2.9 Flue Gas System [PDF]

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Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde – Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



1 (12)



TABLE OF CONTENTS 2.9



FLUE GAS SYSTEM..................................................................................... 2



2.9.1



Purpose of the system ................................................................................ 3



2.9.2



General description of the system............................................................. 3



2.9.3



Design criteria.............................................................................................. 6



2.9.4



Equipment specification ............................................................................. 7



2.9.4.1



Flue gas fans ................................................................................................. 7



2.9.4.2



Electrostatic Precipitator (not in scope) ....................................................... 11



2.9.4.3



Stack ........................................................................................................... 12



2.9.4.4



Recirculation gas nozzles ............................................................................ 12



1 2005 - 08 - 30 T. Anttonen 0 2005 - 03 - 09 T. Anttonen Muut. Rev.



Pvm Date



Laatinut Prepared by



KLY-1 1997-05



Pvm Date



Tarkastanut Reviewed by



Pvm Date



Hyväksynyt Approved by



P:\582-RAPP-PB3\int\Kayttoonotto\koulutus\Training Manuals\Folder 1\2.9 Flue gas system(1).doc



This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



2 (12)



2.9



FLUE GAS SYSTEM



Flowsheets:



T582-00017 T582-00019 T582-00039 T582-00040



Combustion air Flue gas Oil lubrication units of the ID fans Oil lubrication unit of the recirculation fan



This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



3 (12)



2.9.1 Purpose of the system The purpose of the flue gas system is to: − supply flue gas from the boiler to the stack − control flue gas pressure inside the furnace − control combustion temperature by means of flue gas recirculation − clean the flue gas from particulates − purge the boiler before starting the combustion 2.9.2 General description of the system The flue gas system consists of: − furnace − cyclones − second and third pass − flue gas ducts and dampers − electrostatic precipitator (not in scope) − flue gas fans − flue gas recirculation fan − stack (not in scope)



Furnace (283E065) The boiler furnace is a combustion chamber where the thermal energy bound in the fuel is released. The flue gas amount and properties generated in the combustion process depend on the fuels used. U



U



This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



4 (12)



Cyclones (283E066, 283E067, 283E068) In three parallel cyclones most of particles conveyed with flue gas from the combustion chamber are separated and returned back to the furnace. U



U



Second and third pass The walls of the 2nd pass are cooled by superheated steam flowing in the wall tubes. After plain tube economizer (283E004) flue gas is led to third pass where walls are constructed with a plate casing. U



P



P



In the second and third pass flue gas cools down when it flows across superheater, economizer and air preheater sections.



Electrostatic precipitator (not in scope) (283E071, 283E072) Fly ash is removed from the flue gas in electrostatic precipitator (not in scope), which comprises two parallel chambers and three fields. Both ESP chambers are designed for 60% boiler capacity. Flue gas ducts before the ESP chambers are equipped with guillotine dampers. U



U



Dust-laden flue gas from the boiler is sucked by means of a flue gas fan (283K002, 283K003) into the inlet funnel of the electrostatic precipitator and further to the precipitator casing where dust collection takes place. The cleaned gas is led from the precipitator casing through the outlet funnel via the flue gas fan and the flue gas ducts to the stack (283E122). The collected dust falls down to the precipitator bottom cones and is led via ash conveyors to the ash silo (283T021).



This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



5 (12)



Flue gas fans (283K002, 283K003) The two parallel operated radial-type induced draft (ID) fans, located after the electrostatic precipitator (283E071, 283E072), provide the draft required to keep flue gas pressure in upper part of the furnace (283E065) at about -0,1 ... -0,2 kPa. The draft is controlled by the variable frequency drives of the fans. The ID fans also discharge flue gas into the stack (283E122). U



U



Recirculating gas system When needed, part of the flue gas can be recirculated after the ID fans (283K002, 283K003) through recirculation flue gas fan (283K004) to the lower part of the furnace (283E065). Flue gas recirculation system is used to lower combustion temperature in the furnace and it can also be used to increase full superheating range. Recirculation flue gas pressure in controlled by inlet vanes of the fan and flow to separate sections is adjusted by dampers. Recirculation gas nozzles are divided into two separately controlled sections. Recirculation flue gas duct before and after the fan is equipped with guillotine dampers. U



This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



6 (12)



