Turbine, governors and heat exchanger test

Question 1

when working around steam turbines, you must be aware of steam leaks because they

are invisible

can burn you

are dangerous

all the above

Answer 1

All of the above

Question 2

turbines are equipped with an emergency trip mechanism in the event of a/an

under speed

over speed

overlaod

shut down

Answer 2

Over speed

Question 3

Newtons’ 3rd law states the for every action there is a/an

equal and same reaction

an equal and opposite reaction

change in volume

pressure drop when there is a speed drop

Answer 3

An equal and opposite reaction

Question 4

impulse blades harness the steam energy by

change in pressure

change in direction

change in volume

all the above

Answer 4

Change in Direction

Question 5

when you have no pressure drop across the impulse blading (because of their symmetrical design), there will be no need for sealing on either side of the rotating blades

true

False

Answer 5

True

Question 6

reaction blades

are the same distance apart all the way thru the blading

create a pressure drop

cause the steam to accelerate

both the 2nd and 3rd answers are correct

Answer 6

Both second and third answers are correct

Question 7

reaction turbines may have a velocity compounded impulse section at the inlet of the turbine to help make the turbine machine shorter and eliminate the need for sealing at the high pressure end

true

false

Answer 7

True

Question 8

extraction turbines remove steam from the casing which is used for another plant process

true

false

Answer 8

True

Question 9

condensing turbines use a condenser to increase the turbines efficiency by creating a high pressure back pressure at the outlet of the turbine

true

False

Answer 9

False

Reduces the backpressure

Question 10

many large turbines have bearings with spherical seats which allows the bearing to tilt according to the sag in the turbine shaft

true

False

Answer 10

True

Question 11

the thrust bearing is usually locate in the

steam outlet end

steam inlet end

before the inlet bearing

after the outlet bearing

Answer 11

Steam inlet end

Question 12

carbon seals are used on small turbines and their match marks are installed facing the pressure

true

False

Answer 12

True

Question 13

when thermal growth exceeds the capacity of the labyrinth seals you would use a

carbon seal

tilting pad seal

higher spring pressure

annulus seals

Answer 13

Annulus Seal

Question 14

moment weight is the weight of the blade

plus the radial distance to the center of gravity of each blade

times the shaft diameter of the rotor

times the radial distance to the center of gravity of each blade

the speed of the blade as it rotates around the axis of the housing

Answer 14

times the radial distance to the center of gravity of each blade

Question 15

coupling bolts are marked for each specific location due to

fit

balance

none of the above

both the 1st and 2nd answers are correct

Answer 15

Both first and third answers are correct

Question 16

speed control of turbines is usually controlled by governors under varying load conditions

true

False

Answer 16

True

Question 17

over-speed trips use centrifugal forces that overcome the spring tension and hit the over-speed trip mechanism. these trips must be manually reset

true

False

Answer 17

True

Question 18

the main stop valve shuts off the steam to the turbine

true

False

Answer 18

True

Question 19

the steam turbine chest has a witches hat that keeps particles from entering the turbine

true

False

Answer 19

True

Question 20

the steam supply to smaller impulse turbines should be free of moiture and super heated

true

False

Answer 20

True

Question 21

steam admission valves can be moved or lifted by a cam lift or bar lift that overcomes spring pressure to open

true

False

Answer 21

True

Question 22

thrust controls for a turbines axial movement can be

balance piston

dummy piston

dual flow rotors

all the above

Answer 22

All of the above

Question 23

a turning gear or barring gear is used on large turbines to rotate the turbine rotor(s) from 1 to 60 rpm. this slow turning allows the sag or bow in the rotor to be removed

true

False

Answer 23

True

Question 24

jacking oil is used to lift the shaft off of the bearing surfaces until the rotor gets up to __________rpm. then the main lubrication system will take over and the jacking oil shut off.

10-20

50-60

100-200

500-600

Answer 24

50-60 rpm

Question 25

debris buildup or deposits on turbine blades and nozzles can be removed by using walnut shells rice temperture changes after shutting down the turbine high pressure dry ice all the above

Answer 25

All of the above

Question 26

removal of flange nuts in most turbines is accomplished by using hydraulic stretch of the bolt heating the bolt internally torque mulitipliers all the above

Answer 26

All of the above

Question 27

when lifting of turbine covers, it is important to install the guide pins so the cover can be lifted off level and straight up, eliminating any potential for damage true false

Answer 27

True

Question 28

bearing height and position for turbines is adjusted in the pedastal by the addition or subtraction of shims under the bearing seat pads true Option 2

Answer 28

True

Question 29

the typical babbitted bearing clearance is about ______ per 1" of shaft diameter 0.001" 0.003" 0.005" 0.010"

Answer 29

.001"

Question 30

oil voscosity for bearings in a turbine is maintained by running them in oil between 0 and 120 degrees C true false

