Numerical Analysis of Coal Combustion in Circulating Fluidized Bed
combustion of coal is used in circulating fluidized bed combustion system. This work is concerned about gas–solid two-phase mixtures flowing upwards through the fast beds. The type of information resulting from various ways of analyzing the pressure variations and the effect of superficial velocity on pressure in fluidized beds are discussed. This paper presents the standard k–є and two-phase turbulence model used to describe the gas–solids flow in a CFB.The analysis of temperature and density in coal combustion is done by discrete phase model (DPM) and non pre mixed combustion in species model through the PDF file creation in DPM model. The flow temperature and density in the system were modeled by solving the continuity and momentum equations of the gas flow by using the CFD analysis. The fluidizing velocity has been taken as 4 m/s and the effects of operating parameters on mole fraction, mean density and mean temperature are discussed in this paper. It is observed that the mean density of minimum and maximum mean mixture fraction along the scaled variance is significant.
Integrated analysis of the excess air on steam power plant CFB boiler using mathematical and CFD modeling
This paper presents the integration of mathematical and Computational Fluid Dynamics (CFD) modeling analysis of the excess air in a Circulating Fluidized Bed (CFB) Boiler steam power plant. The purpose of this study is to analyze the impact of excess air on plant performance and operation, using Engineering Equation Solver (EES™) and CFD tools. Power plant installed with the total power capacity of 2×30 MWe, where steam produced from 2 coal CFB boilers. The stoichiometry calculation used to simulate computationally various secondary air flow while heat balance calculation conducted to evaluate the effect of excess air to heat rate plant. Based on the result, showed that the optimum excess air is below 30% for giving the good performance and reliability more.This paper presents the integration of mathematical and Computational Fluid Dynamics (CFD) modeling analysis of the excess air in a Circulating Fluidized Bed (CFB) Boiler steam power plant. The purpose of this study is to analyze the impact of excess air on plant performance and operation, using Engineering Equation Solver (EES™) and CFD tools. Power plant installed with the total power capacity of 2×30 MWe, where steam produced from 2 coal CFB boilers. The stoichiometry calculation used to simulate computationally various secondary air flow while heat balance calculation conducted to evaluate the effect of excess air to heat rate plant. Based on the result, showed that the optimum excess air is below 30% for giving the good performance and reliability more.
Degradable polymers : principles and applications
1. Why Biodegradable Polymers? G. Scott. 2. An Overview of Biodegradable Polymers and Biodegradation of Polymers S.H. Huang. 3. Degradation and Stabilization of Carbon-Chain Polymers G. Scott. 4. Techniques and Methods of Polymer Degradation S. Karlsson, A.-C. Albertsson. 5. Biodegradation of Aliphatic Polyesters Suming Li, M. Vert. 6. Starch-Polymer Composites C. Bastioli. 7. Polymers from Renewable Sources E. Chiellini, et al. 8. Sustainable Poly(Hydroxyalkanoate) (PHA) Production G. Braunegg. 9. Polyhydroxyalkanoates: Properties and Modification for High Volume Application I. Chodak. 10. Biodegradable Polymers in Medicine E Piskin. 11. Environmentally Biodegradable Water-Soluble Polymers G. Swift. 12. Plastics and the Environment J. Guillet. 13. Degradable Hydrocarbon Polymers in Waste and Litter Control G. Scott, D.M. Wiles. Subject Index.