Multi-fuel combustion system

Abstract

The present invention explains a multi-fuel combustion system. It consist of a combustor basket adapted to combust at least two type of fuels. The combustor basket has got a circumferential wall comprising a plurality of openings. The combustion system further has a first conduit adapted to provide a first type of fuel directly to the combustor basket, a second conduit adapted to provide a second type of fuel directly to the combustor basket and a third conduit adapted to inject at least one of the first type of fuel and the second type of fuel through the openings into the combustor basket.

1 . A multi-fuel combustion system comprising:
 a combustor basket adapted to combust at least two type of fuels, said combustor basket having a circumferential wall comprising a plurality of openings to guide a flow of air into the combustor basket;   a first conduit adapted to provide a first type of fuel directly to the combustor basket;   a second conduit adapted to provide a second type of fuel directly to the combustor basket; and   a third conduit adapted to inject at least one of the first type of fuel and the second type of fuel through at least one of the openings into the combustor basket.   
     
     
         2 . The multi-fuel combustion system according to  claim 1 , wherein the wall of the combustor basket is made of a plurality of cylindrical regions arranged to overlap each other at the transition and extends from the upstream end to the downstream end of the combustor basket. 
     
     
         3 . The multi-fuel combustion system according to  claim 2 , wherein the individual cylindrical region comprises an outer surface, said outer surface is provided with a rib structure and is covered by a perforated layer adapted to provide an air flow for cooling the walls. 
     
     
         4 . The multi-fuel combustion system according to  claim 2 , wherein at least two of the cylindrical regions at the upstream side of the combustor basket further comprise the plurality of openings distributed along the circumference of the cylindrical region to allow a compressor discharge air to flow towards a region of combustion in the combustor basket. 
     
     
         5 . The multi-fuel combustion system according to  claims 2 , wherein at least one of the cylindrical regions at the downstream side of the combustor basket further comprises the plurality of openings distributed along the circumference of the cylindrical region to allow the compressor discharge air to flow towards a region of combustion in the combustor basket. 
     
     
         6 . The multi-fuel combustion system according to  claim 2 , wherein the individual cylindrical region comprises between 5 and 9 openings. 
     
     
         7 . The multi-fuel combustion system according to  claim 6 , wherein the individual cylindrical region comprises an odd number of openings. 
     
     
         8 . The multi-fuel combustion system according to  claim 1 , wherein the first type of fuel is natural gas. 
     
     
         9 . The multi-fuel combustion system according to  claim 1 , wherein the second type of fuel is syngas. 
     
     
         10 . The multi-fuel combustion system according to  claim 1 , wherein the first conduit comprises a nozzle to supply at least one of the first type of fuel and the second type of fuel directly to the combustor basket for combustion, wherein the nozzle comprises a plurality of holes positioned at, at least two different radial distances from the center of the nozzle for enabling a fuel flow into a region of combustion in the combustor basket. 
     
     
         11 . The multi-fuel combustion system according to  claim 1 , further comprises an exit cone at the downstream end of the combustor basket comprising of plurality of slots aligned to the plurality of openings associated with at least one of the cylindrical regions. 
     
     
         12 . The multi-fuel combustion system according to  claim 1 , further comprises a flow conditioner positioned to encircle the combustor basket and having a conical section and a cylindrical section having plurality of holes adapted to allow the compressor discharge air to flow towards a region of combustion in the combustor basket. 
     
     
         13 . The multi-fuel combustion system according to  claim 1 , further comprises a cover plate coupled to the combustor basket and the conduits, such that the combustor basket and the conduits are attached to a casing using said cover plate. 
     
     
         14 . The multi-fuel combustion system according to  claim 1 , wherein the first conduit and the second conduit is concentrically arranged for effective delivery of the first type of fuel and the second type of fuel to the combustor basket. 
     
     
         15 . The multi-fuel combustion system according to  claim 1 , wherein the third conduit is adapted to inject at least one of the first type of fuel and the second type of fuel into a compressor discharge air that flow through at least one of the openings associated with at least one of the cylindrical regions. 
     
     
         16 . The multi-fuel combustion system according to  claim 1 , wherein the third conduit further comprises an injector nozzle having at least one hole to inject at least one of the first type of fuel and the second type of fuel into a compressor discharge air that flow through at least one of the openings associated with at least one of the cylindrical regions. 
     
     
         17 . A method of operating a multi-fuel combustion system comprising a first phase and a second phase,
 wherein the first phase comprises:
 providing ignition to a combustor basket to ignite a first type of fuel, where the first type of fuel is supplied to the combustor basket through a first conduit; 
 supplying steam to the first conduit in addition to the first type of fuel and supplying steam to the second conduit after the ignition; and 
   wherein the second phase comprises:
 supplying a second type of fuel to the combustor basket after ignition of the first fuel through the second conduit, while stopping the supply of the first fuel. 
   
     
     
         18 . A method of operating a multi-fuel combustion system according to  claim 17 , further comprising supplying a portion of the second type of fuel to the combustor basket through the first conduit during the second phase. 
     
     
         19 . A method of operating a multi-fuel combustion system according to  claim 17 , wherein the first type of fuel is natural gas. 
     
     
         20 . A method of operating a multi-fuel combustion system according to  claim 17 , wherein the second type of fuel is syngas.