Answer 30

False

Question 31

when controlling thrust in a steam turbine, you usually only need 1 location for the thrust bearing so the rotor is free to expand in either direction from it true False

Answer 31

True

Question 32

for properly installed diaphragms, you would need to do which of the following use shims use crush pins the halves installed with a slight protrusion all the above

Answer 32

All if the above

Question 33

when using lead wire to check labyrinth seals clearance, you would use a blade micrometer because it can read into the profie left when squished true false

Answer 33

True

Question 34

before installing the blades on the rotor, you need to make sure to check the blades for correct location by checking the match marks or numbers true false

Answer 34

True

Question 35

once the bolts are tightened on the flanges for the turbine casing, they can be checked for tightness with ultrasonic testing. (high frequency sound waves) true False

Answer 35

True

Question 36

which of the following would give you a false reading on bolt stretch (bolts below the required torque) lubrication of the threads heating the stud heating the flange tightening the stud to the specified torque

Answer 36

Heating the flange

Question 37

when doing a coupling alignment on a turbine, you will make movement between the _____ and the _______. foundation, turbine feet sole plate, base plate sole plate, turbine feet base plate, foundation

Answer 37

Sole plate and turbine feet

Question 38

piping for the turbine must be able to handle the ssteam flow not put strain on the casings allow for expansion all the above

Answer 38

All of the above

Question 39

turbines are set on the bed of the foundation on sole plates grout pads wedge blocks all the above

Answer 39

All of the above

Question 40

when initial parts are installed for the turbine (bottom halves of the turbine cylinders), they are installed with lubricated keyways that lock the turbine solidly in place allow for rotor sag allow the turbine to expand in all temperature conditions none of the above

Answer 40

Allow the turbine to expand in all temperature conditions

Question 41

when installing the bearing pedestals and turbine cylinders, you need to add the tops of the cylinders and pedestals so the weight resembles the turbines whole weight and helps take the sag out of the cylinders true False

Answer 41

True

Question 42

a benchmark is the baseline from where all elevations involved in the turbine installation, will be taken from true false

Answer 42

True

Question 43

when installing bearings, you use a bridge gauge to check bearing wear (helps with the maintenace schedualing) or bearing clearance true false

Answer 43

True

Question 44

during startup, steam is admitted to the turbine to rotate it on its own power________ after the jacking oil has lifted the rotor after several hours and when the rotor is straight and up to the proper speed after a few days and and the rotor is striaight and jacking oil still on once the baring gear has it up to 50 to 60 rpm

Answer 44

After several hours wnd when the rotor is straight and up to proper speed

Question 45

once the steam is first admitted, you should make sure the drain lines are plugged until thermal saturation is reached and that the turbine runs thru any critical speeds as fast as possible true False

Answer 45

False Make sure drain lines are all open until just steam comes out

Question 46

the gas turbine is an internal combustion engine that coverts fuel to useable power true False

Answer 46

True

Question 47

the efficiency of a gas turbine depends on the temperature the air can be raised and the use of cold dense air that will create a marked increase in gas turbine output true False

Answer 47

True

Question 48

regeneration is when some of the exhaust air from the gas turbine is used in the process to generate steam power true False

Answer 48

False Exhaust gas is regenerated to assist in the heating of the gasses before the turbine

Question 49

the gas turbine shaft type that has one shaft running inside the other is single shaft split shaft twin spool shaft direct coupled

Answer 49

Twin spool shaft

Question 50

in the gas generation section, the main parts are the compressor and combustion chamber true False

Answer 50

True

Question 51

the power section of a gas turbine harnesses energy from the cold gasses as efficiently as possible true False

Answer 51

False Harnesses hot expanding gases

Question 52

in the split shaft turbine design, the gas generation turbine is connected to the compressor and the power turbine is connected to the load. true False

Answer 52

True

Question 53

the gas turbine cycle that uses a heat exchanger or regenerators to make it more efficient is open cycle semi-closed cycle closed cycle all the above

Answer 53

Semi Closed cycle

Question 54

in the regeneration cycle, the turbine uses exhaust heat to assist in heating and expansion of the gases after the compressor but before the combustion chamber true False

Answer 54

True

Question 55

one of the greatest advantages of the gas turbine is its power to weight ratio true False

Answer 55

True

Question 56

one of the major disadvantages of the gas turbine is its low thermal efficiency true false

Answer 56

one of the major disadvantages of the gas turbine is its low thermal efficiency true false

Question 57

in the gas turbine, the compressor increases the air pressure and air temperature until it hits the diffuser. here the air velocity is slowed down and the air pressure decreased true False

Answer 57

False Lowers the velocity and increase the pressure

Question 58

the air pressure during ignition is always higher than in the diffuser when travelling thru the turbine. true false

