Injector apparatus and method for combusting a fuel for a gas powered turbine

Abstract

A combustor for a gas powered turbine which employs a hypergolic or high energy air stream and an injector design to mix fuel with the high energy hypergolic air stream faster than the combustion rate of the fuel. A heat exchanger and a catalyst combusts a first portion of fuel in air without the production of undesired chemical species. A gas powered turbine requires expanding gases to power the turbine fans or blades. Fuel is generally combusted to produce the required gases. A catalyst is employed to lower the combustion temperature of the fuel. The catalyst is placed on a set of tubes in a heat exchanger such that a portion of the thermal energy may be transferred to the air before it engages the catalyst. After encountering the catalyst, the fuel that was combusted increases the temperature of the air to an auto-ignition temperature so that no other ignition source is needed to combust additional fuel added later. Therefore, as the air exits the heat exchanger, it enters a main combustion chamber and is mixed with a second portion of fuel at a rate that is greater than the combustion reaction rate of the fuel.

What is claimed is:  
     
         1 . A combustion system for use in a gas powered turbine which combusts a fuel in the presence of air while substantially eliminating nitrous oxide emissions, comprising: 
 a pre-heater to heat a volume of an oxidizer to form a volume of high energy;    an injector member to inject a fuel, including a high temperature, into said volume of high energy oxidizer;    an injector port, defined by said injector member, to provide the fuel to said volume of high energy oxidizer before a substantial portion of the fuel combusts; and    wherein substantially all the fuel provided through said injector port reaches its said high temperature at substantially the same time.    
     
     
         2 . The combustion system of  claim 1 , wherein said pre-heater comprises: 
 a fuel supply system to provide a fuel to said volume of oxidizer:    a heat exchanger including: 
 a catalyst pathway extending along a first axis;  
 a cooling pathway extending along a second axis;  
 wherein said catalyst pathway is in thermal contact with said cooling pathway;  
 wherein the oxidizer is adapted to first flow through said cooling pathway and then through said catalyst pathway;  
   a catalyst, placed within said catalyst pathway, and adapted to combust the fuel with said volume of oxidizer; and    wherein said volume of oxidizer is adapted to first flow past said catalyst pathway and through said cooling pathway, thereby receiving thermal energy from said catalyst pathway.    
     
     
         3 . The combustion system of  claim 2 , 
 wherein said catalyst pathway comprises a plurality of catalyst tube, that form a plurality of catalyst tube columns each spaced apart transversally to said first axis and which define a plurality of channels adapted for allowing the oxidizer to flow therethrough;    wherein said cooling pathway comprises a plurality of cooling tubes that form a plurality of cooling tube columns each spaced apart transversally to said second axis; and    wherein said cooling tubes extend substantially adjacent said catalyst tubes along said second axis for at least a portion of the length of said catalyst tubes.    
     
     
         4 . The combustion system of  claim 1 , further comprising: 
 at least a first and a second of said injector ports;    a first fuel stream produced by said first injector port;    a second fuel stream produced by said second injector port;    wherein said first fuel stream and said second fuel stream impinge into one another to form a fuel plume prior to intersecting the high energy air.    
     
     
         5 . The combustion system of  claim 4 , wherein said first fuel stream and said second fuel stream intersect at an angle between about 20° and about 150°.  
     
     
         6 . The combustion system of  claim 4 , further comprising: 
 a fuel path formed in said injector member such that the first fuel stream and the second fuel stream provided by said first and second injector ports intersect to produce said fuel plume.    
     
     
         7 . The combustion system of  claim 1 , wherein said injector port is substantially rectangular in shape such that a fuel stream is flattened as said fuel stream exits said injector port.  
     
     
         8 . A gas powered turbine, comprising: 
 a compressor to produce compressed atmospheric air to provide an oxidizer for the gas powered turbine;    a combustion system for mixing and combusting a fuel injected into the compressed atmospheric air to produce an expanding gas;    a turbine fan which is powered by the expanding gases:    wherein said combustion system comprises: 
 a pre-heat area;  
 a first fuel line to supply a first portion of fuel to the compressed atmospheric air which is combusted in the pre-heat area to heat the compressed atmospheric air to a hypergolic temperature so as to produce hypergolic air;  
 a second fuel line to supply a second portion of fuel to the hypergolic air;  
 an injector system to provide said second portion of fuel to said hypergolic air before any substantial portion of said second portion of fuel combusts; and  
   wherein substantially all of said second portion of fuel combusts at substantially the same time such that the gas powered turbine emits substantially no nitrous oxide compounds.    
     
