Combustion system of a steam generator designed for oxyfuel operation

Abstract

For a steam generator comprising a combustion chamber fired with a fossil fuel and/or with particulate fuel containing carbon and at least one burner level comprising several burners ( 1 ) and/or at least one level comprising nozzles in the form of upper air nozzles and/or side wall nozzles, each having connected feed means ( 9, 10, 11, 12 ) and/or feed lines ( 2, 4, 5, 9 a - 9 d, 10 a - 10 d, 11 a - 11 d, 12 a - 12 d ) through which/by means of which gas flows conveying combustion and/or oxidation oxygen can be fed to burners ( 1 ) and/or the nozzles ( 13 ) and/or the combustion chamber, a solution should be created by means of which undesired oxygen contents in the flue gas can be avoided during oxyfuel operation of the steam generator in the partial-load range. This is achieved in that the feed means ( 9, 10, 11, 12 ) and/or the feed lines ( 2, 2 a - 2 d, 4, 5, 9 a - 9 d, 10 a - 10 d, 11 a - 11 d, 12 a - 12 d ) are designed in such a way that at least one burner ( 1 ) or some of the burners ( 1 ) independently of the other burners ( 1 ) and/or a nozzle ( 13 ) or some of the nozzles ( 13 ) independently of the other nozzles ( 13 ) can be exposed to a gas flow providing the desired oxygen content or the desired oxygen concentration and/or the desired oxygen mass flow.

1 . A steam generator comprising a combustion chamber fired with a fossil fuel and/or with particulate fuel containing carbon, and at least one burner level comprising a plurality of burners and/or at least one level comprising nozzles in the form of upper air nozzles and/or side wall nozzles, each having connected feed means and/or feed lines through which/by means of which gas flows which make available combustion oxygen and/or oxidation oxygen can be fed to the burners and/or to the nozzles and/or to the combustion chamber, wherein the feed means and/or the feed lines are configured such that in each case at least one burner or some of the burners can be provided, independent of the respective other burners, and/or in each case one nozzle or some of the nozzles can be provided, independent of the respective other nozzles, with a gas flow which makes available the respectively desired oxygen content or the desired oxygen concentration and/or the respectively desired oxygen mass flow. 
     
     
         2 . The steam generator as claimed in  claim 1 , wherein at least one burner or some of the burners can be provided, individually and/or separately from the other burners of the respective burner level, and/or one nozzle or some of the nozzles can be provided, individually and/or separately from the other nozzles of a respective nozzle level, with a gas flow which can be adjusted individually in terms of its oxygen content or its oxygen concentration and/or the oxygen mass flow which it carries. 
     
     
         3 . The steam generator as claimed in  claim 1 , wherein at least some of these gas flows which are respectively fed to one or more burner levels or nozzle levels and/or respectively fed to one or more burners and/or one or more nozzles, and are of one type or category that can be respectively provided with oxygen individually and/or separately from the other gas flows of this type or category, and/or can be adjusted, individually and/or separately from these other gas flows of the same type or category, in terms of their oxygen content or their oxygen concentration and/or the oxygen mass flow conveyed with them. 
     
     
         4 . The steam generator as claimed in  claim 1 , wherein at least a part of the burner level or nozzle level and/or some of the burners or nozzles which is/are provided with an oxygen-containing gas flow, in particular for the purpose of cooling, during partial loading of the steam generator, has/have such a feed means and/or such a feed line. 
     
     
         5 . The steam generator as claimed in  claim 1 , wherein the secondary gas supply and/or tertiary gas supply of each burner level and/or of each burner can be provided with oxygen individually and/or separately from other gas flows of this type or category and/or can be adjusted individually and/or separately from these other gas flows, in terms of their oxygen content. 
     
     
         6 . The steam generator as claimed in  claim 1 , wherein the core gas supply of each burner level and/or of each burner can be provided with oxygen individually and/or separately from other gas flows of this type or category, and/or can be adjusted individually and/or separately in terms of its oxygen content. 
     
