Experimental study on the mechanism of water on heat sink variation in catalytic partial steam reforming of supercritical n-decane

Regenerative cooling is an effective method for heat management of hypersonic vehicles and faces a problem of insufficient cooling capacity under higher flight Mach number. Water-assisted hydrocarbon fuels thermal conversion can effectively increase heat absorption and inhibit carbon deposition. The mechanism of water on the variation of heat sink is unclear. In this study, experimental study was conducted to investigate the effect of different water contents, pressure and mass flow rates on the variation of heat sink and the distribution of gaseous products in a continuous experimental system. The results show that catalytic partial steam reforming reaction consists of catalytic steam reforming and catalytic thermal cracking in the low temperature stage (T<490 ℃), and non-catalytic thermal cracking is activated and gradually dominate in the high temperature stage (T>490 ℃). The contribution of water to total heat sink is mainly caused by physical heat sink. Increasing mass flow rate mainly suppress the cracking reaction in the high temperature section by reducing reaction residence time. The flow rate has little effect on the chemical reaction equilibrium. Higher pressure has little effect on heat sink, but accelerates carbon deposition by promoting the formation of olefin products.