In order to protect the temperature of an exhaust stream in an exhaust line, even if the temperature of the exhaust stream discharged from a fuel cell exceeds a temperature during rated operation, a power generation system has: an SOFC; an exhaust air line or an exhaust fuel line, wherein the exhaust air line and exhaust fuel line carry exhaust air and exhaust fuel gas discharged from the SOFC, respectively; a temperature detector for detecting the temperature of the exhaust air or the exhaust fuel gas discharged from the SOFC or the temperature of the exhaust air line or the exhaust fuel line; an exhaust cooling device for cooling the exhaust air in the exhaust air line or the exhaust fuel gas in the exhaust fuel line; and a control device for activating the exhaust cooling device when the temperature detected by the temperature detector exceeds a predetermined temperature.

A method of shutting down operation of a fuel cell system is disclosed, comprising a fuel cell stack, the method comprising the sequential steps of: i) ceasing a supply of fuel to the fuel cell stack; ii) closing a shut-off valve on an exhaust line in fluid communication with a cathode system of the fuel cell system, the cathode system comprising a cathode fluid flow path passing through the fuel cell stack; iii) pressurizing the cathode system with an air compressor in fluid communication with a cathode air inlet port in the fuel cell stack; and iv) ejecting water from the cathode flow path.

A fuel cell assembly comprising an enclosure having a fuel cell stack mounted therein. The fuel cell stack has an inlet face for receiving coolant/oxidant fluid and an outlet face for expelling said coolant/oxidant fluid. The fuel cell stack further includes a pair of end faces extending transversely between the inlet face and outlet face. The enclosure defines a flow path for the coolant/oxidant fluid that is configured to guide the coolant/oxidant fluid to the inlet face, from the outlet face, and over at least one of the end faces.

A fuel cell system includes a first temperature sensor to detect a valve temperature of a sealing valve. A second temperature sensor is provided in a refrigerant circulation circuit to detect a fuel cell temperature of a fuel cell through a refrigerant. The circuitry is configured to calculate a sealing valve estimated temperature by subtracting a correction value from the fuel cell temperature detected by the second temperature sensor after the fuel cell stops generating electric power and after the sealing valve is closed. The circuitry is configured to determine whether at least one of the valve temperature and the sealing valve estimated temperature is lower than a predicted freezing temperature. The circuitry is configured to open the sealing valve when it is determined that the at least one of the valve temperature and the sealing valve estimated temperature is lower than the predicted freezing temperature.

A fuel cell system includes fuel cell stacks, each of which includes a plurality of fuel cells that are connected in series and generate electricity through an electrochemical reaction between a fuel gas and an oxidant gas, fuel cell cartridges, each of which has headers that supplies the fuel gas and the oxidant gas to the fuel cell stacks and discharges a fuel off-gas and an oxidant off-gas from the fuel cell stacks, a fuel gas supply line that supplies the fuel gas to the fuel cell cartridges, a fuel off-gas discharge line that discharges the fuel off-gas from the fuel cell cartridges, and a first adjustment member provided in the fuel gas supply line or the fuel off-gas discharge line, and adjusting a flow rate of the fuel gas or the fuel off-gas, the first adjustment member including a first flexible pipe.

A fuel cell system includes a fuel cell configured to be supplied with fuel and air to generate electricity, a reformer configured to reform the fuel to be supplied to the fuel cell, a heat source device configured to heat an off-gas discharged from the fuel cell to produce a heating gas and configured to heat the reformer, a fuel cell heating device configured to heat the air to be supplied to the fuel cell using the heating gas, a fuel cell temperature acquisition unit configured to acquire a temperature of the fuel cell, and a reformer temperature acquisition unit configured to acquire a temperature of the reformer. The fuel cell system includes a controller configured to, in a warm-up operation to perform a warm-up of the reformer and a warm-up of the fuel cell, control at least one of the heat source device and the fuel cell heating device based on the temperature of the reformer and the temperature of the fuel cell to adjust at least one of a heating amount of the off-gas and a heating amount of the air by the heating gas.

Provided is a method of controlling a fuel cell system having a fuel cell stack, a reformer configured to reform a raw fuel and supply the reformed raw fuel to the fuel cell stack, a fuel flow rate control unit configured to control a flow rate of the raw fuel supplied to the reformer, an air supply pipe configured to supply oxygen to the raw fuel, and a combustor configured to mix a cathode discharged gas and an anode discharged gas discharged from the fuel cell stack and combust the mixed gas. The method of controlling the fuel cell system includes detecting at least one of a current value generated from the fuel cell stack and an oxygen supply amount supplied from the air supply pipe; estimating a composition of the anode discharged gas on the basis of at least one of the current value and the oxygen supply amount; and controlling a temperature of the combustor by adjusting the flow rate of the raw fuel using the fuel flow rate control unit on the basis of the estimated composition of the anode discharged gas.

A fault diagnostic apparatus for a fuel cell electric vehicle and a method therefor are provided. The apparatus includes: a main relay connected to a fuel cell stack; a power converter connected to the main relay; a heater relay connected to the fuel cell stack and the main relay at one end and connected to a cathode oxygen depletion (COD) heater at the other end; and a fuel cell control unit (FCU) connected with the main relay, the power converter, and the heater relay. The FCU diagnoses a fault of the main relay based on an amount of change in stack voltage according to control to turn off and on the heater relay and a power of the power converter according to variable control of a voltage of the power converter, when the vehicle enters a shutdown sequence, and outputs the diagnosed result.

A fuel cell power system and method for identifying and compensating for variations identified in a fuel composition of a fuel cell power system, comprising the fuel cell system components selected from the group consisting of a catalytic oxidizer, a reformer, an exhaust, a fuel cell stack or system, or a combination thereof; and a control device configured to control the fuel cell system components, wherein the control device comprises a computer algorithm to indirectly correlate measurements of the fuel cell system components to a difference in the fuel composition.

A fuel cell system includes a fuel cell that generates electricity using a fuel gas and air, an air supply that supplies air to the fuel cell, a temperature meter that measures a temperature of the fuel cell, and a controller. The controller controls the air supply to increase an amount of air to be supplied to the fuel cell in response to the temperature of the fuel cell exceeding one of a plurality of predetermined temperatures.