2.9.3 Design criteria Flue gas paths, electrostatic precipitators (283E071, 283E072) and flue gas fans (283K002, 283K003) are designed to transfer combustion process products in a controlled way from the furnace (283E065) to the stack (283E122) when fired design fuels at specified boiler operation range. Both flue gas fans are able to generate required draft up to 60% boiler load. Dimensioning basis for ESP at 100% boiler load when both chambers are in service and design fuels are fired is dust content of 135 mg/Nm3 (converted to dry gas @ 7% O2) after the ESP. It is possible also to run 60% boiler load through one ESP chamber, then dust emission is 150 mg/Nm3. P



P



P



B



B



P



Dimensioning basis for recirculation flue gas fan (283K004) is to produce together with fluidizing air fans (283K005, 283K006) such a high fluidizing velocity inside the furnace (283E065) that combustion temperature during coal firing remains at an acceptable level.



This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



7 (12)



2.9.4 Equipment specification 2.9.4.1



Flue gas fans Flue gas (I.D.) fans Equipment number Supplier Number of fans Model Type Control (supplied by RAPP) Bearings



283K002 (1) and 283K003 (2) Fläkt Woods Oy 2 HACP-224-285-cc-d-e radial fan variable frequency control oil lubricated



Motor (supplied by RAPP)



kW



Performance at design point Gas flow / fan Gas flow / fan Inlet density Total pressure rise Inlet temperature Fan efficiency Impeller power demand U



1800



U



Nm3/s m3/s kg/m3 Pa °C % kW P



P



P



P



P



P



122,2 202,4 0,786 5900 155 74,2 1580



Figure 1 shows Flue gas fan curve. Both of the fans are equipped with an oil lubrication unit.



This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



8 (12)



Figure 1 Flue Gas Fan Curve This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



9 (12)



Recirculation flue gas fan Equipment number Supplier Number of fans Model Type Control Bearings Motor (supplied by RAPP)



kW



Performance at design point Gas flow Gas flow Inlet density Total pressure rise Inlet temperature Fan efficiency Impeller power demand U



283K004 Fläkt Woods Oy 1 HACP-090-205-cc-d-e radial fan inlet vane control oil lubricated 710



U



Nm3/s m3/s kg/m3 Pa °C % kW P



P



P



P



P



P



25,1 39,8 0,821 12300 155 81,1 581



Figure 2 shows Recirculation gas fan curve. The fan is equipped with an oil lubrication unit.



This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



10 (12)



Figure 2 Recirculation Gas Fan Curve This document is the exclusive intellectual property of Kvaerner Power Oy and is furnished for the sole purpose of operating and maintaining of the specific project, and re-use of the document for any other project or purpose is prohibited. The document or the information shall not be reproduced or copied, or disclosed to a third party without prior written consent of Kvaerner Power Oy. © Kvaerner Power Oy, Tampere, Finland



2005



Asiakirjan nimi - Name of Document



Tunniste - Identification



Rev.



PROCESS DESCRIPTION 2.9 FLUE GAS



CFBT-582-1



1



Osasto - Department



Kohde - Subject



Sivu - Page



Power Generation Systems



RAPP PB3 PROJECT CFB MULTIFUEL BOILER



11 (12)



2.9.4.2



Electrostatic Precipitator (not in scope) Equipment numbers Supplier Supplier’s type



283E071 (1) and 283E072 (2) F.L.Smidth Airtech 1E400/H2P1/3*45104125/C/C/6P/6A T



T



Number of precipitators Number of parallel chambers Number of fields / chamber



one (1) two (2) three (3)



Process design 115,6 Nm3/s



− design flow / chamber



3



− design flow / chamber



183,6 m /s P



− flue gas temperature



P



136 °C



− flue gas pressure



-2000 Pa



− O2-content B



P



P



2,82 % vol wet



B



− H2O-content



11,86 % vol



− SO2-content



157 ppm



B



B



B



B



− inlet dust contents (in wet flue gas) − outlet dust content (wet gas; O2=3 %) B



B



− collecting efficiency



31,0 g/Nm3 P



P



3



50 mg/Nm P



P



99,458 %



The mechanical operating range of the precipitator − the maximum flue gas temperature − static pressure max / min Pressure drop between the inlet and the outlet flanges at boiler MCR load with 2 chambers



200 °C +6 / - 6 kPa