Double Lift Hot water driven absorption chiller has main cycle and aux. cycle 
 The chilled water is cooled down in evaporator and the vaporized refrigerant is absorbed into concentrated solution which is coming from 2nd generator. The concentrated solution becomes diluted solution and the heat is absorbed into cooling water.
 The diluted solution in absorber flows to 1st generator through low temp. heat exchanger and high temp. heat exchanger, and 95oC of driving hot water heats up the diluted solution and refrigerant vapor is generated.
 The absorbent solution in 1st generator becomes intermediate solution and it flows to 2nd generator through high temp.
 heat exchanger. The intermediated solution in 2nd generator is heated up by driving hot water and the refrigerant vapor is generated. The vaporized refrigerant from 2nd generator is absorbed into absorbent solution in aux. absorber and it becomes aux. diluted solution.
 The aux. diluted solution is delivered to aux. generator through aux. heat exchanger, and the solution is heated up by driving hot water return from 2nd generator and becomes aux. concentrated solution. The aux. concentrated solution is delivered to aux. absorber through aux. heat exchanger.
 The refrigerant vapors which are generated 1st generator and aux. generator are condensed in condenser and then flow into evaporator, and the heat in condenser is absorbed by cooling water.