OPTIONS FOR UPGRADING BAGASSE FURNACE PERFORMANCE

摘要

The design of conventional bagasse suspension boilers has altered little since first introduced into the Australian sugar industry in the early 1960s. The technology is simple and generally effective. However the furnace space is not utilised efficiently for combustion, and problems continue with the capability to generate steam consistently with wet bagasse. There has been minimal work reported in the literature on detailed investigations of furnace performance and related design possibilities. The paper reports on the application of the Computational Fluid Dynamics (CFD) code FURNACE to the modelling of the furnace section of sugar mill boilers. FURNACE has been used to simulate the heat transfer and combustion performance for a range of design modifications which have not previously been attempted on full scale units. The design changes have focussed on secondary air effects, under-grate air distribution and bagasse spreader configuration. The variations of performance indicators such as furnace exit gas temperature, percent burnout and furnace heat absorption are reported. The implications for boiler design are discussed and recommendations given for some design changes which do not depart significantly from established practice but which offer the possibility of increased boiler performance.