Ch.1

Question 1

199. In an impulse steam turbine nozzle, the following events take place:

1)     The steam pressure decreases
2)     The enthalpy of the steam decreases
3)     The velocity of the steam increases
4)     The volume of the steam increases 

a. 1, 2, 4
b. 1, 3, 4
c. 2, 3, 4
d. 1, 2, 3, 4
e. 1, 2, 3

Answer 1

D. 1, 2, 3, 4
1) The steam pressure decreases
2) The enthalpy of the steam decreases
3) The velocity of the steam increases
4) The volume of the steam increases

Question 2

200. Turbine nozzles convert heat energy into:

a. Potential energy
b. Enthalpy
c. Eddy-currents
d. Kinetic energy
e. Pressure

Answer 2

D. Kinetic energy

Question 3

201. The purpose of the bucket or moving blade on the rotor is to convert the ____________ energy of the steam into ________ energy.

a. heat, potential
b. kinetic, useful
c. kinetic, mechanical
d. heat, kinetic
e. mechanical, kinetic

Answer 3

C. kinetic, mechanical

Question 4

202. In an impulse turbine as the steam passes through the moving blades the ________ drops but the ______ remains the same.

a. velocity, pressure
b. enthalpy, velocity
c. pressure, velocity
d. volume, velocity
e. velocity, kinetic energy

Answer 4

A. velocity, pressure

Question 5

203. The pressure at the outlet from the moving blades is the same as the pressure at the inlet to the moving blades in __________ turbine.

a. a topping
b. a reaction
c. a back-pressure
d. an impulse
e. an extraction

Answer 5

D. an impulse

Question 6

204. Steam turbine stationary nozzles serve to:

1)     Decrease steam pressure
2)     Increase steam enthalpy
3)     Decrease steam friction
4)     Increase steam velocity 

a. 1, 2, 3
b. 1, 3, 4
c. 1, 4
d. 2, 3
e. 2, 3, 4

Answer 6

C. 1, 4
1) Decrease steam pressure.
4) Increase steam velocity

Question 7

205. On an extraction turbine the extraction pressure is:

a. Not critical
b. Varied according to turbine load
c. Maintained constant regardless of turbine load
d. Proportional to the turbine load
e. Reduced if load increases

Answer 7

C. Maintained constant regardless of turbine load

Question 8

206. A back-pressure turbine which exhaust steam to an old boiler header still supplying steam to an old boiler header still supplying steam to an old lower pressure turbine is called:

a. Condensing-bleeder turbine
b. Cross compound turbine
c. Condensing turbine
d. Topping turbine
e. Mixed pressure turbine

Answer 8

D. Topping turbine

Question 9

207. A topping turbine is a special application of a ________ turbine.

a. condensing
b. extraction
c. condensing-bleeder
d. tandem compound
e. back-pressure

Answer 9

E. back-pressure

Question 10

208. _____________ turbines are large turbines consisting of two or more turbines in series coupled together as one shaft and applied to one generator.

a. Topping
b. Tandem-compound
c. Condensing-bleeder
d. Cross-compound
e. Mixed pressure

Answer 10

B. Tandem-compound

Question 11

209. A generator coupled on one shaft to a turbine consisting of two or more turbine in series is called?

a. Condensing-bleeder
b. Cross-compound turbine
c. Mixed pressure
d. Tandem-compound turbine
e. Topping

Answer 11

D. Tandem-compound turbine

Question 12

210. __________________ turbines are large turbines with parallel shafts with a generator on each shaft.

a. Condensing
b. Tandem-compound
c. Extraction-bleeder
d. Condensing-bleeder
e. Cross-compound

Answer 12

E. Cross-compound

Question 13

211. In a reaction turbine the steam pressure drops across both the fixed and moving blades while the steam’s ______ velocity rises in the fixed blades and drops in the moving blades.

a. secondary
b. primary
c. stationary
d. moving
e. absolute

Answer 13

E. absolute

Question 14

212. The distinguishing feature of a reaction turbine is the fact that the pressure drop across the _________ blades.

a. cutting
b. moving
c. sectional
d. stationary
e. angular

Answer 14

B. moving

Question 15

213. In a steam turbine having pressure drop across the moving blades, an unbalanced ________ thrust will be developed upon the rotor.

a. axial
b. centrifugal
c. radial
d. impulse
e. rotational

Answer 15

A. axial

Question 16

214. Reaction turbine blades (moving):

1)     Convert the kinetic energy of the steam into mechanical energy
2)     Convert heat energy into kinetic energy
3)     Are nozzle shaped
4)     Increase the absolute velocity 

a. 1, 2, 3
b. 2, 3, 4
c. 1, 3, 4
d. 1, 2, 4
e. 1, 4

Answer 16

A. 1, 2, 3

1) Convert the kinetic energy of the steam into mechanical energy
2) Convert heat energy into kinetic energy
3) Are nozzle shaped

