Employing natural fluids in refrigerating plants at warm climate conditions sometimes impacts negatively on
the system performance. Ejectors can play a key role in configurations aiming at improving the efficiency of
such systems, however their geometry has to be optimized in order to gain the best benefit. Scope of this
work is a numerical investigation on the geometry of the ejector in a cascade plant configuration with natural
refrigerants, aiming at identifying the influence of various geometry aspects on the performance of the
system. A one-dimensional model is employed for the ejector, while the performance of the refrigerating
plant is evaluated in different operating conditions in order to seek the optimal configuration
