VC Cycle

1. CAREER POINT UNIVE
MAJOR ASSIGNMENT
Vapours Compression Refrigeration Cycle

2. Table of Content
 Refrigeration
 Refrigerant
 Vapour compression cycle
 Effect
 Cop
 Merit
 Demerit
 Advantage
 By studying of research paper

3. Refrigeration
 Refrigeration is the process of producing of lower temperature compare to
the surrounding temperature to maintain the lower temperature.
 For example : vapour compression cycle, vapour absorption cycle, gas
refrigeration cycle.

4. Refrigerant
 Refrigerant are the substance which are used for producing lower
temperature .for example ammonia,water,air,R-12,R-22,R-134.
Refrigeration effect: It is the amount of heat which is to be extracted
from the storage space in order to maintain lower temperature is called
desire effect of refrigeration system.

5. Vapour compression Refrigeration System:
There are four component in Vapour compression cycle.
1. Compressor:- Compresses the refrigerant to high pressure and temperature from low
pressure and temperature.
2. Condenser:- The latent heat of refrigerant is removed by circulating water or
atmospheric air.
3. Expansion Valve:- In the throttle valve where the pressure is reduced at a
controlled rate.
4. Evaporator:- A liquid-Vapour mixture refrigerant then enters the evaporator at low
pressure where the latent heat of evaporation is converted into vapour and the cycle repeats.

7. Apply Steady flow energy equation ( Neglect K.E & P.E changes)
1. Compressor:
Q1-2 + C1
2/2 + Z 1 + h1 = W1-2 + C2
2/2 + Z 2+ h2
W1-2 = - ( h2 – h1)
2. Condenser:
Q2-3 + C2
2/2 + Z 2 + h2 = W2-3 + C3
2/2 + Z 3+ h3
Q2-3 = - (h2 - h3)
3. Throttle Valve:
Q3-4 + C3
2/2 + Z 3 + h3 = W3-4 + C4
2/2 + Z 4+ h4
h3 = h4 (Isenthalpic process)
4. Evaporator:
Q4-1 + C4
2/2 + Z 4 + h4 = W4-1 + C1
2/2 + Z 1+ h1
Q4-1 + h4 = h1
Q4-1 = h1 – h4

8. Co-efficient of Performance: It is the ratio of net refrigerating effect to the work
required to produce that effect.
Co-efficient of performance = Refrigerating effect/ Work input
= ( h1 – h4 ) / (h2 – h1)

9. RE= h1-h4
Win=h2-h1
COP= RE/Win

10. Effect
Reduction in Refrigeration effects
Increase in work input
Decrease in COP
Decrease in volumetric efficiency due to increase in pressure ratio.

11. RE= h1-h4
Win=h2-h1
COP= RE/Win
 Case 2:- Increase in condenser pressure

12. Effect
Reduction in Refrigeration effects
Increase in work input
Decrease in COP
Decrease in volumetric efficiency due to increase in pressure ratio.

13. RE= h1-h4
Win=
COP= RE/Win
 Case 3:- Superheating

14. Effect
Increase in Refrigeration effect
Increase in work input due to temperature at the inlet to compressor
increase.
COP may increase or decrease depending on the refrigerant. In case of R-
12 superheating result in increase in COP where as in case of NH3
superheating results in decrease in COP.

15. MERIT
 Cop is high.
 Size of evaporator is small.
 Evaporator temperature adjustment is small.
 Easily available .
 It is used for small places like shops.

16. Demerit
 Initial cost is high.
 Inflammability
 Leakage
 Toxicity

17. Advantages
 Lot of heat can be removed (lot of thermal energy to change liquid to
vapors).
 heat transfer rate become high(temperature of working fluid much lower
than what is being cooled).

18. Studying by research paper
 By getting result of R134a is a best refrigerant among all refrigerant.
 Because COP is lower as compare to other refrigerant
 That’s why R-134 is a eco-friendly in nature .

19. Conclusion
 At finally we conclude that v c cycle is work on high grade energy and it is
where used there is small space
 It is used for making environment cool