Changes in oxygen concentration have a significant impact on pulverized coal combustion.
2019.12.21
In this paper, various coal samples ranging from lignite to lean coal were selected, and oxygen-enriched combustion experiments of pulverized coal were carried out on two test facilities: a drop tube furnace and a thermogravimetric analyzer.
In the drop tube furnace, the ignition temperature decreases with the increase of oxygen concentration. Lean coal with low volatile matter is the most sensitive to changes in oxygen concentration. When the oxygen concentration increases from 16% to 36%, its ignition temperature drops by 24%, equivalent to a decrease of 147 °C. In contrast, the ignition temperature of Kalena lignite shows the smallest variation with oxygen concentration, decreasing by only 36 °C; however, due to its inherently low ignition temperature, the reduction ratio still reaches 12%. The trends of the four types of bituminous coal fall between those of lean coal and lignite, with their ignition temperatures dropping by approximately 15%, or 60–100 °C. Moreover, the decline rate of the ignition temperature of bituminous coal slows down once the oxygen concentration reaches 26%.
Experiments with varying pulverized coal concentrations in the drop tube furnace reveal that an increase in oxygen concentration weakens the effect of coal concentration on ignition temperature. Similarly, the influence of pulverized coal fineness on ignition temperature under different oxygen concentrations is slight and generally similar.
In the thermogravimetric analyzer, the combustion of different coal types...
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