| Summary: | 碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 98 === In this paper, experiments with a numerical simulation of oxygen to carbon dioxide or nitrogen dilution and flow (co-flow) of the oxygen-enriched combustion characteristics of methane diffusion flame. Dilution of oxygen-enriched combustion of methane as carbon dioxide to nitrogen-free combustion system, and the high concentration of carbon dioxide recycled to do the follow-up of carbon dioxide efficient catch them (capture) and the effective storage (sequestration), the combustion system almost all the combustion gases can be be recycled, for reducing environmental pollution and reduce greenhouse there is a big help. To pure oxygen combustion will result in considerable heat in the flame, so still need to return part of the practice of carbon dioxide containing flue gas (flue gas) used as flame cooling diluted, but dilution of the amount returned will cause too much instability in the flame, the amount is too dilute Low oxygen concentrations are likely to cause high local temperature on the combustion chamber design of considerable disadvantage, and high-temperature materials used for the combustion chamber will become extremely difficult, cost will increase.
From the simulation results, when the diffusion combustion of methane, and the flow field around the bottom will get involved in the fuel, resulting in some of the effects of premixed, the flame of oxygen and the early response of early, flame length and then shortened, when the oxygen concentration increases, combustion speed becomes faster, the flame becomes more short, temperature increase with high temperature when the nitrogen dioxide Cp value of 1.67 times, the high endothermic effect will reduce overall flame temperature, flame speed reduces the reaction time becomes more than the nitrogen delay, OH reduced to happen and there is delayed, incomplete combustion of CO made more quantitative.
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