Boiler Interlock and Protection

Boiler Interlock And Protection Manish Dhruw Asst Manager 14843 Cpp-54

Boiler interlock and protection

Boiler Interlock - A Boiler Interlock is an arrangement arrangement of heating controls. It ensures the boiler does not re when there is no demand for heat. Protection o! "oiler – Boiler protection protection are provide to detect the abnormal condition by constantly measuring the various parameter under normal and faulty condition. If any abnormality happened trip the boiler to prevent prevent from major damage. #eed o! Interlocks $ Protection

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 To  To  To  To  To  To  To  To

avoid avoid avoid avoid

operational faults faul ts euipments damage. accidents to individuals. i ndividuals. system disturbances

In case o! M%& &rip @aster $uel Trip 0 it produces trip signal for fuel systems from operation C then trip the boiler out of service away from danger. this relay needs many conditions C these conditions will failure. be found :. ;nit 2ame !. Both I" to fanoperate trip. at the following points. !3. *oss of fuel. #. Both $" fans trip. !!. *oss of scanner %. &mergency manual cooling air + failed. . "rum level low low low +/0%#mm with  sec delay-. 'ther than M%&1. Total air 2ow/%34. !. @<

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Boiler 

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Interlocks cu( protections !. If one I" fan tripsC one $" fan will trip in the same seuence. #. If one $" fan tripsC one I" fan will trip in the same seuence. %. If one A)( tripsC one I" fanC one $" fan and one )A fan will trip in the same seuence. '. In case of DB openingC top elevation mill or non adjacent mill will trip. . If drum level#33 mmC &B" will open. 1. If drum levelE!3 mmC &B" will close. 5. $eed water 2ow/3 T)(C &conomiser recirculation @6F will open. 7. $eed water 2ow873 T)(C &conomiser recirculation @6F will close. :. If superheated steam pressure is higher than !'.71 @)a &,F will open and if pressure is lower than the value &,F will close +if kept in service-.

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'ther Protections 1) Boiler dru( pressurea- (igher than !5.#' @)a *(< safety valve will lift and it will reset G !1.% @)a. b- (igher than !1.5' @)a ,(< safety valve will lift and it will reset G !1.#! @)a. *) +uperheated stea( pressurea- (igher than !.#: @)aC *(< safety valve will lift and it will reset G !'.51 @)a. b- (igher than !.# @)aC ,(< safety valve will lift and it will reset G !'.5'5 @)a. 3) C, stea( pressurea- (igher than %.37 @)aC *(< safety valve will lift and it will reset G #.:'5 @)a. b- (igher than #.:1% @)aC ,(< safety valve will lift

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Dru( le.el !. *evel8!# mmH high priority alarm. #. *evel80!# mmH high priority alarm. %. *evel8#3 mmH emergency priority alarm. '. *evel80#3 mmH emergency priority alarm. %urnace pressure !. )ressure8%3 mm of (#6H high priority alarm. #. )ressure80%3 mm of (#6H high priority alarm. %. )ressure83 mm of (#6H emergency priority alarm. '. )ressure803 mm of

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M+ $ , &e(perature !. @< temperature8'3H high priority alarm. #. @< temperature833H emergency priority alarm. %. ,( temperature8'3H high priority alarm. '. ,( temperature833H emergency priority alarm. 'thers !. A)( 2ue gas inlet temperature/%333H high priority alarm. #. 6#/!H high priority alarm. %. 6# eroH emergency priority alarm. '. $urnace "):3 mm of