     
         7 . The steam generator as claimed in  claim 1 , wherein the primary gas supply of each burner level and/or of each burner can be provided with oxygen individually and/or separately from other gas flows of this type or category, and/or can be adjusted individually and/or separately in terms of its oxygen content. 
     
     
         8 . The steam generator as claimed in  claim 1 , wherein the upper air nozzle supply and/or the side wall nozzle supply of each nozzle level and/or of each nozzle can be provided with oxygen individually and/or separately from other gas flows of this type or category, and/or can be adjusted individually and/or separately in terms of its oxygen content. 
     
     
         9 . The steam generator as claimed in  claim 1 , wherein all the gas flows, feeding combustion oxygen and/or oxidation oxygen to the combustion chamber, of each burner level and/or of each burner and/or of each nozzle level and/or of each nozzle can be provided with oxygen individually and/or separately from other gas flows of the respective type or category, and/or can be adjusted individually and/or separately in terms of their oxygen content. 
     
     
         10 . The steam generator as claimed in  claim 1 , wherein each burner level or nozzle level and/or each burner or each nozzle is connected to at least one feed line feeding an oxygen-containing gas flow, wherein the oxygen content of the gas flow, respectively fed therein, of one type or category can be adjusted independently of the gas flows of this type or category which are respectively fed to the other burner levels or nozzle levels and/or other burners and/or nozzles. 
     
     
         11 . The steam generator as claimed in  claim 1 , wherein the oxygen content in the respective gas flow can be adjusted between 0 and 100% by weight or % by volume. 
     
     
         12 . The steam generator as claimed in  claim 1 , wherein at least in some of the feed lines, a mixture of fed-back CO 2 -containing flue gas and added oxygen is fed to the respective burner level or nozzle level and/or to the respective burner or to the respective nozzle as a gas flow. 
     
     
         13 . The steam generator as claimed in  claim 1 , wherein the steam generator is operated at least at certain times in an oxyfuel operating mode. 
     
     
         14 . A method for feeding combustion oxygen and/or oxidation oxygen to burners and/or nozzles of a combustion chamber of a steam generator which is fired with a fossil fuel and/or with particulate fuel containing carbon and which has at least one burner level comprising a plurality of burners and/or at least one level having nozzles, in particular in the form of upper air nozzles and/or side wall nozzles, wherein in each case at least one burner or some of the burners is/are provided, independently of the respective other burners, and/or in each case one nozzle or some of the nozzles is/are provided, independently of the respective other nozzles, with a gas flow which makes available the respectively desired oxygen content or the respectively desired oxygen concentration and/or the respectively desired oxygen mass flow. 
     
     
         15 . The method as claimed in  claim 14 , wherein at least one burner or some of the burners are provided, individually and/or separately from the other burners of the respective burner level, and/or one nozzle or some of the nozzles is/are provided, individually and/or separately from the other nozzles of a respective nozzle level, with a gas flow which can be adjusted individually in terms of its oxygen content or its oxygen concentration and/or the oxygen mass flow which is carried by it. 
     
     
         16 . The method as claimed in  claim 14 , wherein at least some of the gas flows of one type or category, which are fed to in each case one or more burner levels or nozzle levels and/or to in each case one or more burners and/or one or more nozzles, are provided with oxygen, in each case individually and/or separately from the other gas flows of this type or category, and/or are adjusted individually and/or separately from these other gas flows of the same type or category, in terms of their oxygen content or their oxygen concentration and/or the oxygen mass flow conveyed with them. 
     
     
         17 . The method as claimed in  claim 14 , wherein said method is carried out in a steam generator as claimed in  claim 1 . 
     
     
         18 . The steam generator as claimed in  claim 1 , wherein the oxygen content in the respective gas flow can be adjusted to less than 21% by volume.