Which among the following is undesirable property of a good refrigerant?
Which of the following is not true in respect of an ideal refrigerant?
Desirable properties of an ideal refrigerant:
-Low boiling point
- High critical temperature
- High latent heat of vaporization
- Low specific heat of liquid
- Low specific volume of vapour
- Non-corrosive to metal
- Non-flammable and non-explosive
- Low cost
- Easy to liquify at moderate pressure and temperature
- Easy of locating leaks by odour or suitable indicator
- Mixes well with oil
Match List-I (Characteristics) with
(Refrigerant) the following:
A. Lowest boiling point
B. Highly toxic and flammable
C. Highest freezing point
D. Highest critical
2. Carbon dioxide
4. R-22 pressure
R-12 is generally preferred over R-22 in deep freezers since
Environmental protection agencies advice against the use of chlorofluoro-carbon refrigerants because
A single atom of Cl released from CFC reacts taking out 105 O3 molecules.
The selection of refrigerant for a vapour compression system depends on
2. Environmental effect
3. Saturation pressure-temperature relationship
Q. Which of these statements are correct?
Match the List-I (Refrigerants) with List-II (Application) following
Reciprocating & screw compressors Cold storages ice plants, Food refrigeration
Water-lithium bromide Steam ejector system only for air-conditioning
Reciprocating compressors in small unit Domestic refrigerators, water coolers
Frozen-food transport refrigeration
Used with centrifugal compressors in large capacity central air-conditioning plants.
When there is leakage of ammonia refrigerant, the sulphur stick gives
For ammonia leaks, a burning sulphur taper is used which in presence of ammonia forms white fumes of ammonia sulphate
Which of the following leak-detection method is extensively used in the manufacture and assembly of refrigerant equipment?
An electronic leak detector is most sensitive and is used in the manufacturing and assembly of refrigerant equipment. The operation of the instrument depends on the flow of current due to the ionization of the leakage gas between two opposite-charged platinum electrode.
The leaks in a refrigeration system using Freon are detected by