Browsing by Author "Trochta, Miroslav"

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    Advanced melter operation and training tool
    (Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2002) Muysenberg, Erik; Nováčková, Markéta; Trochta, Miroslav; Viktorin, Pavel
    Glass Service Inc. uses the GS Glass Furnace Model as a base for a glass furnace simulator. It contains a user-friendly graphical front end, a simplified version of a furnace operation station, that allows modifying furnace settings (batch charging rate and properties, setup of bubblers, coolers, fuel profile, etc.). Behind this user interface, coupled glass and combustion models are run. The output of these calculations (shown again as a set of operator-friendly control screens) displays temperatures in positions where thermocouples and pyrometers are located in reality, exhaust gas properties, glass flow patterns, location of spring zone, quality indices, etc. The simulator has been validated and shows good agreement with reality.
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    Mathematical Modeling of Combustion Chamber Using GS GFM Package
    (Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2004) Trochta, Miroslav
    Glass Service, Inc., has been developing own glass furnace simulation CFD package for the last 13 years. An important part of the package is combustion solver, calied GS Combustor. The first part of this paper summarizes quantities that have to be calculated by the combustion solver and what dependencies exist among them. They include momentum, energy, radiation, turbulence, chemical species and pollutant transport equations, approximation of dissociation effects and mutual influence of glass and combustion space via heat transfer, volatilization and release of batch gases. Another part of the paper identifies a common misinterpretation in combustion modeling: Users very often tend to estimate the flame shape from the temperature field, assuming that high-temperature areas are identical with visible flame areas. An example demonstrates how misleading the assumption can be. A better way of judging the shape of a visible flame is suggested. The last part focuses on time-averaging in the furnace models. Many glass furnaces, namely the regenerative ones, do not operate in a steady state. Thus, a simple steady-state calculation is not sufficient. Methods of time averaging for such calculations are described. In some cases, such as regenerator simulations, no time averaging is applicable. However, a recent development has resulted in "regenerator coupling" method. That, combined with another simplification porous wall approximation of the checkerwork geometry has resulted in an easy and reasonably fast regenerator modelling procedure.