Chapter 17 Compression Refrigeration Systems

Question 1

1. As a general rule, in the compression refrigeration system the condensing
   temperature of the vapour will be approximately _______ higher than the
   temperature of the water when a water-cooled condenser is used.
   A. 11°C (20°F)
   B. 15°C (59°F)
   C. 0°C (32°F) to 5°C (41°F)
   D. 20°C (68F) to 25°C (77°F)
   E. 5°C (41°F) to 10°C (50°F)

Answer 1

A. 11°C (20°F)

Question 2

2. In air conditioning systems the air is not cooled any lower than:
A. 15°C (59°F)
B. 10°C (50°F)
C. 13°C (55°F)
D. 25°C (77°F)
E. 18°C (64°F)

Answer 2

C. 13°C (55°F)

Question 3

3. What is the lowest temperature at which a brine solution can operate before it
freezes when used in an indirect system?
A. -10°C (14°F)
B. -50°C (-58°F)
C. 15°C (59°F)
D. -25°C (-13°F)
E. -18°C (0°F)

Answer 3

B. -50°C (-58°F)

Question 4

4. What brine temperature is used when cooling an ice surface?
A. -11°C (12°F)
B. -5°C (23°F)
C. -18°C (0°F)
D. -25°C (-13°F)
E. -50°C (-58°F)

Answer 4

A. -11°C (12°F)

Question 5

5. As a general rule in the compression refrigeration system the evaporation
   temperature should be between _____ lower than that of the cooled medium.
   A. 15°C (59°F) and 20°C (68°F)
   B. 10°C (50°F) and 15°C (59°F)
   C. 0°C (32°F) and 5°C (41°F)
   D. 20°C (68F) and 25°C (77°F)
   E. 5°C (41°F) and 10°C (50°F)

Answer 5

E. 5°C (41°F) and 10°C (50°F)

Question 6

6. In the closed cycle compression refrigeration system the compressor not only
   removes the vapour from the evaporator, but also keeps the pressure in the
   evaporator at a constant value, which gives the desired ________ temperature of
   the liquid refrigerant.
   A. Vaporization
   B. Condensation
   C. Cooling
   D. Regeneration
   E. Expansion

Answer 6

A. Vaporization

Question 7

7. The high-pressure side of the compression refrigeration system consists of all
except the:
A. Compressor discharge
B. Condenser
C. Evaporator
D. Upstream side of the regulating valve
E. Receive

Answer 7

C. Evaporator

Question 8

8. In the compression refrigeration system the low-pressure, low-temperature
liquid/vapour mixture flows through the \_\_\_\_\_, absorbing heat from the
surrounding medium.
A. Evaporator
B. Absorber
C. Regenerator
D. Compressor
E. Condenser

Answer 8

A. Evaporator

Question 9

9. The direct compression refrigeration system is one in which the \_\_\_\_\_ is in direct
contact with the material or space being refrigerated or is located in air circulating
ducts communicating with such spaces.
A. Compressor
B. Absorber
C. Regenerator
D. Evaporator
E. Condenser

Answer 9

D. Evaporato

Question 10

10.Which of the following is not a principle component of a simple closed-cycle
compression refrigeration system ?
A. Evaporator
B. Regenerator
C. Condenser
D. Liquid refrigerant control or regulating valve
E. Liquid receiver

Answer 10

B. Regenerator

Question 11

11.In the compression refrigeration system the work done on the vapour during
compression will cause an increase in the temperature of the vapour to a value
Book 2 PanGlobal Page 107
that is higher than the saturation temperature corresponding to the vapours
pressure. The condition of the vapour is said to be:
A. Super cooled
B. Sub cooled
C. Superheated
D. Super saturated
E. Super tempered

Answer 11

C. Superheated

Question 12

12.The low-pressure side of the compression refrigeration system includes all except
the:
A. Downstream of the regulating valve
B. Condenser
C. Suction of the compressor
D. All interconnected tubing and piping
E. Evaporator

Answer 12

B. Condenser

Question 13

13.A simple closed-cycle compression refrigeration system does NOT contain which
of the following principal components?
A. Evaporator
B. Compressor
C. Condenser
D. Absorber
E. Liquid receiver

Answer 13

D. Absorber

Question 14

14.One of the classes of closed cycle mechanical refrigeration systems is the:
A. Condensation system
B. Absorption system
C. Evaporation system
D. Regeneration system
E. Expansion system

Answer 14

B. Absorption system

Question 15

15.In the compression refrigeration system the pressure in the evaporator is kept low
by the:
A. Regenerator
B. Absorber
C. Evaporator
D. Compressor
E. Condenser

Answer 15

D. Compressor

Question 16

16.In the compression refrigeration system a controlled amount of _____ refrigerant
passes through the regulating valve into the evaporator.
A. High-pressure, low-temperature liquid
B. Low-pressure, high-temperature liquid
C. High-pressure, high-temperature liquid
D. High-pressure, high-temperature vapour
E. High-pressure, low-temperature vapour

Answer 16

C. High-pressure, high-temperature liquid

Question 17

17.In the compression refrigeration system to condense the low-pressure, lowtemperature vapour back to a liquid the \_\_\_\_\_ absorbed in the evaporator must be
removed.
A. Sensible temperature
B. Latent heat
C. Latent temperature
D. Enthalpy
E. Sensible heat

Answer 17

B. Latent heat

Question 18

18.In the compression refrigeration system the low pressure in the evaporator causes
part of the entering liquid to flash into vapour, using the excess _____ in the liquid
as latent heat of vaporization so that the remaining liquid cools down to its boiling
point for that pressure.
A. Latent heat
B. Sensible temperature
C. Latent temperature
D. Enthalpy
E. Sensible heat

Answer 18

E. Sensible heat

Question 19

19.In the compression refrigeration system the high-pressure, superheated vapour is
discharged into the condenser where it gives up, first, the:
A. Sensible temperature
B. Latent heat
C. Latent temperature
D. Sensible heat
E. Enthalpy

Answer 19

A. Sensible temperature

Question 20

20.What is the term used to describe the device used on a centrifugal chiller to
improve efficiency and provide an intercooling effect?
A. Compressor
B. Economizer
C. Expansion valve
D. Condenser
E. Evaporator

Answer 20

B. Economizer