DYNAMIC APPROXIMATION METHOD OF HANDLING VAPOR-LIQUID EQUILIBRIUM DATA IN COMPUTER CALCULATIONS FOR CHEMICAL PROCESSES.

The major cost in computer time for process simulation is incurred by the generation of K values. A description is given of the development of an interpolative or approximation algorithm for use in conjunction with a more accurate K value generator. Traditionally, a modular sequential process simulator iterates around the flow-sheet to a converged solution. Using our approach, the first two iterations use the accurate K value generator to set up the coefficients in an interpolative formula which is then used for successive iterations until a pre-specified convergence is attained. A final iteration is then carried out using the accurate K value generator. Tests indicate savings of up to 50% of the total simulation computer time cost.