TRAVIS CANNING
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power engineering 3b2 Quiz on power prep Steam turbine Auxiliaries and Operation quiz, created by TRAVIS CANNING on 27/02/2016.

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TRAVIS CANNING
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power prep Steam turbine Auxiliaries and Operation quiz

power prep Steam turbine Auxiliaries and Operation quiz

Question 1 of 33

1

In a large steam turbine lubricating oil system the function of the oil is to lubricate and ___________ the bearings.

Select one of the following:

  • keep dirt out of

  • polish

  • cool

  • keep moisture away from

  • support

Explanation

Question 2 of 33

1

what type of instrumentation ins installed on the discharge side of an oil lubricated bearing

Select one of the following:

  • oil filter

  • moisture separator

  • dewpoint monitor

  • flow measuring device

  • thermometer

Explanation

Question 3 of 33

1

When a turbine is left cold and at a standstill, the weight of the rotor will tend to cause the rotor to sag slightly, this is also referred to as

Select one of the following:

  • bowing

  • hogging

  • sagging

  • warping

  • bending

Explanation

Question 4 of 33

1

when a hot turbine rotor has cooled at a standstill, the lower half will cool faster than the upper half. This may cause the rotor to bend upwards which may also be referred to as:

Select one of the following:

  • bowing

  • hogging

  • sagging

  • warping

  • bending

Explanation

Question 5 of 33

1

when a steam turbine is shut down it should be put on barring gear for a minimum of:

Select one of the following:

  • 3 hours

  • 24 hours

  • 72 hours

  • as determined by the plant manager

  • barring should never be shut off

Explanation

Question 6 of 33

1

Barring gear shaft rotation is typically:

Select one of the following:

  • 1-3 rpm

  • 5-10 rpm

  • 20-40 rpm

  • 60 rpm

  • 3600 rpm

Explanation

Question 7 of 33

1

while large steam turbine is on barring gear what other system should be placed in service

Select one of the following:

  • lube oil coolers

  • lube oil filtering

  • hydrogen sealing

  • stator water

  • jacking oil

Explanation

Question 8 of 33

1

which of the following is not a type of steam turbine governing:

Select one of the following:

  • Nozzle

  • Throttle

  • Overload

  • Bypass

  • Impulse

Explanation

Question 9 of 33

1

Nozzle governing is utilized on __________ turbines

Select one of the following:

  • impulse

  • reaction

  • condensing

  • extraction

  • impulse or reaction turbines

Explanation

Question 10 of 33

1

Nozzle governing

Select one of the following:

  • opens a nozzle from 0 % to 100 % as the load is increased on a turbine

  • opens a series of nozzles in succession as the load is increased

  • utilizes flyball weights to control a steam valve

  • is used on the later stages of an impulse turbine to control speed

  • none of the above

Explanation

Question 11 of 33

1

Impulse steam turbine speed can be controlled by throttling the steam supply through a control valve and:

Select one of the following:

  • varying the firing rate on the boiler

  • increasing the load on the generator

  • increasing the superheat to the steam

  • opening or closing a series of nozzles

  • bypassing the low pressure turbine through extraction

Explanation

Question 12 of 33

1

Bypass governing allows

Select one of the following:

  • an increase in load but a decreased efficiency

  • an increase in load with a increase in efficiency

  • a decrease in load with a decrease in efficiency

  • a decrease in load with an increase in efficiency

  • increase load with no change in efficiency

Explanation

Question 13 of 33

1

The difference between the no-load and full-load speed, expressed as a percentage of the set speed, is called the ______ of the governor. As the load increases, the speed will ________ below the set speed.

Select one of the following:

  • lag

  • droop

  • variance

  • offset

  • drag

Explanation

Question 14 of 33

1

In a simple flyweight governor:

Select one of the following:

  • speed is controlled by varying the number of weights in the governor

  • speed is controlled by restricting the inward movement

  • the weights move inward with an increase in speed

  • increasing spring tension increases the controlled spring

  • all of the above

Explanation

Question 15 of 33

1

When a steam turbine exceeds its speed setpoint

Select one of the following:

  • boiler pressure is reduced to limit the steam speed

  • the flyball weights will move outward which will in turn operate an oil relay which will close off the steam valve

  • the turbine will likely catastrophically fail

  • the barring gear will engage and act as a clutch to reduce the speed

  • a braking system is employed until within limits

Explanation

Question 16 of 33

1

Turbine lubricating oil

Select one of the following:

  • Is not required for small impulse turbines

  • must be changed every four months

  • lubricates the blades

  • can be used to operate the turbine governor

  • should be preheated before use

Explanation

Question 17 of 33

1

The turbine overspeed trip:
1. prevents the turbine from vibrating
2. prevents the turbine exceeding the maximum rated speed
3. is operated by a spring loaded pin in the rotating blades
4. will close the steam stop valve
5. should be tested before the turbine is placed in service

Select one of the following:

