Abstract: A fuel cell system includes: a fuel cell stack (S) formed by stacking multiple unit cells (C) horizontally and having, in the stacked body, manifolds through which to supply and discharge reaction gases to and from each of the unit cells (C); and drainage paths (1A, 1B) extending from an anode-off-gas discharge manifold (M), on both end sides of the fuel cell stack (S) in the stacking direction of the unit cells, respectively.

Abstract: A fuel cell stack includes a heat exchange unit that performs heat exchange between a gas mixture containing source hydrogen and a circulating gas and cooling water used for controlling the temperature of the fuel cell stack. A system controller adjusts the temperature of the cooling water by controlling a temperature control unit on the basis of the temperature of source hydrogen flowing into a junction at which the source hydrogen and a circulating gas are mixed such that the temperature of a source/recirculated hydrogen mixture that is mixed at the junction and that is supplied to the fuel cell stack is kept within a managed temperature range.

Abstract: A fuel cell system and method of controlling a fuel cell system capable of preventing deterioration in performance when the system reinitiates a normal operation from an idle stop state. For a predetermined time after reinitiating the supply of fuel gas and oxidant gas from the idle stop state, discharge of off-gas occurs and the cessation of fuel gas and oxidant gas supply is prohibited.

Abstract: A fuel cell system includes: a fuel cell stack (S) formed by stacking multiple unit cells (C) horizontally and having, in the stacked body, manifolds through which to supply and discharge reaction gases to and from each of the unit cells (C); and drainage paths (1A, 1B) extending from an anode-off-gas discharge manifold (M), on both end sides of the fuel cell stack (S) in the stacking direction of the unit cells, respectively.

Abstract: A fuel cell system has a plurality of fuel cells stacked in one or more groups of fuel cells. Each fuel cell includes a fuel electrode supplied with fuel gas at a fuel gas supply pressure, an oxidizing electrode supplied with oxidizing gas at an oxidizing gas supply pressure, and an electrolyte membrane disposed between the fuel electrode and the oxidizing electrode. A pressure-difference control unit generates a pressure difference across the membrane such that the fuel gas supply pressure is greater than the oxidizing gas supply pressure in each fuel cell, a cell-voltage measuring device measures a cell voltage for each fuel cell or each group of fuel cells in the fuel cell stack, and a leakage determination unit determines the presence or absence of a leaking cell based on the behavior of the cell voltage of each fuel cell while the pressure difference is increased with time.

Abstract: A fuel cell system has a purge valve that adjusts the amount of nitrogen in a hydrogen circulation channel and a fuel electrode to be discharged through a discharge channel. A purge rate correcting unit variably sets a target control value of the nitrogen content in the hydrogen circulation channel and the fuel electrode by taking into account whether a driving mode is set in a normal power generation mode or an idle mode. An opening of the purge valve is controlled on the basis of the target control value.

Abstract: A fuel cell system having a fuel cell, a coolant supply device for circulating a supply of the coolant through a coolant path for cooling the fuel cell, a fuel cell temperature detector for detecting a temperature of the fuel cell, a coolant temperature detector for detecting a temperature of the coolant in the coolant path, and a controller for controlling the amount of coolant circulated by the coolant supply device. The controller selects an operation mode of the fuel cell between a power generation mode and a power generation stop mode and calculates the difference between the detected coolant temperature and detected fuel cell temperature. While the operation mode is the power generation stop mode, the controller increases the amount of the coolant circulated as the difference between the detected coolant temperature and the detected fuel cell temperature increases.

Abstract: A fuel cell stack includes a heat exchange unit that performs heat exchange between a gas mixture containing source hydrogen and a circulating gas and cooling water used for controlling the temperature of the fuel cell stack. A system controller adjusts the temperature of the cooling water by controlling a temperature control unit on the basis of the temperature of source hydrogen flowing into a junction at which the source hydrogen and a circulating gas are mixed such that the temperature of a source/recirculated hydrogen mixture that is mixed at the junction and that is supplied to the fuel cell stack is kept within a managed temperature range.

Abstract: A fuel cell system has a purge valve that adjusts the amount of nitrogen in a hydrogen circulation channel and a fuel electrode to be discharged through a discharge channel. A purge rate correcting unit variably sets a target control value of the nitrogen content in the hydrogen circulation channel and the fuel electrode by taking into account whether a driving mode is set in a normal power generation mode or an idle mode. An opening of the purge valve is controlled on the basis of the target control value.

Abstract: A system controller drives a gas circulator with a purge valve closed to supply hydrogen to a fuel cell stack and then increases anode operating pressure and cathode operating pressure to target operating pressures after a predetermined condition is satisfied. This allows an amount of gas mixture of remaining oxygen and hydrogen to be suppressed compared to the case of increasing the anode operating pressure in a state where oxygen remains in the anode circulation path. Accordingly, it is possible to suppress local generation of electric potential and heat and prevent degradation of the components of the fuel cell stack. Moreover, hydrogen is not discharged during activation, which eliminates the need to include dilution equipment of combustion equipment for treating hydrogen and increases the degree of freedom in the layout of the fuel cell system.

Abstract: A fuel cell system has a plurality of fuel cells stacked in one or more groups of fuel cells. Each fuel cell includes a fuel electrode supplied with fuel gas at a fuel gas supply pressure, an oxidizing electrode supplied with oxidizing gas at an oxidizing gas supply pressure, and an electrolyte membrane disposed between the fuel electrode and the oxidizing electrode. A pressure-difference control unit generates a pressure difference across the membrane such that the fuel gas supply pressure is greater than the oxidizing gas supply pressure in each fuel cell, a cell-voltage measuring device measures a cell voltage for each fuel cell or each group of fuel cells in the fuel cell stack, and a leakage determination unit determines the presence or absence of a leaking cell based on the behavior of the cell voltage of each fuel cell while the pressure difference is increased with time.

Abstract: A fuel cell system and method of controlling a fuel cell system capable of preventing deterioration in performance when the system reinitiates a normal operation from an idle stop state. For a predetermined time after reinitiating the supply of fuel gas and oxidant gas from the idle stop state, discharge of off-gas occurs and the cessation of fuel gas and oxidant gas supply is prohibited.

Abstract: A fuel cell system according to this invention comprises: a pressurizing valve (2a) provided on a cooling water circulation path; a reservoir tank (5) into which the cooling water flows through a pipe (4) when the pressurizing valve (2a) is open; an air supply pipe (13) that is connected to the reservoir tank (5) to supply air for diluting a fuel gas when the fuel gas accumulates in the reservoir tank (5); and a diluted gas exhaust pipe (15) for discharging the diluted fuel gas from the reservoir tank (5).

Abstract: A system controller drives a gas circulator with a purge valve closed to supply hydrogen to a fuel cell stack and then increases anode operating pressure and cathode operating pressure to target operating pressures after a predetermined condition is satisfied. This allows an amount of gas mixture of remaining oxygen and hydrogen to be suppressed compared to the case of increasing the anode operating pressure in a state where oxygen remains in the anode circulation path. Accordingly, it is possible to suppress local generation of electric potential and heat and prevent degradation of the components of the fuel cell stack. Moreover, hydrogen is not discharged during activation, which eliminates the need to include dilution equipment of combustion equipment for treating hydrogen and increases the degree of freedom in the layout of the fuel cell system.