Research On Effects Of N-decane Prolysis On Its Combustion Performance

Regenerative cooling is an efficient active cooling system for Scramjet. In cooling channels, endothermic hydrocarbon fuel absorb heat transferred from engine walls, liquid fuel turns into gas fuel or micro molecule hydrocarbon within the physical and chemical process, then those products are being injected into the combustion chamber and release the chemical and physical sink obtained in cooling process. In that case, liquid fuel availability is improved while cooling the engine wall.Currently, the improvement of liquid fuel availability is just limited to qualitative analysis, quantitative calculation is needed to be done and the direction of improve the combustion performance of thermal pyrolysis product is needed to be put forward. As a main ingredient of aviation fuel, n-Decane is used in the research of subcritical and supercritical heat transfer and pyrolysis. Based on the above analysis, in this research, nDecane is used as working medium, the high-temperature pyrolysis and combustion experiment were conducted, and the combustion of pyrolysis gaseous product was simulated, the law of pyrolysis of fuel on the product’s combustion performance was primarily obtained.In this research, first pyrolysis-combustion system was established based on existing high temperature fuel pyrolysis experiment platform. This paper first introduce the experiment system and its operating principle, and then introduce several important parts and their measured principle. Meanwhile, experiment data analysis method is detailedly stated, measuring error and error of data processing is analyzed to ensure the accuracy of below experiment data.Secondly, based on the pyrolysis-combustion platform, the high-temperature combustion experiment was conducted, as well as n-Decane pyrolysis experiment under low pressure and the diffusion combustion of gaseous product. The influence of gas mass flow, fuel temperature and species concentration on flame structure, laminar flame velocity, flame temperature and flame intensity were studied, and the varying rule was summarized.Finally, the oxidation mechanism of n-butane was reduced by Path Flux Analysis(PFA) method, and its accuracy was verified within CHEMKIN. After that, the simplified mechanism was used to simulate the combustion of n-Decane gaseous product under different fuel gas temperature and different species, the influence of alkene/alkane ratio on diffusion combustion was gained. Simultaneously, the influence of gas temperature and species concentration on distribution of intermediate products and how those parameters affect the combustion process was clarified.