Vol.3, No 12, 2002 pp. 487-488
Review of monografies:
"DYNAMICS OF DISTRIBUTED PARAMETER SYSTEMS:
ANALYSIS AND SYNTHESIS IN PARAMETER PLANE ",
"STEAM GENERATOR DYNAMICS", "HEAT EXCHANGER
DYNAMICS"
Written by Debeljković Dr. Dragutin
More then fifty years scientists from all over the world are interest to
processes with distributed pa-rameters presented in their typical represent
recuperative heat exchangers which are objects of automatic control. Their
priority interest were in mathematical modelling of this processes, researching
their dynamics through conventional and unconventional criteriumes of stability,
like as usage of many important concepts of control engineering in conventional
and modern theory of systems.
In mathematical meaning this complex objects of control are presented
by partial differential equa-tions although it is reasonable to use a solutions
which are based on description of processes with com-mon differential equations
which clearly means that presupposition of field homogeneity of relative
physical values are imported. Their mathematical models in forms of partial
differential equations gener-ate a lot of additional difficulties in their
mathematical treatment and only in few cases gives as analytical solutions
in closed form. In the other way, like as systems of infinite dimension
their researching in com-plex, frequency domain are reservation with presence
of transcendent members which practically, in any way, caused serious numerical
problems that we cannot use results from classical theory of common systems
(with lumped parameters) of automatic control.
Authors of this monographs were noticeable the importance of this class
of objects and processes for modern theory and more for practices and decided
to write three particular, independent monographs for this complex domain
of researching.
In the introduction common for all of three monograph authors treats
basic and global problems of mathematical modelling of objects and processes
of modern systems of control engineering. In this sense especially problems
of control volumes and selection process models are treated out, which
practically give as a basic postulates for usage of elementary law of conservation,
often gives in form of rebalance of mass, energy and impulse, written for
non stationary states of processes. Because of complete cognition about
modern problems of modelling it is discuse too about importance and category
of models.
The second whole of monographs are about classification of control
systems, objects and processes and gives basic theory and particular mathematical
foundation which have to help in later dynamical analysis of behaviour
mentioned classes of objects. In that sense a detailed analysis of finite
and infinite dimension systems, which practically cover all of essential
questions about processes with pure time lag described with common differential
equations with shifted argument and processes with distributed pa-rameters
described with partial differential equations were discussed.
In first monograph brunt of modelling were turned to well known thermal
processes with standard configuration and with one part to original consideration
of dynamic of extraction of glass capillaries where is given a solution
of problem of stationary and non-stationary temperature field inside of
industry fry for that destinations like as dynamical behaviour of carrier
of shape this capillaries. Odd part of monograph is dedicated to problems
of drain of zealot dust with dynamics of simultaneous transfer of heat
and mass. In the two last mentioned cases, unique diagrams of simulate
results are undoubted ap-prove very high available value of obtain mathematical
models and their engineering and technical com-patibility with really behaviour
of mentioned systems, objects and processes.
Seventh, eighth, ninth and tenth chapters present a skeleton of this
monograph about steam genera-tors. Altogether it is presented eight different
models of steam coppers with specific construction and for it of them it
is presented results of their simulation, like as correlate with experimentally
collect refer-ences.
In the last chapter of this monograph, authors are presented several
original results, which relate on promotion and development of mathematical
models of mill plant. In that sense, it is presented results which in mathematical
model of mill plant include also dynamics of rotors and dynamics of processes
of coal drying. It is also presented adequate structure and block diagrams
which enable efficiency review of essence of a problem.
Central part of monograph of heat exchangers consists basic scientific
and professional contributions. It is presented altogether twenty different
mathematical models of heat exchangers with specific con-structions and
for same of them it is presented results of their simulation, like as correlate
with experi-mentally collect references.
Presented mathematical models are give in the forms of systems of common
non-linear and linear ordinary or partial differential equations and give
as good foundation for development and usage for form of equivalent models
in state space.
Special view of problematic of modelling of heat exchanger is presented
in tenth and eleventh chap-ter of monograph.
Seeing that very much of mathematical models of heat exchangers are
in form of systems of linear partial differential equations it is suggestion,
instead of classical approach in position of mathematical discretization
of basic systems of equations, so called procedure of physical "discretization
of processes" with this write of basics balance equations are done for
each single "cells", so in finite model we don't have partial differential
equation yet common equation in form of systems of common differential
equa-tions with high order which for computers isn't a problem to solve.
By specifically definition of matrix it is easy to pick boundary conditions
which is correlate with first and last cells of discretization mathe-matical
model. Successful of proposed approach is illustrated by adequate simulation
diagrams and re-sults of experimental investigations. An example of one
pipe heat exchanger was used to illustrate a particular approach for this
problems known by name: " transport approach", which very efficiently systems
of differential equations convert in the system of algebraic equations.
Special scientific contribution of authors is also that in monograph
about processes with distributed parameters they are presented known results
of other authors about application of parameter method for analysis and
synthesis of systems with distributed parameters and also presented their
original results. On this way, without structures catch, it is enable to
picture optimal contours from basic plain in plain of reclamation parameters
and all of that enable to pick adequate model of control, which gives high
level of quality in work of whole system using their demanding degree of
relative stability. In that sense, it is presented and originally solved
problems of using of D – partioning method, extraction of region of a priori
propose settling time and degree of damping ratio first by usage Mitrovic
method then modify Mitrovic method and at last with universal algebraic
method. In all of considerable cases it is taken in respect linear relation
of adjustable parameters in coefficient of kvazipolinomial system except
in the last case when it was permit also relation of non-linear type in
form of derivation which presented a full gen-eralisation of problems.
In the last comments, in all monographs, it is given a short recapitulations
of basic results like as critical attention on requisites for written this
monographs, with respect on actuality of heat exchangers like as considerable
objects of automatic control and definite deficiency of literature in this
area in our country.
All of monographs consist also detailed chronological summary of published
results on field of mathematical modelling of objects and processes under
consideration. In the numbers of appendixes needful theoretical comments
and mathematical proves of second order were given. Also, a lot of con-structive
and work characteristics of different types of heat exchangers and steam
coppers, like as other considerable processes, were attached at the same
place.
On the base of detailed review of monographs and books material which
is compatibility rabbet, it is especially pleasure to recommend this edition
to reader like as needful text to known existent and modern performance
in mathematical modelling and in simulation of work of modern heat exchangers
whether that they are in process industry or in steam generating plants.
Reviewers of monographs were: Dr Svetislav Zaric, prof., Dr Dimitrije
Voronjec, prof., Dr Velimir Simonovic, prof. and Dr Branislav Jacimovic,
prof.
The monografies with hronological order were:
"Dynamics of Distributed Parameter Systems: Analysis and Synthesis
in Parameter Plane ",
D.Lj. Debeljkovic et. al, GIP Kultura, Belgrade, 2000,(in Serbian),
pp. 271.
"Steam Generator Dynamics",
D. Lj. Debeljkovic, V. S. Mulic, Cigoja press, Belgrade, 2001, (in
Serbian), pp. 351.
"Heat Exchanger Dynamics",
D. Lj. Debeljkovic, V. S. Mulic, G. Simeunovic, Cigoja press, Bel-grade,
2002, (in Serbian), pp. 268.
Katica (Stevanović) Hedrih and Julijana Simonović
