A cooling circuit for a fuel cell includes at least one channel, a mechanical support, a first sensor, and a second sensor. Each channel is formed in a bipolar plate of the fuel cell, and is adapted to permit a cooling fluid to flow. The first sensor senses a flow rate of the cooling fluid. The second sensor senses an electrical conductivity of the cooling fluid. Both the first sensor and the second sensor are installed on the mechanical support.

In one aspect, an apparatus and a method for monitoring a hydrogen storage system of a vehicle to always monitor the hydrogen storage system of the vehicle are provided. The apparatus comprises a first temperature sensor that measures an internal temperature of a hydrogen tank, a second temperature sensor that measures an outdoor temperature, a comparator that determines whether a hydrogen leak occurs based on the result of comparing the internal temperature with the outdoor temperature and outputs a wake-up signal, and a controller that performs failure diagnosis of a hydrogen storage system, when receiving the wake-up signal.

In one aspect, an apparatus and a method for monitoring a hydrogen storage system of a vehicle to always monitor the hydrogen storage system of the vehicle are provided. The apparatus comprises a first temperature sensor that measures an internal temperature of a hydrogen tank, a second temperature sensor that measures an outdoor temperature, a comparator that determines whether a hydrogen leak occurs based on the result of comparing the internal temperature with the outdoor temperature and outputs a wake-up signal, and a controller that performs failure diagnosis of a hydrogen storage system, when receiving the wake-up signal.

In one aspect, disclosed are a hydrogen leak sensing device and method for a fuel cell vehicle. The device comprises a processor configured to control a valve of a hydrogen tank, wherein the processor may calculate a state of fuel (SOF) of the hydrogen tank when the valve is closed and a SOF of the hydrogen tank when the valve is opened, and determine whether hydrogen leak has occurred based on the calculated SOFs.

A method for transitioning between fuel cell and electrolysis modes in a Reversible Solid Oxide Fuel Cell (RSOFC) system includes measuring and recording sensor data indicating a status of components associated with an RSOFC system coupled to an electrical power grid, the system comprising an RSOFC unit, a hydrogen compression system, a hydrogen storage system, and a water supply, determining a state of the RSOFC system based on the sensor data through a conditional logic algorithm, and transitioning the RSOFC system between the fuel cell mode and the electrolysis mode based upon the sensor data and the system state.

A method for transitioning between fuel cell and electrolysis modes in a Reversible Solid Oxide Fuel Cell (RSOFC) system includes measuring and recording sensor data indicating a status of components associated with an RSOFC system coupled to an electrical power grid, the system comprising an RSOFC unit, a hydrogen compression system, a hydrogen storage system, and a water supply, determining a state of the RSOFC system based on the sensor data through a conditional logic algorithm, and transitioning the RSOFC system between the fuel cell mode and the electrolysis mode based upon the sensor data and the system state.

A method of shutting down a fuel cell system includes a fuel cell includes generating power via an electrochemical reaction between a fuel gas and an oxidant gas. A shutdown command is output to the fuel cell to stop generating power. The fuel cell is controlled to continue generating power during an oxygen consumption process to consume oxygen in the oxidant gas remaining in a cathode system of the fuel cell even when the shutdown command is output to the fuel cell. At least one of voltage, current, and power output from the fuel cell is detected during the oxygen consumption process. Whether an abnormality occurs during the oxygen consumption process is determined based on at least one of the voltage, the current, and the power. The fuel cell is controlled to stop generating power during the oxygen consumption process when it is determined that abnormality occurs.

A method of shutting down a fuel cell system includes a fuel cell includes generating power via an electrochemical reaction between a fuel gas and an oxidant gas. A shutdown command is output to the fuel cell to stop generating power. The fuel cell is controlled to continue generating power during an oxygen consumption process to consume oxygen in the oxidant gas remaining in a cathode system of the fuel cell even when the shutdown command is output to the fuel cell. At least one of voltage, current, and power output from the fuel cell is detected during the oxygen consumption process. Whether an abnormality occurs during the oxygen consumption process is determined based on at least one of the voltage, the current, and the power. The fuel cell is controlled to stop generating power during the oxygen consumption process when it is determined that abnormality occurs.

An FC system disclosed herein may comprise a plurality of FC units, a cooler, and a controller. Each of the FC units may comprise a FC stack, a supply passage / a return passage / a circulating passage through which refrigerant passes, and first temperature sensor. The supply passage supplies the refrigerant from the cooler to the FC stack. The return passage returns the refrigerant to the cooler. The circulating passage is connected to the supply passage and the return passage. The first temperature sensor is configured to measure a temperature of the refrigerant in the supply passage at a position upstream of a merging point of the supply passage and the circulating passage. When measured values of the first temperature sensors of the plurality of the FC units do not match, the controller is configured to provide notification about malfunction of the first temperature sensor.

An FC system disclosed herein may comprise a plurality of FC units, a cooler, and a controller. Each of the FC units may comprise a FC stack, a supply passage / a return passage / a circulating passage through which refrigerant passes, and first temperature sensor. The supply passage supplies the refrigerant from the cooler to the FC stack. The return passage returns the refrigerant to the cooler. The circulating passage is connected to the supply passage and the return passage. The first temperature sensor is configured to measure a temperature of the refrigerant in the supply passage at a position upstream of a merging point of the supply passage and the circulating passage. When measured values of the first temperature sensors of the plurality of the FC units do not match, the controller is configured to provide notification about malfunction of the first temperature sensor.