Vapour Absorption Refrigeration(VAR) System
Simple Vapour absorption system consists of evaporator, absorber, generator, condenser, expansion valve, pump & reducing valve. In this system water vapor is used as refrigerant and solution used is LiBr+water. Strong solution of LiBr+water contains as much as water as it can and weak solution contains less water. The compressor of vapour compressor system is replaced by an absorber, generator, reducing valve and pump. The heat flow in the system at generator, and work is supplied to pump. Water vapour coming out of evaporator are drawn in absorber. The weak solution containing very little water is spread in absorber. The weak solution absorbs water vapor and gets converted into strong solution. This strong solution from absorber is pumped into generator. The addition of heat liberates water vapour and solution gets converted into weak solution. The released vapour is passed to condenser and weak solution to absorber through a reducing valve. Thus, the function of a compressor is done by absorber, a generator, pump and reducing valve. The simple vapour compressor system is used where there is scarcity of Electricity and it is very useful at partial and full load. This system is also compatible for aqua ammonia as refrigerant.