System and method for increasing the efficiency for a solid oxide fuel cell system

Abstract

System and method for increasing efficiency of a solid oxide fuel cell (SOFC) system by recapturing water via a condensate extraction system that extracts water from a hot cathode exhaust flow of the SOFC stack. Further, the SOFC system can include a radiant heater which has a fuel inlet, an air intake, and an exhaust outlet independent and separate from the power generating components in the SOFC system. The radiant heater can bring the SOFC stack up to operating temperature quickly and/or maintain near operational mode temperatures of the SOFC stack during a hibernation mode.

What is claimed is: 
     
         1 . A solid oxide fuel cell system, comprising:
 a hot box containing a fuel cell;   a reformer which provides a reformed fuel to the fuel cell; and   a condensate chiller mechanism, wherein the condensate chiller mechanism receives anode exhaust from the fuel cell and condenses liquid water from the anode exhaust.   
     
     
         2 . The system of  claim 1 , wherein the condensate chiller mechanism comprises a Peltier cooler for separating the liquid water from the anode exhaust. 
     
     
         3 . The system of  claim 1 , wherein the condensate chiller mechanism comprises a phase change cooler for separating the liquid water from the anode exhaust. 
     
     
         4 . The system of  claim 3 , wherein the phase change cooler comprises an absorption chiller utilizing heat from the fuel cell or an exhaust of the fuel cell to condense liquid water from the anode exhaust. 
     
     
         5 . The system of  claim 1 , wherein the condensate chiller mechanism comprises a compressor driven refrigerant cooler for separating the liquid water from the anode exhaust. 
     
     
         6 . The system of  claim 1 , further comprising:
 a fuel-based radiant heater, wherein the fuel-based radiant heater directs radiation to the fuel cell to heat the fuel cell.   
     
     
         7 . The system of  claim 6 , wherein the fuel-based radiant heater is one of a diesel, gasoline, methanol, ethanol, natural gas, propane, methane, landfill gas, digester gas, reformate, or syngas fuel-based radiant heater. 
     
     
         8 . The system of  claim 6 , wherein the fuel-based radiant heater is a directed fuel-based radiant heater. 
     
     
         9 . The system of  claim 6 , further comprising a fuel inlet, wherein the fuel-based radiant heater has a radiant heater fuel inlet that is independent and separate from a fuel inlet of the solid oxide fuel cell system. 
     
     
         10 . The system of  claim 6 , wherein the fuel-based radiant heater has a radiant heater exhaust outlet that is independent and separate from an exhaust outlet of the fuel cell of the solid oxide fuel cell system. 
     
     
         11 . The system according to  claim 10 , wherein the radiant heater exhaust outlet is directed to provide heat to the fuel cell. 
     
     
         12 . The system according to  claim 1 , wherein the condensate chiller mechanism further vaporizes the liquid water to water vapor, and directs the water vapor to the reformer. 
     
     
         13 . A system for heating a solid oxide fuel cell, comprising:
 a hot box containing a fuel cell; and   a fuel-based radiant heater, wherein the fuel-based radiant heater directs radiation to the fuel cell.   
     
     
         14 . The system of  claim 13 , wherein the fuel cell is heated to an operating temperature to start operation of the fuel cell by the directed radiation. 
     
     
         15 . The system of  claim 13 , wherein the fuel cell is heated to maintain the fuel cell near an operating temperature during a hibernation mode. 
     
     
         16 . The system of  claim 13 , wherein an operating temperature of the fuel cell is maintained by the directed radiation. 
     
     
         17 . A method for increasing an efficiency of a solid oxide fuel cell (SOFC) system, comprising:
 directing an anode exhaust from a fuel cell to a condensate chiller;   extracting water vapor from the anode exhaust;   directing the water vapor to an air intake of a reformer;   producing a reformed fuel with an increased water balance based at least on the directed water vapor; and   supplying the reformed fuel with the increased water balance to the SOFC fuel cell.   
     
     
         18 . The method of  claim 17 , further comprising:
 generating radiation from a fuel-based radiant heater, wherein the fuel-based radiant heater directs the radiation to the fuel cell to heat the fuel cell.   
     
     
         19 . The method of  claim 18 , wherein heat from an exhaust of the fuel-based radiant heater is directed to the fuel cell. 
     
     
         20 . The method of  claim 18 , further comprising:
 maintaining, by the generated radiation, a temperature of the fuel cell near an operating temperature of the fuel cell.   
     
     
         21 . The method of  claim 20 , wherein maintaining the temperature of the fuel cell increases an efficiency of the SOFC system. 
     
     
         22 . The method of  claim 17 , wherein the fuel-cell is heated to an operating temperature. 
     
     
         23 . A method, comprising:
 generating, by a fuel-based radiant heater, radiation based at least on supplying a fuel to the fuel-based radiant heater; and   directing, by the fuel-based radiant heater, the radiation to a fuel cell, wherein the directed radiation heats the fuel cell.   
     
     
         24 . The method of  claim 23 , further comprising:
 raising, by the directed radiation, a temperature of the fuel cell to near an operating temperature of the fuel cell.   
     
     
         25 . The method of  claim 24 , further comprising:
 maintaining, by the directed radiation, a temperature of the fuel cell near a predetermined temperature.   
     
     
         26 . The method of  claim 25 , wherein the predetermined temperature is an operating temperature of the fuel cell.