Title: Evaluation of the equations of state for air, nitrogen and oxygen on throttle reduction efficiency by using exergy analysis

Authors: M.M. Rashidi; N. Rahimzadeh; N. Laraqi

Addresses: Engineering Faculty, Mechanical Engineering Department, Bu-Ali Sina University, Hamedan 65175-4161, Iran. ' Engineering Faculty, Mechanical Engineering Department, Bu-Ali Sina University, Hamedan 65175-4161, Iran. ' Laboratoire Thermique Interfaces Environnement, Universite Paris Ouest, EA 4415, GTE, 50 Rue de Sevres, F-92410 Ville d'Avray, France

Abstract: Exergy (available energy) analysis was applied to calculate the efficiency of throttling process by using some of equations of state. Differences between calculations by using three equations of state, Soave–Redlich–Kwong (S–R–K), Van der Waals and Beattie–Bridgeman on three substances air, nitrogen and oxygen are shown. The calculations for nitrogen are found to be close to air because almost 79% of air is nitrogen. In addition, the results of exergy efficiency graphs show that some of the equations of state may not be useful for specific ranges of temperature and pressure.

Keywords: exergy analysis; throttling process; equations of state; air; nitrogen; oxygen; exergy efficiency; temperature; pressure; throttle reduction efficiency.

DOI: 10.1504/IJEX.2011.043039

International Journal of Exergy, 2011 Vol.9 No.3, pp.297 - 318

Received: 27 Jul 2010
Accepted: 19 Feb 2011
Published online: 12 Oct 2011 *

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