     
         9 . The turbine of  claim 8 , wherein said pre-heat area includes a heat exchanger including: 
 a catalyst pathway extending along a first axis;    a cooling pathway extending along a second axis which is parallel to said first axis;    wherein said catalyst pathway forms a plurality of columns spaced transversally to said first axis and defining a plurality of channels; and    wherein said cooling pathway extends a distance along said catalyst pathway and generally perpendicular to said channels.    
     
     
         10 . The turbine of  claim 9 , wherein said catalyst pathway includes a plurality of catalyst tubes and said cooling pathway includes a plurality of cooling tubes.  
     
     
         11 . The turbine of  claim 8 , further comprising: 
 a pre-mix area for mixing the fuel from said first fuel supply with the air before the air enters the pre-heat area;    a main injector plate comprising at least a first and a second of said injectors; and    a combustion area wherein said second supply of fuel is combusted.    
     
     
         12 . The turbine of  claim 11 , further comprising: 
 a first fuel stream produced by said first injector port;    a second fuel stream produced by said second injector port;    wherein said first fuel stream and said second fuel stream impinge into one another forming a fuel plume prior to intersecting the hypergolic air.    
     
     
         13 . The turbine of  claim 12 , wherein said first fuel stream and said second fuel stream intersect at an angle between about 20° and about 150°.  
     
     
         14 . The turbine of  claim 12 , further comprising 
 a fuel path formed in said main injector plate such that fuel provided by said first and second injector ports intersects to produce said fuel plume.    
     
     
         15 . The turbine of  claim 8 , wherein said injector port is substantially rectangular in shape such that a fuel stream is flattened as said fuel stream exits said injector port.  
     
     
         16 . A method of combusting a fuel for a gas powered turbine in the presence of atmospheric air while substantially eliminating the emission of nitrous oxide compounds, the method comprising: 
 producing an auto-ignition air stream wherein a fuel homogeneously combusts spontaneously upon reaching the temperature of said auto-ignition air stream;    providing a first portion of the fuel to said auto-ignition air stream;    mixing said first portion of fuel with said auto-ignition air stream before substantially any of said first portion of fuel combusts to thereby substantially eliminate emission of nitrous oxide compounds.    
     
     
         17 . The method of  claim 16 , further comprising: 
 producing an expanding gas by combusting said first portion of fuel in said auto-ignition air-stream, said expanding gas occurring when said portion of fuel in said auto-ignition air-stream combusts upon reaching the temperature of the auto-ignition air stream.    
     
     
         18 . The method of  claim 17 , further comprising powering a turbine with said expanding gas.  
     
     
         19 . The method of  claim 16 , wherein said auto-ignition air stream has a temperature between about 1400° F. and 1600° F.  
     
     
         20 . The method of  claim 16 , wherein mixing said first portion of fuel further comprises: 
 impinging a first fuel stream upon a second fuel stream to form a fuel plume prior to intersecting the auto-ignition air stream.    
     
     
         21 . The method of  claim 20 , wherein impinging said first fuel stream upon said second fuel stream occurs at an angle between about 20° and about 150°.  
     
     
         22 . The method of  claim 21 , further comprising: 
 forming said first fuel stream and said second fuel stream as substantially flat streams before allowing said streams to impinge one another.    
     
     
         23 . The method of  claim 16 , wherein mixing said first portion of fuel further comprises providing a substantially flat fuel stream to said auto-ignition air stream.  
     
     
         24 . The method of  claim 16 , wherein producing an auto-ignition airstream further comprises: 
 forming a fuel-air mixture by mixing a second portion of fuel with a volume of air; and    combusting said second portion of fuel in said volume of air, wherein combusting said second portion of fuel increases the temperature of said volume of air to an auto-ignition temperature.