Power generation systems and methods utilizing cascaded fuel cells

Patent metadata

Field	Value
Publication number	US-10256496-B2
Application number	US-201414321124-A
Country	US
Kind code	B2
Filing date	Jul 1, 2014
Priority date	Jul 1, 2014
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

A power generation system including a first fuel cell configured to generate a first anode tail gas stream is presented. The system includes at least one fuel reformer configured to receive the first anode tail gas stream, mix the first anode tail gas stream with a reformer fuel stream to form a reformed stream; a splitting mechanism to split the reformed stream into a first portion and a second portion; and a fuel path configured to circulate the first portion to an anode inlet of the first fuel cell, such that the first fuel cell is configured to generate a first electric power, at least in part, by using the first portion as a fuel. The system includes a second fuel cell configured to receive the second portion, and to generate a second electric power, at least in part, by using the second portion as a fuel.

First claim

The invention claimed is:

1. A power generation system, comprising:
a first solid-oxide fuel cell configured to generate a first anode tail gas stream and a first cathode tail gas stream;
(ii) at least one fuel reformer located downstream of the first solid-oxide fuel cell, the fuel reformer configured to receive the first anode tail gas stream, and to mix the first anode tail gas stream with a reformer fuel stream to form a reformed stream;
(iii) a splitting mechanism to split the reformed stream into a first portion and a second portion;
(iv) a fuel path configured to circulate the first portion to an anode inlet of the first solid-oxide fuel cell, such that the first solid-oxide fuel cell is configured to generate a first electric power, at least in part, by using the first portion as a fuel;
(v) a second solid-oxide fuel cell configured to receive the second portion, and to generate a second electric power, at least in part, by using the second portion as a fuel, the second solid-oxide fuel cell further configured to generate a second anode tail gas stream and a second cathode tail gas stream;
(vi) a first recuperator configured to receive and extract heat from at least a portion of the first cathode tail gas stream and the second cathode tail gas stream to form a cooled cathode tail gas stream, and to transfer at least a portion of the extracted heat to the first portion of the reformed stream;
(vii) a recycle loop extending from an outlet of the first recuperator to a cathode inlet of the first solid-oxide fuel cell, wherein the recycle loop is configured to circulate at least a portion of the cooled cathode tail gas stream to the cathode inlet of the first solid-oxide fuel cell; and
(viii) an air pre-heater configured to extract heat from at least another portion of the cooled cathode tail gas stream directed via a channel coupled to the recycle loop, and to transfer at least a portion of the extracted heat to a cathode inlet stream of the first solid-oxide fuel cell, wherein the recycle loop extends from the first recuperator to the first solid-oxide fuel cell bypassing the air pre-heater.

2. The power generation system of claim 1 , wherein a ratio of the first portion of the reformed stream to a second portion of the reformed stream is in a range from about 0.6 to about 0.95.

3. The power generation system of claim 1 , further comprising a second recuperator located downstream of the reformer and upstream of the splitting, mechanism, the second recuperator configured to extract heat from the reformed stream to form a cooled reformed stream, and to transfer at least a portion of the extracted heat to the first portion of the reformed stream.

4. The power generation system of claim 3 , further comprising a first water separation twit located downstream of the second recuperator and upstream of the splitting mechanism, the water separation unit configured to separate at least a portion of water from the cooled reformed stream.

5. The power generation system of claim 4 , further comprising a first fuel pre-heater located downstream of the reformer and upstream of the second recuperator, the first fuel pre-heater configured to extract heat from the reformed stream, and to transfer at least a portion of the extracted heat to the fuel stream entering the reformer.

6. The power generation system of claim 5 , further comprising a second fuel pre-heater located downstream of the splitting mechanism and upstream of the second solid-oxide fuel cell, the second fuel pre-heater configured to extract heat from the second anode tail gas stream to form a cooled second anode tail gas stream, and to transfer at least a portion of the extracted heat to the second portion of the reformed stream.

7. The power generation system of claim 6 , further comprising:
a second water separation unit configured to separate at least a portion of water from the cooled second anode tail gas stream;
a combusting unit configured to receive at least a portion of the cooled second anode tail gas stream and at least a portion of the cooled cathode tail gas stream; and
an external combustion engine configured to receive an exhaust from the combusting unit to generate a third electric power.

8. A power generation system, comprising:
(i) a first solid-oxide fuel cell configured to generate a first anode tail gas stream and a first cathode tail gas stream;
(ii) a splitting mechanism to split the first anode tail gas stream into a first portion and a second portion;
(iii) a fuel path configured to circulate the first portion to an anode inlet of the first solid-oxide fuel cell, such that the first solid-oxide fuel cell is configured to generate a first electric power, at least in part, by using the first portion as a fuel;
(iv) a second solid-oxide fuel cell configured to receive the second portion, and to generate a second electric power, at least in part, by using the second portion as a fuel, the second solid-oxide fuel cell further configured to generate a second anode tail gas stream and a second cathode tail gas stream;
(vi) a first recuperator configured to receive and extract heat from at least a portion of the first cathode tail gas stream and the second cathode tail gas stream to form a cooled cathode tail gas stream, and to transfer at least a portion of the extracted heat to the first portion of the reformed stream;
(vii) a recycle loop extending from an outlet of the first recuperator to a cathode inlet of the first solid-oxide fuel cell, wherein the recycle loop is configured to circulate at least a portion of the cooled cathode tail gas stream to the cathode inlet of the first solid-oxide fuel cell; and
(viii) an air pre-heater configured to extract heat from at least another portion of the cooled cathode tail gas stream via a channel coupled to the recycle loop, and to transfer at least a portion of the extracted heat to a cathode inlet stream of the first solid-oxide fuel cell, wherein the recycle loop extends from the first recuperator to the first solid-oxide fuel cell bypassing the air pre-heater.

Assignees

• Gen Electric

Inventors

• Hussaini Irfan Saif
• Shapiro Andrew Philip
• Alinger Matthew Joseph

Classifications

• H01M2250/407

  Combination of fuel cells with mechanical energy generators · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M8/249 Primary

  comprising two or more groupings of fuel cells, e.g. modular assemblies · CPC title

• H01M8/0618

  Reforming processes, e.g. autothermal, partial oxidation or steam reforming · CPC title

• H01M8/04201

  Reactant storage and supply, e.g. means for feeding, pipes · CPC title