Patents by Inventor Tsutomu Okusawa
Tsutomu Okusawa 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).
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Patent number: 8349505Abstract: A fuel cell power generation system of the invention includes a hydrogen supply unit for reforming hydrocarbon fuel to generate reformed gas including hydrogen or generating reaction gas including the hydrogen from a hydrogen material, an oxygen supply unit, a fuel cell for receiving the hydrogen from the hydrogen supply unit and oxygen from the oxygen supply unit, for power generation, temperature sensors each for detecting a temperature of the hydrogen supply unit, and a temperature control unit for adjusting generated power, thereby controlling the temperature of the hydrogen supply unit, based on the detected temperature. The temperature control unit includes a target power setting unit for setting first and second target powers as generated power target values, and a target power switching unit for performing target value switching between the first and second target powers according to a predetermined change in the detected temperature.Type: GrantFiled: August 31, 2005Date of Patent: January 8, 2013Assignee: Hitachi, Ltd.Inventors: Takaaki Mizukami, Hidekazu Fujimura, Tsutomu Okusawa
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Patent number: 8277996Abstract: A fuel cell according to the present invention comprises a membrane electrode assembly, a bipolar plate for guiding a reaction gas to the membrane electrode assembly, two layers of coolant flow fields formed on the bipolar plane opposite to another plane on which a reaction gas flow field is formed, and an interlayer separation plate; wherein the interlayer separation plate separates the two layers of coolant flow fields and has permeability or jet orifices so as to allow a coolant to pass through.Type: GrantFiled: August 28, 2007Date of Patent: October 2, 2012Assignee: Hitachi, Ltd.Inventors: Tsutomu Okusawa, Masaya Kozakai, Hidekazu Fujimura, Ko Takahashi
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Publication number: 20120082915Abstract: A polymer electrolyte membrane fuel cell of the present invention has a simple structure in a cooling part and is small. The polymer electrolyte membrane fuel cell includes a membrane electrode assembly, a porous gas flow field for anode which is conductive and supplies fuel gas, a porous gas flow field for cathode which is conductive and supplies oxidant gas, and a bipolar plate which separates the fuel gas flow field and the oxidant gas flow field. Channels are formed in a surface of the porous gas flow field for cathode, the surface facing the bipolar plate. Preferably, plural concave portions are provided in at least one surface of flow field walls forming the channels. Preferably, the oxidant gas is mixed with cooling water and the mixture is supplied to the porous gas flow field for cathode.Type: ApplicationFiled: September 8, 2011Publication date: April 5, 2012Applicant: Hitachi, Ltd.Inventors: Masaya Kozakai, Tsutomu Okusawa
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Patent number: 8137856Abstract: Excellent gas sealing properties were difficult to achieve with a structure that uses a meal material to control material cost and does not increase the number of components. A cell is configured by using a metal separator having at least one protruding structure between a manifold and an electrode channel, and having a communicating channel structure that forms a fluid circulating space by being folded back at the side containing a connection so that the tip of the protruding structure is in contact with a surface of the separator. Accordingly, a gas channel from the manifold to an electrode surface can be easily formed integrally. This can be applied to a metal material easily. Further, the present invention can provide excellent gas sealing properties.Type: GrantFiled: February 13, 2009Date of Patent: March 20, 2012Assignee: Hitachi, Ltd.Inventors: Kenji Yamaga, Tsutomu Okusawa, Masaya Kozakai
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Publication number: 20110229787Abstract: A proton exchange membrane fuel cell stack comprises a plurality of stacked unit cells, the unit cells each including: a membrane electrode assembly; an anode side-conductive gas diffusion layer and an anode side-fuel gas flow field to feed a fuel gas to an anode of the membrane electrode assembly; and a cathode side-conductive gas diffusion layer and a cathode side-oxidant gas flow field to feed an oxidant gas to a cathode of the membrane electrode assembly; and a bipolar plate for separating between the anode side-fuel flow field and the cathode side-oxidant gas flow field. Then, the fuel gas flow field and the oxidant gas flow field are constituted by respective porous media flow fields each which is a conductive porous medium, and the porous media flow field for the oxidant gas flow field is configured so that liquid water is supplied mixedly together with the oxidant gas thereto.Type: ApplicationFiled: February 25, 2011Publication date: September 22, 2011Inventors: Masaya KOZAKAI, Tsutomu Okusawa
