Hybrid fuel heat exchanger—pre-reformer in SOFC systems
View Patent ↗A fuel cell system includes at least one fuel cell stack, a fuel inlet conduit, and a fuel heat exchanger containing a fuel reformation catalyst. The fuel heat exchanger is connected to the fuel inlet conduit and to at least one fuel cell system exhaust conduit which in operation provides a high temperature exhaust stream to the fuel heat exchanger.
1. A fuel cell system, comprising:
at least one fuel cell stack;
a fuel inlet conduit;
a fuel exhaust conduit;
a fuel exhaust recycling conduit;
an anode tail gas oxidizer (ATO);
a splitter; and
a fuel heat exchanger containing a fuel reformation catalyst, wherein:
the fuel heat exchanger is connected to the fuel inlet conduit and to the fuel exhaust conduit which in operation provides a high temperature exhaust stream from the fuel cell stack to the fuel heat exchanger;
the fuel heat exchanger is fluidly connected to the splitter which is connected to the fuel exhaust recycling conduit which in operation recycles a first portion of the high temperature exhaust stream from the fuel heat exchanger via the splitter to the fuel inlet conduit;
the splitter is fluidly connected to the ATO and provides a second portion of the high temperature exhaust stream to the ATO; and
the first portion of the high temperature exhaust stream and the second portion of the high temperature exhaust stream have a same relative hydrogen content upon immediate output from the splitter.
2. The system of claim 1 , wherein the at least one fuel cell stack comprises at least one SOFC stack.
3. The system of claim 1 , wherein the fuel heat exchanger comprises a multi-stream heat exchanger which contains passages for at least three flow streams.
4. A fuel cell system, comprising:
at least one fuel cell stack;
a fuel inlet conduit;
an anode tail gas oxidizer (ATO); and
a multi-stream heat exchanger containing a fuel reformation catalyst and passages for at least three flow streams,
wherein:
the multi-stream heat exchanger is connected to the fuel inlet conduit and to at least one fuel cell system exhaust conduit which in operation provides a high temperature exhaust stream to the multi-stream heat exchanger,
the fuel inlet conduit is connected to a first inlet of the multi-stream heat exchanger;
an air inlet conduit is connected to a second inlet of the multi-stream heat exchanger;
a fuel cell stack anode exhaust conduit is connected to a third inlet of the multi-stream heat exchanger;
an ATO exhaust conduit is connected to fourth inlet of the multi-stream heat exchanger;
a fuel cell stack fuel inlet is connected to a first outlet of the multi-stream heat exchanger; and
a fuel cell stack air inlet is connected to a second outlet of the multi-stream heat exchanger.
5. The system of claim 4 , wherein the at least one fuel cell stack, the ATO and the multi-stream heat exchanger are located inside a hotbox.
6. The system of claim 1 , wherein the fuel heat exchanger comprises fins coated with the fuel reformation catalyst.
7. The system of claim 6 , wherein the fuel reformation catalyst comprises at least one of nickel or rhodium.
8. The system of claim 7 , wherein rhodium is located in a leading segment and nickel is located in a trailing segment of the fuel heat exchanger.
9. The system of claim 1 , further comprising a hydrocarbon fuel source connected to the fuel inlet conduit.