Journal ArticleDOI
A 1-D analysis of ejector performance
TLDR
In this paper, a 1D analysis for the prediction of ejector performance at critical-mode operation is carried out, where constant pressure mixing is assumed to occur inside the constant-area section of the ejector and the entrained flow at choking condition is analyzed.Abstract:
A 1-D analysis for the prediction of ejector performance at critical-mode operation is carried out in the present study. Constant-pressure mixing is assumed to occur inside the constant-area section of the ejector and the entrained flow at choking condition is analyzed. We also carried out an experiment using 11 ejectors and R141b as the working fluid to verify the analytical results. The test results are used to determine the coefficients, h p, h s, f p and f m defined in the 1-D model by matching the test data with the analytical results. It is shown that the1-D analysis using the empirical coefficients can accurately predict the performance of the ejectors. q 1999 Elsevier Science Ltd and IIR. All rights reserved.read more
Citations
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Proceedings ArticleDOI
Numerical Optimization of Ejector Geometry Based on Non-Dimensional Parameters
TL;DR: In this paper, a new method of size selection for different geometrical parameters of ejectors is introduced, which is based on defining a non-dimensional volume in terms of ejector dimensions.
Experimental investigations of low-temperature driven ejector for isobutane.
TL;DR: In this paper, an experimental and numerical investigation of ejection refrigeration system dedicated for short-time storage of food products for local retail market, especially in rural areas, is described.
Journal ArticleDOI
Exergy analysis of industrial waste heat recovery based ejector vapour compression refrigeration system
Rajesh Kumar,Abdul Khaliq +1 more
TL;DR: In this article, the authors employed a thermodynamic analysis through energy and exergy for the performance evaluation of waste heat recovery based ejector compression refrigeration in which internal heat exchanger and cooler are used to enhance the performance of the cycle.
Dissertation
Development of a hybrid ejector-compressor refrigeration system with improved efficiency
Abstract: The present doctoral dissertation addresses the design of an ejector suitable for a thermally driven hybrid ejector-compressor cooling system; research was aimed at improving the performance of the ejector in terms of both critical backpressure and entrainment ratio. A n ejector efficiency analysis is presented to establish a theoretical limit for the máx imum achievable entrainment ratio of an ejector undergoing a fully reversible process without entropy generation; the main sources of irreversibility wi thin the ejector are subsequently discussed. The shock circle model is implemented as a mean to predict the entrainment ratio for an ejector wi th a given set of nozzle and constant área section diameters; experimental results from the literature are presented and used to valídate the model. A Computational Fluid Dynamics design exploration aimed at identifying the effects of the rest of the key geometrical parameters that are not covered by the mathematical model is also presented. In order to generalize the findings from this study for ejectors of different scales, the results are presented using non-dimensional parameters. The study showed that in order to guarantee a critical mode operation at the range of operating conditions suitable for a hybrid ejector-compressor cycle, only the constant área section or the nozzle throat diameters need to vary accordingly wi th the condenser backpressure. The optimum geometrical parameters found by the design exploration are used to propose an optimized ejector design, the Constant Rate of Momentum Change method is also implemented to genérate a diffuser geometry that reduces one of the sources of entropy generation identified during the first stages of this research. The assessment of the performance increase for the proposed ejector is measured against a baseline design; the results showed that the new ejector outperforms the baseline in terms of both entrainment ratio and critical condenser backpressure. The thesis concludes wi th a study to quantify the thermal efficiency increase of a hybrid ejector-compressor system employing the proposed ejector, lastly, the design for a test stand to experimentally verify the findings of this research work is proposed.
Dissertation
Control of a Fuel Delivery System for Polymer Electrolyte Membrane Fuel Cells based on a Two-Phase Transient Model
TL;DR: This book presents a monograph on the reconstruction of the fluid dynamics of the response of the immune system to the presence of foreign substances.
References
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Journal ArticleDOI
An Investigation of Ejector Design by Analysis and Experiment
Journal ArticleDOI
A theoretical and experimental study of a small-scale steam jet refrigerator
TL;DR: In this paper, a small-capacity steam jet refrigerator has been tested with boiler temperatures in the range 120-140°C and the experimental data were found to be within 85% of the theoretical values.
Journal ArticleDOI
A New Ejector Theory Applied to Steam Jet Refrigeration
John T. Munday,David F. Bagster +1 more
Journal ArticleDOI
A small capacity steam-ejector refrigerator: experimental investigation of a system using ejector with movable primary nozzle
Satha Aphornratana,Ian W. Eames +1 more
TL;DR: In this article, an experimental study of a steam-ejector refrigerator using an ejector with a primary nozzle that could be moved axially within the mixing chamber section was performed.
Journal ArticleDOI
Variable geometry ejectors and their applications in ejector refrigeration systems
TL;DR: In this article, the effect of ejector geometries on performance was analyzed for a 5kW steam-jet refrigerator with variable-geometry ejectors, including flow rates, entrainment ratio and ejector geometry.