加温加压下CFD-PBM耦合模型空气-水两相流数值模拟研究

计算流体力学与群体平衡模型（CFD-PBM）结合可有效地模拟鼓泡塔内流体行为，较准确地预测流场、相含率以及局部气泡尺寸分布。以直径100 mm、高1.3 m的加温加压鼓泡塔为模拟对象，在系统压力为1 MPa、表观气速为0.08~0.24 m/s、温度为30~160℃条件下系统地考察了空气-水体系的表观气速、温度以及固含率对平均气含率、大小气泡气含率、气泡直径和气泡尺寸分布等参数的影响。结果表明，平均气含率的模拟结果和实验值在10%的误差范围内吻合较好；温度的变化主要影响了塔内气泡的聚并和破碎，并用聚并破碎的机理解释了温度对其流体行为的影响。

Numerical simulation of air-water two-phase flow under elevated pressures and temperatures using CFD-PBM coupled model

The combination of computational fluid dynamics and the population balance model (CFD-PBM) can effectively simulate the fluid behavior in the bubble column, and more accurately predict the flow characteristic, phase holdup and local bubble size distribution. In this paper, numerical simulations of air-water two-phase flow are studied under thermal conditions by using CFD-PBM coupled model in a pressurized bubble column with a 100 mm diameter and 1.3 m height. The system has been investigated in the range of 1MPa, the superficial gas velocity of 0.08—0.24 m/s, and the temperature of 30—160℃. The effect of the superficial gas velocity, temperature and solid content of air-water system on the average gas holdup, large and small bubbles gas holdup, bubble diameter, and bubble size distribution are discussed. The results show that the simulation results of the average gas holdup are in good agreement with the experimental values within the error range of 10%. The temperature change mainly affects the coalescence and breakage of bubbles in the tower, and the coalescence and breakage mechanism is used to explain the influence of temperature on the fluid behavior.