煤基化学链燃烧串行流化床的冷态试验研究

Cold-flow Model Experiment of Interconnected Fluidized Bed for Chemical Looping Combustion of Coal

采用"湍动床+快速床"作为煤基化学链燃烧(CLC)系统的空气反应器(AR),鼓泡床作为燃料反应器(FR),设计了流动密封阀和旋风分离器,分别用于隔绝2个反应器之间的气氛和进行气固分离,在冷态试验装置上分析研究了CLC系统的压力分布、固体循环流量、气体泄漏率及煤灰与循环载体的分离效果.结果表明:该串行流化床反应器之间气氛隔绝性良好,气体泄漏率较低,固体循环流量达到甚至超过设计标准,FR二级旋风分离器的分离效率接近100%,FR中煤灰进入AR的质量分数小于1.55%,煤灰分离效果良好;装置可以长时间连续稳定运行,且操作气速范围较广,自行设计建造的循环流化床作为煤基化学链燃烧试验装置是可行的.

Taking the configuration of ＂turbulent bed ＋ fast fluidized bed＂ as the air reactor （AR） and a bubbling bed as the fuel reactor （FR）, a coal fueled chemical looping combustion （CLC） system was de- signed, where two loop seals are used to prevent gas leakage between AR and FR, and a cyclone for gas- solid separation. Cold-flow model experiments were carried out to study the pressure distribution, solids circulation rate, gas leakage rate and ash-carrier separation efficiency of the CLC system. Results show that for the interconnected fluidized bed, its AR and FR are well sealed; the solids circulation rates meet or even exceed the design requirement; the separation efficiency of secondary cyclone at the FR exit nearly reaches 100%; the mass fraction of coal ash entering into AR from FR is less than 1.55%; the coal ash separation efficiency is high. The experimental setup may operate stably and continuously for a long time in a wide range of controllable gas superficial velocities, proving it to be feasible to design and operate the interconnected fluidized bed for coal-fueled chemical looping combustion.