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An efficient surrogate fuel formulation methodology, which directly uses the chemical structure information from nuclear magnetic resonance (NMR) spectroscopy analysis, has been proposed. Five functional groups, paraffinic CH2, paraffinic CH3, aromatic C-CH, olefinic CH-CH2, and cycloparaffin CH2, have been selected to show the basic molecular structure of the fuels for the advanced combustion engines (FACE) fuels. A palette that contains six candidate components, n-heptane, iso-octane, toluene, 2,5-dimethylhexane, methylcyclohexane, and 1-hexene, is chosen for different FACE fuels, based on the consideration that surrogate mixtures should provide the representative functional groups and comparable molecular sizes. The kinetic mechanisms of these six candidate components are chosen to assemble a detailed mechanism of each surrogate fuel for FACE gasoline. Whereafter, the accuracy of FACE A and F surrogate models was demonstrated by comparing the model predictions against experimental data in homogeneous ignition, jet stirred reactor oxidation, and premixed flame. [ABSTRACT FROM AUTHOR]

Abstract: A modeling method for a large-scale circulating fluidized bed (CFB) boiler is presented. The method uses the cell approach to simulate the axial distribution of solid and gas phases in the bed and uses ‘core–annular’ construction to describe the radial distributions of solid particles and particle clusters. At the same time, it takes into account the influence of the wide size distribution of both bed and feed materials on hydrodynamics, chemical reactions and heat transfer. The steam side dynamic characteristics of the boiler are also considered based on the modular modeling method. Based on the method, simulations of static and dynamic performances of a 410t/h Pyroflow CFB boiler are carried out. The results show that the model is capable of predicting the complete performance of the CFB boiler. The modeling method has important theoretical and engineering values for the research of combustion technology, large-scale design and operating performances of a circulating fluidized bed. [Copyright &y& Elsevier]