ID %an interlock $ protection 

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!. Jo I" fan AKB converterK device fault. #. Jo I" fan protection acted. A#D %. I" fan AKB inlet L outlet damper closed. '. I" fan IDF in minimum position. . A)( AKB 2ue gas inlet L outlet damper open. 1. A)( AKB running !. I" fan AKB breaker protection acted. 6r ', #. B@< trip I" fan AKB. 6r %. $" fan AKB tripped. 6r '. A)( AKB tripped. 6r . I" fan AKB temperature protection

e Interl ockH

 T,I) enabl e Interl ockH

A0A,M !. $anK motor bearing temperature5 3H high priority alarm. #. $anK motor bearing temperature73 3H emergency priority alarm. %. $an bearing vibration1.% mmKsecH high priority alarm. '. $an bearing vibration!!mmKsecH emergency priority alarm. . @otor winding temperature!!3 3H high priority alarm. 1. @otor winding temperature!#3 3H emergency priority alarm   &,IP !. @otor winding temperature!%3 3 +# out of 1 temperatures with 13sec time delay-. #. $anK motor bearing temperature:3 3 +with 

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%D %an interlock $ protection 

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!. Jo $" fan AKB converterK device fault. #. Jo $" fan protection acted. +tart %. $" fan AKB outlet damper closed. ena"le '. $" fan IDF in minimum position. Interlo . A)( AKB 2ue gas inlet L outlet damper  A# ck open. D 1. A)( AKB running. 5. I" fan AKB running. !. $" fan AKB breaker protection acted. 6r #. B@< trip $" fan AKB. 6r %. I" fan AKB tripped. 6r  ', '. A)( AKB tripped. 6r . $" fan AKB temperature protection

&,IP ena"le Interlo ck

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A0A,M !. $anK motor bearing temperature5 3H high priority alarm. #. $anK motor bearing temperature73 3H emergency priority alarm. %. $an bearing vibration1.% mmKsecH high priority alarm. '. $an bearing vibration!!mmKsecH emergency priority alarm. . @otor winding temperature!!3 3H high priority alarm. 1. @otor winding temperature!#3 3H emergency priority alarm. &,IP  !. @otor winding temperature!%33 +# out of 1 temperatures with 13sec time delay-.

PA %an interlock $ protection

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!. Jo )A fan AKB converterK device fault. #. Jo )A fan protection acted. %. )A fan AKB outlet damper closed. AJ" '. )A fan IDF in minimum position. . A)( AKB 2ue gas inlet L outlet damper open. 1. A)( AKB running. 5. I" fan AKB running. 7. $" fan AKB running. :. Jo boiler trip command. !. )A fan AKB breaker protection acted. 6r #. @$T trip )A fan AKB. 6r %. I" fan AKB tripped. 6r '. $" AKB tripped. 6r . )A fan AKB temperature protection acted.

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 Trip enabl e Interl ockH

A0A,M !. $anK motor bearing temperature5 3H high priority alarm. #. $anK motor bearing temperature73 3H emergency priority alarm. %. $an bearing vibration1.% mmKsecH high priority alarm. '. $an bearing vibration!!mmKsecH emergency priority alarm. . @otor winding temperature!!33H high priority alarm. 1. @otor winding temperature!#33H emergency priority alarm. 

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&,IP !. @otor winding temperature!%33 +# out of 1 temperatures with 13 sec time delay-. #. $anK motor bearing temperature:3 3 with 13 sec time delay. %. $an bearing vibration!!mmKsec with 13 sec time delay. '. )A fan motor protection +over currentC earth faultC negative seuenceC phase fault etc- acted. . @$T trip )A fan. 1. I" fanK $" fan AKB trip to )A fan AKB trip. 5. )A fan running and fan discharge damper closed. 

