Catalytic combustion device with liquid fuel vaporisation on hot walls

Abstract

The present invention relates to a catalytic combustion device comprising a main combustion zone ( 20, 200 ) including at least one catalytic section ( 5, 103 ) and at least one air/fuel mixing zone ( 11, 117 ), said mixing zone comprising at least one pressurized air inlet ( 1, 101 ) and injection means ( 12, 105 ) for injecting a liquid fuel. According to the invention, injection means ( 12, 105 ) project the liquid fuel onto a hot wall ( 13, 15, 107 ) of said device so as to allow vaporization of said fuel on contact with this wall.

1 ) A catalytic combustion device comprising a main combustion zone ( 20 ,  200 ) including at least one catalytic section ( 5 ,  103 ), at least one air/fuel mixing zone ( 11 ,  117 ), said mixing zone comprising at least one pressurized air inlet ( 1 ,  101 ), and liquid fuel injection means ( 12 ,  105 ), characterised in that injection means ( 12 ,  105 ) project the liquid fuel onto a wall heated by the combustion of the air/fuel mixture main combustion zone ( 13 ,  15 ,  107 ) so as to allow vaporization of said fuel on contact with said wall.  
     
     
         2 ) A device as claimed in  claim 1 , characterised in that the fuel is projected substantially perpendicular to hot wall ( 13 ,  15 ,  107 ).  
     
     
         3 ) A device as claimed in  claim 1  or  2 , characterised in that said hot wall ( 15 ) consists at least partly of at least one of the walls of main combustion zone ( 20 ).  
     
     
         4 ) A device as claimed in  claim 1  or  2 , further comprising a combustion initiation zone ( 4 ,  102 ), characterised in that said hot wall ( 13 ) consists at least partly of at least one of the walls of combustion initiation zone ( 4 ).  
     
     
         5 ) A device as claimed in any one of claims  1  or  2 , wherein at least one postcombustion zone ( 14 ,  108 ) is arranged downstream from main combustion zone ( 20 ,  200 ), characterised in that hot wall ( 15 ,  107 ) consists at least partly of at least one of the walls of said postcombustion zone.  
     
     
         6 ) A device as claimed in any one of the previous claims, characterised in that the means allowing injection of the liquid fuel are injectors ( 12 ,  105 ) providing primary spraying such that the size of the droplets coming from said injectors ( 12 ,  105 ) ranges between 5 and 60 μm, preferably between 10 and 40 μm  
     
     
         7 ) A device as claimed in any one of the previous claims, characterised in that hot wall ( 13 ,  15 ,  107 ) of the zone opposite said injection means has a substantially plane shape.  
     
     
         8 ) A device as claimed in any one of  claims 1  to  6 , characterised in that hot wall ( 13 ,  15 ,  107 ) of the zone opposite the injectors has a concave curved shape.  
     
     
         9 ) A device as claimed in any one of the previous claims, characterised in that the temperature of said hot wall ( 13 ,  15 ,  107 ) of said device is substantially equal to or higher than the maximum boiling temperature of the liquid fuel on said wall.  
     
     
         10 ) A device as claimed in any one of the previous claims, characterised in that wall ( 107 ) receiving the impact of the fuel jets is equipped with means allowing to increase the heat transfer from the hot zone to the spraying zone.  
     
     
         11 ) A device as claimed in any one of the previous claims, characterised in that wall ( 107 ) is covered at least partly with an insulating material, except for a zone ( 120 ) receiving the impact of the fuel jets.  
     
     
         12 ) Application of the device as claimed in any one of the previous claims to gas turbines provided with a heat recuperator.  
     
     
         13 ) Application of the device as claimed in any one of  claims 1  to  11  to combustion chambers of annular geometry.