Dual reaction zone fuel reformer and associated method

Abstract

An apparatus comprises a supplier of air and/or fuel, a main passageway fluidly coupled to the supplier to receive air and/or fuel therefrom to provide a fuel-rich air-and-fuel main mixture in the main passageway, and a pilot flame generator mounted in the main passageway. The pilot flame generator defines therein a pilot passageway that is fluidly coupled to the supplier to receive air and/or fuel therefrom and is fluidly coupled to the main passageway to receive air and/or fuel therefrom to provide an air-and-fuel pilot mixture in the pilot passageway. The pilot flame generator comprises an ignition device configured to ignite the pilot mixture to generate a pilot flame that initiates a partial oxidation reaction of the main mixture so as to generate reformate gas. An associated method is disclosed.

1 . A method of operating a fuel reformer, comprising the steps of:
 supplying air and fuel to a main passageway so as to provide an air-and-fuel main mixture in the main passageway, the main mixture being fuel-rich,   supplying air and fuel to a pilot passageway located within the main passageway in part by air and/or fuel supplied to the main passageway so as to provide an air-and-fuel pilot mixture in the pilot passageway, the pilot mixture being less fuel-rich than the main mixture,   igniting the pilot mixture so as to generate a pilot flame, and   initiating a partial oxidation reaction of the main mixture with the pilot flame so as to generate reformate gas.   
   
   
       2 . The method of  claim 1 , further comprising heating a pilot tube defining the pilot passageway by use of the pilot flame, wherein:
 the step of supplying air and fuel to the main passageway comprises dispensing fuel against an outer surface of the heated pilot tube so as to vaporize the dispensed fuel in the main passageway, and   the initiating step comprises partially oxidizing the vaporized fuel by use of the pilot flame.   
   
   
       3 . The method of  claim 1 , wherein:
 the igniting step comprises generating the pilot flame in a pilot tube located in the main passageway and defining the pilot passageway, and   the initiating step comprises partially oxidizing fuel of the main mixture outside the pilot tube.   
   
   
       4 . The method of  claim 1 , wherein:
 the step of supplying air and fuel to the main passageway comprises introducing the fuel-rich air-and-fuel main mixture to the main passageway upstream from a pilot inlet of the pilot passageway,   the step of supplying air and fuel to the pilot passageway comprises (i) advancing a fuel-rich portion of the fuel-rich air-and-fuel mixture through the pilot inlet into the pilot passageway, and (ii) introducing air into the pilot passageway for mixture with the fuel-rich portion of the fuel-rich air-and-fuel mixture to provide the pilot mixture.   
   
   
       5 . The method of  claim 1 , wherein:
 the step of supplying air and fuel to the main passageway comprises (i) introducing air into the main passageway upstream from a pilot inlet of the pilot passageway, and (ii) introducing fuel into the main passageway downstream from the pilot inlet, and   the step of supplying air and fuel to the pilot passageway comprises (i) advancing a portion of the air introduced into the main passageway through the pilot inlet into the pilot passageway, and (ii) introducing fuel into the pilot passageway for mixture with the portion of the air therein to provide the pilot mixture.   
   
   
       6 . The method of  claim 1 , wherein:
 the step of supplying air and fuel to the main passageway comprises (i) introducing exhaust gas into the main passageway upstream from a pilot inlet of the pilot passageway, and (ii) introducing fuel into the main passageway downstream from the pilot inlet, and   the step of supplying air and fuel to the pilot passageway comprises (i) advancing a portion of the exhaust gas from the main passageway through the pilot inlet into the pilot passageway, and (ii) introducing fuel into the pilot passageway for mixture with the portion of the exhaust gas therein to provide the pilot mixture.   
   
   
       7 . An apparatus, comprising:
 a supplier of air and/or fuel,   a main passageway fluidly coupled to the supplier to receive air and/or fuel therefrom to provide a fuel-rich air-and-fuel main mixture in the main passageway, and   a pilot flame generator mounted in the main passageway, the pilot flame generator defining therein a pilot passageway fluidly coupled to the supplier to receive air and/or fuel therefrom and fluidly coupled to the main passageway to receive air and/or fuel therefrom to provide an air-and-fuel pilot mixture in the pilot passageway, the pilot flame generator comprising an ignition device configured to ignite the pilot mixture to generate a pilot flame that initiates a partial oxidation reaction of the main mixture so as to generate reformate gas.   
   
   
       8 . The apparatus of  claim 7 , further comprising a controller electrically coupled to the supplier and the ignition device, wherein the controller comprises a processor and a memory device electrically coupled to the processor, the memory device having stored therein a plurality of instructions which, when executed by the processor, causes the processor to operate the supplier and the ignition device. 
   
   
       9 . The apparatus of  claim 7 , wherein:
 the main passageway is defined in a conduit,   the pilot flame generator comprises a pilot tube that is positioned within the conduit, defines the pilot passageway, and cooperates with the conduit to define at least a portion of the main passageway therebetween, and   the ignition device is mounted in the pilot tube.   
   
   
       10 . The apparatus of  claim 9 , wherein the supplier comprises a fuel dispenser secured to the conduit and aimed at an outer surface of the pilot tube to dispense fuel against the outer surface. 
   
   
       11 . The apparatus of  claim 9 , wherein the conduit and the pilot tube are coaxial. 
   
   
       12 . The apparatus of  claim 7 , wherein the supplier supplies the fuel-rich air-and-fuel mixture to the main passageway upstream from the pilot flame generator. 
   
   
       13 . The apparatus of  claim 7 , wherein the supplier supplies air to the main passageway upstream from an air inlet of the pilot flame generator and supplies fuel to the main passageway downstream from the air inlet and fuel to the pilot passageway. 
   
   
       14 . The apparatus of  claim 7 , wherein:
 the main passageway is an exhaust gas passageway, and   the supplier supplies fuel to the exhaust gas passageway and the pilot passageway.   
   
   
       15 . The apparatus of  claim 7 , wherein the supplier comprises a fuel dispenser aimed at an outer surface of the pilot flame generator. 
   
   
       16 . The apparatus of  claim 7 , wherein the apparatus is devoid of a fuel-reforming catalyst. 
   
   
       17 . The apparatus of  claim 7 , further comprising a fuel-reforming catalyst downstream from the pilot flame generator. 
   
   
       18 . An apparatus, comprising:
 an exhaust gas main passageway,   a main fuel dispenser and a pilot fuel dispenser, and   a pilot flame generator mounted in the main passageway, the pilot flame generator defining therein a pilot passageway open to the main passageway to receive exhaust gas therefrom, the pilot fuel dispenser arranged to introduce fuel into the pilot passageway for mixture with exhaust gas introduced from the main passageway into the pilot passageway to provide an air-and-fuel pilot mixture in the pilot passageway, the pilot flame generator comprising an ignition device arranged to ignite the pilot mixture to generate a pilot flame, the main fuel dispenser arranged to dispense fuel into the main passageway against the outer surface which is heated by the pilot flame for vaporization of such fuel to provide a fuel-rich air-and-fuel main mixture in the main passageway, the pilot flame for initiating a partial oxidation reaction of the main mixture to generate reformate gas.   
   
   
       19 . The apparatus of  claim 18 , wherein:
 the main passageway and the pilot passageway are coaxial relative to an axis, and   the main fuel dispenser is oriented relative to the axis to direct fuel axially and radially toward the axis.   
   
   
       20 . The apparatus of  claim 18 , further comprising another main fuel dispenser arranged to dispense fuel into the main passageway against the outer surface.