A MODIFIED SOAVE - REDLICH - KWONG EQUATION OF STATE
FOR PREDICTION OF JOULE-THOMSON INVERSION CURVE
K. Fnena*, A. Bellagi
Energy engineering department,
U. R. Thermal and thermodynamics of Industry Process,
E. N. I. M., Av. Ibn Jazzar, 5060 Monastir -
* Corresponding author. E-mail: Chimiphy@yahoo.fr
Received: 25 November 2008; revised version accepted:28 February 2009
Experimental Inversion data of 13 fluids (air, nitrogen, oxygen, argon, xenon, neon, krypton, methane, propene, water, ammonia, carbon monoxide and carbon dioxide) are used for determination of four adjustable parameters of Soave – Redlich – Kwong new modified equation of state. A non linear optimization procedure is used. The covolume in the proposed equation of state is given by a simple function of reduced temperature. We note here that developed equation gives a so precise description of inversion curve for all studied fluids in all range of inversion temperature. In particular at high reduced temperatures (Tr ³ 2.5) the equation estimates well the maximal inversion temperature, Tr,LIM.
Keywords: Joule – Thomson effect; Equation of state; Covolume; Inversion curve; Nonlinear optimization; Inversion maximum temperature.