低温储罐大流量排液过程数值模拟研究

Numerical Simulation of Large Flow Liquid Discharge Process in Cryogenic Tank

大型低温储罐广泛应用于航空航天、能源、化工等领域的大规模低温液体储存。在大型低温储罐的大流量排液过程中,确保排液稳定且不夹带气体对于系统的安全运行至关重要。针对某3000 m^(3)液氮储罐2000 m^(3)/h的大流量排液工况,建立了该储罐及其排液管路的计算流体力学(CFD)模型,重点分析了大流量低温流体排液过程的气液界面、流场、涡量场和管道压力波动,讨论了影响临界液位高度的因素及防涡板在排液过程中发挥的作用。结果表明,在从静止液面开始的大流量排液过程中,当临界液位高度在0.15 m以下时,不会形成明显的漩涡;低温储罐初始液位高度对临界液位高度的影响较小,而防涡板在排液过程中阻碍了流体流动,会导致临界液位高度升高。研究可为大型低温储罐排液系统的稳定操作提供指导。

Large cryogenic storage tanks are widely used in large-scale cryogenic liquid storage in aerospace,energy,chemical and other fields.It is very important for the safe operation of the system to ensure the stability of discharge and no entrain of gas in the process of large flow discharge of large cryogenic storage tank.The computational fluid dynamics(CFD)model of a 3000 m^(3) liquid nitrogen storage tank and its drainage pipelines was established for the discharge of liquid at a high flow rate of 2000 m^(3)/h,and the gas-liquid interface,flow field,vortical field and pressure fluctuation of pipeline were analyzed.The influence factors of critical submergence level of cryogenic tank and the role of the anti-vortex plate in the liquid discharge process were further discussed.The results show that the critical submergence level is below 0.15 m in the large flow discharge process from stable state,and the liquid level remains stable without an obvious vortex.The initial liquid level of the cryogenic storage tank has little influence on the critical submergence level,while the anti-vortex plate hinders the fluid flow during the discharge process,which will lead to an increase in the critical submergence level.This study can provide guidance for stable operation of drainage system of large cryogenic storage tanks.