IJE TRANSACTIONS A: Basics Vol. 20, No. 1 (February 2007) 94-104   

downloaded Downloaded: 914   viewed Viewed: 3540



G. Soleimani Alamdari

Department of Mechanical Engineering, Azarbaijan University of Tarbiat Moallem
35 km Tabriz - Azarshahr Main-Road, Tabriz, Iran P.O. Box 53714-161

( Received: September 17, 2005 – Accepted in Revised Form: January 18, 2007 )

Abstract    The engineering calculation and simulation of absorption refrigeration systems require the availability of simple and efficient functions for the determination of thermodynamic property values of the operating fluid. This work presents a set of five simple and explicit functions for the determination of the vapor - liquid equilibrium properties of the ammonia-water mixture. The functions are constructed by least square method for curve fitting using the valid available data in the literature. The presented functions are valid for - 20 ≤ T ≤ 140º C, 0.2 ≤ P ≤ 100 bar, and the entire composition range (i. e. 0 ≤ x ≤ 1) which cover the region within which absorption cycles commonly operate. Obtained results are compared in detail with other correlations in the literature in graphical and statistical forms and reasonable accuracy are observed. Standard deviation of presented functions are 3.44 kJ/kg for enthalpy of saturated liquid mixture, 14.06 kJ/kg for enthalpy of saturated vapor mixture, and 0.0123 kg - NH3/kg - mix for ammonia mass fraction in vapor phase.


Keywords    Ammonia-Water Mixture, Thermodynamic Properties, Absorption Refrigeration Systems



1. Kalina, A. L., “Combined cycle system with novel bottoming cycle”, ASME Journal of Engineering for Power, Vol. 106, No. 4, (1984), 737-742.

2. Thorin, E., Dejfors, C. and Svedberg, G., “Thermodynamic properties of ammonia-water mixture for power cycles”, International Journal of Thermophysics, Vol. 19, No. 2, (1998), 501-509.

3. Thorin, E., “Comparison of correlations for predicting thermodynamic properties of ammonia-water mixture”, International Journal of Thermophysics, Vol. 21, No. 4, (2000), 853-870.

4. Thorin, E., “Thermophysical properties of ammoniawater mixture for prediction of heat transfer areas in power cycles”, International Journal of Thermophysics, Vol. 22, No. 1, (2001), 201-214.

5. Suzuki, J. and Uematsu, M., “Equation of state for fluid mixtures based on the principle of corresponding states with a two-fluid model: Application to fluid mixtures of water-ammonia”, Heat Transfer-Asian Research, Vol. 31, No. 4, (2002), 320-330.

6. Tillner-Roth, R. and Friend, D., “A Helmholts free energy formulation of the thermodynamic properties of the mixture {ammonia-water}”, J. Phys. Chem. Ref. Data, Vol. 27, No. 1, (1998), 63-96.

7. Stecco, S. and Desideri, U., “Thermodynamic Analysis of the Kalina Cycles: Comparisons”, Problems, Perspectives, ASME Paper 89-GT-149, (1989).

8. Ziegler, B. and Trepp, C., “Equation of state for ammonia-water mixture”, International Journal of Refrigeration, Vol. 7, No. 2, (1984), 101-106.

9. Xu, F. and Goswami, Y., “Thermodynamic properties of ammonia-water mixture for power cycle applications”, Energy, Vol. 24, No. 6, (1999), 525-536.

10. Ibrahim, O. M. and Klein, S. A., “Thermodynamic properties of water-ammonia mixtures”, ASHRAE Transactions, Vol. 99, (1993), 1495-1502.

11. IAPWS, Guideline on the IAPWS Formulation 2001 for the Thermodynamic Properties of Ammonia-Water Mixture, Gaithersburg, MD, USA, (2001).

12. Patek, J. and Klomfar J., “Simple functions for fast calculations of selected thermodynamic properties of he ammonia-water system”, International Journal of Refrigeration, Vol. 31, No. 4, (1995), 228-234.

International Journal of Engineering
E-mail: office@ije.ir
Web Site: http://www.ije.ir