Effervescent aerodynamic system for injecting an air/fuel mixture into a turbomachine combustion chamber
View Patent ↗An aerodynamic injection system for injecting an air/fuel mixture into a turbomachine combustion chamber comprises a tubular structure of axis XX′ that opens out at a downstream end for delivering the air/fuel mixture, at least one air feed channel that opens out into the structure so as to introduce air at a pressure P A therein, an annular fuel passage that is formed in the structure around its axis XX′, that is connected to at least one fuel feed channel in which there flows fuel at a pressure P C , and that opens out at a downstream end into the structure, and means for injecting gas into the at least one fuel feed channel, said gas being at a pressure P G that is greater than P A and greater than or equal to P C so as to create effervescence in the fuel on being introduced into the structure.
1. An aerodynamic injection system for injecting an air/fuel mixture into a turbomachine combustion chamber, the system comprising:
a tubular structure of axis XX′ that opens out at a downstream end for delivering the air/fuel mixture;
at least one air feed channel that is connected to a compressor stage of the turbomachine and that opens out into the tubular structure in such a manner as to introduce air at a pressure PA into the tubular structure;
an annular fuel passage that is formed in the tubular structure around its axis XX′, that is connected to at least one fuel feed channel in which fuel flows at a pressure PC, and that opens out at a downstream end into the tubular structure, forming an enlargement therein;
means for injecting gas into the at least one fuel feed channel, the gas being at a pressure PG that is greater than the pressure PA and greater than or equal to PC so as to create effervescence in the fuel on being introduced into the tubular structure;
at least one gas injection channel that opens out into the fuel feed channel(s) and that is connected to a gas feed duct; and
an annular gas distribution cavity that is formed in the tubular structure around the fuel passage, that is connected to the gas feed duct, and that opens out into the gas injection channel.
2. An aerodynamic injection system for injecting an air/fuel mixture into a turbomachine combustion chamber, the system comprising:
a tubular structure of axis XX′ that opens out at a downstream end for delivering the air/fuel mixture;
at least one air feed channel that is connected to a compressor stage of the turbomachine and that opens out into the tubular structure in such a manner as to introduce air at a pressure PA into the tubular structure;
an annular fuel passage that is formed in the tubular structure around its axis XX′, that is connected to at least one fuel feed channel in which fuel flows at a pressure PC, and that opens out at a downstream end into the tubular structure, forming an enlargement therein;
means for injecting gas into the at least one fuel feed channel, the gas being at a pressure PG that is greater than the pressure PA and greater than or equal to PC so as to create effervescence in the fuel on being introduced into the tubular structure,
wherein the air feed channel is disposed around the tubular structure and opens out axially into the fuel passage at an upstream end thereof.
3. A system according to claim 2 , including at least one gas injection channel that opens out into the fuel feed channel(s) and that is connected to a gas feed duct.
4. A system according to claim 1 , wherein the gas injection channel opens out substantially perpendicularly into the fuel feed channel(s).
5. A system according to claim 2 , further comprising an annular gas distribution cavity that is formed in the tubular structure around the fuel passage, that is connected to the gas feed duct, and that opens out into the gas injection channel.
6. A system according to claim 1 , further including an annular fuel distribution cavity that is formed in the tubular structure, that is connected to a fuel feed duct, and that opens out into the fuel feed channel.
7. A system according to claim 1 , wherein the fuel feed channel(s) is/are inclined tangentially relative to the annular fuel passage.
8. A system according to claim 1 , wherein the air feed channel opens out into the tubular structure at an upstream end thereof with the air being set into rotation.
9. A system according to claim 8 , further including an outer air swirler that is disposed around the tubular structure, that is radially offset relative to the fuel passage, and that is designed to inject air into the outlet of the tubular structure in a direction that is substantially axial together with movement in rotation.
10. A system according to claim 8 , wherein the outer air swirler is connected to a compressor stage of the turbomachine.
11. A system according to claim 8 , further including a bowl forming a diverging portion mounted downstream from the tubular structure.
12. A system according to claim 2 , wherein the annular fuel passage presents a narrowing of section in the fuel flow direction in order to accelerate the flow of fuel in the tubular structure.
13. A system according to claim 1 , wherein the gas is air.
14. A system according to claim 13 , wherein the air constituting the gas is taken after compression from a compressor stage of the turbomachine and prior to being further compressed.
15. A system according to claim 1 , further comprising a device for controlling the flow rate of the gas injected into the fuel feed channel.
16. A turbomachine combustion chamber including an aerodynamic injection system for injecting an air/fuel mixture and in accordance with claim 1 .
17. A turbomachine including a combustion chamber fitted with an aerodynamic injection system for injecting an air/fuel mixture and in accordance with claim 1 .