1. Lecture Objectives:
Aabsorption cooling cycles

2. Absorption cooling cycle
Rich solution of
Heat
H2O
H2O + NH3
Rich solution of
H2O
H2O + NH3

3. Simple absorption system3V 3L
3LLP

4. Simple absorption system
Saturated vapor at p2=p3=p4 3V 6 3 5V
mixing 1’
Needed
thermal
energy
Useful
cooling
energy 3L 4
3LLP 5 2
Saturated liquid at p2=p3=p4 1 5L
Saturated liquid at p1=p5=p6=p3_LLP

5. Heat transfer with separation into liquid and vapor (Generator)
How to move
point 4 to right ?
=2V
=2V
heating m4
Q12 /m1
2L=
2L=
=m2 m1
=m2
mixture
Separator
sub cooled
liquid
mixture x1 x1
Q12 m3
Q12 m3

6. Heat rejection with separation into liquid and vapor (Enrichment NH3 in the vapor mixture)
This is our point
cooling 1
4=2V
Separator
6=5V
Q12 /m1
cooling
Q45 /m4 x8 m8 8 7 m1
=m2 5 2
sub cooled
liquid
mixture
isotherm m3 2L
Q12 x1 x8

7. Simple absorption system
Generator with of Enrichment NH3
Different 8V 9 8L 10
8LLP 11

8. Absorption system with
Saturated vapor at p2=p3=p4 3V 8V 3
mixing 11 8L 1’
Useful
cooling
energy
8LLP 10 3L 2 9
Saturated liquid at p2=p3=p4 1
Saturated liquid at p1=p5=p6=p3_LLP

9. More detailed absorption cooling
Refrigeration and air conditioning (Ramesh et al)

10. Carnot Cycle
COPvapor_compression=Qcooling/Pelectric COPmax=Tcooling/(Tenviromnet-Tcooling)
COPabsorption=Qcooling/Qheating COPmax= Tcooling/Theat_source ∙ (Theat_source-T environment)/(Tenviromnet-Tcooling)