Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Systems > Circ Water > Flashcards

Circ Water Flashcards

1
Q

What do the CW Canal & Intake Structure provide ?

A

Provides suction for the CW pumps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What’re the Trash Screens used for ?

A

Used to protect CW pumps from debris that has fallen into Canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Other than the trash screens slot, what is the other slot used for ? What’re stop gates used for ?

A

Other slot is used for stop gate when maintnence needs to work on CW pump while system is operating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How can you tell a trash screen needs to be cleaned ?

A

The DP across screen causes a big level difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When cleaning a trash screen what needs to be placed temporarily, while the dirty screen is being cleaned ?

A

There has to be a clean screen placed BEFORE removing dirty screen so CW pump is always protected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What water is used to spray & clean the trash screens ? Where does the water drain ?

A

-Discharge of the PW pump is used to clean the screens
-Drains to Screen Wash Sump & water is returned to intake structure by Screen Wash Sump Pumps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where are the Turbine Building roof drains routed to ?

A

-Routed directly to the CW intake canals, this assist n prevention of ADEQ Aquifer protection permit violations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the CW canal level automatically maintained at ? How is it controlled ?

A

It’s automatically maintained at 23’ by one of two level control valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the design makeup rate to the canal ?

A

19600gpm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the rejection rate of the CW Pumps determined by ?

A

-Based on valves-wide-open(VWO) steam flow
-Condenser back pressure less than 3.6HgA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What’re the parameters of the CW pumps ?

A

-25% capacity
-140000gpm pumps
-13.8kv

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What cooling water cools CW Pump Lube Oil Coolers ? What is the flow rate ?

A

Turbine Cooling Water is sent at 12.5gpm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the low flow rate alarm for turbine cooling water associated with the CW pump lube oil cooler ?

A

Low flow alarm at 9gpm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the normal discharge pressure of all four CW pumps ?

A

Normally discharging at 45psig

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where is CW pump operated from ?

A

Control switch provided in control room for each CW pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What condition does CW Pump need to start ?

A

-Discharge valve fully closed
-Either same flow train condenser outlet valve is open
OR
-Condenser outlet valve interlock override Pushbutton depressed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does a CW pump start signal also sends an opening/permissive signal to?

A

-Open signal to discharge valve
Permissive signals to:
-CI system acid injection pump
-CI system chlorine injection valve
-same flow train CW pump discharge valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens when CW Handswitch is placed in STOP-CLOSE position ?

A

-Close signal is sent to discharge valve
-Once Discharge is less than 8% open, pump breaker will open stopping pump
-signal also sent to CW Supply header cross tie valve & other CW pump discharge valve control logic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens when CW Pump discharge valve closes less than 8% open ?

A

Pumps breaker will open stopping the pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens when CW Emergency trip Pushbutton is used ?

A

-Pumps breaker will immediately open stopping pump
-Signal also sent to CW Supply Header Crosstie valve & other CW Pump discharge valve control logics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does main condenser receive ?

A

Received low energy turbine exhaust steam & condenses for reuse in secondary cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why’re Tube Lengths in B & C condenser sections greater?

A

Higher Circ. Water inlet temperatures are present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where are the butterfly MOV for Circ Water Loop Condenser outlet/inlet valves at?

A

At the inlet of the first condenser section & outlet of the third section condenser isolation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why are MOVs used for CW system ?

A

-Allows remote operation
-Prevents operator fatigue
-Aids in normal & emergency operation
-Provides opportunity protective interlocks & relays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the design time for MOVs to open/close ?

A

Closes the valves in 30 seconds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How is each discharge valve interlocked with its respective pump ?

A

-One pump operating in its train has discharge valve open to 44%
-Supply Header Crosstie Valve is closed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Why does each discharge valve motor control circuit have a 3 minute timer? When is activated ?

A

-Controls automatic opening of discharge valve
-Timer is activated once pump is started

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What must happen to valve before its opened beyond 44% ?

A

The 3 minute timer for the MOV must time out before valve can open beyond 44%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Why is 44% position maintained indefinitely when only one CW pump is operating in associated loop?

