The spouted-fluidized bed is modified from the classical fluidized bed device,which combines the features of spouted and fluidized beds.In the present work,the performance of oxy-fuel spouted-fluidized bed combustion ...The spouted-fluidized bed is modified from the classical fluidized bed device,which combines the features of spouted and fluidized beds.In the present work,the performance of oxy-fuel spouted-fluidized bed combustion with under bed feeding and its effect on NO emission were systematically investigated.The results revealed that it was feasible to use a spouted-fluidized bed combustor for oxy-fuel combustion with real flue gas recycling.The transition from air combustion to oxy-fuel combustion was smooth and the concentration of CO_(2) in the flue gas could be as high as 90%steadily(dry base).Increasing the reaction temperature exhibited a negative effect on NO emission.Compared with that under the shallow bed,the concentration of NO in the flue gas was lower under the deep bed condition.Besides,the utilization of crush particles was favorable for suppressing NO emission because of the promoted mixing between coal particles and solid bed materials.Furthermore,the addition of limestone was proven to undesirably increase the NO emission during oxy-fuel spouted-fluidized bed combustion.展开更多
The flow characteristics in a spouted-fluid bed differ from those in spouted or fluidized beds because of the injection of the spouting gas and the introduction of a fluidizing gas. The flow behavior of gas-solid phas...The flow characteristics in a spouted-fluid bed differ from those in spouted or fluidized beds because of the injection of the spouting gas and the introduction of a fluidizing gas. The flow behavior of gas-solid phases was predicted using the Eulerian-Eulerian two-fluid model （TFM） approach with kinetic theory for granular flow to obtain the flow patterns in spouted-fluid beds. The gas flux and gas incident angle have a significant influence on the porosity and particle concentration in gas-solid spouted-fluid beds. The fluidizing gas flux affects the flow behavior of particles in the fountain. In the spouted-fluid bed, the solids volume fraction is low in the spout and high in the annulus. However, the solids volume fraction is reduced near the wall.展开更多
基金supported by the National Natural Science Foundation of China(No.51806220,51922040)China Postdoctoral Science Foundation Funded Project(No2019M660594)+1 种基金Grants from Fok Ying Tung Education Foundation(161051)Fundamental Research Funds for the Central Universities(No.2019QN003,2020DF01,2018ZD08)。
文摘The spouted-fluidized bed is modified from the classical fluidized bed device,which combines the features of spouted and fluidized beds.In the present work,the performance of oxy-fuel spouted-fluidized bed combustion with under bed feeding and its effect on NO emission were systematically investigated.The results revealed that it was feasible to use a spouted-fluidized bed combustor for oxy-fuel combustion with real flue gas recycling.The transition from air combustion to oxy-fuel combustion was smooth and the concentration of CO_(2) in the flue gas could be as high as 90%steadily(dry base).Increasing the reaction temperature exhibited a negative effect on NO emission.Compared with that under the shallow bed,the concentration of NO in the flue gas was lower under the deep bed condition.Besides,the utilization of crush particles was favorable for suppressing NO emission because of the promoted mixing between coal particles and solid bed materials.Furthermore,the addition of limestone was proven to undesirably increase the NO emission during oxy-fuel spouted-fluidized bed combustion.
基金supported by the Natural Science Foundation of China through Grant No.21076043 and No.51206020Province in Heilongjiang's Outstanding Youth Science Foundation(JC201202)Program for New Century Excellent Talents in Heilongjiang Provincial University(1252-NCET-010)
文摘The flow characteristics in a spouted-fluid bed differ from those in spouted or fluidized beds because of the injection of the spouting gas and the introduction of a fluidizing gas. The flow behavior of gas-solid phases was predicted using the Eulerian-Eulerian two-fluid model （TFM） approach with kinetic theory for granular flow to obtain the flow patterns in spouted-fluid beds. The gas flux and gas incident angle have a significant influence on the porosity and particle concentration in gas-solid spouted-fluid beds. The fluidizing gas flux affects the flow behavior of particles in the fountain. In the spouted-fluid bed, the solids volume fraction is low in the spout and high in the annulus. However, the solids volume fraction is reduced near the wall.
