Integrated fuel cell block with a revised fuel cell cycle for in block reforming fuel cells

Patent metadata

Field	Value
Publication number	US-2018123151-A1
Application number	US-201715801112-A
Country	US
Kind code	A1
Filing date	Nov 1, 2017
Priority date	Nov 2, 2016
Publication date	May 3, 2018
Grant date	—

Abstract

A fuel cell system having a cathode, anode and auxiliary loop is provided. The anode loop may be configured to deliver reformed and unreformed fuel to the fuel cells. Unreformed fuel may be provided to the fuel cells by bypassing a portion of the fuel around a reformer. The unreformed fuel may be reformed in the fuel cell block. The cathode loop may direct a portion of oxidant exhausted from said fuel cells back to the fuel cell through a cathode ejector. The ejector may be supplied with pressurized oxidant that may be heated prior to entering the cathode ejector. The auxiliary loop may combust unused fuel and oxidant to provide the heat transferred to the oxidant prior to the oxidant entering the cathode loop.

First claim

We claim:

1 . A fuel cell system comprising:
a source of unreformed fuel; a source of oxidant; a fuel cell stack comprising a plurality of fuel cells, each fuel cell comprising an anode, a cathode and an electrolyte, said fuel cell stack further comprising:
a fuel supply manifold configured to receive a reformate and unreformed fuel and to supply the reformate and unreformed fuel to said plurality of anodes;
a fuel exhaust manifold configured to exhaust unused fuel from said fuel cell stack;
an oxidant supply manifold configured to receive an oxidant and to supply the oxidant to said plurality of cathodes; and
an oxidant exhaust manifold configured to exhaust the oxidant from said fuel cell stack;
an anode ejector configured to receive unreformed fuel from said source of fuel and to receive a portion of the unused fuel exhausted from said fuel cell stack; a reformer comprising a plurality of cold-side channels and a plurality of hot-side channels, said reformer further comprising:
a fuel supply manifold configured to receive fuel from said anode ejector and to supply the fuel to said plurality of cold-side channels;
a fuel exhaust manifold configured to exhaust reformate from said plurality of cold-side channels and to supply the reformate to said fuel supply manifold of said fuel cell stack;
an oxidant inlet manifold configured to receive a portion of the oxidant exhausted from said fuel cell stack and to supply the oxidant to said plurality of hot-side channels; and
an oxidant exhaust manifold configured to exhaust the oxidant from said plurality of hot-side channels;
an auxiliary ejector configured to receive oxidant from said oxidant source, a second portion of the unused fuel exhausted from said fuel cell stack, the oxidant exhausted from said plurality of hot channels, and a portion of a recycled auxiliary flow; a combustor configured to receive unused fuel and oxidant exhausted from the auxiliary ejector and exhaust a combustion product; a turbine configured to receive the exhaust from the combustor; a compressor configured to receive oxidant from said oxidant source; a cathode ejector configured to receive oxidant from said compressor and to receive a second portion of the oxidant exhausted from said oxidant exhaust manifold of said fuel cell stack and to supply oxidant to said oxidant inlet manifold of said fuel cell stack; and, a heat exchanger comprising a plurality of cold-side channels and a plurality of hot-side channels, said heat exchanger being configured to receive oxidant from said compressor in said cold-side channels and being configured to receive exhaust from said combustor in said hot-side channels.

2 . The fuel cell system of claim 1 further comprising a bypass duct configured to receive unreformed fuel exhausted from said anode ejector and to combine the unreformed fuel and the reformate exhausted from said cold-side channels of said reformer upstream of said fuel supply manifold of said fuel cell stack.

3 . The fuel cell system of claim 2 wherein at least 10% of said fuel exhausted by said anode ejector passes through said bypass duct.

4 . The fuel cell system of claim 2 wherein between 10% and 90% of said fuel exhausted from said anode ejector passes through said bypass duct.

5 . The fuel cell system of claim 1 wherein the oxidant exhausted from said cathode ejector is supplied to said oxidant inlet manifold of said fuel cell stack without passing through a heat exchanger.

6 . The fuel cell system of claim 1 wherein no more than 33% of the oxidant exhausted from said oxidant exhaust manifold of said fuel cell stack passes through said hot-side channels of said reformer.

