Optimization Study on Air Distribution of an Actual Agriculture Up-draft Biomass Gasification Stove

Abstract

The effect of air distribution on the performance of an actual agricultural up-draft biomass gasification stove was investigated, and the temperature distribution in gasification stove, gas composition, gas heat value and global energy utilization efficiency were measured. Results show that in the present gasification stove the highest temperature located at 75mm above bottom and in the range of 950–1100°C. Along the gasifier height from bottom, the content of H2, CO and CH4 increased until 250mm and the content of CO2 showed a peak value around 150mm. With the increasing in the global air, the furnace temperature, the content of CO and H2 in gas, gas heating value and gasification efficiency increased first and then decreased while the content of CO2 and CH4 in gas decreased first. Moreover, the air distribution between gasifier and burner was important and there was an optimum distribution ratio. With the increasing in the ratio of gasifier air and burner air, the global energy utilization efficiency increased first and then decreased, and the optimum ratio was around 1:3 when the flame above burner showed blue and stable. Results of dynamic test indicated that the gasified gas composition and energy output achieved stability until 20min after ignition. The present work could provide an optimum guide for high-efficiency operating of the agricultural up-draft biomass gasification stove.