Study on the performance of catalytic reactor for aircraft fuel tank inerting system

Abstract

The catalytic reactor, which plays a pivotal role in the novel aircraft fuel tank green inerting system, encounters complex and alternating inlet boundary conditions. In this study, a transient theoretical model of the catalytic reactor was established and solved through programming, and its accuracy was verified through self-built experimental setups. The dynamic performance of the catalytic reactor and the impact of operational parameters were investigated. Additionally, a method for determining the operational range of the catalytic reactor was proposed. The results indicate that the bed temperature gradually increases to 370°C along the axial direction as the reaction progresses over time. In addition, the concentrations of fuel vapor and oxygen gradually decrease along the axial direction or with time, while achieving a fuel vapor conversion rate of 70.13% under design conditions. The promotion of catalytic reactions can be achieved by lowering the inlet gas velocity, elevating temperature, or increasing the concentrations of fuel vapor and oxygen. However, the bed's maximum temperature may surpass the self-ignition temperature of fuel vapor by 425°C. A novel indicator for oxygen consumption rate is proposed, which should be comprehensively evaluated in conjunction with the conversion rate to determine the performance of catalytic reactors. Moreover, increasing the reactor diameter can enhance both conversion rate and oxygen consumption rate. Pressure drop is detrimental to the catalytic reaction, therefore, high altitude and low-pressure conditions should be considered as the standard for reactor design. Meanwhile, this paper proposes a theoretical model to determine the operational range of the catalytic reactor based on criteria such as suitable catalytic efficiency and flight temperature. The research findings presented in this study provide a solid theoretical foundation for optimizing catalytic reactor design, thereby significantly promoting the application of green inerting systems.