into an anode system, a purge valve (36) that discharges an off-gas from the anode system, a pressure detecting unit (34) configured to measure a pressure inside the anode system, and a purge flow rate estimating unit (4) configured to estimate a purge flow rate of the off-gas discharged from the anode system through the purge valve (36) based on a pressure decrease in a purge valve open state and a pressure decrease in a purge valve close state when an anode gas supply into the anode system stops.
    Type: Application
    Filed: September 16, 2015
    Publication date: November 16, 2017
    Applicant: NISSAN MOTOR CO., LTD.
    Inventor: Yoshitomo ASAI
  • Patent number: 9755253
    Abstract: A fuel cell system includes a fuel cell stack, a compressor, a cathode flow passage, a bypass flow passage branching from the cathode flow passage, thereby bypassing the stack, a bypass valve adjusting a bypass flow rate, a stack flow rate sensor detecting a flow rate to the stack, and a compressor flow rate sensor detecting a flow rate into the compressor. A flow rate for the stack depending on a state of a fuel cell and a flow rate the compressor controls depending on a requirement different from that of the stack are calculated. A control unit controls, when the flow rate required from the compressor is more than that required by the stack, the compressor based on the flow rate required from the compressor and a detected compressor flow rate, and controls the bypass valve based on the flow rate required by the stack and a detected stack flow rate.
    Type: Grant
    Filed: February 27, 2013
    Date of Patent: September 5, 2017
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yoshitomo Asai, Hiroshi Takeda
  • Patent number: 9728794
    Abstract: A fuel cell system is configured to: calculate a target stack supply flow rate; calculate a compressor supply flow rate based on a stack supply flow rate and the target stack supply flow rate; set a larger one of the compressor supply flow rate and a lower limit flow rate, determined depending on an operation state of the fuel cell system, as a target compressor supply flow rate; control a bypass valve based on the stack supply flow rate and the target stack supply flow rate; fix the bypass valve when the stack supply flow rate is in a predetermined bypass valve fixing range, and the stack supply flow rate becomes less than the target stack supply flow rate; and release the fixation of the bypass valve when the target compressor supply flow rate becomes more than the lower limit flow rate after the bypass valve is fixed.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: August 8, 2017
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yoshitomo Asai, Hiroshi Takeda
  • Patent number: 9640812
    Abstract: The fuel cell system of the present invention comprises: an electric motor, a fuel cell stack, a fuel supply unit, and a controller that controls a power-plant including the fuel cell stack and the fuel supply unit. The controller comprises further: a stack output-response request computing unit to compute a stack output-response request requested for the fuel cell stack; a stack voltage setup unit during idle-stop to set up a lower limit of stack setup-voltage during idle-stop that is set up as a stack voltage during execution of idle-stop so as to be higher as the stack output-response request is larger, and so as to be lower as the request is smaller; and an operation unit of recovering a stack voltage during idle-stop to execute a recovery operation when an actual stack voltage becomes, during execution of idle-stop, lower than the lower limit of stack setup-voltage during idle-stop.
    Type: Grant
    Filed: April 5, 2012
    Date of Patent: May 2, 2017
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Mitsunori Kumada, Shinichi Makino, Yoshitomo Asai
  • Patent number: 9601790
    Abstract: In a fuel cell system which executes a stop process of stopping an output from a fuel cell when a required power generation amount for the fuel cell is smaller than a predetermined power generation amount and supplies oxidant during a stop process period, fuel gas is intermittently supplied to a fuel electrode at a basic supply interval, which is set in advance and at which carbon dioxide is not generated in an oxidant electrode, during the stop process period.
    Type: Grant
    Filed: April 3, 2012
    Date of Patent: March 21, 2017
    Assignee: NISSAN MOTOR CO., LTD.
    Inventors: Shinichi Makino, Yasushi Ichikawa, Michihiko Matsumoto, Mitsunori Kumada, Yoshitomo Asai