| US 7,601,302 B2 | ||
| Self-regulating feedstock delivery systems and hydrogen-generating fuel processing assemblies and fuel cell systems incorporating the same | ||
| David J. Edlund, Bend, Oreg. (US); and R. Todd Studebaker, Bend, Oreg. (US) | ||
| Assigned to Idatech, LLC, Bend, Oreg. (US) | ||
| Filed on Sep. 16, 2005, as Appl. No. 11/228,637. | ||
| Prior Publication US 2007/0062116 A1, Mar. 22, 2007 | ||
| Int. Cl. G05D 7/00 (2006.01); G05B 9/00 (2006.01); G05D 16/00 (2006.01); F17D 3/00 (2006.01); H01M 8/18 (2006.01) | ||
| U.S. Cl. 422—110 [422/105; 422/111; 422/112; 422/114; 48/61; 48/127.9; 48/198.7; 48/190; 48/191; 429/19; 429/25] | 12 Claims |
| 1. A method for delivering feedstock to a hydrogen-producing fuel cell system that includes at least a hydrogen-producing
region adapted to produce a stream containing hydrogen gas from at least one feedstock, and a fuel cell stack adapted to produce
a power output from an oxidant and hydrogen gas produced in the hydrogen-producing region, the method comprising:
drawing a liquid stream from a supply containing at least one carbon-containing feedstock for the hydrogen-producing region
of a hydrogen-producing fuel cell system;
pumping at a constant flow rate regardless of changes in demand for hydrogen production by the hydrogen-producing region when
the hydrogen-producing region is in a hydrogen-producing operating state, a flow of the liquid stream through an outlet conduit
that is in fluid communication with a delivery conduit and a first portion of a recycle conduit, wherein the delivery conduit
is in fluid communication with the hydrogen-producing region of the hydrogen-producing fuel cell system, wherein the recycle
conduit is adapted to provide a flow path to return at least a portion of the liquid stream to at least one of the supply
and a location upstream from a delivery mechanism that is adapted to propel the liquid stream to the outlet conduit, and further
wherein the pumping step produces a flow rate of the liquid stream that exceeds a threshold flow rate through the hydrogen-producing
region, with an excess portion of the flow flowing into the recycle conduit;
regulating the distribution of the flow between the delivery conduit and the recycle conduit, wherein the regulating includes
creating backpressure in the recycle conduit with a flow restrictor that separates the recycle conduit into at least a first
portion that extends between the outlet conduit and the flow restrictor and a second portion that extends from the flow restrictor,
wherein the regulating further includes selectively permitting the excess portion of the flow to bypass the flow restrictor
by flowing through a bypass conduit in fluid communication with portions of the recycle conduit upstream and downstream of
the flow restrictor;
receiving at least a portion of the flow from the delivery conduit in the hydrogen-producing region and producing a stream
containing hydrogen gas therefrom; and
producing an electrical power output from an oxidant and at least a portion of the stream containing hydrogen gas.
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