Question 17

215. A reaction turbine results in a long machine due to a large number of alternate rows of:

a. Nozzles and moving blades
b. Nozzles and stationary blades
c. Fixed and moving blades
d. Stationary blades
e. Moving blades and nozzles

Answer 17

C. Fixed and moving blades

Question 18

216. A turbine that expands the steam in two or more sets of nozzles in series, each set having velocity-compounded blades to receive the steam issuing from the nozzles is called:

a. Extraction turbine
b. Velocity compounded turbine
c. Pressure compounded turbine
d. Pressure-velocity compounded turbine
e. Mixed-pressure turbine

Answer 18

D. Pressure-velocity compounded

Question 19

217. In pressure compound steam turbine:

1)     The expansion of steam from boiler pressure to exhaust pressure is carried out in a number of steps or stages
2)     Each stage has a set of nozzles and a row of blades
3)     All of the velocity available is developed in one set of nozzles
4)     The rows of moving blades are separated from each other by partitions or diaphragms into which the nozzles are set 

a. 1, 2, 3
b. 2, 3, 4
c. 1, 3, 4
d. 1, 2, 4
e. 1, 2, 3, 4

Answer 19

D. 1, 2, 4

1) The expansion of steam from boiler pressure to exhaust pressure is carried out in a number of steps or stages

2)     Each stage has a set of nozzles and a row of blades

4) The rows of moving blades are separated from each other by partitions or diaphragms into which the nozzles are set

Question 20

218. In a steam turbine using velocity compounding _____________ expands the steam from initial to exhaust pressure.

a. two sets of nozzles and moving blades
b. stationary blades
c. stationary and moving blades
d. moving blades
e. one of the nozzles

Answer 20

E. one of the nozzles

Question 21

219. In a condensing-bleeder turbine up to 20% of the total steam flow may be bled off. What is the bleed-steam used for.

a. Building heating
b. Relieving pressure
c. Atomization of the fuel
d. To be reheated in boiler
e. Feed-water heating

Answer 21

E. Feed-water heating

Question 22

220. A condensing-bleeder turbine can bleed up to ______ of the total steam flow.

a. 0.1
b. 0.15
c. 0.2
d. 0.25
e. 0.3

Answer 22

C. 0.2

Question 23

221. The primary purpose of a back-pressure turbine is electrical generation.

a. True
b. False

Answer 23

B. False

Question 24

223. Extraction turbines are turbines where steam is extracted at one or more points at constant _________.

a. flow
b. pressure
c. load
d. temperature
e. efficiency

Answer 24

B. pressure

Question 24

222. In a back-pressure turbine the process steam pressure is: a. Kept constant and the generator output depends on the demand for process steam b. Varied and the generator output remains constant c. Kept constant and the generator output remains constant d. Not important e. Dependant on the generator output

Answer 24

A. Kept constant and the generator output depends on the demand for process steam

Question 25

223. Extraction turbines are turbines where steam is extracted at one or more points at constant _________. a. flow b. pressure c. load d. temperature e. efficiency

Answer 25

B. pressure

Question 26

224. Labyrinth seals are: 1) Made of cast iron 2) A positive leak-proof seal arrangement 3) Design to have large clearances between the shaft and casing 4) Made of brass or stainless steel 5) Use on larger diameter turbine shaft a. 1, 2, 5 b. 2, 4, 5 c. 3, 4, 5 d. 4, 5 e. 1, 2, 3

Answer 26

D. 4, 5

Question 27

225. A steam turbine water seal is used ________ to insure that no air leaks in along the shaft. a. on start-up b. at speed below 2000 rev/min c. on shut-down d. only on condensing turbine e. at speed above 2000 rev/min

Answer 27

E. at speed above 2000 rev/min

Question 28

226. On larger turbines, the _________ is split in a horizontal direction. a. shaft b. governor c. cylinder d. rotor e. drum

Answer 28

C. cylinder

Question 29

227. It is general practice to let the thickness of the walls and flanges ___________ from inlet to exhaust end of a steam turbine casing. a. decrease b. fluctuate c. be the same d. vary e. increase

Answer 29

A. decrease

Question 30

228. Materials at the given maximum temperature and under constant pressure continue to deform with very slowly increasing strain of the material; this phenomenon is called _________________. a. creep b. elongation c. deformation d. jerking e. movement

Answer 30

A. creep

Question 31

229. Steam turbine casing joints are made steam tight by matching _______ exactly. a. thin high temperature gasket b. bowel pins c. alignment notches d. flange faces e. rubber gasket