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Publication number: 20110076590Abstract: The object of the present invention is to provide a bipolar plate for a fuel cell, suppressing the stay of condensed water in a gas diffusion layer and improving gas diffusion performance. The bipolar plate supplies reaction gas to a power generating surface and has a channel for the reaction gas. The channel is formed with ribs which are made of a conductive material laminate. The ribs have a porous structure and water repellency. The water repellency of the ribs is set lower than that of an adjacent gas diffusion layer. Thus, the condensed water can be moved from the gas diffusion layer to the ribs in an area where the gas diffusion layer and the ribs are in contact with each other. Therefore, deterioration of the gas diffusion performance due to the stay of the condensed water in the gas diffusion layer can be prevented.Type: ApplicationFiled: August 18, 2010Publication date: March 31, 2011Inventors: Masaya KOZAKAI, Tsutomu Okusawa, Ko Takahashi, Hiroyuki Satake
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Publication number: 20100209803Abstract: Excellent gas sealing properties were difficult to achieve with a structure that uses a meal material to control material cost and does not increase the number of components. A cell is configured by using a metal separator having at least one protruding structure between a manifold and an electrode channel, and having a communicating channel structure that forms a fluid circulating space by being folded back at the side containing a connection so that the tip of the protruding structure is in contact with a surface of the separator. Accordingly, a gas channel from the manifold to an electrode surface can be easily formed integrally. This can be applied to a metal material easily. Further, the present invention can provide excellent gas sealing properties.Type: ApplicationFiled: February 13, 2009Publication date: August 19, 2010Inventors: Kenji YAMAGA, Tsutomu Okusawa, Masaya Kozakai
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Publication number: 20080248346Abstract: A methanol water solution circulation system having a smaller heat capacity than that of a methanol water solution circulation system used at time of regular operation or a methanol water solution circulation system having a small total volume is installed for startup. Startup fuel is supplied to an anode, and the temperature thereof is raised using heat generation action of the fuel cell, thus the temperature of the cell rises. Fuel at the exit of the anode is circulated again to the entrance of the anode, and the processing is repeated, thus the power generation cell is heated up to the operating temperature.Type: ApplicationFiled: April 2, 2008Publication date: October 9, 2008Inventors: Hidekazu Fujimura, Tsutomu Okusawa
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Publication number: 20080081239Abstract: A fuel cell according to the present invention comprises a membrane electrode assembly, a bipolar plate for guiding a reaction gas to the membrane electrode assembly, two layers of coolant flow fields formed on the bipolar plane opposite to another plane on which a reaction gas flow field is formed, and an interlayer separation plate; wherein the interlayer separation plate separates the two layers of coolant flow fields and has permeability or jet orifices so as to allow a coolant to pass through.Type: ApplicationFiled: August 28, 2007Publication date: April 3, 2008Inventors: Tsutomu OKUSAWA, Masaya KOZAKAI, Hidekazu FUJIMURA, Ko TAKAHASHI
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Patent number: 7091625Abstract: During a time zone where a power demand is smaller than an average value of the entire power demands of homes, an excess portion obtained by subtracting a power demand from a base power portion supplied by PEFC (1) is charged in a capacitor (7) and a lead storage battery (8) in advance; and during a time zone where a power demand is larger than the average value, a peak power portion exceeding this average value is discharged from the capacitor (7) and the lead storage battery (8); thereby enabling the system to sufficiently meet daily home-use demand with requisite minimum equipment while effectively using surplus power. Thus, energy efficiency can be enhanced without wasting energy, and also cost efficiency can be improved.Type: GrantFiled: April 7, 2004Date of Patent: August 15, 2006Assignee: Hitachi, Ltd.Inventors: Tsutomu Okusawa, Osamu Yokomizo, Toshiki Kahara, Kouichi Chino, Takaaki Mizukami, Shin Takahashi
