ПУБЛИКАЦИИ
V.S. Iorish, G.V. Belov. On Quality of Adopted Values in Thermodynamic
Databases. Netsu Sokutei (Calorimetry and Thermal Analysis), v. 24, No. 4,
1997, pp.199-205.
Abstract
Thermodynamic databases are
widely used in scientific research, engineering calculations, physicochemical
experiments planning as well as for teaching and other purposes. Progress of
recent decades in petrochemistry and metallurgy, creation of rocket engines and
modern structural materials, development of traditional and nuclear power
engineering and many others could not have been achieved without preliminary
thermodynamic analysis of the relevant processes. Successful solution of many
global problems facing humankind today depends to some extent on the
reliability of theoretical models of complex physicochemical systems. One of
the most important parts of such models is set of thermodynamic properties of
the system being studied. The development of new methods of supplying humankind
with energy, the choice of the optimum ways for utilization of industrial
wastes, solution of the safety problems of nuclear power engineering, as well
as solution of many other problems will be impossible without preliminary analysis
based on thermodynamic modeling.
Basic part of any complex
petrochemical system's model incorporates an idea about individual substances.
The characteristics of the whole system are largely determined by the
properties of substances, which form the system. That is why so necessary are
further experimental and theoretical study of thermodynamic properties of
individual substances and accumulation of this information. This information is
intended for scientists and engineers who work in various branches of science
and engineering and it must be delivered them in an intelligible form. One may
regard the thermodynamic properties of substances (enthalpy of formation, heat
capacity, entropy etc.) as fundamental physicochemical properties, which are
used for analysis of processes with participation of these substances in a wide
range of pressure and temperature. However, the array of thermodynamic
properties as distinct from fundamental physical constants is practically
unlimited, it is determined first of all by multitude of species in various
phase states. Because of perpetual growth of the experimental and theoretical
information about substances, it is necessary to systematize it in the form of
reference books, as well as in the electronic form (data bases and data banks).
The evaluation of quality
of the information published in reference books and stored in databases is a
very complicated task. Still more difficult and practically insoluble task is
the evaluation of results of the use of unreliable information for
thermodynamic analysis of various processes. Main reason of complexity of the
first task is absence of the complete information about the adopted values,
i.e. absence of all primary data and details of their processing. It should be
mentioned here that well known problem of thermodynamic consistency can't be
investigated within limited set of data, it's necessary to take into
consideration information from other databases or original data sources.
Another reason of the problem complexity is difficulties of algorithmization of
the data quality expert analysis procedure, which is usually fulfilled by
qualified specialists. At present, it is not easy to find financial support for
such investigations, and the number of qualified specialists in this area is
very small.
In present report, we are
trying to evaluate data quality of one of known databases by means of computer
processing, to carry out the analysis of reasons that caused gross errors and
to discuss possible ways of their preventing.
В.С. Иориш, Г.В. Белов, В.С. Юнгман. ПРОГРАММНЫЙ КОМПЛЕКС ИВТАНТЕРМО ДЛЯ WINDOWS И ЕГО ИСПОЛЬЗОВАНИЕ В ПРИКЛАДНОМ ТЕРМОДИНАМИЧЕСКОМ АНАЛИЗЕ, Препринт ОИВТ РАН, 1998.
Аннотация
Настоящая
работа состоит из двух частей. В первой части приводится подробное описание
концепции и основных возможностей программного комплекса ИВТАНТЕРМО для
Windows. В состав комплекса входит база данных, которая на сегодняшний день
содержит сведения о свойствах около 2600 веществ, образованных из 96 химических
элементов, а также 6 автономных программ, реализующих следующие функции: работа
с базой данных; расчет состава и параметров
равновесного состояния многокомпонентных гетерогенных термодинамических систем;
поиск корреляционных зависимостей между термодинамическими свойствами веществ,
сведения о которых содержатся в базе данных; расчет коэффициентов полинома,
аппроксимирующего зависимость теплоемкости от температуры; расчет теплового
баланса.
