300MW机组循环流化床锅炉外置床运行特性试验

Test on operation characteristics of fluidized bed heat exchanger of a 300 MW unit circulating fluidized bed boiler

在测量某台燃用贫煤的300 MW机组循环流化床(CFB)锅炉外置床热力参数及烟气成分基础上,对大型CFB锅炉外置床运行特性进行了试验研究。结果表明:燃烧贫煤的CFB锅炉外置床内存在燃烧现象;不同类型的外置床内吸热份额、燃烧释放热量及流经外置床的循环灰流量不同;通过建立外置床平衡方程或者直接测量外置床烟气成分均可获得满足工程精度的外置床内燃烧释放热量。该研究结果可为超(超)临界CFB锅炉外置床设计与运行提供参考。

On the basis of measuring the thermodynamic parameters and flue gas components of the fluidized bed heat exchanger(FBHE)of a 300 MW CFB boiler fueled by lean coal under different thermal loads,the actual operation characteristics of the FBHE were experimentally investigated.The results indicate that,post-combustion phenomenon exists in the FBHE of the CFB boiler firing lean coal.The heat absorption shares of the different FBHEs are quite different from each other,as well as heat released by char combustion and ash flow rates through the FBHE.The heat release by char combustion in the FBHE can be obtained by establishing equilibrium equation in the FBHE or directly measuring the flue gas composition at outlet of the FBHEs.These results can provide referential materials for design and operation of the FBHE in large-scale CFB boilers.