Ejector Selection Made Easy: A New Way of Mapping Performance of Two-phase Ejectors

摘要

Ejector as a work recovery device offers potential for developing energy efficient heating and cooling systemsbased on vapor compression technology. For many applications, the operating conditions vary significantly,leading to considerable performance degradation when system is operated in off-design conditions. Therefore,the system designing warrants development of accurate ejector performance models for wide range ofoperating conditions. In this paper, a novel methodology for ejector performance maps is proposed using theejector efficiency as performance parameter and the volumetric entrainment ratio as characterizing parameter.The proposed performance map is developed after conducting experiments to find appropriate performancerepresentation where ejector driven flow can be characterized using ejector motive flow. The developedperformance map can predict ejector pressure lift within an accuracy of 20% using an iterative solver. In alater part of the paper, a system design study is conducted to select optimum ejector for a given compressorusing proposed ejector performance maps.