Fuel cell system with waste heat recovery for production of high pressure steam

Patent metadata

Field	Value
Publication number	US-2016149233-A1
Application number	US-201414550320-A
Country	US
Kind code	A1
Filing date	Nov 21, 2014
Priority date	Nov 21, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A fuel cell system for generating electrical power and high level heat comprising at least one high temperature fuel cell stack having an anode side and a cathode side and adapted to generate electrical power, and a gas oxidizer/high level heat recovery assembly comprising an oxidizer adapted to oxidize one or more of exhaust output from the at least one high temperature fuel cell stack and a gas derived from the exhaust, and to generate high level heat, and a high level heat recovery system adapted to recover the high level heat generated in the oxidizer.

First claim

What is claimed is:

1 . A fuel cell system for generating electrical power and high level heat comprising:
at least one high temperature fuel cell stack having an anode side and a cathode side and adapted to generate electrical power; and a gas oxidizer/high level heat recovery assembly comprising an oxidizer adapted to oxidize one or more of exhaust output from the at least one high temperature fuel cell stack and a gas derived from the exhaust, and to generate high level heat, and a high level heat recovery system adapted to recover the high level heat generated in the oxidizer.

2 . The fuel cell system in accordance with claim 1 , wherein the high level heat recovery system comprises a boiler adapted to receive feed water and to generate high pressure high temperature steam using the high level heat generated by the oxidizer.

3 . The fuel cell system in accordance with claim 1 , wherein the exhaust is anode exhaust and the oxidizer oxidizes one or more of anode exhaust output from the at least one high temperature fuel cell stack and the gas derived from the anode exhaust.

4 . The fuel cell system in accordance with claim 3 , further comprising one or more of:
an exhaust recuperator adapted to cool the exhaust output from the at least one fuel cell stack before the exhaust or the gas derived from the exhaust is provided to the oxidizer and to pre-heat input oxidant gas using heat in the exhaust before the heated oxidant gas is provided to the oxidizer; and a water transfer assembly adapted to recover water from the exhaust and to output water-separated exhaust, wherein the gas derived from the exhaust includes the water-separated exhaust.

5 . The fuel cell system in accordance with claim 4 , wherein the system comprises the exhaust recuperator and the water transfer assembly and wherein the exhaust recuperator is further adapted to pre-heat the water-separated exhaust and to output the heated water-separated exhaust to the oxidizer.

6 . The fuel cell system in accordance with claim 1 , further comprising a heater adapted to heat oxidant gas using waste heat from fuel-cell oxidant exhaust output from the at least one high temperature fuel cell stack before the heated oxidant gas is provided to the oxidizer.

7 . The fuel cell system in accordance with claim 2 , wherein the exhaust is anode exhaust and the oxidizer oxidizes one or more of anode exhaust output from the at least one high temperature fuel cell stack and the gas derived from the anode exhaust, and the system further comprising a fuel processing assembly for processing input fuel before supplying the processed fuel to the at least one high temperature fuel cell stack, the fuel processing assembly including a humidifier/heat exchanger assembly adapted to humidify the input fuel using one or more of water and a first portion of the high pressure high temperature steam generated in the boiler and to pre-heat humidified fuel using waste heat from oxidant exhaust output by the at least one high temperature fuel cell stack.

8 . The fuel cell system in accordance with claim 7 , wherein the system further comprises a water transfer assembly adapted to recover water from the anode exhaust and to output recovered water to the humidifier/heat exchanger assembly for humidifying the input fuel and to output water-separated anode exhaust for use in the oxidizer.

9 . The fuel cell system in accordance with claim 7 , further comprising an expander assembly adapted to expand the first portion of the high pressure high temperature steam and to output lower pressure steam to the humidifier/heat exchanger assembly while generating power from the expansion process, wherein the power generated by the expander assembly is output from the system or used by within the system.

10 . The fuel cell system in accordance with claim 9 , further comprising an air blower for supplying oxidant gas to the system, wherein the air blower is directly coupled with the expander assembly so that the power generated by the expander assembly is directly used by the air blower.

11 . The fuel cell system in accordance with claim 1 , wherein the gas oxidizer/high level heat recovery assembly is coupled with the at least one high temperature fuel cell stack so that the gas oxidizer/high level heat recovery assembly outputs high temperature oxidant gas to the cathode side of the at least one high temperature fuel cell stack.

12 . The fuel cell system in accordance with claim 1 , wherein the high level heat recovery system provides high level heat to one or more of: a fuel reforming assembly, a refinery coker unit, a heavy oil distillation unit and an expander.

13 . A method of generating electrical power and high level heat using a fuel cell system comprising the steps of:
operating at least one high temperature fuel cell stack having an anode side and a cathode side so as to generate electrical power; and oxidizing one or more of exhaust output from the at least one high temperature fuel cell stack and a gas derived from the exhaust in an oxidizer while generating high level heat as a result of the oxidizing process; and recovering the high level heat generated as a result of the oxidizing process.

14 . The method in accordance with claim 13 , wherein the step of recovering high level heat comprises generating high pressure high temperature steam from feed water by directly using the high level heat generated in the oxidizing step.

15 . The method in accordance with claim 13 , wherein the exhaust is anode exhaust and the oxidizing step comprises oxidizing one or more of anode exhaust output from the at least one high temperature fuel cell stack and the gas derived from the anode exhaust.

16 . The method in accordance with claim 15 , further comprising one or more of:
cooling the exhaust output from the at least one fuel cell stack before the exhaust or the gas derived from the exhaust is oxidized in the oxidizer step, pre-heating input oxidant gas using at least heat in the exhaust and providing the heated oxidant gas for use in the oxidizing step; and recovering water from the exhaust to output water-separated exhaust, wherein the gas derived from the exhaust includes the water-separated exhaust.

17 . The method in accordance with claim 16 , further comprising pre-heating the water-separated exhaust using the heat in the exhaust while pre-heating the input oxidant gas using the heat in the exhaust, and providing the heated water-separated exhaust for use in the oxidizing step.

18 . The method in accordance with claim 16 , further comprising further heating the pre-heated oxidant gas using waste heat from fuel-cell oxidant exhaust output from the at least one high temperature fuel cell stack before the heated oxidant gas is provided for use in the oxidizing step.

19 . The method in accordance with claim 14 , further comprising processing input fuel before supplying processed fuel to the at least one high temperature fuel cell stack, the processing step including humidifying the input fuel using one or more of water and a first portion of the high pressure high temperature steam generated in the generating step and pre-heating humidified fuel using waste heat from oxidant exhaust output by the at least one high temperature fuel cell stack.

20 . The method in accordance with claim 19 , further comprising recovering water from the anode exhaust, outputting recovered water for humidifying the input fuel in the processing step and outputting water-separated exhaust for use

Assignees

• Fuelcell Energy Inc

Inventors

• Jahnke Fred C
• Lambrech Matthew
• Patel Pinakin

Classifications

• H01M8/04111

  using a compressor turbine assembly · CPC title

• H01M8/04014 Primary

  Heat exchange using gaseous fluids; Heat exchange by combustion of reactants · CPC title

• Y02P90/40

  Fuel cell technologies in production processes · CPC title

• H01M8/0612

  from carbon-containing material · CPC title

• H01M2250/405

  Cogeneration of heat or hot water · CPC title