Fuel lance

Abstract

A lance ( 3 ) for introducing a fuel into a mixing path ( 2 ) of a burner ( 1 ) which is provided with a swirler for producing a swirled combustion air flow, especially a burner of a turbine plant, includes a lance head ( 5 ), a fuel feed ( 8 ) and an oxidator feed ( 10 ). The lance head ( 5 ) projects into the mixing path ( 2 ), has at least one fuel nozzle ( 6 ) for injection of the fuel into the mixing path ( 2 ), and also has at least one oxidator outlet orifice ( 7 ) for introducing an oxidator into the mixing path ( 2 ). The fuel feed ( 8 ) extends in the lance ( 3 ) and is connected to the at least one fuel nozzle ( 6 ). The oxidator feed ( 10 ) extends in the lance head ( 5 ) and is connected to the at least one oxidator outlet orifice ( 7 ). In order to improve the operation of the burner ( 1 ), the at least one oxidator outlet orifice ( 7 ) is located centrally on the lance head ( 5 ), and the at least one fuel nozzle ( 6 ) is installed on the lance head ( 5 ), being offset radially outwards with regard to the at least one oxidator outlet orifice ( 7 ).

1 . A lance for introducing a fuel into a mixing path of a burner having a swirler for producing a swirled combustion air flow, the lance comprising:
 a lance head which, when installed, projects into the mixing path, the lance head having at least one fuel nozzle for injection of the fuel into the mixing path and at least one oxidator outlet orifice for introducing an oxidator into the mixing path;   a fuel feed extending in the lance and connected to the at least one fuel nozzle;   an oxidator feed extending in the lance head and connected to the at least one oxidator outlet orifice;   wherein the at least one oxidator outlet orifice is located centrally on the lance head; and   wherein the at least one fuel nozzle is positioned on the lance head and offset radially outwards with respect to the at least one oxidator outlet orifice.   
   
   
       2 . The lance as claimed in  claim 1 , wherein at least one of:
 the fuel feed has a fuel line extending in the lance; or   the fuel feed has a supply passage located in the lance head for each fuel nozzle, to which supply passage is connected a respectively associated fuel nozzle; or   the fuel feed has an annular fuel passage located in the lance head, to which annular fuel passage is connected the at least one fuel nozzle; or   the fuel feed has a plurality of fuel connecting passages which connect the annular fuel passage or the supply passages to the fuel line.   
   
   
       3 . The lance as claimed in  claim 1 , wherein at least one of:
 the oxidator feed has an oxidator chamber located centrally in the lance head, the oxidator chamber having an end open towards the mixing path forming the oxidator outlet orifice; or   the oxidator feed has an inlet port positioned radially on the outside of the lance head, and a plurality of oxidator connecting passages which in each case connect the oxidator chamber to the oxidator inlet port.   
   
   
       4 . The lance as claimed in  claim 2 , wherein at least one of:
 the oxidator feed includes a plurality of oxidator connecting passages and the fuel feed includes a plurality of fuel connecting passages, the oxidator connecting passages and the fuel connecting passages positioned in the lance head circumferentially alternating with each other; or   the oxidator feed has an oxidator chamber and the fuel feed has an annular fuel passage located in the lance head which coaxially encloses the oxidator chamber.   
   
   
       5 . The lance as claimed in  claim 1 , wherein at least one of:
 the lance head has a larger external cross section than a lance section adjacent to the lance head; or   the at least one fuel nozzle is positioned on a larger radius than the external cross section of the lance outside the lance head; or   the lance head has a conical transition section by which the lance head is connected to an adjacent lance section.   
   
   
       6 . The lance as claimed in  claim 5 , wherein the lance head has a conical transition section by which the lance head is connected to an adjacent lance section, and wherein at least one of:
 the oxidator feed has an inlet port located in the transition section; or   the fuel feed includes a plurality of fuel connecting passages located in the transition section; or   the oxidator feed includes a plurality of oxidator connecting passages located in the transition section.   
   
   
       7 . The lance as claimed in  claim 1 , wherein at least one of:
 the at least one oxidator outlet orifice comprises only a single central oxidator outlet orifice; or   the at least one fuel nozzle comprises a plurality of circumferentially distributed fuel nozzles on the lance head.   
   
   
       8 . The lance as claimed in  claim 1 , wherein the at least one fuel nozzle is configured and arranged so that the at least one fuel nozzle injects fuel obliquely into the mixing path relative to the axial direction of the lance, with respect to a central longitudinal plane of the lance, or both. 
   
   
       9 . The lance as claimed in  claim 1 , further comprising at least one of:
 liquid fuel in the fuel feed; or   oxidator in the oxidator feed.   
   
   
       10 . A burner comprising:
 a burner body;   a swirler configured and arranged to produce a swirled combustion oxidator flow;   a mixing path formed in the burner body; and   a lance according to  claim 1  projecting into the mixing path.