主动配气式生物质气化炉流场模拟与试验

对下吸式固定床气化炉采用两层配气口实现气化剂进给量的主动控制,利用Fluent软件对炉内气压分布和速度进行模拟分析,结果表明气化炉主要反应区气压场呈现"梯级分布、层界分明"规律,速度场由上而下逐渐递增,同一截面流场具有较高的均匀性。以玉米秸秆为原料,对本气化炉压力场和温度场进行了试验研究,结果表明采取主动配气有利于促进气化炉的均匀反应,同一反应截面反应温度相对稳定,燃气组分波动较小,热值保持在5 500 kJ/m3以上。

Flow Fields Simulation of Biomass Gasifier under Active Air Distribution

Two layers of air distribution were designed to actively control the agent feed in down-draft fixed bed biomass gasifier. The pressure and velocity distribution inside the gasifier were studied by simulation analysis. The pressure field displayed the law of step distribution and obvious boundaries. The velocity pattern was higher from top to down with high level of uniformity in the same section. Experiments were done to test the pressure and temperature distribution in the gasifier by using corn stalk as materials. The results showed that it had an important effect of active air distribution on promoting the reaction uniformity. The temperature kept stability at the same section with little changes of the gas components, and calorific value kept above 5 500kJ/m3.This method can provide a new way to improve the working performance of the fixed gasifier.