Development of a modular software system for the dynamic simulation of coal conversion plants. Annual report, June 1, 1976--June 30, 1977
William E. Schiesser, F. Stein, S. Johnson · 1977
A series of state-of-the-art temporal integrators, based on the variable-step, variable-order algorithm of C. W. Gear, were implemented and evaluated. Three of these integrators have been tentatively selected for use in dynamic simulation codes which have extended stability domains and will accommodate large sets of ODEs. A general-purpose numerical-method-of-lines dynamics simulation code, DSS/2 (Differential Systems Simulator, Version 2), was written as a series of FORTRAN IV subroutines and tested with a series of ordinary and partial differential equation problems. In particular, the code was used to compute the complete transient response of a fixed-bed catalytic methanator. The ODE and PDE sections of the DSS/2 system have been documented in two general-purpose user's manuals. These manuals are based on the assumption that the user can write FORTRAN IV subroutines and link them through labelled COMMON. The steady-state methanator for the methanation section of the RMProcess has been modeled as a catalytic, adiabatic, plug-flow reactor which considers simultaneous water-gas shift and methanation reactions. The unsteady-state methanator has been modeled as a catalytic, adiabatic, flow reactor with axial dispersion of mass which considers simultaneous water-gas shift and methanation reactions. Complete transient responses have been calculated.