循环流化床广泛应用于矸石、污泥等低品位燃料转化,近年来随着其用途和需求变化,进行了广泛的适应性改造,准确模拟和预测流化床炉内燃烧状况可为此提供基础支撑。针对当前流化床模型复杂,难以兼顾多参数精准预测问题,构建了基于热力学和动力学的流化床模型,计算了燃料变化对需氧量的影响以及空隙率和温度随床层高度的变化。通过构建热力学模型,预测了碳含量为74.05%、17.71%、24.27%、34.01%的4种煤矸石,理论需氧量分别为15.17、4.00、4.47、6.20kg/h。计算结果关联了燃料类型与理论需氧量,可辅助风机功率、风量等参数设计;通过串联10个RCSTR动力学模块嵌入动力学模型,实现不同床层的空隙率、温度、气体分布等关键参数计算,单点参数误差低于15%。多过程模型融合方法的建立可实现不同类型静态指标分类预测,为燃料变换时调控流化床进风量、一二次风风口位置等参数提供理论依据和设计参考。

Circulating fluidized bed (CFB) has been widely used for the conversion of low-grade fuels such as gangue and sludge. In re⁃cent years, with the changes in the applications and requirements, extensive adaptive modifications have been made to the CFB. Accuratesimulation and prediction of the combustion performance inside the fluidized bed can provide fundamental support for these modifications.A fluidized bed model based on thermodynamics and kinetics was constructed to address the complexity of current fluidized bed models andthe difficulty of accurately predicting multiple parameters. The influence of fuel variation on the oxygen demand, as well as the variation ofvoid fraction and temperature with bed height were calculated. By constructing the thermodynamic model, the theoretical oxygen demandsfor four types of coal gangue with carbon contents of 74.05%, 17.71%, 24.27% and 34.01% were predicted, with theoretical oxygen de⁃mand of 15.17, 4.00, 4.47 and 6.20 kg/ h, respectively. The calculated results were related to fuel type and theoretical oxygen demand,which can assist in the design of parameters such as fan power and air volume. Furthermore, by embedding 10 RCSTR dynamic modules inseries into the kinetic model, the key parameters, including void fraction, temperature, and gas distribution, for different bed layerswere calculated,with the single-point parameter error of less than 15%. The classification and prediction of different types of static indica⁃tors can be achieved by the establishment of a multi process model fusion method, providing theoretical basis and design references for reg⁃ulating parameters such as fluidized bed air flow rate and primary-secondary air inlet positions during fuel transformation.

0 引言

1 工艺设计

   1.1 CFB燃烧器的燃煤过程

   1.2 基于热力学方法的CFB燃烧室模拟

   1.3 基于动力学模型的循环流化床燃烧室模拟

2 结果与讨论

   2.1 不同燃料燃烧的需氧量预测

   2.2 床层空隙率对碳流量的影响

   2.3 CFB温度随床层高度的变化

   2.4 CO和CO2摩尔分数随床层高度的变化

3 结论