冰浆存储过程冰晶粒径演化数值模拟

Numerical simulation of evolution of ice crystal size distribution during storage

为了探索冰浆存储过程冰晶粒径演化规律,运用数群平衡模型对冰浆存储过程冰晶粒径演化进行数值模拟,采用改进有限容积法对数群平衡方程进行离散求解,把数值结果与实验结果进行对比验证模型的可靠性,并研究冰晶团聚、破碎2个动力学事件对冰晶粒径分布演化的影响。研究结果表明:冰晶粒径演化数值模拟结果与实验结果的拟合曲线基本吻合,因此数群平衡方程模拟冰晶粒径演化可靠。对破碎与团聚作用下冰浆存储过程中冰晶粒径演化进行模拟,团聚作用使得大粒径冰晶颗粒增多,小粒径冰晶颗粒减少;破碎作用使得小粒径冰晶颗粒增多,大粒径冰晶颗粒减少;团聚和破碎共同作用下,团聚比破碎对冰晶粒径演化的影响明显,使得大粒径冰晶颗粒增多,小粒径冰晶颗粒减少。

In order to study the principle of the evolution of ice crystal size distribution during the process of ice slurry storage, population balance model was introduced to make a numerical simulation on the evolution of ice crystal size distribution. The improved finite volume method is used to solve the population balance equation. Population balance model＇s reliability was tested based on the comparison of numerical results and experiment results. Then it is time to research the effect of breakage and aggregation on the evolution of ice crystal size distribution. The results show that the changing curve for the evolution of ice crystal size distribution based on numerical results and experiment results is generally the same. So it is reliable to use population balance model to imitate the evolution of ice crystal size distribution.Aggregation makes the big size ice crystal increase and the small size ice crystal decrease. Breakage makes the small size ice crystal increase and the big size ice crystal decrease. When breakage and aggregation happen at the same time, the effect of aggregation on the ice crystal size distribution is more striking than that of breakage.