Experimental Investigation On Flow And Heat Transfer Of N-decane Micro/Nanocatalytic Pyrolysis

Endothermic hydrocarbon fuels have the function of absorbing physical heat, and the heat absorption capacity can be enhanced due to the severing of chemical bond after absorb abandon heat. So endothermic hydrocarbon fuels are wildly utilized on active regenerative cooling in scramjet. Physical heat transfer at low temperature and components of pyrolysis products influence the heat sink. Catalyst debases chemical reaction activation energy, so the fuels pyrolysised at lower temperature than thermal pyrolysis, and increase the selectivity of components of pyrolysis products. In addition, nanocatalyst can increase the turbulence intensity and enhance heat transfer. The influence about heat transfer and pyrolysis was investigated of nano ZSM-5 to N-decane flow and heat transfer.Dodecyltriethoxysilane was used to modify ZSM-5 and got lipophilicity surface. Mechanical stirring and ultrasonic dispersion were used to prepare stable nanofluids. Four kinds of nanoparticles were ZnO, SiO₂, Al₂O₃ and nanoZSM-5, due to the reinforcement of ZSM-5 are componented by SiO₂ and Al₂O₃.Investigated whether different nanoparticles influence decane heat transfer at the temperature lower than initial pyrolysis temperature, got the optimum concentration of the nanofluids which enhanced heat transfer and analysised part of coke deposition. Developed the heat transfer correlations contained multilayer adsorption due to Maxwell Model and agglomerate mechanism.Selected optimum non-catalytic and catalyst nanoparticles on the basis of above to investigate the influence of those to heat transfer and pyrolysis of decane at pyrolysis temperature interval. Including heat transfer enhance, decrease of initial pyrolysis temperature and component distribution of pyrolysis product. Then acquired the optimum concentration about on-catalytic and catalyst nanoparticles at the temperature interval.Compared the results of nanoZSM-5-decane to the same concentration of microZSM-5-decane and nanoZSM-5-cyclohexane to investigate the role of nano effects about increaseing decane pyrolysis and enhancing heat transfer at high temperature. Put forward appropriate correlations based on catalytic reaction kinetics, exposited the mechanism of enhance heat transfer at high temperature and provide theoretical foundation in order to increase heat sink.