Chapter 32 Microturbines

Question 1

1.	Lubrication problems are reduced in microturbines by using: 
A.	only synthetic oil
B.	keeping oil temperature low
C.	using roller bearings
D.	preheating the oil
E.	using foil bearings

Answer 1

E. using foil bearings

Question 2

2.	The most common fuel used for microturbines is:
A.	Natural gas
B.	Kerosene
C.	Diesel fuel
D.	Gasoline
E.	Light oil

Answer 2

A. Natural gas

Question 3

3. The main advantage of foil bearings in microturbines is:
   A. The noise reduction
   B. The elimination of oil systems
   C. The use of an external pressurization system
   D. The anti-wear coating
   E. The high speed of shaft rotation

Answer 3

B. The elimination of oil systems

Question 4

4.	Microturbines operate at high speeds, which are typically in the range of \_\_\_\_\_\_\_\_\_\_\_ rpm.
A.	25 000 to 80 000
B.	50 000 to 100 000
C.	50 000 to 120 000
D.	60 000 to 120 000
E.	25 000 to 50 000

Answer 4

C. 50 000 to 120 000

Question 5

5.	An undesirable feature of microturbines is:
A.	Noise
B.	Large floor space
C.	Size
D.	Oil System
E.	Heavy Oils as Fuel

Answer 5

A. Noise

Question 6

6. Boiler checks are unnecessary on a microturbine because:
   A. boilers are automatic
   B. a separate circuit energizes the boiler
   C. an operator is not required by code
   D. there is no boiler

Answer 6

D. there is no boiler

Question 7

7. 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

A.	1, 3, and 5
B.	2, 4, and 5
C.	1, 2, and 3
D.	3, 4, and 5
E.	1, 2, and 4

Answer 7

A. 1, 3, and 5

Question 8

8.	The foil bearings used in a microturbine are a type of \_\_\_\_\_ bearing.
A.	Antifriction
B.	Journal
C.	Sleeve
D.	Water
E.	Air

Answer 8

E. Air

Question 9

9. For a micro-turbine combined heating system, which of the following statements is NOT true?
   A. Atmospheric air is drawn into an axial flow compressor where it is compressed
   B. The compressor discharges to the combustor
   C. Fuel is added and ignited in a very rapid combustion process
   D. The hot gases are allowed to expand through the gas turbine, creating rotational energy
   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

10.	The exhaust gas from the microturbine in a combined heating system is: 
A.	used to directly heat a building
B.	recycled through the compressor
C.	sent through a boiler or water heater
D.	exhausted directly to atmosphere
E.	at about room temperature

Answer 10

C. sent through a boiler or water heater