Energy Tab

HP & LP Bypass Operation and Protection Purpose Boiler operation independent of the turbine Minimum steam flow through SH & RH tubes during start-ups, low load operation & sudden unloading of unit Utilized or building up of steam parameters Avoiding the boiler trip on Reheat protection No steam flow through Boiler steam tubes will lead to starvation & thereby overheating and lead to premature failure of tubes  The capacity of HPLP bypass is 60% of full load turbine steam flow  Reheat Protection: RH protection (delay=10 sec) will act if TURBINE HP V/V & HPBP CLOSED [ either turbine HP stop v/v or HP CV in both HP line closed ] & [ both HP BP <2%]             OR TURBINE IP V/V & LP BP closed [ Either IP stop v/v or IP CV v/v in both IP line closed ] & [ Either LP BP stop v/v or LP BP C/V in both LP line is closed] OR   Generator ckt bkr open & [both HP BP closed OR both L...

Boiler Start-Up After BTL Boiler is out for 1-2 days due to BTL. HP Casing Temp in b/w 300-400 Deg One HFO i/s. HFO charged with >110 Deg upto Boiler Front Start ID and FD fan. Purge Boiler (5 min cycle) Check SH/RH vents Open. APH Soot Blowing lined up.Charge Oil Carry over Probe. Turbine on Barring. Start AB all 4 guns(Atom Steam Pr in b/w 6-7 ksc) Take Another gun CD(all 4). HFO Prssure~8-10 ksc. Drum Metal Temp Rise~2 Deg/min APH Soot Blowing(10-12 ksc Pr) to be done non-stop. Drum  Pr~2 ksc. Close SH/RH Vents. Open HPBP Warm-Up valves. Open BSV bypass valves. Drum Pr~5 ksc. Open BSVs. Open HPBP~10%. Close HPBP Warm up Valves.  Close SH/RH Header drains at ~ 14 ksc(Drum Pr). Put HPBP spray on Auto. FG path of PA fan through. Start one PA Fan and one Seal Air Fan MS Pr~80 ksc & MS Temp~365 Deg. HRH Pr~12 ksc & HRH Temp~325 Deg. Maintain using HPBP and LPBP valves. Float A mill(charge air). Cut in A mill ~ min flow 17 TPH. No SH/RH spray till now....

1 MDBFP – Available & Standby 2 Oil gun: HFO Pr/Temp=16 ksc/>110 Deg , Atom Steam: 6.5ksc/>220 Deg (Open steam drains @AB elevation) 3 Turbine on LP mode, Boiler Master in Manual(Manual Mode) 4 Isolate PRDS from CRH for this unit, Increase the set point to other units @ 13.5 ksc/ Temperature >280 deg 5 Open GS supply line drain to atmosphere 6 Charge APH soot blowing line from PRDS 7 Load-500 MW with 6 Mills(Roughly @ 55 tph each) 8 Cut feeding in top mill & Stop mill, other 5 mills >=40 tph/ load ~325 MW,In b/w reduce ThrotPr- 170 to 150 ksc 9 Take AB & CD elevation gun/ Start APH Soot blowing 10 Start MDBFP in Manual(cold) & Load/ unload anyone TDBFP(<=3500 rpm), MDBFP-auto & FW master-Auto 11 Switch off ESP fields as guns been taken & proved 12 Cut feeding in Bottom Mill & stop it/ Now 4 mills/ Ms Pr ~130 ksc/ load <=300 MW (Reduce feed in top mill too) 13 14 Load~225 MW with 3 Mills+ 2 elev oil guns/ Unload TDBFP, keep lo...

PA Fan : Stg-II : Operation & Important Important Information : Capacity: 700 TPH Total Head Devleoped: 1200 mm WC Speed: 1480 rpm Rating: 2.775 MW and 11 KV Full Load current: 169 Amp Overload alarm: 180 Amp (TD 20 sec) Overload Trip: 192 Amp Normal Header Pressure: 820 mm WC Current: 90 Amp Blade-Pitch: 60 % Blade Pitch Locking: 85 % Trip : Low =650 mmWC(TD-5 sec) | Low-Low=550 mmWC(Instant) Prestart checks & Loading: Check air path is available  .   At least one PAPH is ON and air path of the APH available (APH air I/L & O/L dampers are open), for second PA fan both PAPH must be on   Remote / local selector switch of blade pitch mounted on the actuator is selected in remote and the blade pitch is in minimum position.   Check that the outlet (discharge) damper is in closed position and in remote   Check the PA fan discharge duct drain valve is in closed position .After shut down with air preheater water washing this duct...

PTW Preparing steps Use T-code WCLE Enter Planning Plant-1005 Set filter- Operational WCDs Select Prepared  WCDs Enter- Valide From and TO Date Select " Reference Object" tab Type " cr2" in train blank place click " Execute" button (clock button) Select  PTWs to be prepared(Using Checks) Click " Hierarchy" Button Click "Switching Screen" (gear shape) Click " Select all Button" Click " tag" button Click " continue" button Click " Edit/ Print/ Operational List/ tagging List Click "Print Preview" button Click back button Click " tagged" button Click back button Click " Operational WCD/ function/Print Check Information below.

PTW Closing steps Use T-code WCLE Enter Planning Plant-1005 Set filter- Operational WCDs Select CLOSED (green) WCDs Enter- Valide From and TO Date Select " Reference Object" tab Type " cr2" in train blank place click " Execute" button (clock button) Select  PTWs to be closed(Using Checks) Click " Hierarchy" Button Click "Switching Screen" (gear shape) Click " Select all Button" Click " Untag" button Click " continue" button Click " Edit/ Print/ Operational List/ Untagging List Click "Print Preview" button Click back button Click " Untagged" button Click back button Click " Operational WCD/ function/Close Check Information below.

Equipment availability: CW duct charged ACW pump available,ACW strainer boxed up ECW pump available ECW tank filled. DM/CST pump available. Boiler fill pump available. Wet Lay up pump, NH3, N2H4 pump available. Condenser Hotwell normal level. CEP available, DA level C/V, Isol. Valve operation OK CPU one stream available. Deaerator boxed up, level normal. MD BFP’C’ available, lined up. Feed line vented upto FRS. FRS LOW range C/V, Isol. Valve opn OK OK LPH, HPHs bypass valve available & lined up. Eco inlet valve E2 open (Operation) OK Eco R/C valve E18, E20 Opn OK. Boiler drum clearance. Low point drains header valve clearance. SH header valves clearance. SH spray valve clearance & all valve closed. All CC pumps cavity filled. Boiler stop valve (L&R) opn checked, Integral bypass opn OK EBD, CBD, IBD valve cleared, opn checked. SH drain valve before Blr. Stop valve opn OK. SH air/startup vents opn OK. Drum vents Opn OK. Soot blowing steam Isol....