7 . The fuel cell system of claim 1 wherein between 10% and 33% of the oxidant exhausted from said oxidant exhaust manifold of said fuel cell stack passes through said hot-side channels of said reformer.

8 . The fuel cell system of claim 1 further comprising a second heat exchanger comprising a plurality of cold-side channels and a plurality of hot-side channels, said second heat exchanger being configured to receive oxidant from said compressor in said cold-side channels and being configured to receive exhaust from said turbine in said hot-side channels.

9 . The fuel cell system of claim 1 , further comprising a combustor unit located between said cathode ejector and said fuel cells of fuel cell block, said combustor unit configured to inject a fuel into said oxidant and combust said second fuel with a catalytic combustor unit.

10 . The fuel cell system of claim 9 , wherein said fuel is natural gas.

11 . The fuel cell system of claim 9 , wherein said fuel is hydrogen.

12 . The fuel cell system of claim 1 , wherein said combustor is configured to directly receive fuel from said source of fuel and oxidant from said source of oxidant.

13 . A fuel cell system comprising:
a fuel cell stack comprising at least one fuel cell, each fuel cell comprising an anode, a cathode, and an electrolyte; a reformer comprising cold-side channels and hot-side channels; a source of fuel; an anode loop for supplying fuel and reformate to the anode of each fuel cell, said anode loop comprising:
a fuel inlet manifold in said fuel cell stack configured to supply fuel and reformate to the anode of each fuel cell;
a fuel exhaust manifold configured to receive unused fuel from the anode of each fuel cell;
an anode ejector configured to receive fuel from said fuel source and said fuel exhaust manifold;
the cold-side channels of said reformer configured to receive fuel from said anode ejector;
a source of oxidant; a cathode loop for supplying oxidant to the cathode of each fuel cell, said cathode loop comprising:
an oxidant inlet manifold in said fuel cell stack configured to supply oxidant to the cathode of each fuel cell;
an oxidant exhaust manifold in said fuel cell stack configured to receive unused oxidant from each cathode of said fuel cells;
a cathode ejector configured to receive oxidant from said oxidant source and said oxidant exhaust manifold and configured to supply oxidant to said oxidant inlet manifold;
wherein a portion of the oxidant exhausted from said oxidant exhaust manifold of said fuel cell stack passes through the hot-side channels of said reformer; a heat exchanger comprising hot-side and cold-side channels located upstream of said cathode ejector, wherein oxidant from said source of oxidant passes through said cold-side channels
and
an auxiliary loop for combusting a portion of the unused fuel from said fuel exhaust manifold and said portion of the unused oxidant from said oxidant exhaust manifold, said auxiliary loop comprising:
an auxiliary ejector configured to receive the oxidant from the hot-side channels of said reformer, a portion of the oxidant from said oxidant source, and said portion of the unused fuel from said fuel exhaust manifold;
a combustor configured to combust the exhaust from said auxiliary ejector; and
the hot-side channels of said heat exchanger configured to receive the combusted exhaust from said combustor.

14 . The fuel cell system of claim 13 further comprising a compressor configured to receive oxidant from said source of oxidant.

15 . The fuel cell system of claim 13 further comprising a turbine configured to receive the combusted exhaust from said combustor.

16 . The fuel cell system of claim 15 further comprising a heat exchanger having hot-side channels and cold-side channels, wherein said cold-side channels of said heat exchanger are disposed in said cathode loop and are configured t

Assignees

• Lg Fuel Cell Systems Inc

Inventors

• Cunningham Robert
• Dean Eric
• Agnew Gerry
• Bozzolo Michele

Classifications

• H01M8/04283 Primary

  Supply means of electrolyte to or in matrix-fuel cells · CPC title

• H01M8/04007 Primary

  related to heat exchange · CPC title

• H01M8/2465

  Details of groupings of fuel cells · CPC title

• H01M8/22

  Fuel cells in which the fuel is based on materials comprising carbon or oxygen or hydrogen and other elements; Fuel cells in which the fuel is based on materials comprising only elements other than carbon, oxygen or hydrogen · CPC title

• H01M8/0662

  Treatment of gaseous reactants or gaseous residues, e.g. cleaning · CPC title