低温容器夹层真空度对内罐压升率的影响研究

针对低温容器夹层真空失效工况,建立了低温容器夹层真空度与通过内罐壁面热流密度的理论模型,结合ANSYS-FLUENT软件对某立式低温容器内的液氮蒸发过程进行了仿真模拟,研究了初始充满率为50%时,低温容器内罐空间温度及压力随夹层真空度变化的规律。结果表明,随着夹层真空度降低,通过低温容器内罐壁面的平均热流密度增大,内罐中液体温度升高速率增大;当夹层真空完全失效时,内罐压升率分别是夹层真空度为10-3 Pa、1 Pa和10 Pa时的10.4倍、5倍和1.2倍。

Effects of interspace vacuum of cryogenic vesselon pressure rise of inner tank

Aiming at loss of vacuum of cryogenic vessels interspace,a theoretical model between vacuum degree of cryogenic vessels interspace and heat flux density through the inner tank wall was established.The liquid nitrogen evaporation process in a vertical cryogenic vessel was simulated by ANSYS-FLUENT software,the variations of temperature and pressure of the inner tank with vacuum degree of the interspace were studied when the initial filling rate was 50%.The results show that with the vacuum degree decreases of the interspace,the average heat flux through the tank wall of the cryogenic vessel increases,and the temperature rise rate of the liquid in the inner tank increases;when the interspace vacuum completely fails,the pressure rise rate of the inner tank is 10.4 times,5 times and 1.2 times faster than that of the condition when the interspace vacuum is 10-3Pa,1Pa and 10Pa respectively.