Method of operating a combustion chamber

Abstract

A method of operating a “rich burn” combustion chamber includes supplying 10% of the air through an inlet in an upstream wall; supplying 64% to 80% of the air for mixing and supplying 10% to 26% of the air for cooling at least one double skin wall and the upstream wall; supplying a first portion of the 64% to 80% of the air for mixing through mixing ports into the combustion chamber; supplying a second portion of the 64% to 80% of the air for mixing to provide convective cooling of the at least one double skin wall before being supplied through additional mixing ports into the combustion chamber; and supplying the 10% to 26% of the air for cooling the at least one double skin wall and the upstream wall to provide convective and/or effusion cooling of the at least one double skin wall and the upstream wall.

1 . A method of operating a combustion chamber, the combustion chamber comprising an upstream wall having at least one inlet for a fuel injector and primary air, at least one double skin annular wall, the at least one double skin annular wall comprising an inner wall and an outer wall, the at least one double skin annular wall having at least one mixing port extending there-through, the inner wall or the outer wall having at least one additional mixing port extending there-through adjacent the mixing port,
 the method comprising supplying air for the combustion chamber,   the method comprising supplying 10% of the air for the combustion chamber through the inlet in the upstream wall, supplying 64% to 80% of the air for mixing, and supplying 10% to 26% of the air for cooling the at least one double skin annular wall and the upstream wall,   the method further comprising supplying a first portion of the 64% to 80% of the air for mixing through the at least one mixing port into the combustion chamber and supplying a second portion of the 64% to 80% of the air for mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the additional mixing port into the combustion chamber and supplying the 10% to 26% of the air for cooling the at least one double skin annular wall and the upstream wall to provide convective cooling and/or effusion cooling of the at least one double skin annular wall and the upstream wall.   
     
     
         2 . A method as claimed in  claim 1  wherein the at least one mixing port extending through the at least one double skin annular wall comprising at least one primary mixing port extending through the at least one double skin annular wall and at least one secondary mixing port extending through the at least one double skin annular wall and arranged downstream of the at least one primary mixing port, the at least one additional mixing port in the inner wall or outer wall comprising at least one additional primary mixing port extending through the inner wall or the outer wall adjacent the primary mixing port and at least one additional secondary mixing port extending through the inner wall or the outer wall adjacent the secondary mixing port,
 the method comprising supplying 10% of the air for the combustion chamber through the inlet in the upstream wall, supplying 32% to 40% of the air for primary mixing, supplying 32% to 40% of the air for secondary mixing and supplying 10% to 26% of the air for cooling the at least one double skin annular wall and the upstream wall, 
 the method further comprising supplying a first portion of the 32% to 40% of the air for primary mixing through the at least one primary mixing port into the combustion chamber and supplying a second portion of the 32% to 40% of the air for primary mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the at least one additional primary mixing port into the combustion chamber, supplying a first portion of the 32% to 40% of the air for secondary mixing through the at least one secondary mixing port into the combustion chamber and supplying a second portion of the 32% to 40% of the air for secondary mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the at least one additional secondary mixing port into the combustion chamber and supplying the 10% to 26% of the air for cooling the at least one double skin annular wall and the upstream wall to provide convective cooling and/or effusion cooling of the at least one double skin annular wall and the upstream wall. 
 
     
     
         3 . A method as claimed in  claim 2  comprising supplying 10% of the air for the combustion chamber through the inlet in the upstream wall, supplying 35% to 40% of the air for primary mixing, supplying 35% to 40% of the air for secondary mixing and supplying 10% to 20% of the air for cooling the at least one double skin annular wall and the upstream wall,
 the method further comprising supplying a first portion of the 35% to 40% of the air for primary mixing through the at least one primary mixing port into the combustion chamber and supplying a second portion of the 35% to 40% of the air for primary mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the at least one additional primary mixing port into the combustion chamber, supplying a first portion of the 35% to 40% of the air for secondary mixing through the at least one secondary mixing port into the combustion chamber and supplying a second portion of the 35% to 40% of the air for secondary mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the at least one additional secondary mixing port into the combustion chamber and supplying the 10% to 20% of the air for cooling the at least one double skin annular wall and the upstream wall to provide convective cooling and/or effusion cooling of the at least one double skin annular wall and the upstream wall. 
 
     
     
         4 . A method as claimed in  claim 2  comprising supplying 10% of the air for the combustion chamber through the inlet in the upstream wall, supplying 40% of the air for primary mixing, supplying 40% of the air for secondary mixing and supplying 10% of the air for cooling the at least one double skin annular wall and the upstream wall,
 the method further comprising supplying a first portion of the 40% of the air for primary mixing through the at least one primary mixing port into the combustion chamber and supplying a second portion of the 40% of the air for primary mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the at least one additional primary mixing port into the combustion chamber, supplying a first portion of the 40% of the air for secondary mixing through the at least one secondary mixing port into the combustion chamber and supplying a second portion of the 40% of the air for secondary mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the at least one additional secondary mixing port into the combustion chamber and supplying the 10% of the air for cooling the at least one double skin annular wall and the upstream wall to provide convective cooling and effusion cooling of the at least one double skin annular wall and/or the upstream wall. 
 
     
     
         5 . A method as claimed in  claim 2  comprising supplying half of the air for primary mixing through the at least one primary mixing port into the combustion chamber and supplying half of the air for primary mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the at least one additional primary mixing port into the combustion chamber. 
     
     
         6 . A method as claimed in  claim 2  comprising supplying half of the air for secondary mixing through the at least one secondary mixing port into the combustion chamber and supplying half of the air for secondary mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the at least one additional secondary mixing port into the combustion chamber. 
     
     
         7 . A method as claimed in  claim 2  wherein the at least one double skinned annular wall comprises a plurality of circumferentially spaced primary mixing ports and a plurality of circumferentially spaced secondary mixing ports. 
     
     
         8 . A method as claimed in  claim 2  wherein the at least one double skinned annular wall comprises a plurality of circumferentially spaced additional primary mixing ports and a plurality of circumferentially spaced additional secondary mixing ports. 
     
     
         9 . A method as claimed in  claim 2  wherein the at least one additional primary mixing port is arranged around the at least one primary mixing port. 
     
     
         10 . A method as claimed in  claim 2  wherein the at least one additional secondary mixing port is arranged around the at least one secondary mixing port. 
     
     
         11 . A method as claimed in  claim 1  comprising supplying half of the air for mixing through the at least one mixing port into the combustion chamber and supplying half of the air for mixing to provide convective cooling of the at least one double skin annular wall before being supplied through the at least one additional mixing port into the combustion chamber. 
     
     
         12 . A method as claimed in  claim 1  wherein the combustion chamber is an annular combustion chamber comprising a radially inner double skinned annular wall and a radially outer double skinned annular wall. 
     
     
         13 . A method as claimed in  claim 1  wherein the combustion chamber is a tubular combustion chamber comprising a single double skinned annular wall. 
     
     
         14 . A method as claimed in  claim 1  wherein the combustion chamber is a gas turbine engine combustion chamber.