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Publication number: 20060046109Abstract: A fuel cell power generation system of the invention includes a hydrogen supply unit for reforming hydrocarbon fuel to generate reformed gas including hydrogen or generating reaction gas including the hydrogen from a hydrogen material, an oxygen supply unit, a fuel cell for receiving the hydrogen from the hydrogen supply unit and oxygen from the oxygen supply unit, for power generation, temperature sensors each for detecting a temperature of the hydrogen supply unit, and a temperature control unit for adjusting generated power, thereby controlling the temperature of the hydrogen supply unit, based on the detected temperature. The temperature control unit includes a target power setting unit for setting first and second target powers as generated power target values, and a target power switching unit for performing target value switching between the first and second target powers according to a predetermined change in the detected temperature.Type: ApplicationFiled: August 31, 2005Publication date: March 2, 2006Inventors: Takaaki Mizukami, Hidekazu Fujimura, Tsutomu Okusawa
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Publication number: 20040212194Abstract: During a time zone where a power demand is smaller than an average value of the entire power demands of homes, an excess portion obtained by subtracting a power demand from a base power portion supplied by PEFC (1) is charged in a capacitor (7) and a lead storage battery (8) in advance; and during a time zone where a power demand is larger than the average value, a peak power portion exceeding this average value is discharged from the capacitor (7) and the lead storage battery (8); thereby enabling the system to sufficiently meet daily home-use demand with requisite minimum equipment while effectively using surplus power. Thus, energy efficiency can be enhanced without wasting energy, and also cost efficiency can be improved.Type: ApplicationFiled: April 7, 2004Publication date: October 28, 2004Inventors: Tsutomu Okusawa, Osamu Yokomizo, Toshiki Kahara, Kouichi Chino, Takaaki Mizukami, Shin Takahashi
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Patent number: 6688106Abstract: A waste-to-energy incineration system, in which the amount and heat value of exhaust gas largely changes in long and short periods, comprises an incinerator for burning waste, a boiler in the incinerator for generating steam with exhaust heat generated by the incinerator, a superheater for superheating steam generated in the boiler, a steam turbine driven by steam superheated by the superheater, a generator driven by the steam turbine, a fuel reformer for reforming source fuel, and a combustor burning fuel gas reformed by the fuel reformer and at least a part of exhaust gas led from the incinerator which is able to stably decompose generated dioxin in waste incineration exhaust gas.Type: GrantFiled: February 13, 2001Date of Patent: February 10, 2004Assignee: Hitachi, Ltd.Inventors: Tsutomu Okusawa, Kazuhito Koyama, Masahiko Yamagishi, Shigeo Hatamiya, Taiko Ajiro, Megumi Sunou, Yukio Ishigaki, Kenji Tokunaga
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Patent number: 6442938Abstract: A waste-to-energy incineration system, in which the amount and the heat value of exhaust gas largely changes in long and a short periods, comprises an incinerator for burning waste, a boiler in the incinerator for generating steam with exhaust heat generated by the incinerator, a superheater for superheating steam generated in the boiler, a steam turbine driven by steam superheated by the superheater, a generator driven by the steam turbine, a fuel reformer for reforming source fuel, and a combustor burning fuel gas reformed by the fuel reformer and at least a part of exhaust gas led from the incinerator which is able to stably decompose generated dioxin in waste incineration exhaust gas.Type: GrantFiled: February 13, 2001Date of Patent: September 3, 2002Assignee: Hitachi, Ltd.Inventors: Tsutomu Okusawa, Kazuhito Koyama, Masahiko Yamagishi, Shigeo Hatamiya, Taiko Ajiro, Megumi Sunou, Yukio Ishigaki, Kenji Tokunaga
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Publication number: 20010032468Abstract: A waste-to-energy incineration system, in which the amount and the heat value of exhaust gas largely changes in a long and a short periods, comprises an incinerator for burning waste, a boiler in the incinerator for generating steam with exhaust heat generated by the incinerator, a superheater for superheating steam generated in the boiler, a steam turbine driven by steam superheated by the superheater, a generator driven by the steam turbine, a fuel reformer for reforming source fuel, and a combustor burning fuel gas reformed by the fuel reformer and at least a part of exhaust gas led from the incinerator which are able to stably decompose generated dioxin, whereby it becomes possible to stably and almost completely decompose dioxin in waste incineration exhaust gas.Type: ApplicationFiled: February 13, 2001Publication date: October 25, 2001Applicant: Hitachi, Ltd.Inventors: Tsutomu Okusawa, Kazuhito Koyama, Masahiko Yamagishi, Shigeo Hatamiya, Taiko Ajiro, Megumi Sunou, Yukio Ishigaki, Kenji Tokunaga
