Power generation system and method to operate

Abstract

A power generation system includes an oxy-fuel-burner, a steam cycle, and a recirculation line for feeding a part of working media of the steam cycle into the oxy-fuel-burner. A system and a method provides at least one first feed-water-preheater and wherein the steam cycle joins into the recirculation line downstream the at least one first feed water pre-heater and extracting a tenth working-media-stream from the steam cycle, extracting an eighth working-media-stream as carbon-dioxide downstream the first condenser, wherein the at least one first feed water-preheater is heated with a working media stream extracted from the first steam turbine, namely a fifth working-media-stream.

1 . A power generation system (PGS) comprising
 an oxy-fuel-burner (OXB), wherein said oxy-fuel-burner (OXB) is made to generate a first burner-discharge-fluid from burning fuel (F) with an oxygen containing gas (O2), said oxygen containing gas (O2) having oxygen content which is higher than the oxygen content of ambient air,   a recirculation line (RCL) for feeding a first liquid into said oxy-fuel-burner (OXB) to mix with said generated first burner-discharge-fluid to a first working-media-stream (EXH 1 ),   a steam cycle (RC) operated with said first working-media-stream (EXH 1 ),   wherein said steam cycle (RC) comprises at least one first steam turbine (ST 1 ) expanding at least a part of said first working-media-stream (EXH 1 ), namely a third working-media-stream (EXH 3 ), wherein said first steam turbine (ST 1 ) has at least one output port for expanded fluid, one of which providing a seventh working-media-stream (EXH 7 ),   wherein said steam cycle (RC) comprises at least one first water separator (CON 1 ), downstream said first steam turbine (ST 1 ) condensing part of said seventh working-media-stream (EXH 7 ), wherein said first water separator (CON 1 ) has at least one output port for condensed fluid, one of which providing a ninth working-media-stream (EXH 9 ),   wherein said steam cycle (RC) comprises at least one first feed-water-pump (FWP 1 ) downstream of said first water separator (CON 1 ) delivering said ninth working-media-stream (EXH 9 ) to a higher pressure level, with an output of a feed-water-pump-output-stream,   wherein said steam cycle (RC) comprises at least one first feed-water pre-heater (WPH 1 ) downstream said first feed-water-pump (FWP 1 ) heating at least a part of said feed-water-pump-output-stream, namely a thirteenth working-media-stream (EXH 13 ),   wherein said steam cycle (RC) leads into said recirculation line (RCL) downstream said at least one first feed water pre-heater (WPH 1 ) feeding said thirteenth working-media-stream (EXH 13 ) into said recirculation line (RCL) as said first liquid,   wherein a part of working media in said steam cycle (RC) is extracted from said steam cycle (RC), as a tenth extraction-fluid-stream (EXH 10 ),   said first water separator (CON 1 ) further extracts carbon-dioxide from said seventh working-media-stream (EXH 7 ) via a further output port of said first water separator (CON 1 ) as an eighth carbon-dioxide-stream (EXH 8 ),   wherein one of said output ports of said first steam turbine (ST 1 ) provides a fifth working-media-stream (EXH 5 ) and wherein said at least one first feed water-pre-heater (WPH 1 ) is heated via said fifth working-media-stream (EXH 5 ).   
     
     
         2 . The power generation system (PGS) according to  claim 1 , further comprising
 a second steam turbine (ST 2 ) downstream of said oxy-fuel-burner (OXB) and upstream of said first steam turbine (ST 1 ) receiving said first working-media-stream (EXH 1 ) from said oxy-fuel-burner (OXB).   
     
     
         3 . The power generation system (PGS) according to  claim 2 , further comprising
 a first heat exchanger (HEX 1 ), downstream said oxy-fuel-burner (OXB) and upstream said second steam turbine (ST 2 ) wherein at least a part of said first working-media-stream (EXH 1 ) exiting said second steam turbine (ST 2 ), comprising a third working-media-stream (EXH 3 ) is heated up by said first heat exchanger (HEX 1 ) receiving thermal energy from said first working-media-stream (EXH 1 ).   
     
     
         4 . The power generation system (PGS) according to  claim 1 ,
 wherein said recirculation line (RCL) comprises at least one adjustable valve (WSV) to control the flow through said recirculation line (RCL).   
     
     
         5 . The power generation system (PGS) according to  claim 1 ,
 wherein said at least one first feed water-pre-heater (WPH 1 ) comprises a degasification part to collect gaseous working media from the condensing of the provided said fifth working-media-stream (EXH 5 ).   
     
     
         6 . The power generation system (PGS) according to  claim 1 , further comprising
 upstream said oxy-fuel-burner (OXB), an air separation unit (ASU) as part of said power generation system (PGS) to provide pure oxygen from ambient air.   
     
