REFRIGERATION & AIR CONDITIONING c c c
Refrigeration:-
It is a process of maintaining a lower temperature as compared to thesurroundings.
c c c c c c c c c c c c c
(Special type of cooling where our working range is below the atmospherictemperatur
c c c c c c c c c c c c
e.)
Refrigerants:-
A substance that is used to maintain lower temperature as compared tosurroundings.
c c c c c c c c c c c c
Unit of Refrigeration (TON of Refrigeration):-
c c c c c
1 TON = 907 Kg
c c c c (British-US) or 1016 Kg c c c (British-
UK)1 Tonne = 1000 Kg (Metric)
c c c c c c
1 TR = 12000 BTU (British Thermal Unit)
c c c c c c c
British Thermal Unit:-
c c
It is the amount of heat required to raise the temperature of 1 pound of water by10 F
c c c c c c c c c c c c c c c c c c
ahrenheit.
1 BTU = 0.2522 Kcal or 1055 J
c c c c c c c
1 Kcal = 3.965 BTU
c c c c
1 TON Refrigeration:-
c c
It is the amount of heat required to reduce from 1 TON of water at 00C in orderto co
c c c c c c c c c c c c c c c c c c c
nvert it into 00C of ice in 24 hrs.
c c c c c c c c
1 TR = 12000 ×1055 = 3.516 Kw or 210 KJ/min or 50.4 Kcal/min
c c c c c c c c c c c c c
3600
,There are five types of cycles –
c c c c c c
a) Ideal refrigeration cycle c c
b) Ice refrigeration cycle
c c
c) Dry ice refrigeration cycle (Dry CO2, used for transport)
c c c c c c c c
d) Evaporative refrigeration cycle (Maximum use in India) c c c c c c
e) Expansion refrigeration cycle c c
Formulae – c
𝑇2
ƞrev = 1 − c c c c
𝑇1
𝑇𝐿 𝑅.𝐸. 𝑅.𝐶.
COP = c or or
𝑇𝐻c −c𝑇𝐿 𝑊𝐼/𝑃 𝑃𝐼/𝑃
✓ For a given refrigeration capacity greater is the C.O.P. lesserwi
c c c c c c c c c c
ll be the running cost.
c c c c
(It is directly connected with Running Costs)
c c c c c c
❖ COPAC > COPRef
(Running Cost)AC > (Running Cost)Ref c c c c
Ƞ<1 c c
→ Low grade energy (I/P) to High grade energy (O/P)C
c c c c c c c c c c
OP > 1 c c → High grade energy (I/P) to Low grade energy (O/P)
c c c c c c c c c
➢ All reversible process is a prolonged process. But if we aretal
c c c c c c c c c c c
king about the comparison
c c c
(Rev. Adiabatic is a little bit faster than Rev. Isothermal.)
c c c c c c c c c
➢ Ideal Ref. cycle has both isothermal and adiabatic so this cycle isnot
c c c c c c c c c c c c
possible. We are using this cycle only for comparison.
c c c c c c c c c
➢ The isothermal process tends to be a Quasi-static process.
c c c c c c c c
, VCRS (Vapour Compression Refr. System)
c c c c
qrej
Cond.
Exp.
mp
Co
c
(Throttling)
Evap.
qadd
GRAPH – c
Temperature Vs Entropy -
c c c
Refrigeration:-
It is a process of maintaining a lower temperature as compared to thesurroundings.
c c c c c c c c c c c c c
(Special type of cooling where our working range is below the atmospherictemperatur
c c c c c c c c c c c c
e.)
Refrigerants:-
A substance that is used to maintain lower temperature as compared tosurroundings.
c c c c c c c c c c c c
Unit of Refrigeration (TON of Refrigeration):-
c c c c c
1 TON = 907 Kg
c c c c (British-US) or 1016 Kg c c c (British-
UK)1 Tonne = 1000 Kg (Metric)
c c c c c c
1 TR = 12000 BTU (British Thermal Unit)
c c c c c c c
British Thermal Unit:-
c c
It is the amount of heat required to raise the temperature of 1 pound of water by10 F
c c c c c c c c c c c c c c c c c c
ahrenheit.
1 BTU = 0.2522 Kcal or 1055 J
c c c c c c c
1 Kcal = 3.965 BTU
c c c c
1 TON Refrigeration:-
c c
It is the amount of heat required to reduce from 1 TON of water at 00C in orderto co
c c c c c c c c c c c c c c c c c c c
nvert it into 00C of ice in 24 hrs.
c c c c c c c c
1 TR = 12000 ×1055 = 3.516 Kw or 210 KJ/min or 50.4 Kcal/min
c c c c c c c c c c c c c
3600
,There are five types of cycles –
c c c c c c
a) Ideal refrigeration cycle c c
b) Ice refrigeration cycle
c c
c) Dry ice refrigeration cycle (Dry CO2, used for transport)
c c c c c c c c
d) Evaporative refrigeration cycle (Maximum use in India) c c c c c c
e) Expansion refrigeration cycle c c
Formulae – c
𝑇2
ƞrev = 1 − c c c c
𝑇1
𝑇𝐿 𝑅.𝐸. 𝑅.𝐶.
COP = c or or
𝑇𝐻c −c𝑇𝐿 𝑊𝐼/𝑃 𝑃𝐼/𝑃
✓ For a given refrigeration capacity greater is the C.O.P. lesserwi
c c c c c c c c c c
ll be the running cost.
c c c c
(It is directly connected with Running Costs)
c c c c c c
❖ COPAC > COPRef
(Running Cost)AC > (Running Cost)Ref c c c c
Ƞ<1 c c
→ Low grade energy (I/P) to High grade energy (O/P)C
c c c c c c c c c c
OP > 1 c c → High grade energy (I/P) to Low grade energy (O/P)
c c c c c c c c c
➢ All reversible process is a prolonged process. But if we aretal
c c c c c c c c c c c
king about the comparison
c c c
(Rev. Adiabatic is a little bit faster than Rev. Isothermal.)
c c c c c c c c c
➢ Ideal Ref. cycle has both isothermal and adiabatic so this cycle isnot
c c c c c c c c c c c c
possible. We are using this cycle only for comparison.
c c c c c c c c c
➢ The isothermal process tends to be a Quasi-static process.
c c c c c c c c
, VCRS (Vapour Compression Refr. System)
c c c c
qrej
Cond.
Exp.
mp
Co
c
(Throttling)
Evap.
qadd
GRAPH – c
Temperature Vs Entropy -
c c c
