Nissan Motor Company Limited

Hidetaka Nishimura

Masashi Sato

Masanobu Sakai

Hayato Chikugo

Michihiko Matsumoto

Tetsuya Aoki

Keigo Ikezoe

Yasushi Ichikawa

Kotaro Akashi

Kenji Kobayashi

Hiroshi Takeda

Mitsunori Kumada

Ryoichi Shimoi

Kazuhiro Kageyama

Ken Nakayama

Shigetaka Uehara

Keiji Ichihara

Takatada Usami

Daigo Iwasaki

Takahito Osada

Keita Tsuji

A fuel cell system includes: a coolant circulation passage through which a coolant for cooling a fuel cell circulates; a pump that circulates the coolant; a radiation unit that cools the coolant by discharging heat from the coolant; a bypass passage connected to the coolant circulation passage so as to bypass the radiation unit; and an open/close valve that is provided in a convergence portion where low temperature coolant that has passed through the radiation unit and high temperature coolant that has passed through the bypass passage without passing through the radiation unit converge, and that opens when a temperature of the high temperature coolant reaches or exceeds a predetermined opening temperature, whereby the low temperature coolant and the high temperature coolant converge and are supplied thus to the fuel cell, wherein a basic discharge flow of the pump is calculated in accordance with a condition of the fuel cell, and when the temperature of the low temperature coolant is lower than a predetermined temperature, a discharge flow of the pump is increased above the basic discharge flow.

Fuel cell system

A fuel cell system includes a battery, a fuel cell configured to generate power in accordance with a load, an inverter configured to convert power output from the fuel cell into alternating-current power and supply the alternating-current power to a motor, and a converter configured to control voltage between the inverter and the fuel cell using power output from the battery. The fuel cell system includes a voltage control unit configured to control the converter such that the voltage between the inverter and the fuel cell does not fall below a voltage lower limit of the inverter, and a lower limit voltage control unit configured to, when power required by the motor increases, cause the voltage between the inverter and the fuel cell to fall below the voltage lower limit of the inverter.

Fuel cell system and control method for fuel cell system

A fuel cell stack obtained by stacking a plurality of fuel cells has an internal manifold that extends in a stacking direction of the fuel cells to externally discharge a gas used in the fuel cell, and an extension member that adjoins an inner wall surface of the internal manifold and extends in the stacking direction. The extension member is a bar-shaped member provided in an opposite side to a side where a gas from the fuel cells flows to the inside of the internal manifold and has a sloping surface making an acute angle with an inner-wall lower surface of the internal manifold.

Fuel cell stack and fuel cell system

A cell system includes a laminated battery, a plurality of battery cells being laminated in the laminated battery, a first switch connected to a positive electrode of the laminated battery and configured to switch connection to the positive electrode to a shut-off state, and a second switch connected to a negative electrode of the laminated battery and configured to switch connection to the negative electrode to a shut-off state. Furthermore, the cell system includes a circuit to be connected at least either between the positive electrode and the first switch or between the negative electrode and the second switch; and a controller configured to shift control timings of the first switch and the second switch from the shut-off state to a connected state according to an electrical capacitance generated between the positive electrode and the negative electrode.

Cell system and control method for cell system

A fuel cell system that generates electric power by supplying anode gas and cathode gas to a fuel cell includes a control valve adapted to control the pressure of the anode gas to be supplied to the fuel cell; a buffer unit adapted to store the anode-off gas to be discharged from the fuel cell; a pulsation operation unit adapted to control the control valve in order to periodically increase and decrease the pressure of the anode gas at a specific width of the pulsation; and a pulsation width correcting unit adapted to correct the width of the pulsation on the basis of the temperature of the buffer unit.

An impedance measuring device outputs an alternating current of a prescribed frequency to a positive electrode terminal and a negative electrode terminal of the laminated type battery. The impedance measuring device detects an alternating-current potential difference between the positive electrode terminal and an intermediate-point terminal, and an alternating-current potential difference between the negative electrode terminal and the intermediate-point terminal. The impedance measuring device adjusts an amplitude of the alternating current such that the alternating-current potential difference between the positive electrode terminal and the intermediate-point terminal, and the alternating-current potential difference between the negative electrode terminal and the intermediate-point terminal coincide. The impedance measuring device computes an impedance of the laminated type battery on the basis of the alternating current adjusted and the alternating-current potential difference. On the a phase difference between an alternating-current potential generated at the positive electrode terminal and an alternating-current potential generated at the negative electrode terminal, or a parameter related to the phase difference, the impedance measuring device performs any one process of: a diagnosis process for diagnosing whether or not a measurement state is defective; a cancellation process for discarding a measurement result; and a hold process for fixing the measurement result at a prescribed value.

Impedance measuring device and control method for impedance measuring device

An impedance measuring device outputs an alternating current of a prescribed frequency to each of a positive electrode terminal and a negative electrode terminal of a laminated type battery and detects an alternating-current potential difference between the positive electrode terminal and an intermediate-point terminal and an alternating-current potential difference between the negative electrode terminal and the intermediate-point terminal. The impedance measuring device adjusts an amplitude of the alternating current such that the alternating-current potential difference between the positive electrode terminal and the intermediate-point terminal and the alternating-current potential difference between the negative electrode terminal and the intermediate-point terminal coincide, and computes an impedance on the basis of the adjusted alternating current and alternating-current potential differences. Then, the impedance measuring device corrects a phase difference of the alternating currents output to the positive electrode terminal and the negative electrode terminal on the basis of a phase difference between an alternating-current potential generated at the positive electrode terminal and an alternating-current potential generated at the negative electrode terminal.

To prevent inflow of liquid water into a power generating portion even if the liquid water remains in a manifold, and to enable size reduction by making constant the contact or surface pressure. According to the present invention, in a fuel cell comprising a power generating section including an electrolyte membrane joined between an anode and a cathode, and a manifold to cause inflow and outflow of an hydrogen containing gas and an oxygen containing gas separately from each other to the anode and cathode; the manifold is formed with an inflow preventing portion to prevent inflow of a liquid water remaining in the manifold, into the power generating portion.

Fuel cell

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).

Operating method of fuel cell system

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.

Fuel cell system and operating method thereof

A fuel cell system having a fuel cell for causing reactant gas to be electrochemically reacted to generate power, a reactant gas supply path for supplying reactant gas to the fuel cell, a reactant gas recirculation path for recirculating exhaust gas discharged from the fuel cell and combining the recirculating exhaust gas with reactant gas flowing through the reactant gas supply path to the fuel cell, and a pump unit disposed in the reactant gas recirculation path to pump the recirculating exhaust gas through the reactant gas recirculation path. A pump-tempering apparatus increases the temperature of the pump unit and a controller controls the pump-tempering apparatus. After the controller receives a fuel cell system stop signal, the controller controls the pump-tempering apparatus such that the temperature of the pump unit becomes higher than the temperature of piping in the reactant gas recirculation path.

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Yokosuka, Japan

Hidetaka Nishimura