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e interl ock

ea a r an n er oc $ protection 

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!. Jo fan converterK deviceK breaker fault. #. Any one )A fan running. %. $an IDF in minimum position. '. In case of one fan running L other fan standby0 a- If running fan getting tripped due to any protection acting then stand by fan will start in interlock if selected. b- If seal air pressure becomes low +/1 =)a-C then standby fan will start by interlock. '. "uring unit start up fan start enable will come with the start of any )A fan if selected in fan auto start interlock. MMommand will go to
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 A0A,M

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+canner Air %an Interlock Protection

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!. Jo motor or breaker protection acted. #. $an is in remote. %. In case of one fan is running and the other is in stopped condition0 a- By interlock input if one fan is stoppedK trippedC standby fan will start in auto. b- If scanner air header pressure/# =)a for  secC then standby fan will start in auto by interlock input. !.
A#D

+tart 2na"le Interlo ck 

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&rip

Mill Interlock $ Protection 

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!. Jo breakerK motor protection acted. #. *ube oil pressure normal for 8  minutes. %. Jo @$T acted.  A#D '. Boiler drum pressure8%.' kgKcm#. .
 +tart 2na"le Interlock 

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!. $eeder trip and no mill ignition permit. #. @$T. %. @"Fs closed. '. *ube oil pressure low +# out of % lube oil pressure/low switch act-. . erential pressure low low. 1. *oss of primary air +di>erential pressure between A)( outlet primary air and furnace pressure less than '13mm of (#6. 6ther InterlocksH !. 6n tripping of mill lose

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!. @ill lubeK hydraulic oil tank temperature85 3H high priority alarm. #. @ill lube oil thrust pad oil temperature813 3H high priority alarm. %. @ill lube oil thrust pad oil temperature853 3H emergency priority alarm. '. @ill motor frontK rear bearing temperature85 3H high priority alarm. '. @ill motor winding temperature8!33 3H high priority alarm. . @ill outletC roller bearing temperature8:3 3H high priority alarm. 1. @ill current813 ampH high priority alarm.

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!. @ill motor protection +over currentC earth faultC negative seuenceC phase fault etc- acted. #. @$T trip mills. %. @"Fs closed trip mill +# out of ' @"Fs-. '. @ill lube oil pressure low +# out of lube oil pressure/low switch actingtrip mill. . *oss of primary air +di>erential pressure between A)( outlet primary air and furnace pressure less than '13mm of (#6-. 1. $eeder trip and no mill ignition permit. 5. erential pressure low low.

&rip

Coal %eeder Interlock $ Protection 

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!. @ill tripK emergency stop. #. @$T. %. $eeder running and no coal.

 +tart 2na"le

A# D

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Interlo ck 

+top&rip 2na"le Interlo ck

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!. Belt deviation of feeder switch actH high priority alarm. #. Jo coal switch actH high priority alarm. %. oal jam switch actH low priority alarm. '. $eeder cleaner motor faultH low priority alarm. . oal 2ow eroH low priority alarm.

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!. @ill trip to feeder trip. #. @$T to feeder trip. %. $eeder motorK breaker protection acted.

 Mill 0u" 'il Pu(p Interlock $ Protection

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!. Jo breaker or motor protection acted. #. *6) is in remote. %. 6il pool temperature of lube oil8133.

!. 6il pool temperature of lube oil/'3. #. After *6) starting if oil pool temperature of lube oil/' 3 and mill not running +%3 mins time delay-. %. After mill stopping after ' hrs time delay stop command will go for *6).

+tart ena"le Interlo ck 

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+toptri p ena"le Interlo ck 

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!. *ube oil pump stoppedH emergency priority alarm. #. *ube oil pressure/low switch actH emergency priority alarm. %. 6il pool temperature8H 5 3 high priority alarm. '. *ube oil thrust liner sump temperature8H 133 high priority alarm. . *ube oil thrust liner sump temperature8H 53 3 emergency priority alarm. !. *6) motorK breaker protection acted. #. 6il pool temperature of lube

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&rip

AP Interlock $ Protection 

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!. Jo breaker or motor protection acted. #. A)( is in remote. %. Duide and support bearing oil pump running for minimum of %33 sec +for ;N# A)(-.

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Inter ock 

+toptr ip ena"l e Interl ock

!. A)( 2ue gas inlet temperature/733 ', and fans +I"C $" L )A- are running. #. $or A)( auOiliary motorC with the start of A)( main motor trip command will 6ther InterlocksH go. !.
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