LNG Steam Simulator Exercise
005. Run the Simulator to Start a Turbo Feed Pump
[Load Snapshot "Ex_005_Both Blrs in low fire-START Turbo Feed p/p"]
- Asssume scenario as described below [but check to confirm] and then follow the given procedures
Electrical Power:-
Shore Power:Off; Emergency Generator:Auto Stand-by; Both Turbo Generators:Off; Diesel Generator:On
Deaerator:-
Full with guage glass reading between 60~70 mm
Both Boilers:-
Both boilers on low fire. Both Boiler Press - aboout 1.5 Mpa;
Distilled Water Tank (DWT) & Atmospheric Drain Tank (ADT):-
Both DWT & ADT about 60% full.
Important Note
The Boiler Combustion Controller is tuned to respond for load
changes when the plant is under normal use and the burners are
firing on Heavy Oil.
As such a little bit of manipulation is necessary while firing under
low load conditions in order to avoid high pressures in the boilers
due to controller overshoot.
>> Procedures for starting a Turbo Feed Pump:-
Stbd/Port Boiler:
1 Open Stbd/Port De-superheater Stop Valves
Boiler Ctrlls:
2 Ensure Feed Pump PID Controllers are set to Auto.
Comb Ctrlls:
3 Lower Plant Master Setpoint to about 50% (this ensures that
the controller overshoot does not exceed the Safe Working
Pressure of the Boiler)
Cooling:
4 Open the inlet and outlet Feed Pump 1 LO Cooling valves
5 Open the inlet and outlet Feed Pump 2 LO Cooling valves
Emerg Distrib:
6 Close LO Feed Pump # 1 breaker
Main Distrib:
7 Close LO Feed Pump # 2 breaker
T/bines and Feed:
8 Open the Feed Pump discharge to main feed valve.
9 Open Feed pump (1 or 2) steam inlet reg cutout valve.
10 Open Feed pump (1 or 2) steam outlet reg cutout valve.
11 Ensure that the Turbo Feed Pump Regulator by-pass valves are shut.
12 Click the Feed Pump to display the Feed Pump Control panel.
Feed Pump Control panel:
13 Open the feed water inlet valve.
14 Open the Steam Exhaust outlet valve.
15 Put the re-circ valve to AUTO
Note: The following is to be continued once the steam
pressure reaches 5.5 MPa in the boiler drum.
T/bines and Feed:
16 Click the Feed Pump Aux LO Pump (small LO pump near the Main Feed pump) to display the local Feed Pump Aux LO control panel.
17 Select LOCAL operation and start the Main Feed Aux LO pump.
18 Select REMOTE.
Feed Pump Control panel:
19 Start the Main Feed Pump.
20 The Turbo feed pump regulator will adjust automatically to maintain the main feed main pressure. The main feed pressure must exceed boiler pressure for water to be able to enter the drum. The set point for the main feed pressure is adjustable
and is normally set to about 100 psi (700 kPa) above the highest drum pressure.
See Boiler Ctrls display.
21 The Turbo feed pumps have Over speed, LO pressure and Instructor activated trips. A red tripped label appearing next to a Feed Pump indicates a trip condition. Click on the label to re-set. In practice a trip are reset by manually operating a lever
on the feed pump itself.
Note: You will notice that despite setting the controller to 50% the pressure reaches about
6 MPa. As the pressure begins to fall it is advisable to commence increasing the Plant Master Set Point back to about 58%
which corresponds to a working pressure of 6.0 MPa.
22 The second Turbo Feed pump can be placed into a stand-by position by repeating
steps 12 – 14.
23 Put the second Aux LO Pump into Remote and Auto (A).
NOTE:
1) Check Knowledgenase - KB_001 [Critical]
Singapore Polytechnic