Device for stabilizing combustion in gas turbine engines

Abstract

Disclose is a burner for a gas turbine combustor that uses a central bluff body flame holder and a quarl to shape the recirculation zone in order to stabilize the combustion process. The burner includes, among other elements, a cylindrical main body and a flame holder. The flame holder is disposed within a fuel-air mixing chamber and includes a base portion and an elongated bluff body. The base portion engages with the main body of the burner in a supporting manner and the elongated bluff body extends in an axially downstream direction from the base portion through the internal mixing chamber so as to position a combustion ignition point downstream of the internal mixing chamber. In a representative embodiment, the burner further includes a quarl device disposed adjacent to the downstream end portion of the burner main body. The quarl device defines an interior recirculation chamber and a burner exit. The interior recirculation chamber is adapted for receiving precombustion gases from the mixing chamber and for recirculating a portion of the combustion product gases in an upstream direction so as to aid in stabilizing combustion.

1 . A burner for a gas turbine combustor comprising: 
 a) a cylindrical main body having axially opposed upstream and downstream end portions, the main body having at least one fuel inlet passage and at least one air inlet passage formed therein which are adapted to supply fuel and air respectively to a mixing chamber defined in the downstream end portion of the main body, the mixing chamber configured to swirl and mix the fuel and air supplied to the mixing chamber; and    b) a flame holder disposed within the mixing chamber and including a base portion engaged with the main body of the burner and an elongated bluff body extending in an axially downstream direction from the base portion through the internal mixing chamber so as to control the position of a combustion ignition point downstream of the internal mixing chamber.    
   
   
       2 . A burner as recited in  claim 1 , further comprising a quarl device disposed adjacent to the downstream end portion of the burner main body, the quarl device defining an interior recirculation chamber and a burner exit, the interior recirculation chamber adapted for receiving precombustion gases from the mixing chamber and for recirculating a portion of the combustion product gases in an upstream direction so as to aid in stabilizing combustion.  
   
   
       3 . A burner as recited in  claim 1 , wherein the bluff body of the flame holder is axially centered within the mixing chamber.  
   
   
       4 . A burner as recited in  claim 1 , wherein the flame holder bluff body has a tapered region.  
   
   
       5 . A burner as recited in  claim 1 , wherein the flame holder bluff body has a radially enlarged tip region.  
   
   
       6 . A burner as recited in  claim 1 , wherein the flame holder has an axial length, which is adapted for achieving a swirl number of greater than about 0.6.  
   
   
       7 . A burner as recited in  claim 1 , wherein the at least one air inlet passage is formed in a substantially radially inward direction.  
   
   
       8 . A burner as recited in  claim 1 , wherein fuel enters the mixing chamber of the main body in a substantially axial direction.  
   
   
       9 . A burner as recited in  claim 1 , wherein the at least one fuel inlet passage formed in the main body of the burner includes a helical portion for imparting an angular momentum to the fuel.  
   
   
       10 . A burner as recited in  claim 1 , wherein the flame holder bluff body has a plurality of axially extending flutes formed in an outer surface thereof.  
   
   
       11 . A burner for a gas turbine combustor comprising: 
 a) a cylindrical main body having axially opposed upstream and downstream end portions, the main body having at least one fuel inlet passage and at least one air inlet passage formed therein which are adapted to supply fuel and air respectively to a mixing chamber defined in the downstream end portion of the main body, the mixing chamber configured to swirl and mix the fuel and air supplied to the mixing chamber;    b) a flame holder disposed within the mixing chamber and including a base portion engaged with the main body of the burner and an elongated bluff body extending in an axially downstream direction from the base portion through the internal mixing chamber so as control the position of a combustion ignition point downstream of the internal mixing chamber; and    c) a quarl device disposed adjacent to the downstream end portion of the burner main body, the quarl device defining an interior recirculation chamber and a burner exit, the interior recirculation chamber adapted for receiving precombustion gases from the mixing chamber and for recirculating a portion of the combustion products gases in an upstream direction so as to aid in stabilizing combustion.    
   
   
       12 . A burner as recited in  claim 11 , wherein the bluff body of the flame holder is axially centered within the mixing chamber.  
   
   
       13 . A burner as recited in  claim 11 , wherein the flame holder bluff body has a tapered region.  
   
   
       14 . A burner as recited in  claim 11  wherein the flame holder bluff body has radially enlarged tip region.  
   
   
       15 . A burner as recited in  claim 11 , wherein the flame holder has an axial length, which is adapted for anchoring a main recirculation with a swirl number in the range of between about 0.6 and about 2.0.  
   
   
       16 . A burner as recited in  claim 11  wherein the at least one air inlet passage is formed in a substantially radially inward direction.  
   
   
       17 . A burner as recited in  claim 11 , wherein fuel enters the mixing chamber of the main body in a substantially axial direction.  
   
   
       18 . A burner as recited in  claim 11 , wherein the at least one fuel inlet passage formed in the main body of the burner includes a helical portion for imparting an angular momentum to the fuel.  
   
   
       19 . A burner as recited in  claim 11 , wherein the flame holder bluff body has a plurality of axially extending flutes formed in an outer surface thereof.  
   
   
       20 . A burner for a gas turbine combustor comprising: 
 a) a cylindrical main body having axially opposed upstream and downstream end portions, the main body having at least one fuel inlet passage and at least one air inlet passage formed therein which are adapted to supply fuel and air respectively to a mixing chamber defined in the downstream end portion of the main body, the mixing chamber configured to swirl and mix the fuel and air supplied to the mixing chamber; and    b) means disposed within the mixing chamber for controlling the position of a combustion ignition point downstream of the internal mixing.