The Catastrophe Mechanism of Flashover in Biomass Boiler

Abstract

The flashover phenomenon in biomass boiler causes serious damages to the equipments performance as well as security of people due to people are not clear about biomass boiler running, and thus preventing flashover from happening has a positive significance on boiler running. The characteristics of biomass fuel particles have been analyzed at first, and then simplifying the structure of boiler in order to model conveniently. This essay focus on justifying the stability of combustion system of biomass boiler with catastrophe theory in combination with the measured and calculated data, it demonstrates that swallowtail catastrophe conforms to the flashover mechanism. By building energy equation, conducting dimensionless treatment and carrying out the swallowtail catastrophe research method, the instability point is obtained. The gained critical flashover temperature of hot smoke layer is 686.71°C which is similar to predecessors studies, Then changing the parameters values for the sake of calculating different hot gas layer temperatures. The higher the hot gas layer temperature is, more hazardous the flashover tends to be. The research reveals that increasing the initial temperature of air or aggrandizing area of fire grate (larger than 3.36m2) contribute to increase flashover temperatures. However, augment of vapor heat and heat transfer area have the opposite effects.