|
Issue
1, Volume 6, January 2011
Title of the Paper:
Simulation of Adaptive Control Applied on Tubular Chemical Reactor
DOWNLOAD
FULL PDF
Authors:
Jiri Vojtesek, Petr Dostal
Abstract: Simulation has a big importance nowadays when the speed of computers
grows rapidly and the price is on the other hand decreasing. The paper is
focused on the simulation of the steady-state and dynamic behaviour of the
nonlinear system represented by the tubular chemical reactor with the
co-current and countercurrent cooling in the jacket. These analyses are then
used for the choice of the suitable control strategy. The adaptive controller
used here is based on the choice of the External Linear Model as a linear
representation of the originally nonlinear system parameters of which are
identified recursively. The polynomial method together with spectral
factorization and pole-placement method used in control synthesis satisfies
the basic control requirements. The resulted hybrid controller provides good
control results although the system has strongly nonlinear behaviour.
Keywords:
Tubular chemical reactor, Adaptive control, Recursive identification,
Polynomial approach, External Linear Model
Title of the Paper:
Study of Non-Stationary Heat Conduction in a Plane Plate for Symmetric and
Asymmetric Problem
DOWNLOAD
FULL PDF
Authors:
Hana Charvatova, Dagmar Janacova, Karel Kolomaznik
Abstract: In the paper we deal with study of the problems of non-stationary
heat conduction in a plane plate. In the first part of paper we formulate
mathematic model for the cases of symmetric and asymmetric heating or cooling
of a solid plate. In the second part we compute various cases of temperature
fields in the plate during the mentioned process by mathematic software Maple.
Finally we present formulated mathematic models using for optimization of two
real technological operations of natural and synthetic polymers processing –
modelling of moulding of plastic material and modeling of temperature field in
wall of tanning drum by enzymatic hydrolysis.
Keywords:
Modeling, Non-stationary Heat Conduction, Plastic Moulding, Tanning Process
Title of the Paper:
Utilization of Mathematica Environment for Designing the Forecast Model of
Heat Demand
DOWNLOAD
FULL PDF
Authors:
Bronislav Chramcov
Abstract: Time series analysis and subsequent forecasting can be an important
part of a process control system. By monitoring key process variables and
using them to predict the future behavior of the process, it may be possible
to determine the optimal time and extent of control action. We can find
applications of this prediction also in the control of the Centralized Heat
Supply System (CHSS), especially for the control of hot water piping heat
output. Knowledge of heat demand is the base for input data for the operation
preparation of CHSS. The course of heat demand can be demonstrated by means of
the Daily Diagram of Heat Supply (DDHS) which demonstrates the course of
requisite heat output during the day. This diagram is of essential importance
for technical and economic considerations. The aim of paper is to give some
background about analysis of time series of heat demand and identification of
forecast model using Time series package which is integrated with the Wolfram
Mathematica environment. The paper illustrates using this environment for
designing the forecast model of heat demand in specific locality.
Keywords:
Prediction, District Heating Control, Box-Jenkins, Control algorithms, Time
series analysis, modelling
Issue
2, Volume 6, April 2011
Title of the Paper:
A Study of Entropy Generation Minimization in an Inclined Channel
DOWNLOAD
FULL PDF
Authors:
Dalia Sabina Cimpean, Ioan Pop
Abstract: An analysis of a mixed convection and entropy generation for a fluid
flow through porous medium, between two inclined parallel plates has been
performed. The entropy generation is estimated via an analytical solution of
the temperature and velocity profiles obtained from the mass, momentum and
energy equations governing the flow and heat transfer of the problem, with the
given conditions. The optimum values of the involved parameters at which the
entropy generation assumes its minimum is calculated. The Bejan number is also
obtained and discussed.
Keywords:
Entropy Generation, Mixed Convection Parameter, Porous Medium, Bejan number
Title of the Paper:
Experimental Identification of Arrhenius Equation Parameters for Control
Purposes
DOWNLOAD
FULL PDF
Authors:
Lubomir Macku
Abstract: In the process control area, there are a lot of systems with
nonlinear behaviour. Specific case of such nonlinear system is an exothermic
chemical reactor. The reactor nonlinearity can arise from different reasons.
One of them is the changeable reaction speed, which depends on the reactants
concentration and the in-reactor temperature. The second dependence is
described by Arrhenius equation. Knowledge of the Arrhenius equation
parameters is a key for correct mathematical model composition and also for
safe and successful control. Some possibilities of the parameters
determination are described in the literature. However, they are complicated
and not very suitable for online identification of a real process. A new
approach developed by the author is introduced in this article. The
possibility of identification the reaction rate and its temperature dependence
from a measured temperature profiles are shown. The identification method
including all necessary derivation is described. Also the results of
experimentally measured data identification are presented.
Keywords:
Rate constant, exothermic process, semi-batch reactor, identification,
simulation, control
Title of the Paper:
Study of Non-Stationary Heat Conduction in a Plane Plate for Symmetric and
Asymmetric Problem
DOWNLOAD
FULL PDF
Authors:
Hana Charvatova, Dagmar Janacova, Karel Kolomaznik
Abstract: In the paper we deal with study of the problems of non-stationary
heat conduction in a plane plate. In the first part of paper we formulate
mathematic model for the cases of symmetric and asymmetric heating or cooling
of a solid plate. In the second part we compute various cases of temperature
fields in the plate during the mentioned process by mathematic software Maple.
Finally we present formulated mathematic models using for optimization of two
real technological operations of natural and synthetic polymers processing –
modelling of moulding of plastic material and modeling of temperature field in
wall of tanning drum by enzymatic hydrolysis.
Keywords:
Modeling, Non-stationary Heat Conduction, Plastic Moulding, Tanning Process
|
