3B2 Ch 10 Flashcards
The liquid receiver in a refrigeration system is a(n):
Select one:
a.
Oil storage unit
b.
Storage vessel for liquid brine
c.
Contaminated liquid storage tank
d.
Surge vessel for vapour refrigerant
e.
Pressure vessel
e.
Pressure vessel
How many basic elements are common to most compression refrigeration systems?
Select one:
a.
2
b.
3
c.
4
d.
5
e.
6
d.
5
B2C10Q06 The work of compression represented on a pH diagram is the difference in enthalpy __________.
Select one:
a.
h2 – h3
b.
h1 – h2
c.
h1 – h4
d.
h2 – h1
d.
h2 – h1
What is the definition of a refrigerant?
Select one:
a.
A liquid that absorbs heat at high pressure and gives up heat at low pressure
b.
A fluid that absorbs heat at a low temperature and pressure and gives up heat by condensing at a higher temperature and pressure
c.
A fluid that absorbs heat at a high temperature and pressure and gives up heat by condensing at a lower temperature and pressure
d.
A medium for creating heat
e.
A fluid that absorbs heat at a high pressure
b.
A fluid that absorbs heat at a low temperature and pressure and gives up heat by condensing at a higher temperature and pressure
In the basic absorption system, what is the dividing line between the high side and the low side?
Select one:
a.
The aqua pump and the expansion valve
b.
The aqua pump and the condenser
c.
The generator and the receiver
d.
The expansion valve and the generator
e.
The aqua pump and the generator
a.
The aqua pump and the expansion valve
When is a two-stage, duplex compressor refrigeration system used?
Select one:
a.
When moderate, low temperatures are desired
b.
When extremely low temperatures are desired
c.
When small quantities of refrigerant are required
d.
When high quantities of refrigerant are required
e.
When the cost of refrigerant is high
b.
When extremely low temperatures are desired
In a mechanical vapour compression system, what is the function of the compressor?
Select one:
a.
Compress the vapour, so that heat can be easily removed
b.
Establish two pressure levels
c.
Reduce the temperature of the refrigerant gas
d.
Control the flow of refrigerant to the evaporator
e.
Condense the high-pressure gas
b.
Establish two pressure levels
B2C10Q07 For a multi-stage refrigeration system, the expansion valve is controlled by the __________ in the flash economizer.
Select one:
a.
Vapour pressure
b.
Liquid temperature
c.
Liquid level
d.
Vapour temperature
c.
Liquid level
Some reciprocating compressors on ammonia systems are protected from liquid slugs by:
Select one:
a.
Spring loaded safety heads
b.
Automatic drain traps
c.
Extra heavy valves
d.
Low-pressure cut outs
e.
High-water cut outs
a.
Spring loaded safety heads
B2C10Q04 In the ammonia-CO2 cascade system, the __________ for the ammonia system is also the __________ for the CO2 system.
Select one:
a.
Condenser, evaporator
b.
Evaporator, condenser
c.
Condenser, receiver
d.
Receiver, evaporator
b.
Evaporator, condenser
Comparing refrigerating systems is usually done at which temperatures?
Select one:
a.
40°C condensing and 10°C evaporating
b.
30°C condensing and –15°C evaporating
c.
45°C condensing and 0°C evaporating
d.
–15°C condensing and 30°C evaporating
e.
50°C condensing and –5°C evaporating
b.
30°C condensing and –15°C evaporating
An ideal refrigerant should:
Select one:
a.
Be non-poisonous, non-stable, non-flammable, and non-corrosive
b.
Have a high boiling point and be oil miscible, detectable when leaked, and inexpensive
c.
Have an inoffensive odor, boil at a low temperature, and be non-corrosive and stable
d.
Be non-corrosive, stable, and not easily detectable when leaking
e.
Be non-poisonous, stable, flammable, and non-corrosive
c.
Have an inoffensive odor, boil at a low temperature, and be non-corrosive and stable
Where is the difference of the enthalpy of ammonia as a fluid at saturation conditions of 1167.2 kPa (abs) and 236.17 kPa (abs) found?
Select one:
a.
hf column and is 210.54 kJ/kg
b.
hf and hg columns and is 1144.41 kJ/kg
c.
hf and hg columns and is 1313.15 kJ/kg
d.
hg column and is 41.8 kJ/kg
a.
hf column and is 210.54 kJ/kg
