Coefficient of performance of refrigeration
Coefficient of performance of heat pump
Relative coefficient of performance
Refrigerating efficiency
A. Coefficient of performance of refrigeration
Wet bulb temperature
Relative humidity
Dry bulb temperature
Specific humidity
21 kJ/min
210 kJ/min
420 kJ/min
620 kJ/min
1
1.25
2.15
5.12
Reduce compressor overheating
Reduce compressor discharge temperature
Increase cooling effect
Ensure that only liquid and not the vapour enters the expansion (throttling) valve
Bigger
Smaller
Equal
Smaller/bigger depending on capacity
Low boiling point
High critical temperature
High latent heat of vaporisation
All of these
Remains constant
Increases
Decreases
None of these
Reciprocating
Rotating
Centrifugal
Screw
Absolute
Relative
Specific
None of these
It considerably reduces mass of the system
It improves the C.O.P., as the condenser is small
The positive work in isentropic expansion of liquid is very small
It leads to significant cost reduction
A gas will never liquefy
A gas will immediately liquefy
Water will evaporate
Water will never evaporate
Same as
Lower than
Higher than
None of these
1/4
1/3
3
4
Carnot cycle
Rankines cycle
Reversed Carnot cycle
None of the above
Critical pressure of refrigerant
Much below critical pressure
Much above critical pressure
Near critical pressure
CO₂
Ammonia
R-12
All of these
Centrifugal
Axial
Miniature sealed unit
Piston type reciprocating
Decrease in fin spacing and increase in number of rows
Increase in fin spacing and increase in number of rows
Increase in fin spacing and decrease in number of rows
Decrease in fin spacing and decrease in number of rows
Horizontal line
Vertical line
Inclined line
Curved line
Lithium bromide used in vapour absorption cycle is non volatile
Lithium bromide plant can't operate below 0°C
A separator is used in lithium bromide plant to remove the unwanted water vapour by condensing
Concentration of solution coming out of lithium bromide generator is more in comparison to that entering the generator
-56.6°C
-75.2°C
-77.7°C
-135.8°C
After passing through the condenser
Before passing through the condenser
After passing through the expansion or throttle valve
Before entering the compressor
Small
High
Equal
Anything
Very little work input
Maximum work input
Nearly same work input as for vapour compression cycle
Zero work input
Pressure lines
Temperature lines
Total heat lines
Entropy lines
B.P.F. - 1
1 - B.P.F.
1/ B.P.F.
1 + B.P.F.
Heated and dehumidified
Heated and humidified
Cooled and humidified
Cooled and dehumidified
Liquid pump
Generator
Absorber and generator
Absorber, generator and liquid pump
After passing through the condenser
Before passing through the condenser
After passing through the expansion or throttle valve
Before entering the expansion valve
Receiver
Expansion valve
Evaporator
Compressor discharge