Influence of secondary reactions on heat transfer process during pyrolysis of hydrocarbon fuel under supercritical conditions

Convective heat transfer in reacting flow of supercritical hydrocarbon fuel plays an important role in maintaining the reliability and durability of high temperature components in advanced aero-engines. A mathematical model with a detailed pyrolytic reaction mechanism of China RP-3 aviation kerosene was established to understand the influence of secondary reactions on heat transfer in reacting flow of supercritical hydrocarbon fuel. The results indicated that heat transfer was enhanced with conversion of hydrocarbon fuel at mild pyrolysis. As the conversion of hydrocarbon fuel increased, products such as butylene, alkenes and trace alkanes, increased and secondary exothermic reactions occurred, which resulted in a decline of heat transfer. Finally, a heat transfer deterioration region, which was induced by the secondary exothermic reactions, was generated. In addition, when the study on the influence of pressure and heating rate on the convective heat transfer in reacting flow of supercritical hydrocarbon fuel was analyzed, we found that the heat transfer deterioration region moved along the direction opposite to the mass flow at high pressure, and the heat transfer deterioration became more serious with rising pressure and heating rate.