TSS Flashcards
Describe steam flow path from the Stop valves to the condenser
Stop Valves Control Valves HP Turbine MSR CIVs LP Turbine Condenser
State how and why the #2 stop valve is different
Has an integral bypass valve
Allows for Chest and Shell warming
Also allows D/P equalization across all stop valves to facilitate opening
Discuss exhaust hood spray
Fed from condensate
Used to cool LP turbine exhaust hood during low loads to prevent over heating
140-200
Turbine trip at 225 in 1/3 hoods
List turning gear engagement permissives
Generator Breaker Open Lift Pumps in Operation Hi Bearing Oil Pressure >15 psig Both MCB and Local switches in Auto/Start Low speed signal present (1.5 RPM)
Discuss Turning Gear engagement sequence
Piggyback motor starts for 10 seconds engaging the clash pinion then deenergizes
Low speed windings engages for 5 seconds then deenergizes
High speed winding energizes
List Parameteres monitored by Turbine Supervisory instrumentation
Turbine Rotor Eccentricity Turbine Generator Speed Control valve position Main Turbine Bearings Feed Pump Bearings Feed Pump eccentricity Turbine Shell Expansion Turbine Rotor expansion Exhaust hood temp Cross-around pipe temperature First-stage shell temperature Valve chest inner and outer Temperature
State purpose of the Low speed Switch
Auto engages the turbine rotor turning gear when shaft speed reaches 1.5 RPM
Why are induced voltages undesirable in the turbine-generator rotor
Induced voltages can cause pitting in the journal bearings
Discuss how MSRs control reheat steam in Auto Modulate
The Turbine Control Valve Position /reheat tube pressure comparison signal provides the
main positioning signal for the MSR reheat control valves to maintain tube pressure based
on the program band.
5F to 30F
Discuss how MSRs control reheat steam in Auto Follow
In this mode the MSR Δ T signal is the controlling signal and positions the MSR reheat control
valves based on MSR Δ T. Reheat control valves will reposition until Delta-T is 0F.