Во второй части подробно изложен алгоритм расчета равновесных состава и свойств термодинамических систем, реализованный в ИВТАНТЕРМО для Windows. Приводятся результаты расчетов, демонстрирующих возможности программного комплекса для решения практических задач.
Belov G.V. Thermodynamic analysis of combustion products at high
pressure and temperature. Propellants, Explosives, Pyrotechnics. v.23, No 2,
pp. 86-89, 1998.
Abstract
Chemical energy of the fuel, which
during burning process is converted into the heat energy, is wide spread an
energy source for thermal energy units. The transformation of the heat energy
into mechanical is performed with the use of working body, which used to be
formed by combustion products. In order to enhance energy and performance
characteristics of the latter special additions to the fuel are used. These
additions may contain various chemical elements different from traditional C,
H, O and N. Evaluation of thermodynamic and physical properties of combustion
products in order to detect optimal parameters of working processes in energy
units is often necessary. Experimental ways of obtaining of this information
are expensive and time consuming, because the gas temperature is usually very
high.
In the high temperature
range is often successfully used an equilibrium model, which allows to use
methods of thermodynamics for analysis of the processes. In this case the task
is reduced to calculation of phase and chemical composition, which in its turn
is used for computation of equilibrium parameters of the system.
Common way of enhancing
performance characteristics of thermal energy units is pressure growth. If
temperature of the system is more than 1000 K and pressure is below 20 MPa, the
behavior of the gas phase is adequately described by the ideal gas equation of
state. However, if pressure in the system is very high, the deviation from
ideal gas behavior becomes significant and a real gas equation of state should
be used in calculations.
Objective of this work was
development of an algorithm intended to perform computer modeling of a complex
chemically reacting system. The algorithm is derived from an older version of
well known in Russia ASTRA algorithm. The latter is based on fundamental
thermodynamic principle, formulated by Gibbs, from which it follows that
entropy of insulated system is maximum in equilibrium state. The developed
algorithm was used for elaboration of a computer program REAL, supplied with an
extensive database on thermodynamic properties of individual substances.
A.K. Zaytsev, L.I. Leontiev, Y.S. Yusfin, G.V. Belov, V.S. Iorish On
principles of thermodynamic modeling of dioxins formation and behavior in
thermal processes. Organohalogen Compounds, v. 36, 1998, pp. 197-200
Abstract
The investigation of
formation and behavior in thermal processes of polychlorinated
dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF), both of which are often
named “dioxins”, is important in two aspects. On the one hand, various thermal
technologies including the incineration of the domestic and industrial wastes
are recognized as a significant source of the dioxins emission into
environment. On the other hand, these technologies are recognized as one of the
main methods of the annihilation of these extremely toxic compounds. So, the
theoretical analysis and prediction of PCDD/F formation in the wide range of
temperature values, redox conditions and the source composition is of primary
importance. The best way of obtaining of this information is the thermodynamic
modeling (TM) based on calculation of equilibrium composition. The equilibrium
concentrations of PCDD/F should be regarded as maximum available values, what
is the goal of an ecological examination. It should be noted that TM allows
take into account some kinetic restrictions by excluding some substances from
the list of possible products or by assigning the fixed values for the
concentrations of some products.
To apply the TM to the
problem discussed one should create a database on thermodynamic properties of
individual substances and develop the algorithms and related software. The
database and software should make it possible to accomplish all necessary
calculations, informativity and the simplicity of the analysis of the results
of calculations, because the hundreds of substances may be regarded as possible
products. The solution of these tasks led to the development of the new version
of IVTANTHERMO for Windows, which is supplied with the extensive database on
thermodynamic properties of substances.
G. V. Belov, B. G. Trusov, Influence of Thermodynamic and
Thermochemical Data Errors on Calculated Equilibrium Composition, Ber.
