Page 192 - Chemical engineering design

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FLOW-SHEETING
Acronym Type Table 4.1. Simulation packages Internet address
Source
http//www.—
ASPEN steady-state Aspen Technology Inc. Aspentech.com
Ten Canal Park,
Aspen DPS Cambridge, MA
02141-2201,
USA
DESIGN II steady-state WinSim Inc. winsim.com
P.O. Box 1885,
Houston,
TX 77251-1885, USA
HYSYS steady-state Hyprotech hyprotech.com
Suite 900, 125-9 Avenue SE,
dynamic Calgary, Alberta,
T2G-OP6, Canada
Merged with Aspen Tech
PRO/II steady-state SimSci-Esscor simsci.com
5760 Fleet Street,
DYNSIM dynamic Suite 100, Carlsbad,
CA 92009, USA
CHEMCAD steady-state Chemstations Inc. chemstations.net
2901 Wilcrest, Suite 305,
Houston, TX 77042
USA
Note: Contact the web site to check the full features of the current versions of the programs.

Detailed discussion of these programs is beyond the scope of this book. For a general
review of the requirements, methodology and application of process simulation programs
the reader is referred to the books by: Husain (1986), Wells and Rose (1986), Leesley
(1982), Benedek (1980), Mah and Seider (1980), Westerberg et al. (1979) and Crowe
et al. (1971); and the paper by Panelides (1988).
Process simulation programs can be divided into two basic types:
Sequential-modular programs: in which the equations describing each process unit
(module) are solved module-by-module in a stepwise manner; and iterative techniques
used to solve the problems arising from the recycle of information.
They simulate the steady-state operation of the process and can be used to draw-up
the process flow sheet, and to size individual items of equipment, such as distillation
columns.
Equation based programs: in which the entire process is described by a set of differential
equations, and the equations solved simultaneously: not stepwise, as in the sequential
approach. Equation based programs can simulate the unsteady-state operation of processes
and equipment.
In the past, most simulation programs available to designers were of the sequential-
modular type. They were simpler to develop than the equation based programs, and
required only moderate computing power. The modules are processed sequentially, so
essentially only the equations for a particular unit are in the computer memory at one
time. Also, the process conditions, temperature, pressure, flow-rate, are fixed in time.