Artigos Técnicos |
Artigo Técnico |
24.07.2020

DEVELOPMENT OF AN EQUATION-ORIENTED STEADY-STATE EVAPORATION PLANT SIMULATOR

Authors: Márcio R. Vianna Neto 1, Marcelo Cardoso 1, Esa K. Vakkilainen 2, Éder D. Oliveira 1

1 Universidade Federal de Minas Gerais. Brazil

2 Lappeenranta University of Technology. Finland

O PAPEL vol. 81, num. 07, pp. 83 - 89 - JUL 2020

ABSTRACT

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 multipleeffect

counter-current evaporator scenarios were extracted

from the literature and used to validate the simulator: a simple

3-effect system and a realistic 6-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.

Keywords: simulation, multiple-effect, evaporation, equationoriented,

partitioning