Hitachi, Ltd.

Takaaki Mizukami

Keiji Watanabe

Shin Takahashi

Osamu Yokomizo

Toshiki Kahara

Hidekazu Fujimura

Futoshi Furuta

Tsutomu Okusawa

Yuuki Okuda

Kouichi Chino

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.

Power generation system of fuel cell and control method thereof

A fuel cell comprises an anode oxidizing a fuel, a cathode reducing an oxidizing agent, a polymer electrolyte disposed between the anode and the cathode, whereby an assembly is constituted by the anode, cathode and polymer electrolyte, a pair of gas diffusion layers disposed at both sides of the assembly of the anode, and the cathode, a bipolar plate for providing the fuel to the gas diffusion layer, and another bipolar plate for providing the oxidizing agent to the gas diffusion layer, wherein at least one of the gas diffusion layers includes a porous gas diffusion layer substrate having a hydrophilic surface layer, and wherein particles of a water-repellent material are dispersed in pores of the porous gas diffusion layer substrate. This results in a higher cell voltage and a higher power at a high current density, prevention of a flooding and a longer cell lifetime.

Fuel cell

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 () is charged in a capacitor () and a lead storage battery () 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 () and the lead storage battery (); 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.

Home-use fuel cell system

Growing community of inventors

Hitachi, Japan

Takaaki Mizukami