(616h) The Effect of Pressure on Thermal Oxidative Deposit of JP-10 in Near-Isothermal Flowing Reactor

The development of hypersonic flight requires that hydrocarbon fuel has better performance. The hydrocarbon fuel forms undesirable deposits in passages, controls, filters, and nozzles when it absorbs waste heat from aircraft components. Deposits will affect the heat transfer coefficients of heat exchanger, plug engine components and reduce engine life. Although plenty of researches have been done on thermal stability, coke deposition and factors affecting the formation of coke about aviation fuels, there is a little information on the effect of pressure on surface deposit. Moreover, the results about the effect of pressure on surface deposit are inconsistent. There are three different points: no effect of pressure on thermal oxidative deposit, deposit rate increasing with increasing of pressure and deposit rate decreasing with increasing of pressure , respectively.

The first goal of the paper is to study thermal oxidative deposit of JP-10 on SS316. The second and significant goal is to study the effect of pressure on thermal oxidative deposit of JP-10 on SS316. The experiments were conducted in near-isothermal flowing test system at wall temperature 350℃ and pressure from 0.5MPa - 6.8MPa. The amount of coke deposit formed on SS316 was measured using a LECO RC612. The morphologies and natures of deposits were characterized by a field emission scanning electron microscope and temperature-programmed oxidation (TPO) profiles. Amorphous carbon and filamentous carbon were found in the solid deposits. The presence of these two different deposit morphologies can explain the lower temperature and high-temperature peaks seen in the TPO profile of this deposit. The lower temperature peaks can be due to high oxidation reactivity of hydrogen-rich carbon that may have formed by nucleation and growth of precursors in the liquid phase. The high temperature peaks can be due to oxidation of filamentous carbon. It was found that deposits increased with increasing of pressure in gas phase and pressure essentially did not influence thermal oxidation deposit of JP-10 in liquid phase.