The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 21, 2003
Filed:
Jun. 01, 2001
David A. Condit, Avon, CT (US);
Richard D. Breault, North Kingstown, RI (US);
UTC Fuel Cells, LLC, South Windsor, CT (US);
Abstract
A fuel cell system is shut down by disconnecting the primary load, shutting off the air flow, and controlling the fuel flow into the system (including shutting off the fuel flow) and the gas flow out of the system in a manner that results in the fuel cell gases coming to equilibrium across the cells at a gas composition of at least 0.0001% hydrogen (by volume), and preferably between 1.0% and less than 4.0% hydrogen, by volume, with a balance of nitrogen and possibly other gases inert and harmless to the fuel cell, all the oxygen having been consumed by reacting with the hydrogen within the cell. That gas composition is maintained within the cells throughout shut-down, such as by adding hydrogen to replace any that is consumed by reaction with air leaking into the cells during the period of shut-down. This shut-down procedure causes virtually no cell performance losses.