  • 2,4,5

  • 2,3,4,5

  • 1,2,4

  • 3,4,5

  • 4,5

Explanation

Question 18 of 33

1

The overspeed trip of a steam turbine

Select one of the following:

  • operates on turbine vibrations due to high speed

  • is installed on all turbines

  • can be adjusted according to the load demand

  • is regulated by exhaust pressure

  • sheds the load in the event of high pressure

Explanation

Question 19 of 33

1

Turbine overspeed trip

Select one of the following:

  • prevents the turbine from vibrating

  • will close the steam stop valve to the turbine

  • is operated by a spring loaded pin in the rotating blades

  • supplies the operator with rpm indications

  • reduces the turbine speed by increasing the back pressure

Explanation

Question 20 of 33

1

The great majority of steam turbine governing systems utilize

Select one of the following:

  • hydraulic system principle

  • pneumatic system principle

  • mechanical centrifugal principle

  • lever principle

  • bimetal expansion principle

Explanation

Question 21 of 33

1

when starting a steam turbine it is customary practice to:

Select one of the following:

  • analyze the oil for water prior to rolling

  • turn on all cooling water systems first

  • place the speed control system in service once the unit is rolling

  • test the overspeed trip as soon as running speed is attained

  • stop the auxiliary oil pump as soon as steam begins to turn the unit

Explanation

Question 22 of 33

1

which of the following mechanisms would not be sued on an emergency overspeed trip device?

Select one of the following:

  • pneumatic

  • electrical

  • hydraulic

  • mechanical

  • any of the above may be used

Explanation

Question 23 of 33

1

when starting up a cold steam turbine, what position should the main steam valve intitially be opened to?

Select one of the following:

  • 10 % or less

  • 25 %

  • 50 %

  • 75 %

  • 100 %

Explanation

Question 24 of 33

1

when is the barring gear engaged on a large turbine during a shutdown

Select one of the following:

  • when the main steam stop valve is closed

  • at 50 % operating speed

  • when the turbine is rotating at 3rpm or less

  • upon opening the generator breaker

  • when the turbine has come to a complete stop

Explanation

Question 25 of 33

1

On shutting down a large steam turbine what is one of the first steps that an operator should do once the main steam valve is closed?

Select one of the following:

  • shut off the boiler feed pump

  • drain the boiler

  • open the turbine drains

  • put your feet up and have an extended coffee break

  • hang the boiler lock-out tags

Explanation

Question 26 of 33

1

During the operation of a large steam turbine:

Select one of the following:

  • the main auxiliary oil pump supplies oil to the journal bearings

  • the main auxiliary oil pump is driven by the turbine shaft

  • if the main oil pump fails the jacking oil pump may take over

  • the emergency overspeed trip receives the same oil pressure as the journal bearings

  • only answers A) and B) from above

Explanation

Question 27 of 33

1

When a turbine hydraulic overspeed trip is activated
1. a spring closes the main steam valve
2. oil pressure quickly closes the main steam valve
3. the oil pilot drain closes
4. oil pressure to the valve is shut off
5. the stop valve oil cylinder drain is opened

Select one of the following:

  • 1,2,3,4,5

  • 1,4,5

  • 2,4

  • 1,3,5

  • none of the above

Explanation

Question 28 of 33

1

Which of the following parameters are monitored and recorded during the operation on a steam turbine.
1. main steam pressure
2. main steam temperature
3. oil pressure and temperature
4. condenser vacuum
5. hotwell pressure and temperature

Select one of the following:

  • 1,2,3,4

  • 2,3,4,5

  • 1,3,4,5

  • 1,2,4,5

  • all of the above

Explanation

Question 29 of 33

1

The internal spring loaded tripping bold has a center of gravity:

Select one of the following:

  • at midpoint

  • towards the head end of the bold

  • towards the nut end of the bolt

  • concentric

  • perpendicular with the shaft

Explanation

Question 30 of 33

1

The overspeed trip on a steam turbine is typically set to operate at ______________ % overspeed

Select one of the following:

  • 5%

  • 10%

  • 20%

  • 25%

  • 50%

Explanation

Question 31 of 33

1

The purpose of a condenser is to:

Select one of the following:

  • extract heat from the condensate to be returned back to the cooling pond

  • subcool the condensate below the saturation temperature

  • convert the steam to water after the steam has expanded through the turbine

  • remove the non-condensables from the steam

  • improve the boiler overall efficiency

Explanation

Question 32 of 33

1

The addition of a condenser to a steam turbine vs a turbine exhausting to atmosphere may increase the overall efficiency of the turbine by:

Select one of the following:

  • 10%

  • 25%

  • 50%

  • 75%

  • 100%

Explanation

Question 33 of 33

1

A surface condenser: (pick the incorrect answer)

Select one of the following:

  • acts as a dearator

  • converts steam to condensate

  • helps maintain vacuum at the turbine exhaust

  • cools the condensate below the saturation temperature

  • may be cylindrical, oval or rectangular in shape

Explanation

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