Main turbine and reheaters Flashcards
HP turbine spins at ______ RPM, double axial flow, _____ stages in each direction. First stage is ____ blading and remaining stages _____.
1800 RPM
8 stages U1, 7 stages U2
Impulse; reaction
Fourth stage extraction steam and drains are used _______ and _____.
in #_7A and B FW heaters.
as reheat steam in the first stage of the MSR.
Sixth stage extraction steam and drains are routed to_____.
_6A and B FW heaters.
Eighth stage extraction steam and drains are used in ____.
_5A and B FW heaters
LP turbine spins at ______ rpm and the steam flowpath is ______ . How many stages and what type?
1800 rpm
Double axial flow ‑ steam enters in center and flows outward through 10 reaction stages.
Intercept valves (closest to LP turbine) limits steam flow from MSR to LP turbine on a load rejection to prevent _______.
Reheat Stop valves provides added safety to prevent overspeed of turbine if turbine trips and ______.
Turbine overspeed.
intercept valves fail.
Second stage extraction steam and drains from LP turbine are routed to _______.
FW heaters #_4A,B,C.
Fourth stages LP turbines _______.
‑ FW heaters #_3A,B,C.
Sixth stages LP turbines_____.
‑ FW heaters #_2A,B,C.
Eighth and ninth stages LP turbines _________
‑ FW heaters #_1A,B,C
Where do _PT-505 and 506 tap off?
Between 1st and 2nd stages
Purpose of MSRs
Purpose – dry and superheat the HP turbine exhaust prior to use by the LP turbines in order to increase cycle efficiency and protect the low-pressure turbine blading from erosion.
1st and 2nd stage reheat steam have startup drains. Drainage from these lines routed to condenser via crossover drains (_ES034A/B, _ES061A/B/C/D). What signals operate these valves?
Auto open on Turbine trip
Auto close at 27.3 psig crossover pressure
Cold start in AUTO sequence:
Controller opens leakoff valves (_MS114’s)
Controller opens purge valves (_MS067’s) at 10% load.
Opens shutoff valves (_MS009’s) and closes leak off valves (_MS114’s) at 35% load.
Verifies shutoff valves (_MS009’s) open, then begins to increase inlet steam temp at 100F/HR by opening _MS147’s first, then _MS010’s.
_____ is design limit for turbine materials analysis.
550F
Reheat temperature ramps shall be limited to less than______
100F/hr
LP Turbine Inlet Steam Temperature shall not exceed_____differential between turbines
50F
Total loss of power to MSR controller will cause a loss of control system for AUTO and MANUAL control and the _________ will close.
MSR RTC valves will close
High temp steam light will be lit when ____ and automatic action is _____.
Lit if LP inlet steam temp. > 550°F.
Reheat steam control valves (_MS010’s, _MS147’s) ramp back to lower LP inlet temp.
Low load operate light maintains _____F when load is _____ for 5 minutes.
<425F
<10%
Loss of a tube bundle requires it’s counterpart from _____ to be removed from service.
the other MSR
Normally _____ pairs of thermocouples used for RTC with ____ as a backup.
Will shift _____ if backup lost.
A and C
B
manual
Failure of any TC lights the ______.
TC fail light.
MS010/147 Won’t open unless _______.
MS009 shutoff valves are open
MS147A-D and _MS010A-D and some miscellaneous drain valves__________.
fail open on loss of IA
Proper temperature control of MSR is required to prevent: (3 items)
Thermally induced damage
Excessive vibration
Excessive differential expansion
What is the difference between hot reheat header A and B supplies?
Hot reheat header A supplies the steam to drive the turbine driven main feed pumps.
Normally, the MSR drains go to _____, 1st stage reheater drains go to _____ and 2nd stage reheater drains go to_______.
HDT
1st stage=5a/b heaters
2nd stage=7a/b heaters
