Coal, model calculation combustion systems

The studies on NO formation by the traditional MEIS have been performed at Melentiev Energy Systems Institute for a long time. In parallel with MEIS the use was made of kinetic models and full-scale experiments that assisted in turn to gain information for variant calculations on MEIS. The results of these calculations allowed the conditions for nitrogen oxides formation by different mechanisms to be determined and the ways for improvement of coal combustion technology to increase environmental safety of boiler units to be outlined. 

For this system, the data base requirements are more critical since, in pressurized fluidized bed combustion, the alkali tolerance levels for downstream turbine operation are of the order of 0.02 ppm. Spacil and Luthra (3 ) compared their thermochemical predictions with observed combustion gas stream alkali concentrations. Here, Na2S04, NaCl, NaOH, and the K-analogues were included as significant molecular species in the thermochemical model data base. Albite and sanidine were assumed to represent the coal ash alkali-getter substrates. Fair, but encouraging, agreement between calculated and observed gas phase alkali concentration was obtained. 

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