Unit 2 Station Operator

Front 1

Describe the starting, stopping and trip logic for the CW Pumps.

Back 1

Start - Discharge closed, start pump, discharge valve opens and signal position to CCW Valve CRV2-61.
Stopping - Give pump a stop signal, discharge valve starts closed and at 70% pump stops.
Trip - Three phase overcurrent relay, out of step relay and ground fault relay.
Also - 2C CWP will autostart after unit trip.

Hint 1

Start - 4 items
Stop - 3 items

Front 2

Explain in detail the purpose of the Condenser Air Removal System.

Back 2

Remove noncondensables from the condenser. This is achieved in the air removal section which is designed to trap non condensables for removal by the condenser exhausters.

Hint 2

Noncondense?
how?

Front 3

Describe the Aux. Cooling Water System listing the major components and the equipment it serves.

Back 3

Aux Cooling Water gets its suction from CW inlet @ condenser. We have two Aux CW Pumps that supplies the turbine oil coolers, hydrogen coolers, & stator water coolers.

Hint 3

3 sets of coolers

Front 4

Describe the Aux Boiler and Aux Steam system.

Back 4

Aux boiler supplies steam to the aux steam system which can be used for sealing steam for #1 or #2 and for prewarming #2 Turbine.

Front 5

When a circulating water pump is shutdown, the discharge valve closes what percent before the pump shuts down?

Back 5

70%

Front 6

On a unit trip, a CWP will restart automatically?

Back 6

True

Front 7

What must be done if cooling water flow through the condenser can not be established after a unit trip? How long to establish flow?

Back 7

Bottle up boiler to stop any steam flow to the condenser. Break Vacuum when below 2500rpm. After 16 hours condenser will have to be cleaned within 48 hours.

Hint 7

Stop
Break
Clean

Front 8

How many circulating water pumps can be run with the cooling tower by pass open?

Back 8

One

Front 9

Why is it important that the CW system be filled before starting a CWP?

Back 9

to prevent air from damaging CW pipe and condenser tubes or the expansion joints.

Front 10

Why is cooling tower icing a problem? What can be done to correct it?

Back 10

Stress on structure, unbalance of blades, gear box stress.
Rotate running fans frequently, fewer fans running, check cooling tower more often, and last resort, run fans in reverse.

Front 11

With the CW system drained, how is heat removed from the Aux Cooling water system?

Back 11

CRV2-61 diverts bearing water when all CWP's are off. We can also connect SW to the coolers via crow's feet.

Front 12

When does the alarm "Aux Cooling Water 2 Supply High Temp." come in?

Back 12

105 degrees

Front 13

Name the different uses for steam from the Aux Boiler.

Back 13

Sealing steam to #1 & #2 and to prewarm turbine

Front 14

What temperature and pressure does the Aux Boiler operate?

Back 14

195 psi. Temperature is not controlled.

Front 15

How is the Aux Boiler Maintained in Hot Stand by?

Back 15

The boiler will cycle off and on when placed in recycle mode to maintain 195psi.

Front 16

What controls the Aux Boiler Feedwater Regulating valve when in Automatic?

Back 16

There is only a feedwater block valve, the pumps are variable speed and they are controlled by drum level when in auto.

Front 17

During a cold start-up, when do you have the Aux Boiler Vents Closed? Why?

Back 17

30psi. They are open to remove non condensables and impurities. by 30psi, this should be accomplished.

Front 18

In the Aux Boiler, an igniter is used to light the main burner. What lights the igniter?

Back 18

Spark from electronic ignition plug.

Front 19

In order to satisfly the interlocks on the Aux Boiler FD fan, the inlet damper must be closed?

Back 19

True

Front 20

What will cause the Aux Boiler feed pump to start while in stand-by?

Back 20

FW pressure drops to 200psi or suction pressure greater than 10psi.

Front 21

Before lighting the burner, the Aux Boiler must be purged at ____% air flow for ____minutes. Why?

Back 21

25% for 2 Minutes. Remove all combustibles before ignition.

Front 22

The Aux Boiler boiler master is controlled by _______ and ________ when in automatic.

Back 22

Feedwater and Pressure

Front 23

Name 6 things that will trip the Aux Boiler.

Back 23

Loss of Flame.
Loss of FD Fan.
Furnace Pressure.
Low Drum Level (-5).
Low Gas Pressure.
Combustibles - Manual Trip.

Front 24

How do you swap air compressors?

Back 24

Using the lead/lag feature for now. We are installing a system that will change this.

Front 25

At what point will you get a "Low Air Pressure" alarm? Is this a problem?

Back 25

95psi. Yes it is, have ASO/EO start SSR, and TP compressor if needed. Check the compressor that is in Lead for problems, did compressor in Lag start? Look for leaks starting with 1A and 1B puffers.

Front 26

Where does the Closed Cooling Water system get its water supply from? As a station operator, is this important to you?

Back 26

Condensate system is normal source of makeup. Condensate system must be in service to provide automatic makeup.

Front 27

What equipment does the Closed Cooling Water system (Bearing Water) serve?

Back 27

Air Compressors, EHC coolers, SUBFP Lube oil coolers, Condenser Exhauster Coolers, Excitation Cubicle, Sample Coolers, FD Fan Coolers, Bus Duct cooling, BFP oil coolers, and BBFP Oil Coolers.

Front 28

How is the speed of the condensate pumps varied?

Back 28

Limiting motor current while changing voltage and frequency.
VFD Units.

Front 29

Describe in detail the Condensate system listing the major components and the procedure for placing the condensate system in service.

Back 29

The condensate flows from the condenser hotwell to the condensate pumps through the condensate polisher, gland steam condenser, drain cooler, LP heaters and on to the deaerator.
Line up condensate normal & emergency makeup.
Cond. Pump Start Permissives.
Polisher bypass open.
Cond. Pump in manual, establish minimum flow through gland condenser, set to 350psi.
2 polishers in service.
DC Heater level control CRV2-46 min. 20%

Front 30

What will open condensate polisher bypass valve

Back 30

Temp. greater than 140.
Diff press 90psi.
Manual.
Loss of A/C.

Front 31

The condensate recirc valve will open at _____ lb/hr and close at ______ lb/hr.

Back 31

Open 500,000 lb/hr
Close 300,000 lb/hr

Front 32

Explain condensate pressure control and flow control.

Back 32

Pressure - CRV2-46 controls 350psi during startup while FW flow is below 1.0 mlbs/hr.
Flow - COV2-12 opens once over 1.0 mlbs/hr flow and CRV2-46 closes to 20%. FW Flow, Cond Flow, DC Level then controls Cond Flow.

Front 33

What two things will cause the DC Heater Dump valve to open and dump back to the condenser?

Back 33

4" above normal level & Manual operation.

Front 34

Will the HP and LP stop valve on the MBFP close if low deaerator level?

Back 34

Yes. 3'6" below normal

Front 35

List start permissives for the condensate pumps.

Back 35

Suction Open - Hotwell not low - Coupling speed at minimum - Recirc open.

Hint 35

4 of them

Front 36

High seal water temperature of _____ will trip the condensate exhauster.

Back 36

125°

Front 37

A vacuum of _____ inches of merc. will start the stand by exhauster.

Back 37

26

Front 38

What is the purpose of extraction check valves?

Back 38

Prevent the stored energy in the extraction line after a trip from overspeeding Turbine.

Front 39

The condensate pump must be running in order to start an injection water pump. True or False?

Back 39

True - suction comes from the condensate system.