Conceptual design of binary/multicomponent fluid ejector refrigeration systems

Abstract

Low energy efficiency and limitations of cooling temperatures in the ejector refrigeration systems (ERSs) are major obstacles for its widespread use. The application of binary or multicomponent fluids may prove to be one of the successful ways to increase the ERS performance by 30-50%. Zeotropic mixtures, which have unlimited solubility and evaporate at specified pressures and varying temperatures, are considered as possible candidates to be applied in a binary-fluid ERS (BERS). An ideal candidate working fluid should exhibit high molecular weight, low latent heat of evaporation, high normal boiling temperature and high compressibility factor. A refrigerant fluid should have low molecular weight, high latent heat of evaporation, low boiling point and compressibility factor. BERS pursues simultaneous achievement of two main goals: increase in system's efficiency and take the condensation point up to 45-50°C at fixed coefficient of performance, i.e. employ atmospheric condenser in ERS. This article presents schematic diagrams of a multicomponent-fluid ERS; its cascade principle based on BERS enables to produce cold at several temperature ramps, using renewable or low-grade heat sources. Research outcomes from this article can improve the effective application of ejector technology. © The Author 2012. Published by Oxford University Press. All rights reserved.