Answer 31

D. flange faces

Question 32

230. A steam turbine assembled casing is machined off inside in a boring mill to: 1) Make grooves for shaft seals 2) Make grooves for diaphragms 3) Machine surfaces for bearings 4) Machine flange surfaces flat a. 1, 2, 3 b. 2, 3, 4 c. 1, 3 d. 1, 2, 4 e. 1, 4

Answer 32

a. 1, 2, 3 1) Make grooves for shaft seals 2) Make grooves for diaphragms 3) Machine surfaces for bearings

Question 33

231. A Hollow Drum Rotor, for good balance, is machined both outside and inside thus the drum must be open at one end. How is the drum end cover with shaft installed in the rotor? a. Press fitted b. Welded on c. Bolted d. Press fit and belted e. Shrink fit and welded

Answer 33

E. Shrink fit and welded

Question 34

232. When disc rotors are assembled, the discs are heated until they are easily slid along the shaft and then located in the correct position on the shaft and shaft key. A small clearance between the discs prevents ________ . a. noises b. slippage c. thermal stress in the shaft d. acceleration e. vibrations

Answer 34

C. thermal stress in the shaft

Question 35

233. Rotors for high outputs and high temperatures are generally made of________ steels. a. chromium b. chromium-nickel c. nickel-molybdenum d. chromium-nickel-molybdenum e. copper-nickel-bronze

Answer 35

D. chromium-nickel-molybdenum

Question 36

234. The axial thrust in impulse turbines is nearly eliminated by use of a balance or dummy piston. a. True b. False

Answer 36

B. False

Question 37

235. A balance piston on a steam turbine is used to: a. Counteract vibration and therefore ensure a smooth running unit b. Increase turbine output c. Measure axial position d. Counteract end thrust e. Provide an area to install a labyrinth seal

Answer 37

D. Counteract end thrust

Question 38

236. A steam turbine balance piston is fitted with rings to ensure a tight seal. a. True b. False

Answer 38

B. False

Question 39

237. A steam turbine balance piston is fitted with ______ to ensure a tight seal. a. carbon rings seal b. blades seal c. water seal d. diaphragm e. labyrinth seal

Answer 39

E. labyrinth seal

Question 40

238. Reaction steam turbines often use __________________ seals as part of the shroud with the seal clearances kept as small as possible. a. radial b. Water c. radial and axial d. Carbon e. Axial

Answer 40

C. radial and axial

Question 41

239. The purpose of a thrust bearing on large reaction steam turbine is to: 1) Give confidence to the operator 2) To keep the rotor in an exact position in the casing 3) Prevent any steam from escaping 4) To absorb any axial thrust on the rotor 5) Support the dummy piston a. 1, 2, 3 b. 2, 4, 5 c. 2, 4 d. 3, 5 e. 1, 4

Answer 41

C. 2, 4 2) To keep the rotor in an exact position in the casing 4) To absorb any axial thrust on the rotor

Question 42

240. If left at a standstill, while the turbine is still hot, the lower half of the rotor will cool off faster than the upper half and the rotor will ______________________ or "hog". a. turn on it's own b. bend upwards c. twist d. bend downwards e. stall

Answer 42

B. bend upwards

Question 43

241. A barring gear consists of an electric motor and several sets of reducing gears to turn the turbine shaft at a low speed. It is used: 1) After stopping a hot turbine to prevent "hogging" 2) Only on small turbine 3) Continually when the turbine is not operating 4) Prior to start-up for approximately 3 hours a. 1, 2, 4 b. 1, 2, 3 c. 1, 4 d. 2, 3 e. 2, 4

Answer 43

C. 1, 4 1) After stopping a hot turbine to prevent "hogging" 4) Prior to start-up for approximately 3 hours

Question 44

242. A jacking oil pump is used to: 1) Make slight adjustments to the turbine bearing housings during overhaul to maintain alignment 2) Supply oil to a hydraulic motor for the turning gear 3) Supply oil to the bearings under the shaft at all times so lubrication is assured 4) Supply a high volume of oil at high pressure a. 1, 2, 3 b. 2, 3, 4 c. 1, 3, 4 d. 1, 2, 3, 4 e. None of the above

Answer 44

E. None of the above

Question 45

243. In a nuclear power station a _____________ supplies heat through a _________ to the working fluid in place of a steam plant boiler. 1) reactor 2) heat exchanger 3) burner 4) pump a. 1, 2 b. 1, 3 c. 3, 2 d. 1, 4 e. 2, 4

Answer 45

A. 1, 2 1) reactor 2) heat exchanger

Question 46

244. In a nuclear power plant circulating coolant picks up heat in the reactor and rejects it to the _______________ in the steam cycle by means of a heat exchanger. a. hotwell b. condenser c. working fluid d. turbine e. feed pump

Answer 46

C. working fluid