Design and development of a novel self aspirating liquid fuel annular porous medium burner (SLAPMB)

This study presents the design and development of a novel, self-aspirating, liquid fuel, annular, porous medium burner (SLAPMB) with stabilized flame inside a packed bed using liquid ethanol. The SLAPMB is built in an annular shape with an open area at the center for more secondary air (SA) entrainment, and a vaporizer for vaporizing the liquid ethanol is embedded inside the burner wall. The transient period of the SLAPMB during the switching period from LPG to ethanol vapor is investigated for understanding the simultaneous combustion phenomena within the porous medium burner and the vaporization process within the vaporizer. Effects of the primary air (PA), firing rate (FR) on the flame stabilization, temperature profiles within the burner, and emission characteristics are investigated. The PA strongly affects the flame stabilization within the burner. Flame moves upstream as the PA increases and vice versa with the flame moving downstream as the PA decreases. The existence of an SA inlet can significantly reduce CO emission and increase thermal efficiency. The ethanol flame can be successfully stabilized within the burner with a temperature peak occurring at the middle region of the burner with a relatively low emission of CO and NOx of about 900 ppm and 50 ppm, respectively. Thermal efficiency is 33.6%. The SLAPMB can offer a relatively wide turndown ratio with the firing rate (FR) ranging from 16 kW to 23 kW without the problem of flame stabilization and emission.