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Publication number: 20010032451Abstract: A waste-to-energy incineration system, in which the amount and the heat value of exhaust gas largely changes in a long and a short periods, comprises an incinerator for burning waste, a boiler in the incinerator for generating steam with exhaust heat generated by the incinerator, a superheater for superheating steam generated in the boiler, a steam turbine driven by steam superheated by the superheater, a generator driven by the steam turbine, a fuel reformer for reforming source fuel, and a combustor burning fuel gas reformed by the fuel reformer and at least a part of exhaust gas led from the incinerator which are able to stably decompose generated dioxin, whereby it becomes possible to stably and almost completely decompose dioxin in waste incineration exhaust gas.Type: ApplicationFiled: February 13, 2001Publication date: October 25, 2001Applicant: Hitachi, Ltd.Inventors: Tsutomu Okusawa, Kazuhito Koyama, Masahiko Yamagishi, Shigeo Hatamiya, Taiko Ajiro, Megumi Sunou, Yukio Ishigaki, Kenji Tokunaga
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Patent number: 6282902Abstract: A waste-to-energy incineration system, in which the amount and heat value of exhaust gas largely changes in long and short periods, comprises an incinerator for burning waste, a boiler in the incinerator for generating steam with exhaust heat generated by the incinerator, a superheater for superheating steam generated in the boiler, a steam turbine driven by steam superheated by the superheater, a generator driven by the steam turbine, a fuel reformer for reforming source fuel, and a combustor burning fuel gas reformed by the fuel reformer and at least a part of exhaust gas led from the incinerator which is able to stably decompose generated dioxin in waste incineration exhaust gas.Type: GrantFiled: June 30, 1999Date of Patent: September 4, 2001Assignee: Hitachi, Ltd.Inventors: Tsutomu Okusawa, Kazuhito Koyama, Masahiko Yamagishi, Shigeo Hatamiya, Taiko Ajiro, Megumi Sunou, Yukio Ishigaki, Kenji Tokunaga
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Patent number: 6058856Abstract: A waste-to-energy incineration system, in which the amount and the heat value of exhaust gas changes during operation, includes an incinerator for burning waste, a boiler in the incinerator for generating steam with exhaust heat generated by the incinerator, and a superheater for superheating steam generated in the boiler. A steam turbine is provided which is driven by steam superheated by the superheater and a generator is driven by the steam turbine. A fuel reformer is provided for reforming source fuel. A combustor burning fuel gas reformed by the fuel reformer and at least a part of exhaust gas fed from the incinerator is provided which decomposes generated dioxin in waste incineration exhaust gas.Type: GrantFiled: April 1, 1998Date of Patent: May 9, 2000Assignee: Hitachi, Ltd.Inventors: Tsutomu Okusawa, Kazuhito Koyama, Masahiko Yamagishi, Shigeo Hatamiya, Taiko Ajiro, Megumi Sunou, Yukio Ishigaki, Kenji Tokunaga
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Patent number: 6014863Abstract: A waste-to-energy incineration system, in which the amount and heat value of exhaust gas largely changes in long and short periods, comprises an incinerator for burning waste, a boiler in the incinerator for generating steam with exhaust heat generated by the incinerator, a superheater for superheating steam generated in the boiler, a steam turbine driven by steam superheated by the superheater, a generator driven by the steam turbine, a fuel reformer for reforming source fuel, and a combustor burning fuel gas reformed by the fuel reformer and at least a part of exhaust gas led from the incinerator which is able to stably decompose generated dioxin in waste incineration exhaust gas.Type: GrantFiled: October 28, 1997Date of Patent: January 18, 2000Assignee: Hitachi, Ltd.Inventors: Tsutomu Okusawa, Kazuhito Koyama, Masahiko Yamagishi, Shigeo Hatamiya, Taiko Ajiro, Megumi Sunou, Yukio Ishigaki
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Patent number: 5238547Abstract: A gas-liquid separation method for electroconductive gas-liquid two phase flow and the device therefor wherein electrodes are disposed in the vicinity of inlet and outlet portions of the gas-liquid separation region in the flow passage of electroconductive gas-liquid two phase flow so as to flow an electric current thereto. A magnet is disposed in the gas-liquid separation region of the flow passage so as to generate a magnetic field perpendicular to the current and to generate an electromagnetic force acting along the flow passage wall on the electroconductive liquid by taking advantage of the Flemming's left hand law, thereby separating the electroconductive gas-liquid two phase flow into gas phase and liquid phase. A hydrophobic porous material having water permeability is employed as the flow passage wall in the gas-liquid separation region; the gas-liquid separation region is disposed in a reduced pressure region; and the separated gas phase is effectively removed out of the flow passage.Type: GrantFiled: December 22, 1989Date of Patent: August 24, 1993Assignee: Hitachi, Ltd.Inventors: Kuniyoshi Tsubouchi, Tsutomu Okusawa, Nobuo Hamano