Answer 58

False Diffuser has the highest pressure

Question 59

the turbine is attached to the compressor by a shaft running thru the turbine engine and about ____ of the power developed by the gas turbine is used to drive the compressor and accessories 25% 50% 75% 10%

Answer 59

75%

Question 60

if gases back up into the compressor, it will lead to a condition of compressor surge or stall true false

Answer 60

True

Question 61

air filtration for stationary gas turbines can use spiral vane seperators and V-bag filters true false

Answer 61

True

Question 62

pulse type filters are used to reduce icing and hoarfrost build-up true false

Answer 62

True

Question 63

to improve air flow at the intake, you would use dense filtering sharp bends in piping guide vanes none of the above

Answer 63

Guide Vanes

Question 64

in the combustion chamber housing, the ingniter is in the primary zone intermediate zone dilution zone fuel nozzle zone

Answer 64

Primary Zone

Question 65

primary air is used for mixing with the fuel true False

Answer 65

True

Question 66

the secondary air is used to control the temperature and also help in the combustion process true false

Answer 66

false Only control the temperature by moving air around the outside of the liner

Question 67

the transition piece makes sure that all hot gases are mixed with air so there is no hot gas pockets true False

Answer 67

True

Question 68

when using can type combustion chambers, every chamber will need its own igniter true False

Answer 68

True

Question 69

the fuel nozzle or injector is used to spray the fuel in a fine mist or vapourize the the fuel true False

Answer 69

True

Question 70

the turbine assembly harnesses the power of the hot expanding gases and has blades and nozzles made of mild steel true False

Answer 70

False Made of high strength steel

Question 71

you can increase the endurance of the nozzles, by adding new alloys such as ceramic or use air cooled nozzle vanes true false

Answer 71

True

Question 72

the rotor blades on the rotor discs can have clearance when mounted, so that they can allow for thermal expansion true False

Answer 72

True

Question 73

labyrinth seals are used on both compressor and turbine and can have help for sealing from sealing jets of air routed from the compressor section true false

Answer 73

True

Question 74

a starting motor is an essential auxiliary component that needs to route the turbine to about _____% of its maximum speed 10 20-30 40-50 60-70

Answer 74

20-30%

Question 75

power loss in a gas turbine can be caused by dirt deposits on the compressor blades true False

Answer 75

True

Question 76

to check for interference and rubbing between air seals and blades, you would need to manually turn the engine over slowly true False

Answer 76

True

Question 77

when replacing blades on a turbine with new blade, you must make sure the blade has the same moment weight. the blade has the same type of mount. you use proper installation procedures set out by the manufacture. all the above

Answer 77

All of the above

Question 78

when doing an engine wash, you would do it only when using the starting mechanism, not while it is running true false

Answer 78

False About once a month a cleaning solution is sprayed into compressor blades while it is running

Question 79

in regards to the inlet or intake system on a gas turbine, a 1 % loss in intake pressure results to about ______ % loss in engine power 1 2.5 5 10

Answer 79

2.5

Question 80

insulation (thermal) can be used on turbines to help with personal protection, noise reduction and operational efficiency of the turbine true False

Answer 80

True

Question 81

after replacing a governor with a new one, the millwright needs to fill the governors reservoir with the correct oil and adjust the speed at start up true False

Answer 81

True

Question 82

a governor will automatically control the speed of a prime mover under varying load and can also maintain the selected speed limit the slow and fast speed shut down the prime mover if it over speeds all the above

Answer 82

All of the above

Question 83

all automatic governor control systems have 3 main components detection, transmission, maintenance detection, ignition, correction detection, transmission, correction transmission, correction, maintenace

Answer 83

Detection, transmission, correction

Question 84

in spark ignition, the governor actuates a throttle valve in the intake passage between the carburetor and manifold. the governor operates off the engine vacuum to move the throttle valve true False

Answer 84

True

Question 85

the mechanical governor can use centrifugal force to activate it true false

Answer 85

True

Question 86

because of high rotational speeds in steam turbines, it is important that the speed be accurately controlled by 2 systems. operation speed control and over speed control true false

Answer 86

True

Question 87

large steam turbines require intermediate devices to amplify the governors signal into a force powerful enough to operate the control valves. these devices can be hydraulic electronic pneumatic all the above

Answer 87

All of the above

Question 88

the governor on a gas turbine is used to monitor the turbine speed and load and adjust the fuel supply accordingly true false

Answer 88

True

Question 89

isocronous control of a governor will keep a constant speed without fluctuation true False

Answer 89

True

Question 90

variable speed control uses centrifugal fly weights and the speed is adjusted by changing the spring pressure that opposes the fly weights true False

Answer 90

True

Question 91

hunting is a problem with some governors. it is the quick action of the governor to the driver speed, causing a to fast, to slow, to fast, to slow cycle. to help alleviate this problem, you would have a governor with speed droop true False

Answer 91

True