Burner for a gas turbine and method for reducing thermoacoustic oscillations in a gas turbine

Patent metadata

Field	Value
Publication number	US-2016195271-A1
Application number	US-201414911766-A
Country	US
Kind code	A1
Filing date	Sep 23, 2014
Priority date	Sep 23, 2013
Publication date	Jul 7, 2016
Grant date	—

Abstract

A burner for a gas turbine, has an air passage supplied with compressed air and a fuel passage supplied with fuel gas, each passage has a main outlet opening leading into the combustion chamber of the gas turbine, the air and fuel passages connected fluidically together via a connection duct arranged upstream of the main outlet openings. The burner is configured such that, when air passage is supplied with compressed air and fuel passage is supplied with fuel gas, a portion of the fuel gas flowing in the fuel passage flows via at least one connection duct into the air passage and, for combustion thereof, is introduced through the main outlet opening of the air passage into the interior of the combustion chamber and a remaining portion of the fuel gas is introduced through the main outlet opening of the fuel passage into the interior of the combustion chamber.

First claim

1 .- 22 . (canceled)

23 . A burner for a gas turbine, comprising:
at least one air passage to which compressed air is supplied and at least one fuel passage to which at least one fuel gas is supplied, the two passages each comprising a main outlet opening leading into the combustion chamber of the gas turbine, the air passage and the fuel passage being connected fluidically together via at least one connection duct arranged upstream of the main outlet openings, wherein the burner is configured such that, in at least one first operating state of the burner, when air passage is supplied with compressed air and fuel passage is supplied with fuel gas, a portion of the fuel gas flowing in the fuel passage flows via at least one connection duct into the air passage and, for combustion thereof, is introduced through the main outlet opening of the air passage into the interior of the combustion chamber and a remaining portion of the fuel gas is introduced through the main outlet opening of the fuel passage into the interior of the combustion chamber, and at least one adjusting element arranged in the region of the connection ducts, such that the fraction and/or the radial inflow profile and/or the division over the connection ducts of the fuel gas branched off from the fuel passage into the air passage is adjusted and/or adjustable by the at least one adjusting element, such that fluctuations in heat release are fed back to a lesser extent into the pressure fluctuations in the combustion chamber.

24 . The burner as claimed in claim 23 ,
wherein the burner is configured such that the common dwell time profile, brought about by the branching off, of the remaining portion and of the branched-off portion of the fuel stream is adapted to the thermoacoustic behavior of the combustion chamber, such that fluctuations in heat release are fed back to a lesser extent into the pressure fluctuations in the combustion chamber.

25 . The burner as claimed in claim 23 ,
wherein the burner is arranged substantially rotationally symmetrically about a longitudinal axis, such that a main direction of flow of the fluid flowing in the passages of the burner points in the direction of the longitudinal axis or has at least one component in the direction of the longitudinal axis, and the air passage and the fuel passage are arranged coaxially to one another at least in places.

26 . The burner as claimed in claim 23 ,
wherein the main outlet openings of the air passage and fuel passage are arranged such that the coaxially surrounding passage is arranged around the other main outlet opening relative to a projection plane extending perpendicular to the longitudinal axis.

27 . The burner as claimed in claim 23 ,
wherein the air passage and the fuel passage adjoin one another at least in places along a wall which substantially takes the form of a cylindrical casing and/or of a truncated cone-shaped casing, wherein the connection ducts take the form of holes in the wall.

28 . The burner as claimed in claim 23 , further comprising:
a flow guide arranged in the fuel gas passage downstream of at least one fuel passage-side inlet opening of a connection duct, wherein the flow guide increases the static pressure in the region of the inlet openings of the connection duct when the fuel passage is supplied with fuel gas.

29 . The burner as claimed in claim 28 ,
wherein the flow guide comprises a substantially annular metal plate, wherein the metal plate is arranged circumferentially on an inside of a wall delimiting the fuel passage.

30 . The burner as claimed in claim 29 ,
wherein the metal plate extends into the interior of the fuel passage at an angle contrary to a main direction of flow in the fuel passage.

31 . The burner as claimed in claim 29 ,
wherein the metal plate in each case has a cut-out between the regions located downstream of the inlet openings of the connection ducts.

32 . The burner as claimed in claim 28 ,
wherein the adjusting element comprises a number of flow guides, which take the form of triangular or trapezoidal metal plates.

33 . The burner as claimed in claim 28 ,
wherein the flow guide comprises at least one cupped element with an entry opening, which is arranged with the entry opening pointing towards the inlet opening of a connection duct downstream of the inlet opening on an inside of a wall delimiting the fuel passage.

34 . The burner as claimed in claim 33 ,
wherein the cupped element substantially takes the form of a hollow quarter-sphere.

35 . The burner as claimed in claim 23 ,
wherein at least one adjusting element is of tubular configuration, wherein the tubular adjusting element is in each case arranged at least in part in one of the connection ducts.

36 . A combustion chamber, comprising:
at least one burner, wherein the burner is configured as in claim 23 .

37 . A gas turbine, comprising:
at least one combustion chamber, wherein the combustion chamber is configured as in claim 36 .

38 . A method for reducing thermoacoustic oscillations in a gas turbine comprising at least one burner, the method comprising:
adapting a dwell time profile of a fuel stream flowing in a first fuel passage of the burner to the thermoacoustic behavior of the combustion chamber,
wherein, to adapt the dwell time profile, a remaining portion of the fuel stream is introduced into the combustion chamber through at least one main outlet opening of the first passage and a branched-off portion of the fuel stream is introduced, downstream of introduction thereof into the fuel passage and upstream of the main outlet opening, into at least one second passage via at least one connection duct branching off from the first passage,
wherein the branched-off portion of the fuel stream is introduced into the combustion chamber separately from the remaining fuel stream, such that the sub-streams, after exit thereof from the burner, are combusted in the combustion chamber with different dwell times or dwell time profiles,
adjusting the fraction and/or the inflow profile and/or the division over the at least one connection duct of the branched-of portion of the fuel stream prior to start-up of the burner and/or during operation of the burner,
wherein adjustment of the fraction and/or the penetration depth and/or the division over the at least one connection duct proceeds by adapting at least one flow guide arranged in the fuel passage and/or one adjusting element arranged in the region of the connection ducts, such that fluctuations in heat release are fed back to a lesser extent into the pressure fluctuations in the combustion chamber.

39 . The method as claimed in claim 38 , further comprising:
introducing the remaining fuel stream and the branched-off portion of the fuel stream substantially coaxially to one another into the combustion chamber.

40 . The method as claimed in claim 38 ,
wherein adaptation of the at least one flow guide and/or of the at least one adjusting element proceeds by exchange of the flow guide and/or the adjusting element and/or adaptation of the shape and/or position thereof.

Assignees

• Siemens Ag

Inventors

• Köstlin Berthold
• Prade Bernd

Classifications

• F23R2900/00013

  Reducing thermo-acoustic vibrations by active means · CPC title

• F23M20/005 Primary

  Noise absorbing means · CPC title

• F23R3/286 Primary

  having fuel-air premixing devices (F23R3/30 takes precedence) · CPC title

• F23R3/346

  for staged combustion · CPC title

• F23D14/70

  Baffles or like flow-disturbing devices · CPC title