气流床煤气化辐射废锅内多相流动与传热

采用多相流动与传热模型耦合的数值方法，对气流床煤气化辐射废锅内多相流场与传热过程进行了数值模拟。在Euler坐标系中采用组分输运模型计算气体组分扩散过程，并通过realizable k-ε湍流模型计算炉内流场，煤渣颗粒运动轨迹在Lagrange坐标系中计算，并考虑了气固相间双向耦合。利用灰气体加权和模型与离散坐标法相结合，计算了炉内辐射传热过程，并考虑了煤渣颗粒的热辐射特性。结果表明：炉体入口存在张角约为10°的中心射流区，其流速和温度均较高，且周围存在明显回流区，回流区内部分颗粒富集;大部分颗粒直接落入渣池，且粒径越大落入渣池时温度越高;炉内温度分布除中心射流区，整体分布均匀，且随壁面灰渣厚度的增加而升高;计算结果与实验测量结果及文献值基本一致。

Multiphase flow and heat transfer in entrained-flow coal gasification radiant syngas cooler

The process of multiphase flow and heat transfer in an entrained-flow coal gasification radiant syngas cooler (RSC) was simulated by coupling the multiphase flow model and heat transfer model. The gas phase flow field was calculated by realizable k-ε model with an Euler method while the discrete random walk (DRW) was applied to trace the particles, and the interaction between gas and particles was considered. The radiative properties of syngas mixture were calculated by Weighted-Sum-of-Gray-Gases (WSGG) model. The discrete ordinates model (DOM) was used for modeling the radiative heat transfer, and the effect of slag particles on radiative heat transfer was included. Results showed that the expanding angle of inlet jet is 10°, where the temperature and velocity are higher than other area's. The recirculation region around the inlet jet has a higher particle concentration. Most of the slag particles are straightly dropped into the slag pool, and the larger the particle, the faster the dropping and the higher the temperature it will have. The temperature distribution in RSC is uniform except the inlet jet region, and the temperature increases with the increase in ash/slag deposition thickness. The mathematical models for numerical simulation are compared with experimental and literature data. Overall agreement between the predicted and experimental values is good and gives confidence in using these routines for RSC design calculations.