The presentation describes the cold rolling, warm rolling and hot rolling and synchronising of steam turbine. The Temperature Matching Chart for Turbine metal and Steam is also discussed in the presentation

1. THERMAL POWER PLANT
OPERATIONS
Simulator Part 8- Day 5
MANOHAR TATWAWADI
Director, tops
A2-806, PALLADION, BALEWADI, PUNE 411045
Mob: 9372167165, Email:-mtatwawadi@gmail.com
01-Nov-19 total output power solutions 1

2. COVERAGE
• Checking the Drip Diversion
• Cold, Warm and Hot start of the Unit
• Temperature matching with respect
to Turbine for raising of steam
temperature
• Checklist and operations for Hot
Start.

3. HP-LP HEATERS DRIP DIVERSION
Observe the Drip Diversion on MIMICS “LP DRAIN & HP DRAIN
SYSTEM”
Withdraw any Mill and observe the Drip Diversion with load
reduction
For Loads < 165 MW
HD30, HD21 – Open and HD29, HD31 – Close
(HPH6 to Deairator and HPH5 to LPH4)
Extraction Position
ES6 Open
For Loads > 165 MW
HD30, HD21 – Close and HD29, HD31 – Open
(HPH6 to HPH5 to Deairator)
Extraction Position
ES7 Open
For Loads < 100 MW
HD30, HD21 – Open and HD29, HD31 - Close
Extraction Position
ES6 Open/PRDS

4. COLD START UP OF 210 MW UNIT
• All lines and metal temperatures of boiler and turbine are
at atmospheric temperatures.
• All unit auxiliaries checked and tested for proper running.
• All commissioning trials are over.
• All work permits are cleared with men and material.
• All safety measures are implemented.
• The increase in boiler/steam/turbine temperatures are as
per the startup chart given by the manufacturer.
• Clean air flow measurement for all coal mills has been
carried out and as per the manufacturer.
• Procedure for cold startup already discussed in Parts 1 to 7

5. Recommended Cold Startup Curve for 210MW

6. Warm & Hot Rolling of Turbine
• Decide the type of Start depending on the HPT Casing Metal
Temp.
• Above 3500C Hot Rolling
• Between 150 to 3500C Warm Rolling
• Below 1500C Cold Rolling
• Cold Rolling has been already done in parts 1 to 7
• Procedure for Warm rolling is the same as Cold rolling.
• Rolling is done through HP Cylinder as is done in Cold Rolling
• In warm rolling steam temperature required is more in
comparison to cold rolling and hence more No of Oil Guns will
have to be taken in service as per the requirement.
• The Main Steam temp required will be calculated from the
matching Chart Provided.

7. TEMPERATURE MATCHING CHART
Case:- If the HPT Metal
Temp is 380 Deg C shown
as dotted line on X Axis
then
1. The exact matching
Main Steam temp
would be 4700C and
Pressure would be
70Kg/sqcm.
2. The +ve mismatch
temp would be 5150C
at 70 Kg/sqcm
3. The -ve mismatch
Temp would be
minimum 4250C at a
pressure of 70
Kg/sqcm.

8. HOT ROLLING OF TURBINE
• If the machine trips on full load and the fault is located
and cleared immediately, the machine can be rolled
again.
• The Main Steam Temperatures can be increased by using
HPLP Bypass and HOT ROLLING can be done.
• For this type of start up HP Casing Metal Temperature
should be more than 350 Deg C.
• If the fault is located and cleared after some period and
still if the HPT Casing Metal Temperature is more than
350 Deg C, then also it’s a condition of HOT ROLLING.
• Generally in a short period after machine trips (maybe a
period of 12 to 16 Hrs) HOT ROLLING condition prevails.

