Spray combustion characteristics of boron slurry fuel in high particle loading conditions

Abstract

Enhancing the energy density of hydrocarbon fuels is indeed crucial, especially in the context of addressing energy needs. Incorporating energetic particles as additives into conventional liquid fuels garners increased attention due to its potential to enhance energy density. Due to its high energy potential, boron is the most promising additive in several energetic particles. However, the study focusing on the boron-loaded slurry fuels are limited. Therefore, the present work focuses on the effect of boron loading on the spray combustion of boron-loaded slurry fuel, especially at higher loadings (10%, 20% & 30% boron + Jet A-1 fuel) using a swirl-stabilized spray combustor. The research scrutinizes the feed and exhaust particles' surface morphology, chemical composition and active boron content through diverse particle characterization techniques. Furthermore, the study investigates the influence of boron loading on the combustion characteristics of slurry fuel using methods such as colour flame imaging, spectroscopy, and BO₂* Chemiluminescence imaging. The impact of boron loading on the positive thermal contribution of the slurry was examined by analyzing temperature measurements at various locations within the combustor. The BO₂* chemiluminescence imaging and spectroscopy results indicate that the intensity of BO₂ emission increases with a rise in particle loading. The temperature results reveal an increase in temperature compared to pure Jet A-1 for all the boron-loaded cases. In particular, JB10 and JB20 achieved nearly 90% and 85% of the theoretical temperature increase. The diffractogram and thermogravimetric results of the burnt particles collected show that the particles were burnt thoroughly for the boron-loaded cases.