Numerical simulation of pulverized-coal combustion
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摘要: 采用计算流体动力学软件对煤粉实际燃烧过程进行数值计算并结合其热态试验数据进行对比分析,已成为验证数学模型和指导工程实践的一种重要研究手段.应用商业软件FLUENT对煤粉燃烧及流场进行了数值模拟分析,采用混合分数/概率密度函数法模拟湍流燃烧,用P-1辐射模型开展辐射传热模拟,利用拉格朗日/欧拉法处理气固两相间的动量、质量和能量交换,对挥发份的析出采用双速率竞争模型,采用动力/扩散反应速率模型模拟煤粉颗粒的表面燃烧.并对模拟结果进行分析与对比,计算结果与实际燃烧过程有较好的一致性.数值模拟计算结果揭示了挥发分释放与焦炭燃烧的过程,为改善和优化煤粉的燃烧提供了重要的参考依据.Abstract: The comparative study between CFD numerical results of pulverized coal combustion process and the experimental data is becoming an important measure for validating mathematical models and direct engineering practice. The CFD commercial software, FLUENT, was used to simulate the pulverized coal flow and combustion. Mixture-Fraction/PDF model was used to simulate turbulent combustion; P-1 radiation model was used for simulating radiation heat transfer; the Langrange/Euler-s method was used for dealing with momentum, mass and energy exchange between the solid and the gas phase; the two-competing rates model for devolatilization and the kinitics/diffusion limited combustion model for simulating surface combustion of pulverized coal particles. The result of simulation is consistent with the data from actual combustion process. The simulation results show the rules of the volatile releasing and combustion processing of coke, which could provide important references to improve the combustion of the pulverized coal.
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Key words:
- numerical simulation /
- pulverized coal combustion /
- two phase flow
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