以空气-水蒸汽为气化剂下吸式生物质气化炉设计与试验

Design and Experiment of Downdraft Biomass Gasifier with Air-water Vapour as Gasification Agent

针对下吸式生物质气化炉主要部件对气化效果的影响进行了分析,并且设计了1台生物质气化炉。以空气-水蒸汽为气化剂,松木颗粒为原料,对该气化炉进行试验。在仅以空气为气化剂时,确定了最佳空气当量比(ER)为0.263,还原区反应温度达到671℃,燃气热值达到峰值1 569 kcal/Nm3。在ER保持0.263不变的条件下,增加水蒸汽与燃料质量比(S/B),在反应温度高于600℃时,燃气中CO含量逐渐减少,H2含量逐渐增加。当该气化炉以空气-水蒸汽为气化剂,ER为0.263,S/B为0.078时,燃气热值达到最大值1 627 kcal/Nm3。

The influence of main components of downdraft biomass gasifier on gasification efficiency was analyzed and a downdraft biomass gasifier was designed.The gasifier was tested by utilizing air-steam as the gasifying agent and pine particles as a raw material.The result showed that the optimum air equivalent ratio(ER)was 0.263,the corresponding reduction zone temperature and the gas calorific value would reache 671℃ and a peak value of 1569kcal/Nm^3 respectively.Under the condition that the ER was unchanged at0.263and the reaction temperature is higher than600℃,the CO content in the gas gradually would decrease and the H2content gradually increase with the increasing ratio of the water-vapor to fuel(S/B).It was determined that the gas calorific value of the gasifier would reached a maximum of 1627kcal/Nm^3 when the ER was0.263and the S/B was 0.078 with air-water vapor as a gasifying agent.