Review of recent developments in advanced ejector technology

• Review of recent studies on use of ejector to recover expansion work is presented.
• Recent advances made in modeling, control, and commercialization of ejectors.
• Preferred ejector cycle depends on application and working fluid.
• Energy efficiency improvements range between 5 and 20% depending on fluid.
• System conditions, ejector design, and other components also affect improvement.

Previous reviews on ejectors for expansion work recovery have provided detailed discussions of operating characteristics and control of ejector cycles, zero-dimensional ejector modeling, ejector geometry effects, and alternate ejector cycles. However, important advances in the field of ejector technology have occurred since previous reviews were written. Several focuses of recent ejector research are the development of multi-dimensional CFD ejector models, investigation of alternate ejector cycles and uses of the work recovered by the ejector, implementation of effective control strategies for ejector cycles, and application of ejectors in real systems. The objective of this paper is to present a review of developments in the use of ejectors for expansion work recovery in vapor-compression systems focusing on the past several years. Although the first commercial applications are being introduced to the market, it is suggested that future works continue in these areas in order to make ejectors more suitable for additional applications.