CHAPTER 32

Question 1

The main advantage of foil bearings in microturbines is:
Select one:

A.
The high speed of shaft rotation.

B.
The use of an external pressurization system

C.
The elimination of oil systems

D.
The anti-wear coating

E.
The noise reduction

Answer 1

C.
The elimination of oil systems

Question 2

The exhaust gas from the microturbine in a combined heating system is:
Select one:

a.
exhausted directly to atmosphere

b.
recycled through the compressor

c.
sent through a boiler or water heater

d.
at about room temperature

e.
used to directly heat a building

Answer 2

c.
sent through a boiler or water heater

Question 3

The most common fuel used for microturbines is:
Select one:

a.
Natural gas

b.
Diesel fuel

c.
Kerosene

d.
Light oil

e.
Gasoline

Answer 3

a.
Natural gas

Question 4

Boiler checks are unnecessary in the automatic microturbine combined heating system.
Select one:
True
False

Answer 4

False

Question 5

An undesirable feature of microturbines is:
Select one:

A.
Large floor space

B.
Size

C.
Heavy Oils as Fuel

D.
Noise

E.
Oil System

Answer 5

D.
Noise

Question 6

The foil bearings used in a microturbine are a type of _____ bearing.
Select one:

A.
Journal

B.
Sleeve

C.
Water

D.
Air

E.
Antifriction

Answer 6

D.
Air

Question 7

Lubrication problems are reduced in microturbines by using:
Select one:

a.
using roller bearings

b.
only synthetic oil

c.
using foil bearings

d.
keeping oil temperature low

e.
preheating the oil

Answer 7

c.
using foil bearings

Question 8

Microturbines operate at high speeds, which are typically in the range of ___________ rpm.
Select one:

A.
25 000 to 80 000

B.
60 000 to 120 000

C.
25 000 to 50 000

D.
50 000 to 100 000

E.
50 000 to 120 000

Answer 8

E.
50 000 to 120 000

Question 9

For a micro-turbine combined heating system, which of the following statements is NOT true?
Select one:

A.
The compressor discharges to the combustor

B.
Fuel is added and ignited in a very rapid combustion process

C.
The hot gases are allowed to expand through the gas turbine, creating rotational energy

D.
Atmospheric air is drawn into an axial flow compressor where it is compressed

E.
The rotating energy is transferred to the condenser and the alternator via a common shaft

Answer 9

E.
The rotating energy is transferred to the condenser and the alternator via a common shaft

Question 10

Which of the following from a microturbine-driven alternator is/are synchronized by a converter to meet the electrical demand of the facility?
1. voltage
2. amperage
3. frequency
4. resistance
5. phase

Select one:

A.
1, 2, and 3

B.
1 and 2 only

C.
1, 3, and 5

D.
3 only

E.
2 and 4 only

Answer 10

C.
1, 3, and 5