Multi-fuel turbine combustor, multi-fuel turbine comprising such a combustor and corresponding method

Abstract

Combustor ( 50 ) for use in a turbine ( 100 ). The combustor ( 50 ) comprising a multiple fuel atomizers ( 10 ) which has a gas inlet for feeding gaseous fuel as first combustible into an inlet zone of the atomizer, an air inlet for feeding compressed air into the inlet zone, and an orifice for injecting a liquid fuel as second combustible into the inlet zone. The atomizer comprises a diffuser for emitting a gas stream at an exit side. The atomizer ( 10 ) is arranged with respect to a combustion chamber of the combustor ( 50 ) so that the exit side of the diffuser points in a tangential direction relative to the combustion chamber. The combustor ( 50 ) comprises an outlet duct ( 51 ) for discharging an exhaust gas produced by a combustion process of the gas stream inside the combustion chamber. The exhaust gas drives a turbine ( 63 ).

What is claimed is: 
     
         1 . A reverse flow annular combustor for use in a turbine, said combustor comprising at least one air-blast atomizer operating on a combustible, wherein the air-blast atomizer is a multiple fuel atomizer which has
 a gas inlet for feeding gaseous fuel as first combustible into an inlet zone of the atomizer,   an air inlet for feeding compressed air into the inlet zone,   an orifice for injecting a liquid fuel as second combustible into the inlet zone or into an area close to the inlet zone, and   a diffuser for emitting a gas stream at an exit side comprising said gaseous fuel, compressed air and said liquid fuel,
 said atomizer being arranged with respect to a combustion chamber of said combustor so that the exit side of said diffuser points in a tangential direction relative to said combustion chamber, and wherein said combustor comprises an outlet duct for discharging an exhaust gas produced by a combustion process of said gas stream inside said combustion chamber. 
   
     
     
         2 . The combustor according to  claim 1 , wherein said diffuser has a rotationally symmetric shape with a first large diameter area serving as the inlet zone, followed by a second area with constriction of diameter and a third area with a diameter expanding towards the exit side. 
     
     
         3 . The combustor according to  claim 1 , wherein said diffuser has a rotationally symmetric shape with an hourglass shape where an area with constriction separates the inlet zone from a funnel shaped area, and wherein the funnel shaped area opens out into the exit side. 
     
     
         4 . The combustor according to  claim 2 , wherein said orifice is positioned at or close to said constriction. 
     
     
         5 . The combustor according to  claim 1 , wherein said gas inlet is co-axially arranged with respect to a longitudinal axis of said atomizer. 
     
     
         6 . The combustor according to  claim 1 , wherein said gas inlet and said air inlet are arranged so that gaseous fuel and said compressed air are clashing in the inlet zone. 
     
     
         7 . The combustor according to  claim 1 , wherein said atomizer is arranged with respect to the combustion chamber of said combustor so that said gas stream is tangentially discharged via the exit side of said diffuser into said combustion chamber where a vortex is established. 
     
     
         8 . The combustor according to  claim 1 , wherein said combustor comprising a plurality of atomizers, these atomizers being arranged on a common circle. 
     
     
         9 . A multi-fuel turbine comprising a central exit duct pipe and a reverse flow annular combustor in accordance with  claim 1 , said combustors being arranged at the outside of said exit duct pipe so that the exhaust gas discharged by the reverse flow annular combustor is streaming into a direction essentially opposite to a major flow direction of said exit duct pipe. 
     
     
         10 . The multi-fuel turbine according to  claim 9 , which comprises a turbine which is co-axially arranged with respect to a longitudinal axis of said exit duct pipe and which further comprises a cambered outlet duct connected to said combustor for redirecting said exhaust gas onto blades of said turbine. 
     
     
         11 . The multi-fuel turbine according to  claim 10 , wherein said turbine comprises an upstream portion with air blades for taking in air and for releasing compressed air. 
     
     
         12 . The multi-fuel turbine according to  claim 11 , comprising air channels arranged so that compressed air released by said upstream portion is guided towards air inlets of said atomizers. 
     
     
         13 . The multi-fuel turbine according to  claim 9 , wherein said reverse flow annular combustor comprises at least one air inlet arranged so as to provide a direct air entry into the combustion chamber of said combustor. 
     
     
         14 . The multi-fuel turbine according to  claim 9 , comprising a control unit connectable to actuators or valves so as to enable the multi-fuel turbine to be fed by said gaseous fuel and/or by said liquid fuel. 
     
     
         15 . The multi-fuel turbine according to  claim 14 , further comprising liquid fuel pipes and gas fuel pipes for feeding said liquid fuel to said orifices of each vaporizer and said gaseous fuel to said gas inlets of each vaporizer. 
     
     
         16 . The multi-fuel turbine according to  claim 14 , comprising a common ring-shaped liquid fuel pipe and a common ring-shaped gas fuel pipe for feeding said liquid fuel to said orifices of each atomizer and said gaseous fuel to said gas inlets of each atomizer. 
     
     
         17 . The multi-fuel turbine according to  claim 9 , further comprising an igniter arranged inside the combustion chamber for igniting and maintaining a combustion of the gas stream in said combustor. 
     
     
         18 . A multi-fuel turbine according to  claim 17 , comprising a gas fuel supply and a liquid fuel supply in fluid connection with the reverse flow annular combustor, said gas fuel supply and said liquid fuel supply being switchable by a control unit in order to enable said multi-fuel turbine to be operated by said gaseous fuel and/or by said liquid fuel. 
     
     
         19 . A method of combustion within a reverse flow annular combustor of a gas turbine, comprising the steps:
 injecting a liquid fuel into an air-blast atomizer and/or injecting a gaseous fuel into an inlet zone of said air-blast atomizer,   feeding compressed air into said inlet zone of said air-blast atomizer, so that said fuels and said compressed air are mixed inside said air-blast atomizer and that a gas stream leaves said air-blast atomizer via an exit side and enters a combustion chamber of said reverse flow annular combustor, said exit side of said air-blast atomizer pointing in a tangential direction relative to said reverse flow annular combustor to create a main vortex flow in said combustion chamber,   combusting said gas stream in a primary combustor zone of said combustion chamber,   discharging an exhaust gas produced by said combusting in said combustion chamber onto blades of a turbine.   
     
     
         20 . The method of  claim 19 , comprising the following step:
 switching from a first mode of operation where said air-blast atomizer is fed with said liquid fuel and compressed air into a second mode of operation where said air-blast atomizer is fed with said gaseous fuel and compressed air; or   switching from a second mode of operation where said air-blast atomizer is fed with said gaseous fuel and compressed air into a first mode of operation where said air-blast atomizer is fed with said liquid fuel and compressed air.   
     
     
         21 . The method of  claim 20 , wherein said liquid fuel is selected from the group consisting of gasoline, kerosene, diesel oil, palm oil, liquefied natural gas, liquefied hydrogen. 
     
     
         22 . The method of  claim 20 , wherein said gaseous fuel is selected from the group consisting of syngas, natural gas, flare gas.