VAPOUR ABSORPTION SYSTEM

The vapour absorption system uses heat energy instead of mechanical energy in order to change the conditions of the refrigerant required for the operation of the refrigeration cycle. In the vapour absorption system, the compressor is replaced by an absorber, a pump, a generator and a pressure reducing valve. The vapour refrigerant from the evaporator is drawn into the absorber where it is absorbed by the weak solution of the refrigerant forming a strong solution. This strong solution is pumped to the generator where it is heated by some external source like steam or heating oil. During the heating process, the vapour refrigerant is driven off by the solution and enters into the condenser where it is liquefied. The liquid refrigerant then flows into the evaporator, thereby completing the cycle. A line diagram of vapour absorption refrigeration system is shown in Fig. 19.22.

Figure 19.22 Vapour absorption refrigeration system