Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Rinnai Corporation

Toyota Technical Development Corporation

Toyota Jidosha Kabushiki Kaihsa

Hiroaki Mori

Naohiro Yoshida

Kenji Kurita

Kenji Umayahara

Nobuo Fujita

Tadaichi Matsumoto

Kimihide Horio

Atsushi Ota

Shinya Sakaguchi

Hidehiko Kadono

Yukihiro Suzuki

Shinichi Yoshida

Masashi Toida

Tomoya Ogawa

Tetsuya Bono

Shigeto Kajiwara

Mitsuhiro Karaki

Keitaro Yamamori

Fusaki Igarashi

Keiji Kato

Hideki Kitagawa

Mahiro Ozeki

Toshiyuki Sanada

Seizi Uda

Seiji Uda

Masatada Nakamichi

A fuel cell system includes a fuel cell including a fuel electrode being supplied with fuel gas and an oxidant electrode being supplied with oxidant gas and generating electric power by causing the fuel gas and the oxidant gas to react with each other, a voltmeter measuring an output voltage of the fuel cell, an ammeter measuring an output current of the fuel cell, a restricting valve provided upstream and downstream of an oxidant electrode side of the fuel cell and being opened in a power generation state and being closed in a stopped state or under the oxygen consuming control, and a load control unit controlling a current value of an output current to be output by the fuel cell and, under the oxygen consuming control, controlling the output voltage of the fuel cell such that the output current reduces as the output voltage of the fuel cell increases.

Fuel cell system

A fuel cell system includes: a fuel cell that is supplied with a reaction gas to generate electricity; a plurality of auxiliary components used for power generation of the fuel cell; and a control device that causes the fuel cell to generate electricity when a predetermined scavenging start condition is satisfied and controls the auxiliary components using electric power generated by the fuel cell to perform a scavenging process of removing water in a flow path of the reaction gas using the reaction gas, during a stop period in which electric power is not supplied to a load from the fuel cell system.

A fuel cell system () includes: a motor (); a fuel cell () and an electrical storage device () connected to the motor () in parallel with each other; a first voltage converter () between the motor () and the fuel cell (); a second voltage converter () between the motor () and the electrical storage device (); a load circuit between the motor () and both the first () and second () voltage converters; and a control unit (). The control unit () stops boost operation of the first voltage converter () when conditions VFC&#x3e;VM_min and VFC&#x3e;VBAT+a whereas the control unit () prohibits a stop of the boost operation of the first voltage converter () when the conditions are not satisfied, wherein in the conditions, VFC is a fuel cell terminal voltage, VBAT is an electrical storage device terminal voltage and VM_min is a load circuit input terminal voltage, set to minimize a system loss while ensuring a torque required of the motor ().

Fuel cell system and control method therefor

There are provided a fuel cell system capable of reducing power consumption by inhibiting an unnecessary operation of a DC-DC converter, and a power control method therefor. The fuel cell system having an inverter which is connected to a load device, a first converter which is connected between a fuel cell and the inverter and sets an output voltage of the fuel cell, and a second converter which is connected between a power storage device and the inverter and sets an input voltage of the inverter includes fuel cell required output voltage calculation means for calculating a required output voltage of the fuel cell, inverter required input voltage calculation means for calculating a required input voltage of the inverter, comparison means for comparing the required output voltage of the fuel cell and the required input voltage of the inverter, and converter operation control means for causing the operation of the first converter to be suspended when judgment is made that the required output voltage of the fuel cell is not less than the required input voltage of the inverter.

Fuel cell system and power control method therefor

A fuel cell system including a fuel cell, and a converter which is connected between the fuel cell and a high voltage system and which sets an output ceiling voltage of the fuel cell, the fuel cell system comprising fuel gas supply stopping means for stopping the supply of fuel gas to the fuel cell in an intermittent operation mode, remaining fuel gas amount determination means for determining whether fuel gas in at least an amount capable of generating power remains in the fuel cell, converter driving means for driving the converter so that, when it is determined that fuel gas in at least the amount capable of generating power remains in the fuel cell, the output ceiling voltage of the fuel cell becomes a first voltage capable of preventing deterioration of the fuel cell, and converter stopping means for stopping the converter when it is determined that fuel gas in at least the amount capable of generating power does not remain in the fuel cell.

Fuel cell system and control method thereof

Each of the water heatersperforms a master and slave setting process that transmits prescribed response data to the other water heatersvia a communication lineat a timing according to its own identification number and different from those of the other water heaters in a prescribed master and slave setting time period, that sets the water heater itself to slave in a case of receiving the response data from another water heaterassigned with an identification number having a priority higher than its own identification number in the master and slave setting time period, and that sets the water heater itself to master in a case of not receiving the response data from another water heater assigned with an identification number having a priority higher than its own identification number in the master and slave setting time period.

