RECENT DEVELOPMENTS IN THE DESIGN THEORIES AND APPLICATIONS OF EJECTORS - A REVIEW

Since ejectors were first developed, research effort has been devoted to the improvement of design methods and to new applications. Ejectors can be used to pump both incompressible and compressible fluids, but the flow and mixing of compressible fluids within ejectors are difficu lt to analyse. This paper, in reviewing recent achievements, concentra tes on ejectors for compressible fluids. In the analysis and design of ejectors, one-dimensional and two-dimensional methods are available: the one-dimensional methods provide a simple and reasonably accurate w ay but only limited geometrical information, whereas the two-dimension al are more accurate and they provide greater design detail; however, they are difficult to employ in design optimisation. Ejectors have a w ide range of applications, among which refrigeration has a long-establ ished history. Ejector refrigerators working on halocarbon refrigerant s provide a high level of flexibility, but with the phasing-out of ozo ne-damaging refrigerants there is a need for research on alternatives. Ejectors can also be used in solar-powered refrigeration systems and absorption-refrigeration systems. Other newly developed applications a re summarised in this paper, which presents a critical review of more than 100 published papers and is aimed at encouraging further interest among energy researchers in the study and application of ejectors.