An experimental study of biomass ash particle oblique impact at the high-temperature environment of boilers

Experimental research on biomass ash particles’ impact, rebound, or adhesion characteristics could provide necessary reference and guidance for accurate simulation, prediction, and study of the ash behavior of the co-combustion of biomass and coal in power plant boilers. A high-speed camera is used to study the collision characteristics of ash particles at the microscopic scale using particle size, angle of incidence, incident velocity, and different ash samples as experimental variables. This work investigates the oblique impact rebound characteristics of coal and three kinds of biomass fuels (wheat straw, sawdust, corn straw) ash particles in a high-temperature environment. The effects of impact velocity (vi), impact angle (θi), and particle size on the rebound of ash particles are studied based on the restitution coefficient and energy consumption. The results show that the rebound velocity (vr) increases with the increase of vi. The larger particle size of biomass ash means higher rebound velocity and angle. Contact energy dissipation is the main form of energy consumption, and in an oblique collision, the contact energy loss increases gradually with the increase of impact angle. The purpose of this study is to understand the collision characteristics of the ash particles, to derive the accumulation and adhesion characteristics of the ash particles, and then to derive the relevant ash accumulation and slagging model, which can provide certain corrections for the relevant numerical simulations, and, at the same time, to further understand the characteristics of ash accumulation and slagging of biomass ash. •The oblique impact rebound of four kinds of ash particles are investigated.•The particles' impact characteristics are studied based on restitution coefficient.•The ash particles' impact characteristics are studied based on energy consumption.•The main factors that affect the ash particles' impact results are obtained.•Providing correction factors for numerical simulations.