生物质多孔介质气体流动阻力特性实验研究与数值模拟OA

Biomass fuel is a renewable and clean energy source that can replace fossil fuels and reduce carbon emissions.However,during storage and transportation,microbial metabolism in biomass can cause self-heating,which,through the"chimney effect",accelerates air circulation and promotes aerobic reactions,potentially leading to thermal runaway and fires.Given that biomass typically has rod-like and flake-like shapes,conventional porous media gas flow resistance models are poorly adapted for assessing these processes.In this study,a testing platform for the gas flow resistance characteristics of biomass porous media was established.Gas flow resistance tests were conducted on rice straws and soybean shells at different bulk densities.The parameters of the conventional Ergun model and the modified Ergun model were optimized.The results show that the resistance experienced by gas flowing through biomass porous media significantly increases with bulk density and gas velocity,exhibiting a pronounced upward parabolic relationship.As the load applied to the biomass increases from 50 kg/m2 to 2 800 kg/m2,its bulk density can increase by approximately two times.Ignoring the changes in bulk density and porosity caused by stacking height in biomass self-heating numerical simulations can lead to prediction deviations.Both the Ergun model and the modified Ergun model can be used to evaluate the gas flow resistance of typical flake-like or rod-like biomass.The modified Ergun model,with fewer parameters and direct calculation based on bulk density,significantly enhances engineering applicability.