大型液氢球罐分级预冷过程数值模拟研究  

Numerical Simulation on the Graded Pre-cooling Process of Large Liquid Hydrogen Spherical Tank

作　　者：金树峰[1] 张智贤 王静泊 马梓阳 王波 JIN Shufeng;ZHANG Zhixian;WANG Jingbo;MA Ziyang;WANG Bo(School of Petrochemical engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学石油化工学院,兰州730050

出　　处：《真空与低温》2025年第2期229-238,共10页Vacuum and Cryogenics

基　　金：甘肃省重点研发计划项目(24YFGA018)。

摘　　要：大型液氢球罐在投入使用时需要进行罐体预冷以避免因热应力过大而破坏球罐。预冷过程会消耗大量冷量,因此采用合理的预冷方法十分重要。以2 000 m^(3)液氢球罐为研究对象,建立三维数值模型,采用液氮/液氢分级预冷法,通过数值模拟分析了入口流量和预冷介质对球罐预冷过程中温降速率和罐内物理场变化的影响。结果表明:不同入口流量下的温降速率变化趋势一致,均在预冷的第2 h达到峰值后衰减。采用小入口流量作为初始预冷流量,分时段调节入口流量使温降速率保持3~3.5 K/h时,完成预冷所消耗的介质更少且预冷更均匀。液氮预冷前中期,罐壁温度最高点和最低点出现在球罐侧上方和侧下方;液氮预冷后期及整个液氢预冷阶段,罐壁温度最高点和最低点出现在球罐顶部和底部。受壁面温度场影响,预冷过程中最大热应力出现在球罐的顶部及右上方,建议重点监测此区域的应力情况。在预冷后期,罐内流场存在多个流动缓慢的小涡旋,罐内整体温降速率基本不变。Large liquid hydrogen spherical tanks need to be pre-cooled before they are put into service to avoid damage to the tanks from excessive thermal stress,and the pre-cooling process will consume a lot of cold energy,so a reasonable precooling method is the key.This paper takes a 2000 m^(3) liquid hydrogen spherical tank as the research object,establishes a three-dimensional numerical model,adopts the liquid nitrogen/liquid hydrogen graded pre-cooling method,and analyzes the influences of inlet flow rate and pre-cooling medium on the temperature drop rate and the changes of the physical field inside the tank during the pre-cooling process of the spherical tank through numerical simulation.The results show that the temperature drop rates at different inlet flow rates followe the same trend,all of which peaked at the 2nd hour of pre-cooling and then decayed.Adopting small inlet flow rate as the initial pre-cooling flow rate,and adjusting the inlet flow rate in time to maintain the temperature drop rate at 3 to 3.5 K/h,the medium consumed to complete the pre-cooling is less and the pre-cooling is more uniform.In the first and middle stages of liquid nitrogen pre-cooling,the highest and lowest wall temperatures occur at the upper and lower sides of the spherical tank,and in the late stages of liquid nitrogen pre-cooling and throughout the liquid hydrogen pre-cooling phase,the highest and lowest wall temperatures occur at the top and bottom of the spherical tank.Due to the wall temperature field,the maximum thermal stress during pre-cooling occurs at the top and upper right of the spherical tank,and it is recommended to focus on monitoring the stress in this area.In the late pre-cooling stage,there are several small,slow-moving vortices in the flow field of the tank,and the overall temperature drop rate in the tank is basically unchanged.

关 键 词：液氢球罐 预冷 数值模拟 相变 物理场 

分 类 号：TB658[一般工业技术—制冷工程]