Biomass is a renewable energy source helps reduce greenhouse gas emissions.However,combustion and reaction efficiency of biomass are significantly affected by their flow behavior.In this study,the flow characteristics...Biomass is a renewable energy source helps reduce greenhouse gas emissions.However,combustion and reaction efficiency of biomass are significantly affected by their flow behavior.In this study,the flow characteristics of wet elongated biomass particles in a lifting tube were experimentally investigated.Particle Tracking Velocimetry(PTV)was used to explore the particle area and velocity distribution under different gas-to-particle mass ratios(GPMR)and initial moisture contents(IMC).A homogeneity coefficient was also formulated to quantify the flow homogeneity of the particle population.The calculated range for the homogeneity coefficientαis 4.43-6.40,with smaller values indicating better flow homogeneity.Moreover,the factors affecting the fragmentation of larger particle clusters were analyzed with respect to the suspension process,the process of being carried out by the airflow,and the fragmentation process.The results indicated that the flow homogeneity of the particle population was better in the two sets of conditions when IMC was 28.7% and GPMR was 10 and when IMC was 32.5% and GPMR was 9.The homogeneity coefficient α was 4.43 and 4.79.In addition,the degree of fragmentation of larger particle clusters is mainly affected by the IMC.展开更多
A bended ribbon biomass particle model was developed to explore the dynamic transport properties inside a riser reactor.Residence time distribution(RTD)of the particles was analyzed by using the Eulerian-Lagrange meth...A bended ribbon biomass particle model was developed to explore the dynamic transport properties inside a riser reactor.Residence time distribution(RTD)of the particles was analyzed by using the Eulerian-Lagrange method.The effects of sampling height,particle density,particle size and gas-to-solid mass ratio on RTD were investigated.The coupled Computational Fluid Dynamics and Discrete Element Method(CFD-DEM)model was verified firstly by experimental data on pressure drop and residence time distribution density function.The simulation results demonstrated that the ribbon biomass particles display a typical annular-core spatial distribution during transportation.The RTD of particles exhibit an approximate single-peaked normal distribution.The mean residence time(MRT)can reach up to 0.7 s when the particle density is 1200 kg/m^(3).Particle with higher density has longer mean residence time.The flow patterns are closer to plug flow if particle length over 12 mm.The particle flow pattern is not sensitive to changes in particle density and size,while the gas-to-material mass ratio has a significant impact on it.展开更多
基金thefinancial support of the National Natural Science Foundation of China(grant No.51906092)Postgraduate Research&Practice Innovation Program of Jiangsu Province(grant No.SJCX23_2219).
文摘Biomass is a renewable energy source helps reduce greenhouse gas emissions.However,combustion and reaction efficiency of biomass are significantly affected by their flow behavior.In this study,the flow characteristics of wet elongated biomass particles in a lifting tube were experimentally investigated.Particle Tracking Velocimetry(PTV)was used to explore the particle area and velocity distribution under different gas-to-particle mass ratios(GPMR)and initial moisture contents(IMC).A homogeneity coefficient was also formulated to quantify the flow homogeneity of the particle population.The calculated range for the homogeneity coefficientαis 4.43-6.40,with smaller values indicating better flow homogeneity.Moreover,the factors affecting the fragmentation of larger particle clusters were analyzed with respect to the suspension process,the process of being carried out by the airflow,and the fragmentation process.The results indicated that the flow homogeneity of the particle population was better in the two sets of conditions when IMC was 28.7% and GPMR was 10 and when IMC was 32.5% and GPMR was 9.The homogeneity coefficient α was 4.43 and 4.79.In addition,the degree of fragmentation of larger particle clusters is mainly affected by the IMC.
基金support of the National Natural Science Foundation of China (grant No.51906092)China Tobacco Jiangxi Industrial Corporation Limited.
文摘A bended ribbon biomass particle model was developed to explore the dynamic transport properties inside a riser reactor.Residence time distribution(RTD)of the particles was analyzed by using the Eulerian-Lagrange method.The effects of sampling height,particle density,particle size and gas-to-solid mass ratio on RTD were investigated.The coupled Computational Fluid Dynamics and Discrete Element Method(CFD-DEM)model was verified firstly by experimental data on pressure drop and residence time distribution density function.The simulation results demonstrated that the ribbon biomass particles display a typical annular-core spatial distribution during transportation.The RTD of particles exhibit an approximate single-peaked normal distribution.The mean residence time(MRT)can reach up to 0.7 s when the particle density is 1200 kg/m^(3).Particle with higher density has longer mean residence time.The flow patterns are closer to plug flow if particle length over 12 mm.The particle flow pattern is not sensitive to changes in particle density and size,while the gas-to-material mass ratio has a significant impact on it.
