The present invention provides fuel cell stacks comprising effective means to maintain the fuel cell stacks at a constant temperature using plates mated to at least one face of the stack and in contact with the edges of the repeat and non-repeat layers while making use of the phase change of working-fluids such as water or water-organic species mixtures for heat transfer. Also provided are processes for maintaining said fuel cell stacks at a constant temperature by adjusting the flow rate and pressure of the cooling fluid so that both liquid and vapor are present at the same time.

A fuel cell including an electrochemical reactor; a cooling circuit; a controller; a coolant circuit; a first temperature sensor; and a second temperature sensor. The cooling circuit includes a cooling pipe, a water pump, a radiator, a heater, and a thermostatic three-way valve. The cooling circuit is configured to cool the electrochemical reactor. The controller is configured to control operations of the electrochemical reactor and the cooling circuit. The cooling pipe includes a first water inlet and a first water outlet; and the coolant circuit is disposed between the first water inlet and the first water outlet. The first temperature sensor is disposed at the first water inlet. The second temperature sensor is disposed at the first water outlet. The first temperature sensor and the second temperature sensor are configured to detect and transmit temperature data of a coolant in the cooling pipe to the controller.

A method for controlling a fuel cell that includes an electrochemical reactor; a cooling circuit; a controller; a coolant circuit; a first temperature sensor; and a second temperature sensor. The cooling circuit includes a cooling pipe and is configured to cool the electrochemical reactor; the controller is configured to control operations of the electrochemical reactor and the cooling circuit; the cooling pipe includes a first water inlet and a first water outlet; and the coolant circuit is connected to the first water inlet and the first water outlet. The method includes comparing the first temperature of the coolant at the first water inlet to the second temperature at the first water outlet; and controlling operations of the heater and the electrochemical reactor based on the comparison result.

A method for controlling a fuel cell that includes an electrochemical reactor; a cooling circuit; a controller; a coolant circuit; a first temperature sensor; and a second temperature sensor. The cooling circuit includes a cooling pipe and is configured to cool the electrochemical reactor; the controller is configured to control operations of the electrochemical reactor and the cooling circuit; the cooling pipe includes a first water inlet and a first water outlet; and the coolant circuit is connected to the first water inlet and the first water outlet. The method includes comparing the first temperature of the coolant at the first water inlet to the second temperature at the first water outlet; and controlling operations of the heater and the electrochemical reactor based on the comparison result.

A computer is provided for a fuel cell propulsion system of a motor vehicle. The computer includes one or more processors receiving a temperature signal from one or more temperature sensors and a pressure signal from one or more pressure sensors. The computer further includes a non-transitory computer readable storage medium including instructions, such that the processor is programmed to determine a feedback correction based on the temperature of the coolant and the pressure drop of the coolant across the fuel cell stack. The processor is further programmed to generate a pump command signal based on the feedback correction and a nominal pump command, with the pump command signal actuating a pump to pump coolant at a target pump speed.

A fuel cell system includes a fuel cell, a supercharger, a coolant circuit, a pump controller, and a pressure regulating mechanism. The supercharger applies pressure to cathode gas and supplies the cathode gas to the fuel cell. The coolant circuit has a coolant circulation pump and a cooler and circulates a coolant to be supplied to a coolant channel in the fuel cell. The pressure regulating mechanism regulates coolant pressure in the fuel cell. The pump controller controls a rotation speed of the pump in accordance with a heat release amount required by the fuel cell and controls the pump in a range lower than or equal to an upper limit for the rotation speed set based on one or both of inlet coolant pressure of the pump or a correlation value thereof and an inlet coolant temperature of the pump or a correlation value thereof.

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.

A device intended to generate electricity includes a planar fuel cell having: cells each provided with an anode and a cathode associated with a membrane, and a first face and a second face opposite to the first face, the first face being arranged on the side with the anodes of the fuel cell and the second face being arranged on the side with the cathodes of the fuel cell. Furthermore, this device includes a system configured to generate a first air flow intended to cooperate thermally with the first face, and configured to generate a second air flow intended to cooperate with the second face to ensure the supply of oxidizer to the cathodes of the fuel cell.

Systems and methods are provided for monitoring and controlling pump speeds to maintain a balanced pressure drop between each of the multiple fuel cell systems or circuits. In systems where a single radiator is used to maintain desired temperatures of multiple fuel cells, back flow can nevertheless be avoided. Control maps may be used to meet minimum pump speeds as a function of a flow splitting valve position and target flow rate (to prevent or avoid fluid back flow through a fuel cell stack). Control maps may also be used to determine a minimum pump speed as a function of three-way valve position (to prevent fluid back flow across a radiator path).

A PEM fuel or electrolysis cell with an extended lifetime, improved performance and uniform and stable operation is disclosed wherein a membrane electrode assembly is provided with a gradient of one or more properties in combination with a modification of one or more control parameters of the cell during its operation.