Dynamic process simulation using flowsheet structure

Abstract A technique is described for the dynamic simulation of chemical processes which enables an implicit integration method to be used, efficiently and economically, to solve the ordinary differential equations which arise in such simulations. This technique has been used to convert an existing steady state “flowsheet” simulator into a dynamic process simulator. The technique uses the structure of the process and its equation to avoid the generation and manipulation of the Jacobian matrix normally associated with implicit integration methods. The major advantage of such methods, namely the ability to integrate sets of stiff equations with timesteps greater than the smaller time constants, is retained.