Gm Global Technolgoy Operations, Inc.

James S Siepierski

George R Woody

James H Lee

Martin Monroe Hoch

Eric L Thompson

Stephen Farris

Mahmoud H Abd Elhamid

Rainer Pechtold

Joseph D Rainville

Ulrich Dumke

Barbara S Moore

Systems of checking thermal-induced circulation of a coolant in a fuel cell stack are disclosed. The system includes coolant inlet and outlet lines extending from a fuel cell stack. A pump and a radiator are confluently connected to the coolant inlet and coolant outlet lines. In one embodiment, a valve (either check type or automatic type) is provided in the coolant outlet line at the bottom of the fuel cell stack to prevent the flow of cold coolant from the coolant outlet line into the fuel cell stack upon start-up of the fuel cell stack. In another embodiment, a valve (either one-way flow control type or automatic type) is provided in the coolant inlet line at the top of the fuel cell stack. A method of checking thermal-induced circulation of a coolant in a fuel cell stack is also disclosed.

Circulation check for fuel cell coolant

A fuel cell system including a combined injector/ejector system. The pressure of a hydrogen gas being injected into the fuel cell system by the injector acts as a pump that draws an anode exhaust gas being carried by the ejector back into the fuel cell system. The respective gases mix together in proximity to the ejector prior to being introduced back into the fuel cell system. A pressure controller can be provided to control the pressure of the hydrogen gas applied to the injector to more effectively draw the anode exhaust gas. In this manner, the need for a separate pump for the ejector, and the energy required for its operation, is eliminated or at least lessened, thus increasing the overall energy efficiency of the fuel cell system.

Combination of injector-ejector for fuel cell systems

A fuel cell system is provided for storing energy created from the reaction of residual gases at shutdown of a fuel cell stack. This energy can then be used for powering a component of the fuel cell stack and enables air to be used to purge the anode gas.

Residual stack shutdown energy storage and usage for a fuel cell power system

A fuel cell system and process using an organic Rankine cycle to produce shaft work to operate a fuel cell system component such as an air compressor. The air compressor delivers compressed air to a fuel cell stack. The steps of the Rankine cycle include pumping a liquid working fluid to an elevated pressure, heating the fluid to a gas, expanding the high temperature and high-pressure gas through an expander to produce shaft work used to drive a fuel cell system component such as an air compressor, and then removing energy from the cooling fluid to change the gas back to a liquid, and repeating the cycle. The liquid fluid can be heated by an external boiler, or one of the components of the fuel cell system such as the combustor and/or the fuel cell stack.

Cogeneration system for a fuel cell

A fuel cell system that can be used to power a vehicle is disclosed. The system includes a fuel cell stack, which uses hydrogen and an oxidizer to generate electricity, and a re-circulation loop that returns unreacted hydrogen to the fuel cell stack. The system includes a hermetically sealed assembly having a blower portion that pressurizes hydrogen in the re-circulation loop and a motor portion that drives the blower. The system also includes a source of make-up hydrogen for replenishing hydrogen in the re-circulation loop. The source introduces make-up hydrogen in the motor portion of the assembly at a pressure greater than the pressure in the blower portion of the assembly. Consequently, make-up hydrogen flows from the motor portion of the assembly into the blower portion assembly where it mixes with components in the re-circulation loop. A method of replenishing hydrogen in the fuel cell stack is also disclosed.

Hydrogen purged motor for anode re-circulation blower

A fuel cell system including a dry compressor for pressurizing air supplied to the cathode side of the fuel cell. An injector sprays a controlled amount of water on to the compressor's rotor(s) to improve the energy efficiency of the compressor. The amount of water sprayed out the rotor(s) is controlled relative to the mass flow rate of air inputted to the compressor.

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Williamsville, NY, United States of America

James S Siepierski