Book 2: 4-16 - "Refrigerants" Flashcards
Liquid refrigerants absorb heat by evaporating at a low temperature and pressure and then give up that heat by _____ at a higher temperature and pressure.
Select one:
A. Regenerating
B. Condensing
C. Fusing
D. Evaporating
E. Absorbing
B. Condensing
Refrigerants that are highly flammable and highly toxic belong to Group:
Select one:
A. B2
B. B3
C. B1
D. A2
E. A3
B. B3
The saturation temperature (boiling/condensing temperature) of a liquid in a closed vessel can be raised or lowered by altering the _____ the vessel.
Select one:
A. Temperature in
B. Volume of
C. Pressure on
D. Density in
E. Pressure in
E. Pressure in
The ability of a refrigerant to be dissolved into oil and vice versa is called:
Select one:
A. Density
B. Miscibility
C. Enthalpy
D. Moisture reaction
E. Leakage tendency
B. Miscibility
What is the boiling temperature of R-134a (Freon 34a)at atmospheric conditions?
Select one:
A. 3.6°C (38.5°F)
B. -33.3°C (-27.94°F)
C. -26.1°C (-14.98°F)
D. -40.8°C (-41.44°F)
E. 47.6°C (117.68°F)
C. -26.1°C (-14.98°F)
What is the boiling temperature of R-22 (Freon 22) at atmospheric conditions?
Select one:
A. -40.8°C (-41.44°F)
B. 47.6°C (117.68°F)
C. 3.6°C (38.5°F)
D. -26.1°C (-14.98°F)
E. -33.3°C (-27.94°F)
A. -40.8°C (-41.44°F)
Which one of the following factors affect the leakage tendency of a refrigerant?
Select one:
A. Density
B. Specific volume
C. Enthalpy
D. Temperature
E. Miscibility
A. Density
Moisture in the refrigerant may lead to:
Select one:
A. Over cooling of the refrigerant
B. Ice formation between the valve and valve seat of the regulating or expansion valve
C. High pressure in the evaporator
D. Low temperature in the condenser
E. Ice forming in the condenser
B. Ice formation between the valve and valve seat of the regulating or expansion valve
In an ideal situation the refrigerating effect of a refrigerant is equal to the _____ of the refrigerant.
Select one:
A. Latent heat of fusion
B. Sensible heat of fusion
C. Temperature of evaporation
D. Latent heat of evaporation
E. Temperature of fusion
A. Latent heat of fusion
Which of the following refrigerants is not miscible with oil?
Select one:
A. Freon 11 (R-11)
B. Freon 12 (R-12)
C. Ammonia (R-717)
D. Freon 22 (R-22)
E. Freon 134a (R-134a)
C. Ammonia (R-717)
What must be provided when using a halide leak detector or when soldering or brazing on a refrigeration system?
Select one:
A. Sufficient flow from the leak source
B. A Class ABC Fire Extinguisher
C. Adequate ventilation
D. Cool refrigerant temperatures
E. Sufficient detectable odour from the refrigerant
C. Adequate ventilation
Refrigerants are classified in the Canadian Standards Association B52-05 Mechanical Refrigeration Code by their toxicity and flammability into the following _____ groups.
Select one:
A. Four
B. Six
C. Five
D. Two
E. Three
B. Six
Liquid refrigerants are fluids that, at atmospheric pressure, have a boiling point considerably:
Select one:
A. Lower than that of water
B. High than that of water
C. Higher than that of oxygen
D. Lower than that of oil
E. Lower than that of oxygen
A. Lower than that of water
Refrigerants that are non-toxic and non-flammable belong to Group:
Select one:
A. A1
B. B2
C. A2
D. A3
E. B1
A. A1
Refrigerants that are highly flammable with low toxicity belong to Group:
Select one:
A. B2
B. A2
C. B1
D. B3
E. A3
E.
A3
The important physical properties of a refrigerant include all except:
Select one:
A. Leakage tendency
B. Toxicity
C. Enthalpy
D. Moisture reaction
E. Odour
C. Enthalpy
The condition known as “standard condition” indicates a standard evaporator temperature of:
Select one:
A. -10°C (14°F)
B. -15°C (5°F)
C. -30°C (-22°F)
D. 30°C (86°F)
E. 15°C (59°F)
B. -15°C (5°F)
Thermodynamic properties directly affect the movement of heat. Which of these is NOT a thermodynamic property?
Select one:
A. Leakage tendency
B. Enthalpy
C. Pressure
D. Volume
E. Density
A. Leakage tendency
Which one of the following factors affect the leakage tendency of a refrigerant?
Select one:
A. Temperature
B. Viscosity
C. Specific volume
D. Enthalpy
E. Miscibility
B. Viscosity
An ideal refrigerant should NOT have which of the following characteristics:
Select one:
A. A fairly low condensing pressure
B. A non-flammable and non-explosive nature when mixed with air
C. A low boiling point at atmospheric pressure
D. A low latent heat capacity
E. A non-poisonous nature
D. A low latent heat capacity