A

Opened 44% to prevent pump runout

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What happens to discharge valve of second pump when it’s started in same loop where there is already a pump operating with discharge valve at 44%? What happens after second MOV 3 minute timer times out ?

A

-Second pump discharge will open to 44%
-After 3 minutes time the seconds discharge valve will open 100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

After second pump discharge valve opens to 100%, What will happen to the first pump discharge valve in the associated loop ?

A

The first pumps discharge valves will go 100% open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What happens if only one pump is started in SEPARATE loops ?

A

Each pump discharge valve in their separate loops will be opened to 44% & stay there UNTIL a second pump is started in the same loop

33
Q

What is the OPEN/CLOSE times for the Condenser Inlet Valves MOVs ?

A

60 seconds is MOV designed open/close times

34
Q

What’re the interlocks associated with the Condenser Inlet/Outlet Valves ?

A

-Outlet valves won’t open if “water box full” permissive is satisfied, once water boxes are full valve will open
-Inlet valves have NO interlocks; opened/closed based on switch

35
Q

If CW Loops cross-tie valve hand switch is in “auto”, it’s interlocked to go closed when ?

A

Both pumps in one loop are stopped the cross-tie valve will go closed if in AUTO

36
Q

When will CW Loop Cross-Tie Valve be in operation ?

A

Only one CW Pump aligned to both AB & CD loops should not exceed 48hrs

37
Q

Where are the automatic vent & vacuum breaker valves located on the CW system ?

A

-Located at high points on inlet & outlet water boxes of each shell of main condenser
-supply header crosstie line both side of Circ Water Loops cross-tie valve
-Each CW pump discharge

38
Q

What’re the CW Auto Vent Valves used for during normal operation ?

A

-Automatically releases any air that collects in system, while maintaining water in system

39
Q

What’re CW Auto Vent Valves used for during abnormal or infrequent operations, such as, system shutdown & drain or Trip of the CW Pumps ?

A

If pumps trip the system will drain to canal, the vent valves will open to allow air into system to prevent a vacuum inside water box or piping of system

40
Q

How do the Auto Vent Valves work ?

A

-A float chamber is used to open or close valve
-When there’s no water in system float chamber is down allowing air in
-When there’s water in system it’ll make float rise and seat
-Pressure from pump operation helps keep the float seated

41
Q

What must be done to the Auto Vent Valves during fill & vent of the CW system ?

A

-Auto Vent Valves will be isolated due to insufficient pressure to seat the valves
-Isolating Prevents water from flooding turbine building

42
Q

During Filling & Venting of CW system what is used when the Auto Vent valves are isolated ?

A

Manual vents are provided on same line to allow filling & venting

43
Q

When during filling & venting when are the Auto Vent Valves placed back in service ?

A

-Placed in service when enough CW pumps are running to seat the valve

44
Q

What modification for the vent line is used to prevent down powering ?

A

Install Isolation valves in each line to allow isolation for repair in case of leak

45
Q

Which vent lines don’t have isolation valves installed ?

A

1C & 2C outlet vents have relief valves installed, instead of isolation valves

46
Q

What’re the position of all the added Isolation Valves supposed to be in ?

A

They’re all in a “LOCKED OPEN” position

47
Q

What do you need to close the Vent Line Isolation Valves ?

A

You need to have fall prevention equipment

48
Q

What do the cooling towers provide ?

A

They provide medium heat removal from Circ. Water

49
Q

What’re the major sections of the Cooling Towers ?

A

-Water supply riser
-Circumferential distribution flume
-Distribution basin
-Fill ring
-Collection basin
-Fan deck & support columns

50
Q

What does the concrete riser do for cooling towers ?

A

Supplies water from CW return pipe to the top of each cooling tower into the Circumferential Distribution Flume

51
Q

How is each cooling tower isolated ? What can cooling tower #2 do still if CW has been isolated from it ?

A

-Isolated by manually operated valve
-Cooling Tower #2 has PW return line that’s used, when CW isolation valve is closed

52
Q

What does the Circumferential Distribution Flume do ?

