This article presents development of a new 2D ejector
model which is validated by experimental data used in
literature. The ejector is combined with a GAX
(generator-absorber heat exchange) absorption
refrigeration cycle using an ammonia-water pair as the
working fluid. Applying the conservations of mass,
energy as well as the exergy balance, the combined
cycle is analyzed from the viewpoints of first and
second laws of thermodynamic. Three optimum critical
area ratios are selected and the effect of generator and
evaporator temperatures is investigated at the constant
ejector area ratios. Results indicate that an increase in
the evaporator temperature leads to an increase of
optimum critical area ratio and entrainment ratio. Also,
it is observed that increasing the evaporator temperature
from 0oC to 100C could raise the entrainment ratio by up
to 50%. It is found that at constant optimum critical area
ratios increasing the generator temperature results in an
increase of COP as well as second law efficiency.
Meanwhile, exergy analysis reveals that the ejector is
one of the highest irreversible sources in the cycle (25%
of total exergy destruction).