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Full-scale multi-ejector module for a carbon dioxide supermarket refrigeration system: Numerical study of performance evaluation

Abstract

The performance of fixed ejectors installed in a multi-ejector module in a carbon dioxide refrigeration system is discussed in this paper. To analyse the module operation, three-dimensional ejector models including the inlet and outlet collecting ducts were considered. The tests were performed for three of four vapour ejectors of different sizes that compose the multi-ejector pack. The testing modes included the serial and parallel operation of the fixed units in operating conditions that are characteristic for the supermarket refrigeration unit working at high ambient temperatures. All numerical simulations were performed using the validated Homogeneous Equilibrium Model implemented on the ejectorPL computational tool for typical transcritical parameters at the motive nozzle port. The detailed analysis was executed separately for the ejectors and the ducts of the module collectors. The results discussion concerned the crucial parameters for such an installation like the pressure and vapour quality distribution. Negligible influence of the motive nozzle collector and a crucial influence of the outlet collector shape was indicated. The global performance analysis showed that the multi-ejector pack provides high and stable performance of all installed ejectors over the entire range of the considered operating conditions for supermarket application. Areas of the possible pressure loss reduction and the uniformity growth in the vapour quality distribution were presented. Finally, according to the multi-ejector pack ducts analysis, the potential areas for module shape optimisation were indicated as well.

Category

Academic article

Client

  • Research Council of Norway (RCN) / 196445

Language

English

Author(s)

  • Jakub Bodys
  • Michal Palacz
  • Michal Haida
  • Jacek Smolka
  • Andrzej J. Nowak
  • Krzysztof Banasiak
  • Armin Hafner

Affiliation

  • Silesian University of Technology
  • SINTEF Energy Research / Termisk energi
  • Norwegian University of Science and Technology

Year

2017

Published in

Energy Conversion and Management

ISSN

0196-8904

Publisher

Elsevier

Volume

138

Page(s)

312 - 326

View this publication at Cristin