U2 Main Turbine Cooling/SS/LO Flashcards
What are the trips of the Unit 2 Main turbine that are DIFFERENT than Unit 1?
Hardwired:
S tator Cooling Water (10 sec delay)
- Lo Press 28 psig
- Lo Flow 666 gpm
- Hi Temp 95°C (+ 5 sec delay)
T hrust Bearing Wear Abnormal ± 32 mils
PLC:
O il Press (Bearing) < 14.7 psig > 5 seconds
Is there an auto trip for high vibrations trip for the Unit 2 Main Turbine?
NO
When does the U2 Turning gear auto start?
1 min after Main Turbine Trip. Does not engage until < 40 RPM
- Engages when Main Turbine speed < 40 rpm.
When does 2-CMO-40 (Exhaust hood spray) open?
- Generator Load < 7.5%
- Turbine Speed > 900 rpm
- Manual
What does the Main Turbine Thrust Bearing do?
Limits Axial Movement to prevent stationary and rotating blade contact
When does the AC Lube Oil pump supply oil to the U2 Main Turbine?
Turbine speed < 1800 rpm
When does the AC Lube Oil pump auto start for the U2 Main Turbine?
Turbine Trip
- Low Lube Oil # at 16#
When do the 2 DC Lube Oil pumps auto start for the U2 Main Turbine?
- Turbine Trip
-Low pressure of 16 psig
- Low Lube Oil # at 16#
When do the 2 DC Lube Oil pumps supply oil to the U2 Main Turbine?
supplies bearing oil when the Shaft Driven LO Pump or Aux Oil Pump fail
What does LRV-32, LO supply header # Reg Valve, do?
- Maintains U2 turbine supply header pressure at 24.5 psi by dumping excess pressure back to the lube oil tank
What do the reheat stop and intercept valves do?
- Both Close on Main Turbine Trip to minimize the potential for overspeed of Main Turbine
- Intercept valves throttle to limit overspeed on a load rejection to prevent a turbine trip
How do the SRV-26/27, aux steam supply valves fail on U2?
As is
What does SRV-12 (U2 MS Bypass Header supply to steam seals) do?
Keeps HPT Inner Steam Seals 10# > HPT exhaust during normal operation.
What supplies LPT Steam Seals during normal operation?
- HP inner seals supply most of steam for seal stm header after it exits the HPT
- Can receive some steam from HP and LP Stop and Ctrl valve leakoff,
- and some aux steam as necessary when HP and LP stop and ctrl valves are backseated
What supplies Steam Seals during startup, shutdown and low power operation?
50# aux steam supplies steam seals
What dumps excess steam pressure for the steam seals on U2?
SRV-25 (Steam Seal Dump Valve) controls pressure and dumps extra steam to 2A/2B Heaters
How does SRV-22 (Aux Steam reg supply valve) fail on loss of air?
Fails open
How does SRV-25 (Seal disch to 2A/B heaters) fail on loss of air?
-Fails closed
When do the U2 bearing lift pumps auto start?
Turbine Trip
Where in the Lube Oil Flowstream does the DC Emergency Lube Oil Pump discharge?
After the Lube Oil Coolers (bypasses them)
What effect will long term operation on the DC Emergency Lube Oil pump have?
Higher LO temps
The Unit 2 High Pressure Turbine inner steam seal is supplied with Main Steam which normally is controlled ____ psi greater than turbine exhaust pressure.
10#
How do we prevent the MT from tripping on a Rx trip?
Knife switches are opened to allow turbine to stay on grid when Rx is tripped (prevents turbine overspeed)
How do you adjust the Gland Steam Condenser vacuum?
Adjust the blower suction inlet orifice plate (sliding damper) position
