No abstract

The different definitions of exergy efficiency (RE), which have been proposed in the past for the thermodynamic evaluation of expansion and compression devices, operating above and through ambient temperature are discussed. The comparison between these efficiencies is illustrated. An expression for (RE) based on the concept of transit exergy is presented. This concept allows the quantitative and unambiguous definition of two exergy measurements: the exergy produced and the exergy consumed. The development of these (RE) in the case of a non-adiabatic vortex tube with dimensionless thermal conductivity, integrated with a compressor above or through ambient temperature is presented. The methods of calculating the transit exergy are described. Analysis based on the mentioned measurements, combined with traditional exergy loss analysis, identifies the most important factors affecting the thermodynamic performance of compression and expansion in a non-adiabatic vortex tube. It was obtained that the use of a natural reel fluid (CO2) compared to an ideal gas (Air) increases the transit (RE) by 31.5% and decreases the exergy losses by 37.3% under the same operating conditions of the two fluids in the system with the same COP. Mots clés-Tube vortex; rendement exergétique; mesures exergétiques; exergie de transit; fluide naturel; analyse énergétique, analyse exergétique; exergie produite, exergie consommée I.