Chapter 68- Heat Engines And Prime Movers Flashcards Preview

Power Engineering- 4th Class > Chapter 68- Heat Engines And Prime Movers > Flashcards

Flashcards in Chapter 68- Heat Engines And Prime Movers Deck (30):
1

Which has greater thermal efficiency a steam turbine or a steam engine?

Steam turbine

2

Define a heat engine

The operating cycle uses a working fluid to convert thermal energy to mechanical energy by heating the fluid then allowing it to expand under controlled conditions to produce a useful product

3

Define working fluid

A mixture of combustion fluid and air, or steam and water, is expanded under controlled conditions in order to preform work

4

Define a prime mover

A single device which either by itself or as part of an overall heat engine converts a natural source of energy into mechanical motion.
Ex. Steam Turbine

5

Are electric motors considered prime movers?

No, they are not part of a heat engine nor do they convert a natural source of energy

6

What is the rankin cycle

The entire boiler system a example of a heat engine

7

What is the Otto cycle?

Take fuel, mix it with air and burn it to create combustion which forces a piston to create mechanical energy.
Ex- A gas engine

Both a heat engine and a prime mover

8

What ignites the fuel in a Diesel engine?

The compressed air in the engine cause the fuel to auto ignite.

9

Name example of fuels used in large scale power production

Solid fuel, coal
Liquid an gaseous hydrocarbons
Water power
Nuclear energy

10

The main reason a steam plant is so popular

They have the highest overall efficiency

11

Steam engines are still used when

Slow rotation speed is required
When stroke reversal is required without gearing

12

Name the different kinds of steam engine

Single cylinder
Vertical engine with a D-valve slide
And a throttling governor

13

The slide valve of a steam engine is designed to provide for the steam to enter and leave the

Throttling valve

14

Would a steam turbine be considered a prime mover?

Yes

15

Large power production plants tend to be of the thermal type because they can burn solid fuels and

The heat cycle they use is most efficient

16

The cross head of the steam engine

Imparts angular motion to the piston rod

17

A steam engine piston

Moves fastest at the beginning of its stroke

18

A routine inspection of an operating steam engine should cover first and foremost

Lubricators

19

One of the first ways ways to detectable fault in a reciprocating engine is

Sound

20

The slide valve of a steam engine is designed to

Provide for the steam to enter and leave the cylinder

21

A steam engine that introduces steam to both sides of the piston is called a

Double acting piston

22

When the steam is allowed to expand with the inlet valve closed it is called______use of steam

Expansive

23

To prevent leakage of a steam where the pistons and valve rods pass through the cylinder and the valve box ________is installed

Packing

24

Which of the following are heat engines:
1.) steam turbine
2.) hydro dam
3.) steam power plant
4.) gas turbine power plant
5.) gasoline engine

3, 4, 5

25

Which of the following are prime movers:
1.) steam turbine
2.) electric motor
3.) steam engine
4.) gasoline engine
5.) jet engine

1, 3, 4, 5

26

The advantage of the steam engine is:
1.) never requires lubrication
2.) well suited for rotational motion
3.) well suited for slow speeds
4.) can be reversed with out the use of gears
5.)3 & 4

5

27

In a heat engine where the working fluid is recycled the process is called

A closed cycle

28

A steam engine will have the steam supply to the cylinder shut off once the piston has travelled

25-35% of the strokes

29

The reciprocating motion of a steam engine is converted to rotary motion at the

Crankshaft

30

Whenever feasibly possible, when checking bearings on running pieces of equipment it is wise to

Get accustomed to normal running temperatures and vibrations