     
         7 . A method to operate a power generation system (PGS) comprising:
 generating a first burner-discharge-fluid from burning an oxygen containing gas (O2) and fuel (F),   wherein an oxygen content of said oxygen containing gas (O2) is higher than the oxygen content of ambient air,   providing a steam cycle (RC) comprising at least one first steam turbine (ST 1 ), at least one first water separator (CON 1 ), downstream said first steam turbine (ST 1 ), at least one first feed-water-pump (FWP 1 ) downstream said first water separator (CON 1 ), at least one first feed-water-preheater (WPH 1 ) downstream said first feed-water-pump (FWP 1 ),   extracting a part of working media from said steam cycle (RC) by a recirculation line (RCL) and feeding a first liquid, as said part of said working media into said oxy-fuel-burner (OXB) to mix with said generated first burner-discharge-fluid to result in a first working-media-stream (EXH 1 ),   operating said steam cycle (RC) with said first working-media-stream (EXH 1 ),   expanding at least a part of said first working-media-stream (EXH 1 ), comprising a third working-media-stream (EXH 3 ) by said at least one first steam turbine (ST 1 ),   outputting a seventh working-media-stream (EXH 7 ) from at least one output port for an expanded fluid of said first steam turbine (ST 1 ), the expanded fluid being a part of said third working-media-stream (EXH 3 ),   condensing a part of said seventh working-media-stream (EXH 7 ) by said at least one first water separator (CON 1 ),   delivering at least a part of said seventh working-media-stream (EXH 7 ) downstream of said first water separator (CON 1 ) to a higher pressure level, comprising a ninth working-media-stream (EXH 9 ), by said at least one first feed-water-pump (FWP 1 ), and outputting a feed-water-pump-output-stream by said at least one first feed-water-pump (FWP 1 ),   heating at least a part of said feed-water-pump-output-stream, comprising a thirteenth working-media-stream (EXH 13 ) by at least one first feed-water-preheater (WPH 1 ),   feeding at least a part of said thirteenth working-media-stream (EXH 13 ) from said steam cycle (RC) as said first liquid into said recirculation line (RCL) downstream said at least one first feed water pre-heater (WPH 1 ),   extracting a part of working media of said steam cycle (RC) from said steam cycle (RC), as a tenth extraction-fluid-stream (EXH 10 ),   extracting a part of said seventh exhaust-fluid-stream (EXH 7 ) as carbon-dioxide downstream said first water separator (CON 1 ), comprising an eighth carbon-dioxide-stream (EXH 8 ),   heating said at least one first feed water-preheater (WPH 1 ) by an output-stream extracted from said first steam turbine (ST 1 ), comprising a fifth working-media-stream (EXH 5 ).   
     
     
         8 . The method according to  claim 7  further comprising
 expanding received said first working-media-stream (EXH 1 ) from said oxy-fuel-burner (OXB) by a second steam turbine (ST 2 ) downstream of said oxy-fuel-burner (OXB) and upstream of said first steam turbine (ST 1 ). 
 
     
     
         9 . The method according to  claim 7  further comprising
 heating up at least a part of said first working-media-stream (EXH 1 ) exiting said second steam turbine (ST 2 ), comprising a third working-media-stream (EXH 3 ) by a first heat exchanger (HEX 1 ) receiving thermal energy from said first working-media-stream (EXH 1 ), said first heat exchanger (HEX 1 ) being provided downstream said oxy-fuel-burner (OXB) and upstream said second steam turbine (ST 2 ). 
 
     
     
         10 . The method according to  claim 7  further comprising
 controlling the flow through said recirculation line (RCL) by at least one adjustable valve (WSV) or pump or compressor. 
 
     
     
         11 . The method according to  claim 7  further comprising,
 degasifying to collect gaseous working media from the condensing of the provided said fifth working-media-stream (EXH 5 ). 
 
     
     
         12 . The method according to  claim 7  further comprising,
 providing an air separation unit (ASU) as part of said power generation system (PGS) to provide pure oxygen from ambient air upstream said oxy-fuel-burner (OXB). 
 
     
     
         13 . The power generation system (PGS) according to  claim 1 ,
 wherein the first liquid comprises water.   
     
     
         14 . The power generation system (PGS) according to  claim 1 ,
 wherein the at least one first water separator (CON 1 ) comprises a condenser.   
     
     
         15 . The power generation system (PGS) according to  claim 1 ,
 wherein the part of working media in said steam cycle (RC) is extracted from said steam cycle (RC) downstream said first feed-water-pump (FWP 1 ).   
     
     
         16 . The power generation system (PGS) according to  claim 1 ,
 wherein said tenth extraction-fluid-stream (EXH 10 ) comprises water.   
     
     
         17 . The method according to  claim 7 ,
 wherein the first liquid comprises water.   
     
     
         18 . The method according to  claim 7 ,
 wherein the at least one first water separator (CON 1 ) comprises a condenser.   
     
     
         19 . The method according to  claim 7 ,
 wherein extracting the part of working media of said steam cycle (RC) from said steam cycle (RC) is downstream said first feed-water-pump (FWP 1 ).   
     
     
         20 . The method according to  claim 7 ,
 wherein said tenth extraction-fluid-stream (EXH 10 ) comprises water.