10 MWth生物质化学链燃烧双循环流化床装置的降阶模拟OA

Chemical looping combustion(CLC)circulates oxygen carriers(OCs)between a fuel reactor(FR)and an air reactor(AR),thereby enabling inherent CO2 capture and low NOx emissions,making it a promising low-carbon combustion technology.However,CLC involves complex multi-scale and multi-physics coupled processes,and its scale-up faces challenges such as reactor design and OC optimization.In this study,a reduced-order model was developed to simulate a 10 MWth biomass-fueled CLC system with a dual-circulating-fluidized-bed configuration.The model was used to investigate the system's combustion behavior,reaction characteristics,and energy distribution.Simulation results indicate that the system achieves a solids circulation rate of 96 kg/s,a combustion efficiency of 95.56％in the FR,and a carbon capture efficiency of 85.8％.From a system-level energy perspective,both reactors attain thermal equilibrium,thus enabling autothermal operation.Under autothermal operation,the water wall installed in the upper section of the AR absorbs 1.24 MWth,which constitutes the useful heat output of the system.The effects of FR operating temperature,system thermal input,OC performance degradation,and OC type on combustion and carbon capture efficiencies were further examined.Sensitivity analysis shows that increasing the FR temperature increases the carbon capture efficiency from 85.8％to 92.25％and the combustion efficiency from 95.56％to 96.4％,although excessively high temperatures can disrupt the autothermal balance.As the system thermal input increases from 8 MWth to 13 MWth,the combustion efficiency is only marginally affected,whereas the carbon capture efficiency decreases from 89.21％to 81.84％.When the OC performance degrades from 100％to 40％,the combustion efficiency decreases from 95.56％to 71.09％,and the carbon capture efficiency decreases from 85.8％to 81.21％.In contrast,owing to their higher oxygen transport capacity and superior reactivity,perovskite type OCs significantly outperform their ironbased counterparts,with combustion efficiency reaching up to 97.75％.