9. HOT ROLLING STARTUP CURVE

10. CHECKLIST & OPERATION
• Note down TA Set Tripping Time/Date/Load at the time of
Tripping
• Confirm Generator all 3 Phases currents have come to
ZERO.
• Check the tripping of field breaker, trip it if not tripped.
• Start SOP Immediately and check observe Lub. oil and relay
oil pressure.
• Confirm ESV / IV Closed and machine speed starts reducing.
• Confirm MS1, MS2 closed on Interlock.
• Confirm LP / HP Heaters Extraction Valves closed and
Deairator Heating Change over to PRDS
• Confirm Tripping of Boiler with all fuel tripped (All Oil
Elevations, all coal Mills and coal feeders tripped)

11. CHECKLIST & OPERATION…….
• Slowly reduce the total air flow to minimum i. e. 300 TPH.
• Control the drum level by operating Feed water Valve / BFP
scoop positions.
• Check the opening of condenser spray MC39, MC57 on
interlock
• Confirm all SH Spray Valves closed on AUTO.
• Bring Burner Tilt Position to Horizontal. 50%
• Bypass T.T.B.T. switch (Turbine Trip to Boiler Trip on manual)
• Check the Boiler Drum Level NORMAL
• Check PURGE READY indication and give command for Purging
• After Purge Complete and the boiler is reset, open the trip
valves for Ignitor, Warm up Oil and Heavy Oil.

12. CHECKLIST & OPERATION…….
• Select Heavy Oil for AB Elevation
• Take Oil Support in AB, CD and EF Elevations one by
one
• Check and maintain the drum level.
• Check that the IGV of PA fans on Manual and close
them.
• Start PA Fans one by one and put the IG vanes on AUTO
to maintain Header Pressure 800mm.
• Check Vacuum, Condenser Level.
Break Vacuum if
• The machine has tripped on “Low Lub Oil Pressure”
• Axial Shift very High
• Any other abnormality such as sound from Turbine

13. CHECKLIST & OPERATION…….
• Open Gland Steam Valves of HPT/IPT if they are closed and
watch vacuum.
• Watch Differential Pressure between Hydrogen and Seal Oil
during coasting down of the machine.
• Maintain Lub Oil Temp not less than 40 Deg C.
• Note down the Axial Shift and Expansions of HPT IPT and LPT.
• When the speed of turbine comes to zero put Machine on
Barring Gear.
• Note down the HPT and IPT Casing Metal temperatures.
• Open HP LP Bypass Drain, Open HP/LP Heaters Drains.
• Ensure CR5, CR6 valves are open before charging of HP/LP
Bypass.

14. CHECKLIST & OPERATION…….
• Open LP Bypass min 4%, Open HP Bypass also 8%.
• Watch condenser level and maintain.
• Watch Main Steam Pressure and maintain it by
operating HP Bypass Valves.
• Maintain the Pressure in Reheater to 6-7kg/sqcm.
• Open HPT and IPT casing drains by 5%.
• Open Main steam Valves MS1 and MS2.
• Start opening the Speeder gear. At 6.820 mm IV and
ESV will open.
• Open the speeder gear further to 7.120, Control valves
of IPT will start opening.

15. CHECKLIST & OPERATION…….
• Observe the speed of the turbine increasing, watch
expansions, if the expansions are going towards –ve side
give rotor heating.
• When the turbine speed reaches more than 2800 RPM stop
SOP.
• Raise the speed to 3000RPM without stopping at the
critical speeds by operating the HPLP Bypass.
• Make the field flashing supply ON.
• Make the field breaker ON.
• Changeover AVR from AUTO to MANUAL. Raise the
Generator Voltage to 15.75 KV.
• Make the synchroscope ON.

16. CHECKLIST & OPERATION…….
• Synchronise the generator with the grid by closing the
Generator breaker from the control desk when
synchroscope is moving from 11 to 12 position slowly.
• Check the Voltage error for ZERO and put AVR on AUTO.
• As soon as the unit is synchronized, open the CVSM further
and close LP Bypass fully, HP Bypass may be open.
• Observe the increase in Generator load as all the steam is
now flowing through the IP Turbine.
• Check the HPT first stage pressure and check that HPT
Control valves are open.
• Ensuring that the HPT Control Valves are OPEN, close the
HP Bypass valves.

17. CHECKLIST & OPERATION…….
• Stop Rotor heating if it is in service.
• Close all drains
• Maintain Boiler Drum Level from control desk 4
• Similarly maintain the M.S. Pressure by increasing the fuel
input to the boiler. (Increase HO pressure and/or take coal
mill in service.)
• Normalise TT/BT switch. (Turbine Trip to Boiler Trip switch)
• Changeover Station Supply to UAT Supply when load is
more than 50 MW.
• Take LP/HP Heaters in service and increase the load to 210
MW as per the Ramp rate as per Chart