A fuel cell system includes a plurality of fuel cell stacks, a power generation control unit that controls power generation of the plurality of fuel cell stacks based on a required power for the plurality of fuel cell stacks, and a refreshing control unit configured to perform a refreshing process of decreasing a voltage on the plurality of fuel cell stacks. The refreshing control unit performs the refreshing process on the first fuel cell stack when the required power changes from a state in which the required power is less than a first predetermined value to a state in which the required power is equal to or greater than the first predetermined value and when the required power is in a range which is equal to or greater than the first predetermined value and less than the second threshold value.

When a shut-off valve is opened, gas is discharged via a main passage which is disposed at a predetermined height from a bottom of a gas-liquid separator. Water which gathers in the bottom of the gas-liquid separator flows from a bypass passage to the main passage and is discharged when water level difference>height is satisfied. When water which gathers in the bottom of the gas-liquid separator is supercooled water, discharge of water is avoided by controlling an open pressure and a passage pressure such that water level difference<height is satisfied.

In fuel cell system, exhaust material M exhausted from a fuel cell stack flows through the exhaust pipe. The gas-liquid separator is provided at the exhaust pipe and separates the exhaust material M into gas and liquid. The connecting pipe is connected to an exhaust port of the gas-liquid separator. The pressure regulating valve is connected to the connecting pipe and regulates pressures of the gas such that a pressure of the gas at an upstream side is higher than atmospheric pressure. The guide pipe is connected at the downstream side of the pressure regulating valve and guides at least the gas toward the exhaust pipe. The heat exchange unit exchanges heat between the exhaust pipe and the guide pipe.

A fuel cell system includes a hotbox configured to house a fuel cell stack, the fuel cell stack including a temperature sensor configured to detect temperature inside the fuel cell stack. The system includes a first tank including a first valve and configured to store methanol. The system includes a second tank including a second valve and configured to store water. The system includes a controller communicatively coupled to receive signals from the temperature sensor and control each of the first valve and the second valve. The controller is configured to set a dosing rate of methanol, based on a temperature of the fuel cells stack, to a predefined dosing rate and initiate operating at least one of the first valve and the second valve to deliver a mixture of methanol and water at the predefined dosing rate to prevent re-oxidation of an anode of the fuel cell stack.

A fuel cell system comprises a solid oxide fuel cell which generates a power by receiving a supply of an anode gas and a cathode gas. The system comprises a cathode gas supply unit to supply the cathode gas to the fuel cell via a cathode gas supply route; a first burner arranged in the cathode gas supply route, a second burner to burn an anode off-gas and a cathode off-gas, which are discharged from the fuel cell; a first branch path which is branched out from an upstream of the first burner and joins to a downstream of the first burner in the cathode gas supply route; and a second branch path which is branched out from a downstream of the first burner in the cathode gas supply route and joins to a cathode off-gas discharge route through which the cathode off-gas is discharged from the fuel cell to the second burner.

A fuel cell system includes a fuel feeder that supplies fuel, a fuel cell stack that generates power through an electrochemical reaction using air and a hydrogen-containing gas generated from the fuel, a first temperature sensor that senses the temperature of the fuel cell stack, and a controller. The fuel cell stack has a membrane electrode assembly including an electrolyte membrane through which protons can pass, a cathode on one side of the electrolyte membrane, and an anode on the other side of the electrolyte membrane. The controller defines an upper limit of current output from the fuel cell stack on the basis of the temperature of the fuel cell stack, the supply of the fuel, and the hydrogen consumption of the fuel cell stack associated with internal leakage current and keeps the current output from the fuel cell stack at or below the upper limit.

A fuel cell system includes: a fuel cell that generates electricity using a fuel gas and an oxidant gas; a fuel gas supply path through which a fuel gas to be supplied to an anode of the fuel cell flows; a recycle gas path through which an anode off-gas emitted from the anode of the fuel cell is returned to the fuel gas supply path; a water reservoir that holds water separated from the anode off-gas flowing through the recycle gas path; a drainage path through which water stored in the water reservoir is drained; a valve provided on the drainage path; and a controller that determines, on the basis of a history of a flow rate of the anode off-gas, a length of time for which the valve continues to be opened for draining the water stored in the water reservoir.

A fuel cell vehicle on which a fuel cell system including a fuel cell is mounted includes a discharge mechanism configured to discharge moisture, generated by the fuel cell, from the fuel cell system to an outside of the vehicle, a camera configured to capture an image outside the vehicle, and an electronic control unit configured to determine whether predetermined control based on an information obtained from the image and executed or stopped in response to a driving status or drive mode of the vehicle in an on-state of an ignition switch is being executed, and, when it is determined that the predetermined control is being executed, execute a low discharge process in which a discharge flow rate of water vapor that is discharged from the discharge mechanism to the outside of the vehicle is reduced as compared to when it is determined that the predetermined control is stopped.

A fuel cell system includes a gas supply passage configured to supply one of the anode gas and the cathode gas to the fuel cell, a refrigerant supply apparatus that supplies refrigerant for cooling the fuel cell to the fuel cell, a heat exchanger that exchanges heat between the refrigerant increased in temperature by the fuel cell and the gas supplied to the gas supply passage. The fuel cell includes a component that circulates the one of the anode gas and the cathode gas discharged from the fuel cell to the fuel cell, and a warm-up control unit that controls a flow rate of the refrigerant to a predetermined flow rate for warming up the fuel cell when the fuel cell is warmed up. The fuel cell system includes a gas temperature increase control unit increases the flow rate of the refrigerant to be supplied to the heat exchanger on the basis of a temperature of the gas circulated by the component or a parameter related to the temperature when the flow rate of the refrigerant is controlled by the warm-up control unit.

Temperature control system and method for a fuel cell system are disclosed. The temperature control system includes a state detector, a control selector, a normal controller and an internal model controller. The state detector determines whether the fuel cell system is in a leakage condition based on a dynamic transfer function from an air flowrate provided to the fuel cell system to a fuel cell temperature. The control selector selects to switch between the normal controller and the internal model controller based on a determined result. The normal controller is configured for controlling an air flowrate of the fuel cell system which is not in the leakage condition. The internal model controller is configured for controlling the air flowrate of the fuel cell system in the leakage condition to control the fuel cell temperature. A fuel cell system with the temperature control system is also disclosed.