催化柴油管式液相加氢脱硫数值模拟

Computational fluid dynamics simulation of liquid-phase catalytic diesel hydrodesulfurization in tubular reactor

采用计算流体力学(CFD)软件FLUENT,以用户自定义函数(UDF)添加化学反应和反应热,对实验室带有陶瓷膜管分散器的催化柴油管式液相加氢脱硫反应器进行模拟计算,得出反应床层不同部位的硫化物含量分布和温度分布状况。从反应床层的入口到出口,催化柴油的硫化物含量逐渐下降,且下降速度趋缓。在压力6.5 MPa、混氢量0.84%(m)、空速2 h^(-1)、进口温度633 K的条件下,位于床层高度0.15 m处出现最高温度点643.8 K,径向温差最大2.1 K,表明催化柴油管式液相加氢脱硫反应器催化剂装填合适的高径比为4~6。工艺条件的模拟结果表明:随着进口温度上升、混氢量增加、空速减小脱硫率提高,与实验数据吻合程度较好,说明模拟研究过程中采用的模型和控制方程准确性较高。

The computational fluid dynamics （CFD） code, FLUENT, was used to simulate the liquid-phase catalytic diesel hydrodesulfurization tubular reactor with a ceramic membrane tube dispenser. The chemical reaction and reaction heat was added to the model by user-defined function （UDF）, showing the distribution of temperature and content of sulfide in different parts of the reaction bed. The content of sulfide in diesel fuel decreased from the inlet to outlet of the catalytic bed and the rate of decline slowed down. When the pressure was 6.5 MPa, the amount of mixed hydrogen was 0.84 % （m）, the space velocity was 2 hq and the inlet temperature was 633 K, the temperature reached maximum at the height of 0.15 m, and the range of radial temperature reached to maximum （2.1 K） at the height of 0.15 m. It indicated that the proper ratio of height to diameter of catalyst in the liquid-phase catalytic diesel hydrodesulfurization tubular reactor was 4-6. The simulation showed that the rate of desulfurization rose with the decrease of space velocity and the increase of inlet temperature and the amount of mixed hydrogen. The results were in good accordance with experimental data, indicating the higher accuracy of the simulation models and equations used in the research process.