An interactive process flowsheeting and simulation system based on relational data structures

Abstract

An interactive graphical interface has been developed for a modular-sequential steady-state chemical process simulation program. The interface software, called AGPSS (A Graphical Process Simulation System), consists of FORTRAN-IV routines for creating new equipment unit schematics, for drawing a process flowsheet, for accepting process equipment and stream parameters, for performing automatic analysis for recycle nets, for supervising execution of the steady-state material and energy balancing simulator, and for displaying results. The program is designed to operate from refresh terminals functioning as remote time-sharing devices on the University of Michigan's Amdahl 470V/6 computing system. The Integrated Graphics (IG) software package is used for all interactive graphical operations.All data, including both picture and process information, are organized in a relational data structure containing a total of thirteen relations. The general algorithms for addition, retrieval, and deletion of data in the relational structure require just six set-theoretic operators, which are encoded as FORTRAN utility routines. These data structures and the associated set operators assisted materially in simplifying the design, programming, and testing of the interactive graphical interface.