Hot-water supply system

An energy usage display unit for displaying energy usage of gas used for a water heater, water used for the water heater or electricity used in housing where the water heater is set. The energy usage display unit includes a clock section; a counting section for counting usage of gas, water or electricity; a memory section for storing a count value of usage counted by the counting section retroactive to past by a predetermined number with a predetermined time unit; a counting control section for writing the count value of usage at predetermined time; a display control section for reading one or both of the count value and a stored value in the memory section to prepare display data of usage; and a display section for displaying usage based on the display data prepared by the display control section.

Energy usage display unit

The fuel cell system is provided which detects a freeze among specific components and portions thereof by evaluating various conditions upon starting operation of the fuel cell system. If a freeze is detected through those evaluations, the start of the system is prohibited in order to prevent some deterioration in the fuel cell system.

Fuel cell system and method of controlling the same fuel cell system

In a power supply device including a fuel cell unit with a stack of fuel cells or a fuel cell stack and a secondary battery, an intermittent drive mode is selected under a preset condition to receive power supply only from the secondary battery. The control procedure of the invention determines whether a temporary stop of the fuel cell stack or continuance of the stop of the fuel cell stack leads to potential performance deterioration of the fuel cell stack at a restart of the fuel cell unit. In response to estimation of the potential performance deterioration, the control procedure controls the power supply device to continue or start power generation of the fuel cell stack, regardless of selection of the intermittent drive mode under the preset condition.

Energy output device and control method of energy output device

Nitrogen concentration in a fuel-cell stack is estimated more accurately, hence the life of the fuel-cell is prevented from being reduced by operation performed when the impurity concentration in the anode increases. The fuel-cell system comprises: stack temperature detection means for detecting the temperature of the fuel-cell stack; fuel electrode pressure detection means for detecting the pressure of the fuel electrode; and standing time measuring means for measuring the standing time. The fuel electrode nitrogen concentration, which indicates concentration of nitrogen in the fuel electrode of the fuel cell (nitrogen or the like transmitted from the air electrode to the fuel electrode via an electrolyte membrane), is estimated on the basis of the temperature of the fuel-cell stack at the time when operation of the fuel cell is stopped, the pressure in the fuel electrode at the time when the operation of the fuel cell is restarted, and the standing time between when the operation of the fuel cell is stopped and when the operation of the fuel cell is restarted.

Fuel-cell system and method of estimating nitrogen concentration on fuel electrode of fuel cell

In a fuel cell system of the invention, a pressure regulator is provided in the pathway of a hydrogen supply conduit that connects a hydrogen tank to a fuel cell stack. An anode off gas discharged from the fuel cell stack is recirculated through a recirculation pipe into the hydrogen supply conduit. A hydrogen pump is provided in the pathway of the recirculation pipe to increase the pressure of the anode off gas. A control unit of the fuel cell system includes a hydrogen pump control module, an abnormality diagnosis module, and an atmospheric pressure-based correction module. The hydrogen pump control module regulates the rotation speed of the hydrogen pump corresponding to a power demand to be output from the fuel cell system. The abnormality diagnosis module detects an abnormal state, based on a result of determination of whether the pressure of the hydrogen supply measured by a pressure sensor is within a certain range defined by two preset threshold values. The atmospheric pressure-based correction module corrects the rotation speed of the hydrogen pump and the threshold values used for abnormality diagnosis according to the atmospheric pressure measured by an atmospheric pressure sensor. Even in the state of unstable output of the pressure regulator with a variation of the atmospheric pressure, such correction compensates for the varying flow rate of the hydrogen supply to the fuel cell stack and thus effectively prevents misjudgment of abnormality diagnosis. Namely the technique of the invention reduces the potential effect of the varying pressure of the hydrogen supply to the fuel cell system with a variation of the atmospheric pressure.

Operation control of fuel cell system

A process for casting a pipe such as a delivery pipe with transversal holes, the pipe having an elongate longitudinal hole and at least one pair of transversal holes communicating with the longitudinal hole in a substantially normal direction thereto. The process comprises the steps of positioning a rod-like center pin for forming the longitudinal hole in a predetermined positional relation to a cavity formation surface of a casting die, positioning a pair of mandrel pins for forming the pair of transversal holes such that end faces thereof are in contact with side surfaces of the center pin, and charging molten metal into a die cavity after the center pin and the pair of mandrel pins have been positioned. The molten metal is charged under the condition that the center pin is prevented from deforming by the pair of mandrel pins.

Process for casting pipe with transversal hole, and casting die for the

A method of casting a pipe having an axially elongate hole of which a front end is closed, comprises the steps of positioning a rod-like center pin for forming the blind hole in a predetermined positional relation to cavity defining surfaces of a die cavity, supporting the positioned center pin sidewise with a support pin to prevent positional deviation of the center pin, charging molten metal into the die cavity, retreating the support pin apart from the center pin, and replenishing a space formed by the retreat of the support pin with molten metal.

Growing community of inventors

Nagoya, Japan

Hiroaki Mori