惠生-壳牌下行水激冷气化炉的数值模拟

Numerical simulation of Wison-Shell bottom-quench gasifier

利用计算流体力学方法对商业化运行的惠生-壳牌下行水激冷气化炉进行三维数值模拟。采用离散相模型描述气固相流动之间的相互作用,利用随机轨道模型追踪粉煤颗粒的运动,将粉煤气化分为水分蒸发、煤热解、气气均相反应和气固非均相反应等过程;运用realizable k-e模型描述气相湍流流动;运用组分输运模型以及有限速率-涡流耗散模型描述气化过程中的复杂化学反应过程;采用P-1模型描述气化炉内的辐射传热。研究结果表明:建立的计算模型合理准确,气化炉出口有效气含量大于90%,碳转化率大于99%。

A three-dimensional numerical simulation was carried out for the Wison-Shell Bottom-Quench gasifier, which has been running commercially, by using the computational fluid dynamics （CFD） method. The discrete phase method was used to simulate the interaction between gas phase and pulverized coal flow. Random-Trajectory model was used to track coal particles by using a Lagrangian formulation. In the model pulverized coal gasification process was divided into several sub-models including： moisture release, vaporization, devolatilisation, gas-gas homogeneous reactions and gas-solid heterogeneous reactions. The realizable κ-ε model was used for gas phase flow. Turbulent flow mixing and chemical reaction were considered in the species transport and finite-rate chemistry model. P-1 model was used for describing the radiation in the gasifier. The results show that the CFD model is valid and accurate, and the mole fraction of CO＋H2 in syngas and carbon conversion can be over 90% and 99%, reseparately.