A fuel cell system includes a fuel cell configured to produce electrical power by a chemical reaction of a flow of fuel and a flow of oxygen or air with an electrolyte and a cooling system configured to remove thermal energy from the fuel cell via a flow of coolant through the fuel cell. The fuel cell system includes one or more conductivity sensors configured to measure a change in conductivity of the coolant flow. A method of operating a fuel cell system includes producing electrical power at a fuel cell by a chemical reaction of a flow of fuel and a flow of air with an electrolyte, urging a flow of coolant through the fuel cell to remove thermal energy and ions from the fuel cell, and measuring a conductivity of the flow of coolant via one or more conductivity sensors.

A fuel cell system includes a first ion exchanger, a first fuel cell stack and a second fuel cell stack, a first temperature acquisition part and a second temperature acquisition part, a first power generation time acquisition part and a second power generation time acquisition part, a supply path, an ion concentration estimation part that estimates ion concentration of a refrigerant on the basis of the ion concentration estimated by the ion concentration estimation part, a determination part that determines an exchange timing of the first ion exchanger on the basis of the ion concentration estimated by the ion concentration estimation part, and a control part, and a first refrigerant flow path and a second refrigerant flow path are provided in series or in parallel.

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.

An integrated fuel cell control system is provided. The integrated fuel cell control system includes at least one sensor, at least one hydrogen on/off valve, and a fuel control unit (FCU). The FCU is configured to directly operate the at least one sensor and the at least one hydrogen on/off valve in real time and to determine a supply pressure of hydrogen supplied to a fuel cell. Thereby, noise between controllers may be removed and costs may be reduced.

A coolant control system of a fuel cell may include the fuel cell; a coolant line allowing a coolant to circulate therein and connected to the fuel cell to be heat-exchangeable with the fuel cell; an ion removal line provided with an ion filter and connected to a first portion and a second portion of the coolant line to allow a coolant branched from the first portion of the coolant line to pass through the ion filter and then flow into the second portion of the coolant line again; an adjusting valve adjusting a ratio between coolants respectively flowing into the coolant line and the ion removal line; and a controller engaged to the adjusting valve and configured for controlling the adjusting valve based on a temperature of the fuel cell or an output voltage of the fuel cell.

A method of operating a fuel cell system (100) comprising a fuel cell stack (110) and a closed loop water cooling circuit for direct injection of cooling water into the stack (110), the method comprising: measuring an operational parameter of the fuel cell system (100) over a time period; adding an amount of water to the closed loop cooling circuit from the total amount of water generated during operation of the fuel cell stack (110) over the time period; and removing the amount of water from the closed loop cooling circuit generated during operation of the fuel cell stack (110) over the time period is automatically determined by the fuel cell system (100) as a function of the operational parameter.

A main object of the present disclosure is to provide a fuel cell system capable of rapidly determining occurrence of a leak. The present disclosure achieves the object by providing a fuel cell system comprising: a fuel cell, a coolant circuit that circulates a cooling liquid to cool the fuel cell, a conductivity meter that measures a conductivity of the cooling liquid, and a determination device that determines a leak of the cooling liquid; wherein the determination device includes: an acquisition unit that acquires a conductivity of the cooling liquid from the conductivity meter, and a determination unit that determines a leak of the cooling liquid based on a fluctuation of the conductivity.

A fuel cell system includes a fuel cell configured to produce electrical power by a chemical reaction of a flow of fuel and a flow of oxygen or air with an electrolyte and a cooling system configured to remove thermal energy from the fuel cell via a flow of coolant through the fuel cell. The fuel cell system includes one or more conductivity sensors configured to measure a change in conductivity of the coolant flow. A method of operating a fuel cell system includes producing electrical power at a fuel cell by a chemical reaction of a flow of fuel and a flow of air with an electrolyte, urging a flow of coolant through the fuel cell to remove thermal energy and ions from the fuel cell, and measuring a conductivity of the flow of coolant via one or more conductivity sensors.

A fuel cell system FCS includes a fuel cell 10, a high voltage circuit 21 for driving an electromotor 42, and a relay 41 for electrically connecting or blocking the fuel cell 10 to or from the high voltage circuit 21. A control unit 50 obtains insulation decrease information in accordance with a request for starting the fuel cell, and performs, when a specified insulation decrease occurred region is not a fuel cell region SE1 including the fuel cell and the cooling circuit, conductivity reduction process on cooling liquid using a conductivity reduction unit 113 before having a relay 41 connect, and has the relay 41 connect after completing the conductivity reduction process.

A fuel cell system includes a first ion exchanger, a first fuel cell stack and a second fuel cell stack, a first temperature acquisition part and a second temperature acquisition part, a first power generation time acquisition part and a second power generation time acquisition part, a supply path, an ion concentration estimation part that estimates ion concentration of a refrigerant on the basis of the ion concentration estimated by the ion concentration estimation part, a determination part that determines an exchange timing of the first ion exchanger on the basis of the ion concentration estimated by the ion concentration estimation part, and a control part, and a first refrigerant flow path and a second refrigerant flow path are provided in series or in parallel.