Fuel injection staged sectoral combustor for burning low-BTU fuel gas

A fuel injection staged combustion chamber having a main burning zone and a pilot burning zone;

• said combustion chamber being operable to burn low BTU fuel gas for a gas turbine;
• first fuel supply means for introducing a low thermal energy BTU fuel gas at one end, the upstream end, of said pilot burning zone;
• the other end of said pilot burning zone, the downstream end, being connected to and communicating through an opening in a transverse wall at one end of said main burning zone, the upstream end thereof;
• the other end of said main burning zone, the downstream end, having a passage for directing the combustion products from said combustion chamber to said gas turbine;
• an outer shell wall structure for said combustion chamber;
• said outer shell wall comprising a first outer shell wall section for said main burning zone and a second outer shell wall section for said pilot burning zone;
• a first liner wall housed coaxially within said first shell wall section and having an outer surface and an inner surface, said first shell wall section and said liner wall each having a cross-section of a shape substantially equal to an annular sector of said gas turbine;
• said liner wall defining internally thereof the main burning zone and further defining between said first liner wall and said first shell wall section a first coolant channel adapted to accommodate during operation of said combustion chamber a flow of air in countercurrent relationship to flow in said main burning zone for cooling said liner wall outer surface;
• air supply means for introducing air into said combustion chamber;
• second fuel supply means for introducing liquid fuel selectively into the upstream end of said pilot burning zone and said combustion chamber;
• a second liner wall housed coaxially within said second outer shell for said pilot burning zone;
• said second liner wall defining between said second liner wall and said second outer shell a second coolant channel adapted, during operation of said combustion chamber, to accommodate a flow of air in countercurrent relationship to flow in said pilot burning zone for cooling the outer surface of said second liner wall;
• the downstream end of said second coolant channel being connected to the upstream end of said first coolant channel;
• and
• second stage fuel injection means for low BTU fuel gas, said second stage fuel injection means being connected to an additional opening in said transverse wall for direct entry into said main burning zone.