Pressure lines
Temperature lines
Total heat lines
Entropy lines
C. Total heat lines
Ammonia
Carbon dioxide
Sulphur dioxide
R-12
Commercial refrigerators
Domestic refrigerators
Air-conditioning
Gas liquefaction
1/4
1/3
3
4
Ammonia
R-12
Sulphur dioxide
Carbon dioxide
Wet bulb temperature
Relative humidity
Dry bulb temperature
Specific humidity
High
Low
Optimum
Any value
Between the combustion chamber and the first heat exchanger
Between the first heat exchanger and the secondary compressor
Between the secondary compressor and the second heat exchanger
Between the second heat exchanger and the cooling turbine
100°C
50°C
33.3°C
0°C
1 m3 of wet air
1 m3 of dry air
1 kg of wet air
1 kg of dry air
Increases C.O.P
Decreases C.O.P
C.O.P remains unaltered
Other factors decide C.O.P
Condenser
Evaporator
Absorber
None of these
Wet vapour region
Superheated vapour region
Sub-cooled liquid region
None of these
Suction pressure
Discharge pressure
Critical pressure
Back pressure
The standard unit used in refrigeration problems
The cooling effect produced by melting 1 ton of ice
The refrigeration effect to freeze 1 ton of water at 0°C into ice at 0°C in 24 hours
The refrigeration effect to produce 1 ton of ice at NTP conditions
Equal to
Less than
Greater than
None of these
Frosting evaporator
Non-frosting evaporator
Defrosting evaporator
None of these
(td₁ -td₃)/( td₂ -td₃)
(td₂ -td₃)/( td₁ -td₃)
(td₃ -td₁)/( td₂ -td₃)
(td₃ -td₂)/( td₁ -td₃)
Cost is too high
Capacity control is not possible
It is made of copper
Required pressure drop cannot be achieved
-56.6°C
-75.2°C
-77.7°C
-135.8°C
It is toxic to mucous membranes.
It requires large displacement per TR compared to fluoro carbons.
It reacts with copper and its alloys.
All of these
Freezing coil
Cooling coil
Chilling coil
All of these
Heat of compression
Work done by compressor
Enthalpy increase in compressor
All of the above
Ineffective refrigeration
High power consumption
Freezing automatic regulating valve
Corrosion of whole system
Saturated liquid
Wet vapour
Dry saturated vapour
Superheated vapour
Same as
Lower than
Higher than
None of these
Vertical and uniformly spaced
Horizontal and uniformly spaced
Horizontal and non-uniformly spaced
Curved lines
Increase
Decrease
May increase or decrease depending on the type of refrigerant used
Remain unaffected
In vapour absorption refrigerator, the compression of refrigerant is avoided.
Sub-cooling can be achieved by circulating more quantity of cooling water through the condenser.
In vapour compression refrigeration, the vapour is drawn in the compressor cylinder during its suction stroke and is compressed adiabatically during the compression stroke.
All of the above
Absolute
Relative
Specific
None of these
Can be lower or higher than that of the entering air
Is lower than that of the entering air
Is higher than that of the entering air
None of the above