Kinetics and modeling of supercritical pyrolysis of endothermic hydrocarbon fuels in regenerative cooling channels

Abstract

Abstract Endothermic hydrocarbon fuel (EHF) is used as on-board coolant quenching the combustors of advanced aircrafts through sensible and endothermic pyrolysis reactions. The supercritical pyrolysis of EHFs was experimentally investigated under conditions (3.5\u202fMPa, 525–600\u202f°C) in a stainless steel mini-tubular reactor heated by a fluidized sand bath system. A simplified molecular reaction kinetic model (16 species and 11 reactions) was proposed based on the primary/secondary pyrolysis mechanism and the residence time estimation using computational fluid dynamics simulations. The experimental and predicted results using the developed kinetics model agree very well with the errors less than 10% under the conversion up to 70%. The pyrolysis model was also used in modeling EHF flowing and pyrolysis in an electrically heated tube showing the conversion prediction errors less than 15% and the fuel and wall temperature prediction deviations less than 20\u202fK, which is a significant improvement on the previous model (Energy Fuels 2013, 27, 2563).