Numerical research on heat transfer and thermal oxidation coking characteristics of aviation kerosene RP-3 under supercritical pressure

Utilizing aviation kerosene to cool the cooling air of aviation aircraft is an efficient and anticipated method. However, aviation kerosene undergoes thermal oxidation coking, which hinders its use as a cold source for high-performance aircraft engines. This article first validates a 34-step pseudo-detailed coking reaction kinetics model for the thermal oxidation coking process of Chinese RP-3 aviation kerosene, with a deviation of 10.2 % between the predicted coking amount and the experimental value. Subsequently, the phenomenon of RP-3 thermal oxidation coking inside a straight tube under typical conditions is analyzed, and the effects of inlet temperature, mass flow rate, residence time, and system pressure on heat transfer and thermal oxidation coking characteristics are discussed. The research results indicate that variations in the inlet temperature can affect the tube axial temperature gradient, which can shift reaction markers and coking rate distribution curve upstream while decreasing the total coking amount. Changes in mass flow rate impact the Reynolds number, and the coking rate is primarily determined by the balance between the oxidation reaction and substance diffusion. The deposition rate initially rises and then decreases with an increase in mass flow rate, and the coking peak value moves downstream. Variation in residence time affects the intensity of the coking reaction. As the residence time increases, the total deposition rate rises, while the coking rate per unit area decreases. The thermal properties of kerosene alter in response to variations in system pressure, which slightly increases the total coking amount.