Analysis And Experimental Studies Of Biomass Powder Burning Process

The vast majority of China's industrial boilers and furnaces use combustion equipments whose burning power among 0.5～7MW."Combustion for biomass powder" is a R & D project of school-enterprise cooperation in joint. The work of this paper is part of the project.Compared with other forms of biomass, such as bulk material and particle material, biomass powder has its advantages in certain conditions when using as bunkers. Its better economical efficiency is reflected in burning as fuels in small and medium sized combustion equipments, especially in the construction of "Green Energy County" at range of the county.This paper gives a discussion about basic properties and slagging tendency of biomass powder. And then some experiments are taken to determine the ash content of the powder samples. The structure system and performance index of the combustor for biomass powder are expounded in this paper. Also some detailed calculations about the combustion process are made here.Slag was taken and experimented in allusion to the phenomenon of serious slagging in the combustor. Further more, a design scheme was discussed and determined for the structure of a combustor among the research group. Optimizations about structure scheme and operation parameters were done using Fluent in this paper. The new model of biomass powder combustor has many structure characteristics as follows:It's a cyclone-type burner with an assembled fire ring inside of the furnace; There is secondary air close to the wall inside of the furnace to prevent slagging. An ejective section is fixed at the back of the furnace to organize secondary combustion.A test-bed for hot state experiments was designed and established at a industrial scale in cooperation with the partner, and many hot state experiments were done on the sample of biomass powder combustor. All the technology index of the sample combustor can satisfy actual requirements after a long period assessment on the user's boiler. It almost reach to a practical level in the aspect of preventing slagging and extinct protection.