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25 Cards in this Set
- Front
- Back
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1) The function of an oil turbine-driven booster pump is to --
A) increase oil pressure to the bearings B) increase oil pressure for control C) supply oil to the main pump suction D) supply oil to the jacking or lift pumps |
C) supply oil to the main pump suction
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2) Steam turbine bearing oil supply header pressure usually in the range of ---
A) 5 to 10 PSIG B) 10 to 30 PSIG C) 30 to 50 PSIG D) 50 to 100 PSIG |
B) 10 to 30 PSIG
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3) Steam turbine bearing oil supply header temperature is usually in the range of ---
A) 70 to 100 degrees F B) 100 to 120 degrees F C) 120 to 160 degrees F D) 160 to 175 degrees F |
B) 100 to 120 degrees F
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4) Turbine oil is vacuum treated before it is used in the ---
A) lubrication system B) control system C) bowser system D) hydrogen seal oil system |
D) hydrogen seal oil system
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5) The function of bowser system polishers is to ---
A) remove sludge B) remove solid particles C) remove water haze D) rest the oil |
C) remove water haze
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6) The speed sensing unit for electronic governors is usually ---
A) a permanent magnet generator B) a mechanical tachometer C) a flyball arrangement D) belt drive |
A) a permanent magnet generator
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7) The speed governor unit is driven by the turbine shaft through a ---
A) helical gear drive B) worm gear drive C) direct drive D) fluid drive |
B) worm gear drive
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8) The division of increased system load between generators is directly proportional to their ---
A) speed droop B) speed regulation C) capacity D) governor dead band |
C) capacity
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9) The division of reduced system load between generators is inversely proportional to their ---
A) speed droop B) control setting C) capacity D) governor dead band |
A) speed droop
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10) In power genrating systems the speed droop of steam turbine governors is usually set at ---
A) 1 percent B) 2 percent C) 5 percent D) 7 percent |
C) 5 percent
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11) The speed changer on a hydraulic governor is able to control the unit speed (or load) by effecting adjustments to ---
A) the main oil pressure B) the speed droop C) the speed regulation valves D) the spring tension on the pressure transformer |
D) the spring tension on the pressure transformer
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12) In the event of a turbine trip which one of the below valves is closed through the action of the air-relay dump valve?
A) main stop valves B) intercept valves C) packing blowdown valve D) non-return valve |
D) non-return valve
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13) Turbine overspeed trip mechanisms utilizes the principle of ---
A) speed pressure ratio B) centrifugal force C) inertia D) levers |
B) centrifugal force
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14) What is the primary purpose of the pre-emergency governor used on reheat turbines?
A) trip the unit on overspeed B) trip the unit before the emergency C) reduce steam flow to the high pressure turbine on overspeed D) reduce steam flow to the intermediate pressure turbine on overspeed |
D) reduce steam flow to the intermediate pressure turbine on overspeed
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15) The initial or throttle pressure regulator protects the turbine from extreme pressure and temperature changes by starting to close the control valves when the steam pressure lowers to what percent of normal pressure?
A) 10 percent B) 50 percent C) 60 percent D) 90 percent |
D) 90 percent
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16) Eccentricity is a measurement of the turbine shaft for -
A) straightness B) variable diameter C) axial movement D) vibration |
A) straightness
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17) Large turbine generator units are usually left on turning gear until the eccentricity is reduced to ---
A) one mil or less B) two mils or less C) five mils D) ten mils |
B) two mils or less
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18) Which one of the below instruments is the most accurate detector for measuring shaft vibration?
A) bearing cap mounted detector B) shaft-riding detector C) horizontal cap detector D) vibration tachometer generator |
B) shaft-riding detector
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19) What is the name of the turbine supervisory instrument used to monitor the clearance between stationary and rotating parts of the turbine?
A) shell expansion detector B) shaft expansion detector C) differential expansion detector D) shaft riding detector |
C) differential expansion detector
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20) Most turbine difficulties can be readily understood by personnel who knows how to ---
A) interpret the supervisory instruments B) start the turbine correctly C) analyze design start-up curves D) listen for rubs when the turbine is started |
A) interpret the supervisory instruments
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21) Use the following data for Questions #21 and #22
Two generators (Unit A and Unit B) are running in parallel on their governors and carrying a 30 MW laod. Unit A is a 10 MW capacity machine; Unit B is a 50 MW capacity machine. The governor speed droop is 5 percent for each machine. If the load is increased by 12 MW, the load increase on Unit A would increase --- A) 1 MW B) 2 MW C) 4 MW D) 5 MW |
B) 2 MW
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22) If the load was decreased by 24 MW, the load on Unit B would decrease ---
A) 4 MW B) 12 MW C) 20 MW D) 22 MW |
C) 20 MW
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23) Use the following data for Questions #23, #24, #25:
Four gnerators are running in parallel on their governors. The system load is 450 MW at 60 Hz (100 percent speed) Capacity Speed Droop LOAD AT 60 Hz (Governor Setting) Unit A 200 MW 2% 100 MW Unit B 200 MW 4.45% 100 MW Unit C 100 MW 4% 50 MW Unit D 400 MW 5% 200 MW If the system load increased 125 MW, the load on Unit D would increase to --- A) 240 MW B) 250 MW C) 260 MW D) 270 MW |
A) 240 MW
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24) If the system frequency decreased to 99 percent (59.4 Hz) Unit A load would increase to ---
A) 120 MW B) 150 MW C) 180 MW D) Full load |
D) Full load
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25) If the system load increased to 575 MW and no changes were made to the unit governors, the frequency would go to ---
A) 59.50 Hz B) 59.60 Hz C) 59.70 Hz D) 59.80 Hz |
C) 59.70 Hz
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