RFRG 6005 - Compression Refrigeration Systems (Chp 17) Flashcards
Which of the following is “not a component of the low pressure”side of the system?
A) The accumulator B) The evaporator C) The downstream side of the regulating valve D) Compressor inlet E) Compressor discharge
E) Compressor discharge
The function of the condenser is to:
A) Vent off vaporised refrigerant
B) Vaporize the liquid refrigerant
C) Pressurise low pressure refrigerant vapour
D) Lower the liquid refrigerant pressure
E) Change high pressure refrigerant vapour to liquid
E) Change high pressure refrigerant vapour to liquid
Note: Function of Condenser
Which of the following are ‘’principal parts” in a closed cycle compression refrigeration system?
i. Absorber
ii. Evaporator
iii. Compressor
iv. Condenser
A) iii only B) Both i and ii C) ii, iii, iv D) i, ii, iv E) i, ii, iii
C) ii, iii, iv Note: Evaporator Compressor Condenser Keyword: ECC
Which of the following statements about high-side pressure and temperature is true?
A) The heat flow is from the cooling medium to the hot refrigerant
B) The condenser functions by taking latent heat from the surrounding air and adding it as sensible heat to the refrigerant
C) The condensation temperature of the refrigerant will be higher if the pressure of the vaporized refrigerant is lowered
D) The condensing temperature of the vapour is 15°-30°C higher than the temperature of the medium used in the condenser
E) None of the above
D) The condensing temperature of the vapour is 15°-30°C higher than the temperature of the medium used in the condenser
Brine used for producing ice is generally a solution of:
A) Calcium chloride B) Glycol C) Sodium sulphite D) Sodium chloride E) Alcohol
A) Calcium chloride
Note: Brine Producing Ice
The heat lost by the brine in the evaporator, must equal the heat:
A) Gained by the receiver B) Gained by the refrigerant C) Lost by the condenser D) Gained by the condenser E) Produced by the compressor
B) Gained by the “refrigerant”
Note Keyword:Refrigerant
Which of the following statements about a refridgeration system that circulates warm brine back to a chiller tank is true?
A) The evaporator in the system is located in direct contact with the material being refrigerated
B) The brine or water is the refrigerant
C) The evaporator cools the brine
D) The condenser in the system is located in direct contact with the material being refrigerated
E) The system is a direct refrigeration system
C) The evaporator cools the brine
For a direct expansion system which of the following statements is true?
A) The evaporator in this system is never in direct contact with the material or space being refrigerated
B) For large system calcium chloride brine is cooled by the evaporator then pumped to the area being refrigerated
C) Chilled water is pumped to unit ventilators
D) Water cooled by the chiller evaporation coils is used to refrigerate at temperature below 0°C
E) The evaporator can be located in air circulating ducts communicating with the material or space being refrigerated
E) The “evaporator can be located in air circulating ducts” communicating with the material or space being refrigerated
Which of the following statements about low-side pressure and temperature is false?
A) The evaporation temperature of the refrigerant will be lower if the evaporator lowers the refrigerant pressure
B) The evaporation temperature of the refrigerant should be 5° - 10°C higher than that of the cooled medium
C) The low side pressure depends on the type of evaporation used
D) For a given amount of heat transfer an oversized evaporator can be operated at a higher temperature
E) All of the above
B) The evaporation temperature of the refrigerant should be 5° - 10°C higher than that of the cooled medium
The primary difference between direct and indirect refrigeration systems is the:
A) Compressor location B) Type of refrigerant C) Evaporator pressure D) Type of heat transfer medium E) Location of the medium being cooled
E) Location of the medium being cooled
In actual refrigeration systems there will be a gradual pressure drop through each side of the system due to:
A) Superheating effects
B) Coefficients of expansion of system components
C) Friction in the evaporator, condenser, and piping
D) Decomposition of refrigerants
E) The economizer
B) Coefficients of expansion of system components
