A Numerical and Experimental Study of Ejector Internal Flow Structure and Geometry Modification for Maximized Performance

A wide range of industrial refrigeration systems are good candidates to benefit from the cooling and refrigeration potential of supersonic ejectors. These are thermally activated and can use waste heat recovery from industrial processes where it is abundantly generated and rejected to the environmen...

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Bibliographic Details
Published inIOP conference series. Materials Science and Engineering Vol. 280; no. 1; pp. 12011 - 12018
Main Authors Falsafioon, Mehdi, Aidoun, Zine, Poirier, Michel
Format Journal Article
LanguageEnglish
Published Bristol IOP Publishing 01.12.2017
Subjects
Biomass energy production
Compression ratio
Cooling effects
Ejectors
Entrainment
Flow distribution
Internal flow
Low cost
Mathematical models
Performance evaluation
Prototypes
Refrigeration
Solar energy
Topology
Two dimensional models
Waste heat recovery
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Summary:A wide range of industrial refrigeration systems are good candidates to benefit from the cooling and refrigeration potential of supersonic ejectors. These are thermally activated and can use waste heat recovery from industrial processes where it is abundantly generated and rejected to the environment. In other circumstances low cost heat from biomass or solar energy may also be used in order to produce a cooling effect. Ejector performance is however typically modest and needs to be maximized in order to take full advantage of the simplicity and low cost of the technology. In the present work, the behavior of ejectors with different nozzle exit positions has been investigated using a prototype as well as a CFD model. The prototype was used in order to measure the performance advantages of refrigerant (R-134a) flowing inside the ejector. For the CFD model, it is assumed that the ejectors are axi-symmetric along x-axis, thus the generated model is in 2D. The preliminary CFD results are validated with experimental data over a wide range of conditions and are in good accordance in terms of entrainment and compression ratios. Next, the flow patterns of four different topologies are studied in order to discuss the optimum geometry in term of ejector entrainment improvement. Finally, The numerical simulations were used to find an optimum value corresponding to maximized entrainment ratio for fixed operating conditions.
ISSN:1757-8981
1757-899X
DOI:10.1088/1757-899X/280/1/012011