## THERMAL SCIENCE

International Scientific Journal

### A SHORT REMARK ON THE SOLUTION OF RACHFORD-RICE EQUATION

**ABSTRACT**

A fast flash calculation of the Rachford-Rice equation is very much needed in many engineering applications, especially in multi-component mixtures. This paper suggests a direct and hands-on calculation by a pocket calculator or a Chinese abacus. The calculation is based on an ancient Chinese mathematics called as He Chengtian average. An example is given to show the simplicity and effectiveness of the ancient Chinese algorithm.

**KEYWORDS**

PAPER SUBMITTED: 2017-03-03

PAPER REVISED: 2017-11-14

PAPER ACCEPTED: 2017-11-15

PUBLISHED ONLINE: 2018-09-10

**THERMAL SCIENCE** YEAR

**2018**, VOLUME

**22**, ISSUE

**4**, PAGES [1849 - 1852]

- Petitfrere, M., Nichita, D. V., On a Choice of Independent Variables in Newton Iterations for Multiphase Flash Calculations, Elsevier, 427 (2016), Nov., pp. 147-151
- Hinojosa-Gomez, H., et al., An Improved Algorithm for the Three-Fluid-Phase VLLE Flash Calculation, AICHE J, 61 (2015), 9, pp. 3081-3093
- Michelsen, M. L., Phase Equilibrium Calculations. What is Easy and what is Difficult? Computers & Chemical Engineering, 17 (1993), 5-6, pp. 431-439
- Michelsen, M. L., Calculation of Multiphase Equilibrium, Computers & Chemical Engineering, 18 (1994), 7, pp. 545-550
- Liu, P., et al., Facile Preparation of Alpha-Fe2O3 Nanobulk via Bubble Electrospinning and Thermal Treatment, Thermal Science, 20 (2016), 3, pp. 967-972
- Li, Y., et al., Bubble Electrospinning of PA66/Cu Nanofibers, Thermal Science, 20 (2016), 3, pp. 993-998
- Fatoorehchi, H., et al., A New Parametric Algorithm for Isothermal Flash Calculations by the Adomian Decomposition of Michaelis-Menten Type Nonlinearities, Fluid Phase Equilibria, 395 (2015), June, pp. 44-50
- He, J.-H., He Chengtian's Inequality and Its Applications, Applied Mathematics and Computation, 151 (2004), 3, pp. 887-891
- He, J.-H., Application of He Chengtian's Interpolation to Bethe Equation, Computers & Mathematics with Applications, 58 (2009), 11-12, pp. 2427-2430
- Liu, Y. Q., He, J.-H., On Relationship Between Two Ancient Chinese Algorithms and Their Application in Flash Evaporation, Results in Physics, 7 (2017), Dec., pp. 320-322