TC- Turbine Cooling Water Flashcards
What is the capacity of each TC pump?
100%
Where are the TC pumps located?
100’ Turbine Building North East end
Where can the pumps be started from?
Normally from Control Room
Can be started locally at the breaker
What is normal TC system header pressure?
105 Psig
What happens if header pressure drops to 55 psig?
Standby pump will auto start
What is TC maximum allowed temperature? What is the Hi-alarm setpoint?
105F
120F
What are the TC pump power supplies?
‘A’ – NBN-S01
‘B’ – NBN-S02
What is the capacity of the TC heat exchangers?
100% each
What is the heat sink for TC?
PW system
Where are the TC HXs located?
The north yard just north of the Turbine building
What is the purpose of the TC Surge Tank?
Accommodates changes in system volume due to temperature changes
Provides NPSH for the TC pumps
Provides means of detecting leakage into or out of the TC system
Where is the Surge Tank located? What is its capacity?
140’ Turbine Building above the TC pumps
500 gallons
Why is Nitrogen used in the Surge Tank? What is the nitrogen pressure kept at? How else is the surge tank protected?
To prevent oxygen intrusion that could lead to corrosion
~25psi
over and under pressure protection
local level and pressure indication
What system provides makeup water to the TC surge tank? What is the maintained level band?
Demineralized Water
45-51”
Where is the TC Chem Add Tank located? What is the capacity?
100’ turbine building just north of the pumps
11 gallons
During normal operations, how far open is the PW outlet valve for the TC HXs?
33%
Why are the vent valves on top of the hydrogen coolers cracked open during normal ops?
To keep air out of the system high point
Is the turbine cooling system safety related equipment?
no
How does the turbine cooling water surge tank maintain level?
provided with a level control that signals a demin water make up line control valve to actuate open or closed
What system powers the TC pumps?
NB
How does the TC system interface with NH?
powers TC pump motor space heaters
How does TC interface with CW?
cools the CW pump lube oil coolers
Where are the TC system drains routed to?
OW system via turbine building drains
What type of seals do the TC pumps have?
mechanical seals
What is the discharge capacity of the TC pumps? Where are they located?
17,500 gpm
100’ turbine building north east side
What type of heat exchangers are the TC HXs? Is TC in the tubes or shell side?
single-pass, counter-flow, shell and tube type
shell side
Each TC HX has a relief valve for both the shell and tube side of the HXs. Where is the discharge routed to if there was over-pressurization?
the ground
What is the required status of the TC HX outlet valve and TCHX bypass valve during operation?
one is required to be full open at all times to ensure good system flow
What is the normal operating temp. for the TC system?
~90-95*F
What is the most restrictive HX in the TC system?
main turbine lube oil cooler
What does keeping TC temp. < 85F ensure?
temp. oscillations in support system does not occur
How are temperature adjustments made in the TC system?
manually at the direction of the control room by adjusting TCHX outlet valve or bypass valve
(when approaching upper limit in the summer, adjustment to the PW outlet valve can be made)
When will the TC surge tank pressure relief valve open? When will the safety valve open? Under pressure relief valve?
30 psi
100 psi
2” HG or .98 psi
What is the impact of the plant if TC system is lost?
if TC can not be restored, plant must trip
What are the loads cooled by the TC system?
CW pump motor lube oil coolers generator hydrogen coolers stator coolers CD pump lube oil coolers isophase bus duct cooling gland steam packing exhauster main turbine lube oil coolers (2) main feed pump turbine lube oil coolers (2) control oil coolers (2) heater drain pump lube oil coolers (2) Instrument (3) and service air compressors secondary sample coolers (4)
If there was a tube leak in the TCHX, what system would leak into the other due to higher pressure?
PW would leak to TC because the HX is the point in the system where PW is higher pressure than TC
