After that, the absorbate in liquid phase is throttled to the evaporator at state 4 of which an evaporator pressure (P ) is lower than that of the condenser. The evaporator is heated at a low temperature (T ) around 0-20°C and the absorbate in form of vapor enters the absorber which has the same pressure as the evaporator at state 5. Meanwhile, liquid mixture from the generator, at state 6 is sent through a solution heat exchanger at state 7 into the absorber to the low pressure at state 8 through expansion device.