Abstract: The process of gas-liquid two-phase flow of internal circulation anaerobic （IC） reactor （25L） was simulated by Fluent software. The influence of internal circulation flow rate with different riser pipe diameters （0.006m，0.009m，0.012m，0.015m，0.018m，0.021m）and volume loading rates [8.64kgCOD/(m3?d)，10.08kgCOD/(m3?d)，11.52kgCOD/(m3?d)，12.96kgCOD/(m3?d)，14.40 kgCOD/(m3?d)，15.84kgCOD/(m3?d)] were investigated. When volume loading rate was 11.52kgCOD/(m3?d)，and riser diameter was 0.015m，a maximum internal circulation flow rate of 0.0079m3/h was observed. When riser diameter was 0.015m，and volume loading rate was 12.96 kgCOD/(m3?d)，a maximum increase amplitude of 9.28% was observed. The correlation of Y=1.0514X+0.004 between internal circulation flow rate（Y） and biogas production（X） was obtained by fitting.

Key words: internal circulation anaerobic reactor, fluent simulation, internal circulation flow rate, riser pipe diameter, volume loading rate, internal circulation anaerobic reactor, numerical simulation, internal circulation flow rate, gas-liquid flow, optimal design

摘要： 采用Fluent技术对25L内循环（IC）厌氧反应器内气液两相的流动过程进行了数值模拟，考察了提升管直径（0.006m、0.009m、0.012m、0.015m、0.018m、0.021m）和反应器容积负荷[8.64kgCOD/(m3?d)、10.08kgCOD/(m3?d)、11.52kgCOD/(m3?d)、12.96kgCOD/(m3?d)、14.40kgCOD/(m3?d)、15.84kgCOD/(m3?d)]变化对其内循环量的影响。研究结果表明：①当反应器容积负荷为11.52kgCOD/(m3?d)、提升管直径为0.015m时，该反应器内循环量达到最大值0.0079m3/h；②当提升管直径为0.015m、容积负荷为12.96kgCOD/(m3?d)时，该反应器内循环量增幅达到最大值9.28%，通过拟合获得了内循环量Y与产气量X间的经验关联式为Y=1.0514X+0.004。

关键词: 内循环厌氧反应器, Fluent模拟, 内循环量, 提升管直径, 容积负荷, 内循环厌氧反应器, 数值模拟, 内循环量, 气液两相流, 优化设计