Experimental investigation into the influence of vortex control on transcritical R744 ejector and cycle performance

Jingwei Zhu, Stefan Elbel

Research output: Contribution to journalArticle

Abstract

Vortex control over a diphasic convergent-divergent nozzle through adjustable nozzle inlet vortex can improve the performance of transcritical R744 ejector cooling cycle due to its potential for flow control with less sacrifice of nozzle efficiency and no requirement of geometry change. In this study, the influence of vortex control on transcritical R744 ejector and cycle performance has been experimentally investigated. Vortex control was applied to ejectors with different geometric parameters. The results with vortex control were compared with those with series expansion valve control and needle control. Design guidelines for ejector with vortex control were provided. It was found that the total work recovery efficiency of ejector with vortex control can be better than series expansion valve control and is close to needle control. Vortex control can be used to improve system performance by adjusting the high-side pressure of the transcritical R744 ejector cycle. Under off-design conditions, system capacity and COP can be improved by 11.0% and 8.1%, respectively, by applying vortex control.

Original languageEnglish (US)
Article number114418
JournalApplied Thermal Engineering
Volume164
DOIs
StatePublished - Jan 5 2020

    Fingerprint

Keywords

  • Coefficient of performance
  • Ejector efficiency
  • Motive nozzle
  • Transcritical R744
  • Vortex control

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Industrial and Manufacturing Engineering