A1 Journal article (refereed), original research

Development of an equation-oriented steady-state evaporation plant simulator

Open Access publication

Publication Details
Authors: Neto Márcio, Cardoso Marcelo, Vakkilainen Esa, Oliveira Éder
Publisher: Associacao Brasileira Tecnica de Celulose e Papel
Publication year: 2020
Language: English
Related Journal or Series Information: O Papel
Volume number: 81
Issue number: 7
Start page: 83
End page: 89
Number of pages: 7
ISSN: 0031-1057
JUFO-Level of this publication: 0
Open Access: Open Access publication


An equation-oriented process simulator was developed for simulating evaporation
plants. The simulator graphical user interface was written in Python 2.7, and
its engine, in C++. The simulator orders and partitions the system of equations
that describe the evaporator system under study and solves the partitions
sequentially using the Newton-Raphson method. If no good initial estimates can
be provided by the user, the simulator solves a simplified problem to generate
the estimates, which greatly facilitates convergence. Calculations are based on
steam table correlations and on black liquor enthalpy correlations described in
the literature. Two multiple-effect counter-current evaporator scenarios were
extracted from the literature and used to validate the simulator: a simple
3-effect system and a realistic 7-effect system. The simulator converged to the
solutions with relative ease, provided that the model equations were written as
described, that equations were ordered and partitioned, and the simplified
model was used to generate good initial estimates. Good agreement was found
between the calculated values and those reported in the literature, indicating
that the proposed simulation framework could be extended to accommodate more
complex systems. Deviations from the reported values can be explained by the
different choices of physical properties correlations.

Last updated on 2020-06-08 at 13:31