Premixed duct burner

Abstract

A fully premixed duct burner is provided that receives exhaust gas from a power generating device, such as a gas turbine or reciprocating engine. The burner may include a burner surface adapted to combust the mixture on or above the surface in blue-flame mode. Substantially all exhaust gas passes through the burner with the exception of some small fraction of exhaust gas that passes through cooling holes or slots. The burner assembly can also include an array of burner modules that receive substantially all of the exhaust gas and fully premixes the exhaust gas with burner fuel prior to combusting the mixture on or above an array of burner surfaces.

1 . A duct burner assembly for use with a power generating device that generates exhaust gas, comprising: 
 a premix section that is fluidly coupled to an exhaust duct of the heat generating device for receiving substantially all of the exhaust gas;    one or more injectors that are operatively disposed within the premix section for injecting burner fuel and premixing the exhaust gas with the burner fuel; and    a burner surface for receiving the premixed exhaust gas and fuel combination, and combusting the combination on or above the burner surface.    
   
   
       2 . The duct burner assembly of  claim 1  wherein the injectors comprise one or more conduits that laterally extend through the premix section.  
   
   
       3 . The duct burner assembly of  claim 3  wherein the one or more conduits comprise three conduits.  
   
   
       4 . The duct burner assembly of  claim 1  wherein the injectors are adapted to inject burner fuel perpendicular to a flow path of exhaust gas through the premix section.  
   
   
       5 . The duct burner assembly of  claim 1  wherein the premix section includes a enclosing duct that is coupled to the exhaust duct and that communicates the fully mixed exhaust gas and fuel combination to the burner surface.  
   
   
       6 . The duct burner assembly of  claim 4  wherein the enclosing duct is configured to receive 80% or more of the burner fuel from the exhaust duct.  
   
   
       7 . The duct burner assembly of  claim 1  wherein the burner surface is a stabilized burner surface capable of operating in blue flame mode.  
   
   
       8 . The duct burner assembly of  claim 1  wherein the burner surface is formed from a sintered or unsintered metal fiber or ceramic fiber mat.  
   
   
       9 . A duct burner assembly for use with a power generating device that generates exhaust gas, comprising: 
 an array of burner modules, the array of burner modules comprising: 
 one or more premix sections that are fluidly coupled to an exhaust duct of the heat generating device for receiving substantially all of the exhaust gas;  
 one or more injectors that are operatively disposed within the one or more premix sections for injecting burner fuel and fully mixing the exhaust gas with the burner fuel; and  
 an array of burner surfaces for receiving the fully mixed exhaust gas and fuel combination, and combusting the fuel on or above the burner surface.  
   
   
   
       10 . The duct burner assembly of  claim 9  further comprising: 
 an outer duct that encloses the array of burner modules.    
   
   
       11 . The duct burner assembly of  claim 9 , wherein each of the burner modules includes an individually enclosed premix section.  
   
   
       12 . The duct burner assembly of  claim 9 , wherein each of the burner modules includes a premix section.  
   
   
       13 . The duct burner assembly of  claim 12 , wherein the premix sections are individually enclosed and communicate with a single burner surface.  
   
   
       14 . The duct burner assembly of  claim 9 , wherein the array of burner modules is arranged in a plurality of rows and columns, and wherein each row of burner modules includes one or more premix sections that are fluidly coupled together.  
   
   
       15 . The duct burner assembly of  claim 14 , wherein the injectors comprise one or more conduits, each of the conduits laterally extending through each premix section in a particular row.  
   
   
       16 . The duct burner assembly of  claim 9 , wherein the injectors comprise one or more conduits that laterally extend through the one or more premix sections.  
   
   
       17 . The duct burner assembly of  claim 16  wherein the injectors are adapted to inject burner fuel perpendicular to a flow path of exhaust gas through the premix section.  
   
   
       18 . The duct burner assembly of  claim 9  wherein the one or more premix sections are configured to receive 80% or more of the burner fuel from the exhaust duct.  
   
   
       19 . The duct burner assembly of  claim 9  wherein each of the burner surfaces is a stabilized burner surface capable of operating in blue flame mode.  
   
   
       20 . The duct burner assembly of  claim 9  wherein the each of the burner surfaces is formed from a sintered or unsintered metal or ceramic fiber mat.  
   
   
       21 . The duct burner assembly of  9  wherein each of the burner modules is capable of selectively being turned on and off.