MATLAB PROJECT

Chemical Reaction Engineering: MATLAB Project



Chemical Reaction Engineering: MATLAB Project

Task 1

The paper shows advantages of the computer technology for the simulation of the technological system's behaviour and control. The technological process here is represented by the Continuous Stirred Tank Reactor (CSTR) as a typical member of a nonlinear lumped-parameters system widely used in the industry. The computer simulation has great importance nowadays with the decreasing value of the computer components together with the growing computer speed. The adaptive control used here fulfils all basic control requirements and it can be used for the systems with nonlinear behaviour. The benefit of this paper can be found in the simulation program made in mathematical software MATLAB with the use of Graphical User Interface (GUI) that provides user possibilities to examine simulations without changing of the program code. (Duff ,1986).

Simulation Program

The simulation program which deals with the simulation of the steady-state, dynamics and of course adaptive control of the CSTR was made in mathematical software MATLAB Simulink. The use of this tools enable programmer to make program user-friendly and close to the users who do not know or do not like programming. They can use all features of Matlab as a simulation tool by just changing of the most important variables and pressing buttons for computing.

The program can be start by the typing the command go in the program's directory. It is divided into two main windows mainly because of the space.

Structured Modeling Methodology

A modeling methodology can be defined as an algorithmic procedure intended to lead from specific knowledge of physical and topological nature of a process to a mathematical model of that process (Weiss 2000). The modeling methodology we use (Preisig 1994b) is based on the hierarchical decomposition of processes into networks of elementary systems and physical connections. Elementary systems are regarded as thermodynamic simple systems and represent (lumped) capacities able to store extensive quantities (such as component mass, energy and momentum) (Egelhoff, 1998). The connections have no capacity and represent the transfer of extensive quantities between these systems. The construction of a process model with our methodology consists of the following steps:

Break the process down into elementary systems that exchange extensive quantities through physical connections. The resulting network represents the physical topology.

Describe the distribution of all involved chemical and/or biological species as well as all reactions in the various parts of the process. This represents the species topology.

For each elementary system and each fundamental extensive quantity (the collection of which is the fundamental state) that characterizes the system write the corresponding balance equation. The result has the following form:

In this (simplified) form, the balance equations run over all the fundamental extensive quantities (x) of all defined systems, over all the defined connections (z) and over all the defined reactions (r) of the physical topology (Elmqvist, 1997). The matrices A and B are completely defined by the model designer's definition of the physical and species topology of the process.

Add algebraic equations to the model definition:

Augment the model equations with ...