Bunsenges. Phys. Chem. v. 102, No. 12, pp.1874 -1879, 1998
Abstract
Thermodynamic modeling is
widely used now for the investigation of metallurgical and other high
temperature processes. So the problem of reliability of the results of
thermodynamic modeling is very important. Reliability of the results of
thermodynamic modeling is determined mostly by the following factors:
In
present study an attempt is made to estimate the influence of the errors in
thermodynamic and thermochemical data upon the results of thermodynamic
calculations. It was found that this factor often being neglected may be very
important. Special attention to data errors should be paid when a complicated
model with many parameters is used for analysis of the process.
In practice investigators often explain discrepancy between the experimental
data and the results of calculations by absence of chemical equilibrium in the
system or by wrong parameters of the model used, while the true reason may be
the errors of thermodynamic data. This problem has been examined in the
past. But the approach used in these works is based on an assumption that the
thermodynamic data errors does not influence upon the phase composition of the
system investigated. This assumption is not valid in general case.
While investigating the
influence of thermodynamic data errors upon the results of modeling one needs
an answer to the following questions:
The answers
to these questions allow on the one hand to detect the upper and the lower
limits of the calculated results. On the other hand this information may help
to define more precisely the uncertainties of properties of individual
substances by comparing the experimental data and the results of modeling.
G.V. Belov, V.S. Iorish, V.S. Yungman. IVTANTHERMO for Windows –
Database on Thermodynamic Properties and Related Software. CALPHAD, Vol. 23,
No. 2, 1999, pp. 173-180.
Abstract
Importance of thermodynamic
modeling cannot be overestimated. A number of examples illustrating how
thermodynamic calculations may be used as a basic tool in the development and
optimization of materials and processes are presented in the excellent book Thermodynamics
at Work. Of course, thermodynamic modeling cannot absolutely substitute the
experiments. However, it may help to estimate the area of parameters where the
experiment should be accomplished. As the computer becomes more custom
instrument for a researcher, applicability field of methods of computational
thermodynamics is perpetually growing. And the requirements to related software
are growing too. Now any serious computer program intended for thermodynamic
modeling of processes should contain at least three parts: the database on
thermodynamic properties of substances, modeling software itself and special
service software for database handling. A software interface should be clear
and intelligible. The user should not spend too much time for reading manuals before
he can accomplish simple calculations. The database on thermodynamic properties
should be reasonably extensive and reliable, as incompleteness of information
or wrong data may easily result in errors of modeling and therefore in lost of
time and efforts.
All the requirements
mentioned were taken into consideration at the development of IVTANTHERMO for
Windows.
The whole software package
IVTANTHERMO contains the database and six programs:
The
database and software allow to carry out theoretical study of the
An
extensive database on thermodynamic properties of individual substances and
modeling abilities make IVTANTHERMO a useful tool for scientists, chemical
engineers, who investigate high temperature processes with chemical
transformations, and for the senior students of chemical engineering
departments. As the software has relatively simple interface, accomplishing of
thermodynamic calculations is possible without the thorough study of
documentation. The basic modules of IVTANTHERMO are supplied with a chart
analyzer. So the user can easily convert most of the data or the results into
curves, which can be modified, printed or exported to other programs.
Г. В. Белов, В. С.
Иориш, В. С. Юнгман. МОДЕЛИРОВАНИЕ РАВНОВЕСНЫХ СОСТОЯНИЙ
ТЕРМОДИНАМИЧЕСКИХ СИСТЕМ С ИСПОЛЬЗОВАНИЕМ ИВТАНТЕРМО ДЛЯ WINDOWS. // Теплофизика
высоких температур. – 2000. - Т 38, No. 2, C.191 - 196.
Предложены алгоритм расчета равновесного состава многокомпонентных гетерогенных термодинамических систем, а также метод и алгоритм расчета давлений насыщенных паров над конденсированной фазой. Указанные алгоритмы были использованы при разработке программного комплекса ИВТАНТЕРМО для Windows.
Белов Г.В. Расчет равновесного состава и свойств термодинамических
систем при повышенных давлениях.//Математическое моделирование. – 2001. - Т.13,
No. 8. - С.9-12.
Представлены метод, алгоритм и программа расчета равновесного состава и свойств термодинамических систем при высоких давлениях. Приведены примеры, иллюстрирующие возможности алгоритма и программы.