Physical Chemistry of Aqueous Systems: Meeting the Needs of Industry

ISBN Print: 978-1-56700-034-4

ISBN Online: 978-1-56700-445-8

AN ALGORITHM FOR SETTING UP NUMERICALLY CONSISTENT FORWARD AND BACKWARD EQUATIONS FOR PROCESS MODELLING

DOI: 10.1615/ICPWS-1994.260
pages 194-201

Resumo

The algorithm has been designed for setting up simplified, fast equations for use in energetic process modellings. Simplified numerically consistent equations h=h(T,p), derived from an equation g=g(T,p), and T=T(p,h) for use in power cycle calculations were set up for demonstration purposes. The algorithm finds numerically consistent equations with a minimized total number of terms automatically and with hardly any subjective influences. Only the corresponding banks of terms have to be established by the equation maker. The algorithm connects the structure optimization method of Setzmann and Wagner with the simultaneous steady approximation method of Zschunke. So the disadvantages of one method can be compensated by the advantages of the other one. Subalgorithms for optimizing the distribution of the input data calculated from a very precise equation of state and for optimizing their weightings have been developed in order to get good equations automatically. The algorithm can be used for setting up the numerically consistent equation pairs T=T(p,h) and h=h(T,p) as well as T=T(p,s) and s=s(T,p) needed for the IAPWS-project "New Industrial Formulation", too.