A

-It radially distributes water down to the distribution basin

53
Q

What is used to control flow from the Circumferential Distribution Flume down to the Distribution Basin ?

A

There are adjustable weirs at top of flume outboard wall control flow to distribution basin

54
Q

How does the distribution basin work ?

A

-Has precast panels with small holes in the floor
-Each hole had flow orifice for proper flow & help diffuse uniformly over fill ring

55
Q

What does the Fill Ring do for the cooling towers ?

A

-Helps water be broken down over extremely large surface area into individual droplets

56
Q

What do the cooling fans provide for the cooling towers ?

A

-It allows turbulent mixing of air & water for optimum heat transfer

57
Q

What causes the rapid evaporation of water from the cooling towers ?

A

It’s the combination of broke down droplets and mixed by airflow that causes the rapid evaporation

58
Q

How does the water in the collection basin get cool ?

A

It’s cooled by energy being removed by evaporation and dropping into collection basin

59
Q

What does the collection basin do for the cooling tower ? What can be put in at the exit of the cooling tower for isolation ?

A

-It collects the cooled water and reuses it
-Basin floor is pitched for proper drainage
-Can place a stop gate at the exit of cooling tower

60
Q

What’s the purpose for the Cooling Tower Fans ?

A

Provide forced draft air flow needed for efficient evaporative cooling

61
Q

What is each fan driven by? What is the fans motor powered by ?

A

-Driven by a 200hp motor through gear reducer & drive train
-Powered from 480VAC Load Center

62
Q

How do the fans receive there start/ stop signal for Control Room switches ?

A

Fiber optic Plant Multiplex system

63
Q

What does each fan have for vibration?

A

Has a high vibration switch to trip fan during operation

64
Q

If fans trips on high vibration what happens when trying to start again ?

A

Start signals sends a reset signal to High Vibration trip coil

65
Q

When starting fan how long is High Vibration trip coil overridden ?

A

Overridden for 30 seconds so it doesn’t trip on start up

66
Q

What’re indications for a fan tripping on high vibration ?

A

Blue light on LoadCenter, computer input, & annunciator in control room

67
Q

Can the fans be started locally if PMUX system isn’t working ?

A

Yes it can be started locally

68
Q

Why’re fans started/stopped in specified order ?

A

Equalizes loading of fans & cooling tower structure & to match heat transfer requirements

69
Q

Why would cooling tower fans be shutdown during winter months ?

A

Maintains condenser vacuum, to low of a vacuum will cause increased tube corrosion due to high steam velocities

70
Q

Where does the Screen Wash Sump collect its water from ?

A

-Trash Screen cleaning
-CW Pump seal leakage
-Overflow from CW Pump Bays

71
Q

Where do the two sump pumps transfer the collected water to?

A

Transfer collected water to CW Canal

72
Q

How do the two float-type level control switch operate for the CW screen wash sump?

A

-Lead pumps starts on HI level
-Standby pump starts on HI-HI Lvl
-Both pumps stop on LO-LO Lvl

73
Q

What is the alternator used for on the Screen Wash Sump Pumps ?

A

It’s used to change lead pump each cycle to equalize wear on the pumps

74
Q

What is the flow orifice installed at discharge of sump pump ?

A

Used to balance flow to control sump runout during one or two pump operation

75
Q

What level in the CW Canal do the CW pumps start to lose suction ?

A

Will start to lose suction at approx. 19’

76
Q

What will happen on complete loss of CW system ? How will decay heat be rejected ?

A

-Results in immediate plant shutdown due to high condenser pressure
-Decay Heat will be rejected to atmosphere by steam bypass valves 1007 & 1008

77
Q

What will happen to plant operation during a partial loss of CW system ?

A

Plant will have to be down powered depending on severity of the loss of Vacuum

78
Q

Since we don’t have DP alarms on the CW Trash Screens how do we when to clean them to prevent downpowering?

A

Rely on AOs routine checks for screen level delta

Systems (62 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions