This document discusses different types of vapor absorption refrigeration systems. It describes a simple system that uses an absorber, pump, generator and pressure reducing valve instead of a compressor. Ammonia vapor is absorbed by water in the absorber and heated in the generator to drive off the vapor. A practical system improves on this with accessories like an analyzer and rectifier. An Electrolux system uses ammonia, water and hydrogen as three fluids, with hydrogen increasing evaporation and ammonia as the refrigerant. Finally, lithium bromide absorption systems are mentioned.

1. Refrigeration
and
Air-Conditioning
Lecture-5
Mechanical Engg. Department
Geeta Engineering College
Naultha Panipat

2. Simple vapour absorption system

3. Simple vapour absorption system
• In this system an absorber, a pump, a generator and a pressure
reducing valve replace the compressor.
• The low pressure ammonia vapour leaving the evaporator
enters the absorber where it is absorbed by the cold water in
the absorber.
• The water has the ability to absorb the large quantity of
ammmonia vapour.
• Heat is removed in the absorber to increase the absorption
capacity of water.
• The strong solution in the absorber is pumped to the genarator.
• The strong solution is heated in the generator during the
heating the ammonia vapours are driven off the solution and
the weak solution flows back to the absorber.

4. Practical vapour absorption system

5. Practical vapour absorption system
• The simple vapour absorption system discussed previously is
not very economical.
• To improve the effectiveness it is fitted with the accessories an
analyser, a rectifier and two heat exchangers

6. Ammonia Hydrogen (Electrolux)
Refrigeration system

7. Electrolux Refrigeration system
• This type of refrigerator is also called three fluid absorption
system
• The main purpose of this system is to eliminate the pump so
that in the absence of moving part the machine becomes
noiseless.
• The three fluids used are ammonia, water and hydrogen.
• The ammonia act as the refrigerant.
• The hydrogen being the lightest gas is used to increase the rate
of evaporation of the liquid ammonia passing through the
evaporator.
• Water acts as the solvent.

8. Lithium Bromide Absorption system

9. THANKS