Compared to mechanical compressors, ejector-based refrigeration systems can make direct use of many forms thermal energy, including waste heat, solar thermal, or biogases. It is known that SE have a lower efficiency compared compressors because their performance at high compression ratios. In the present work, binary fluid ejector heat pumps with are presented based on proper selection fluids a...

Abstract The large-scale deployment of ejector refrigeration systems (i.e., solar-based systems), although representing a promising alternative compared with mechanical compressor ones, is hindered due to limitations regarding control modes. Indeed, ejectors are fluid-dynamics controlled devices and, because their fixed geometry, they operate at highest efficiency in narrow range operating cond...

In this work, a novel dual-nozzle ejector enhanced triple-evaporator refrigeration cycle (DETRC) without separator is proposed to improve the performance of the conventional ejector one (CETRC). The performance of DETRC is analyzed and compared with CETRC in term of energy coefficient of performance (COPen). Under given operating conditions, the COPen improvement of the no...

Ejectors are simple mechanical devices with no moving parts which convert the pressure energy of a motive fluid to kinetic and generate suction secondary fluid. The ability recover waste heat, operate using solar power use geothermal make ejector-based systems attractive in different industrial applications. main challenge refrigeration is their relatively low coefficient performance (COP). In ...

In the present work, the performances of improved two-stage multi inter-cooler trans- critical carbon dioxide (CO2) refrigeration cycles with ejector and internal heat exchanger have been examined. In the new improved cycles, an internal heat exchanger is append to the cycles. Also, second inter-cooler in improved cycles, cooled with the refrigeration of the cycle, so that in first c...

Abstract The following work documents the effect of streamwise vortices generated at the nozzle exit of an axisymmetric air jet on the amount of mass entrained into an ejector. In an experimental analysis of the mass entrainment of circular jet ejectors, we found that the introduction of half delta wing vortex generators in the exit of the jet nozzle (Reynolds number of 50,000) increased the am...

A semi-empirical control-volume approach to ejector modeling for transient performance prediction is presented. This new approach is motivated by the need for a predictive real-time ejector sub-system simulation for STOVL integrated flight and propulsion controls design applications. Emphasis is laced on discussion of the approximate characterization of the suggests transient flow predictions a...