Compressor system with a freewheeling expander
AssigneeGM Global Technology Operations LLC
InventorsMarc Becker, Remy Fontaine, Thomas W. Tighe
Life of this patent
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Abstract
A fuel cell system is disclosed that employs an expander for recovering mechanical energy from a cathode exhaust fluid produced by the fuel cell system to generate torque. The expander is coupled to a shaft of a compressor with a freewheel mechanism, wherein the freewheel mechanism transfers the torque from the expander to the compressor when a rate of rotation of a driveshaft of the expander is greater than the rate of rotation of the shaft of the compressor, and selectively militates against the expander acting as a restrictor to the shaft of the compressor when a rate of rotation of the driveshaft of the expander is substantially equal to or less than a rate of rotation of the shaft of the compressor.
Claims20
A fuel cell system comprising:
- a fuel cell stack including a cathode having an inlet and an outlet, wherein a first fluid flows through the inlet of the cathode and a second fluid flows through the outlet of the cathode;
- a compressor for compressing the first fluid, an inlet of the compressor in fluid communication with a source of the first fluid and an outlet of the compressor in fluid communication with the inlet of the cathode;
- an expander coupled to the compressor, wherein the expander is in fluid communication with the outlet of the cathode to recover mechanical energy from the second fluid and generate torque to power the compressor;
- and
- an overrunning clutch coupled to the compressor and the expander for transferring the torque from the expander to the compressor, wherein the overrunning clutch militates against the expander acting as a restrictor to the compressor.
A fuel cell system comprising:
- a fuel cell stack including a cathode having an inlet and an outlet, wherein a first fluid flows through the inlet of the cathode and a second fluid flows through the outlet of the cathode;
- a compressor for compressing the first fluid, the compressor including a shaft, an inlet, and an outlet, wherein the inlet of the compressor is in fluid communication with a source of the first fluid and the outlet of the compressor is in fluid communication with the inlet of the cathode;
- an expander coupled to the shaft of the compressor, wherein the expander is in fluid communication with the outlet of the cathode to recover mechanical energy from the second fluid and generate torque to power the compressor;
- and
- a freewheel mechanism including a driving race, a driven race disposed in the driving race, and at least one torque transfer element disposed therebetween, the driving race coupled to a shaft of the expander and the driven race coupled to the shaft of the compressor for transferring the torque from the expander to the compressor, wherein the torque transfer element militates against the expander acting as a restrictor to the compressor.
A method of operating a fuel cell system comprising the steps of:
- providing a fuel cell stack including a cathode having an inlet and an outlet, wherein a first fluid flows through the inlet of the cathode and a second fluid flows through the outlet of the cathode;
- providing a compressor for compressing the first fluid, an inlet of the compressor in fluid communication with a source of the first fluid and an outlet of the compressor in fluid communication with the inlet of the cathode;
- providing an expander coupled to the compressor, wherein the expander is in fluid communication with the outlet of the cathode;
- providing a freewheel mechanism for transferring the torque from the expander to the compressor, wherein the freewheel mechanism militates against the expander acting as a restrictor to the compressor;
- and
- causing the second fluid to flow through the expander to recover mechanical energy therefrom and generate torque to power to the compressor.
Dependencies are inferred from the claim text.