Method and device for combusting hydrogen in a premix burner
View Patent ↗A device for combusting fuel which contains or consists of hydrogen, is described, with a burner provided with a swirl generator and also a feeder for feeding fuel and a feeder for feeding combustion air into the swirl generator. A first feeder, for feeding liquid fuel along a burner axis, and a second feeder for feeding liquid fuel or gaseous fuel along air inlet slots which are tangentially delimited by the swirl generator, with a transition section connected downstream to the swirl generator, and with a mixer tube connected downstream to the transition section and with a changeable flow cross-sectional transition leads into a combustion chamber are provided. Along the transition section, a third feeder for feeding fuel which contains or consists of hydrogen, and also a fourth feeder for the selective feed of fuel which contains or consists of hydrogen, or of the gaseous fuel are also provided.
1. A burner for operating a premix combustion system with one or more fuels, wherein the burner comprises a swirl generator ( 1 ) on a head side, a fuel feeder for feeding a fuel and a combustion air feeder for introducing combustion air (L) into the swirl generator ( 1 ), the fuel feeder comprising a first feeder ( 3 ), for feeding a liquid fuel (Bfl) and/or a gaseous fuel (Bg) along a burner axis (A), and a second feeder for feeding liquid fuel (Bfl) and/or gaseous fuel (Bg) along air inlet slots ( 4 ), which are tangentially delimited by the swirl generator ( 1 ), and are provided, downstream of the swirl generator ( 1 ), the burner further comprises a directly connected transition section ( 6 ) and a mixer tube ( 8 ), which is connected downstream to the transition section ( 6 ), the mixer tube ( 8 ) leads into a combustion chamber (B), the fuel feeder further comprising a third feeder ( 9 ) provided along the transition section ( 6 ) and/or downstream of the transition section ( 6 ) for feeding fuel which contains hydrogen, or consists of hydrogen, and a fourth feeder( 10 ) for feeding fuel which contains hydrogen, or consists of hydrogen, and/or a further gaseous fuel, the third ( 9 ) and fourth ( 10 ) feeders each comprise a multiplicity of discharge openings ( 9 ′, 10 ′), which are arranged and oriented, relative to each other, along the transition section ( 6 ) in such a way that over flowing of the third feeder ( 9 ) discharge openings ( 9 ′) by fuel that is discharged from the fourth feeder ( 10 ) does not occur.
2. The device as claimed in claim 1 , wherein the third multiplicity of individual discharge openings ( 9 ′) of the third feeder ( 9 ) are arranged in a circularly equally distributed manner in the transition section ( 6 ), from which the fuel which contains hydrogen, or consists of hydrogen, can be fed, and the multiplicity of individual discharge openings ( 10 ′) of the fourth feeder ( 10 ) are arranged in a circularly equally distributed manner in the transition section ( 6 ), from which the fuel which contains hydrogen, or consists of hydrogen, or the gaseous fuel, can be selectively fed.
3. The device as claimed in claim 1 , wherein the third and the fourth feeders ( 9 , 10 ) can be supplied with the respective fuel separately from each other in each case via at least one supply line ( 9 ′″, 10 ′″).
4. The device as claimed in claim 3 , wherein along the at least one supply line ( 10 ″), which supplies the fourth feeder ( 10 ) with fuel, a three-way valve is provided, to which are connected both a supply line for feeding the fuel which contains hydrogen, or consists of hydrogen, and a supply line for feeding the gaseous fuel.
5. The device as claimed in claim 1 , wherein the discharge openings ( 9 ′) of the third feeder ( 9 ) comprises a larger opening width than the discharge openings ( 10 ′) of the fourth feeder ( 10 ).
6. The device as claimed in claim 1 , wherein the gaseous fuel is natural gas.
7. The device as claimed in claim 1 , wherein the discharge openings ( 10 ′) of the fourth feeder ( 10 ) are arranged along the transition section ( 6 ) downstream of the discharge openings ( 9 ′) of the third feeder ( 9 ).
8. The burner as claimed in claim 1 , wherein the swirl generator ( 1 ) comprises at least two hollow partial cone shells which are nested inside each other in the flow direction, completing a body, the cross section of the interior space which is formed by the hollow partial cone shells increases in the flow direction, respective longitudinal symmetry axes of these partial cone shells extend in an offset manner in relation to each other in such a way that the adjacent walls of the partial cone shells form tangential slots or passages in their longitudinal extent for the inflow of combustion air into the interior space which is formed by the partial cone shells.
9. The burner as claimed in claim 1 , wherein the swirl generator comprises at least two hollow partial shells which are nested inside each other in the flow direction, completing a body, the cross section of the interior space which is formed by the hollow partial shells extends in a cylindrical or virtually cylindrical manner in the flow direction, respective longitudinal symmetry axes of these partial shells extend in an offset manner in relation to each other in such a way that the adjacent walls of the partial shells form tangential slots or passages in their longitudinal extent for the inflow of combustion air into the interior space which is formed by the partial shells, and in that the interior space has an inner body, the cross section of which decreases in the flow direction.
10. The burner as claimed in claim 9 , wherein the inner body extends in a conical or essentially conical manner in the flow direction.