卧式低温液体贮罐电加热增压排放数值模拟

Numerical simulation of the pressurization discharge of a cryogenic liquid horizontal storage tank with electrical heating

针对卧式液氧贮罐电加热排放过程,对其内部的物理场进行了数值模拟,分析了流体的流动对温度分层的影响以及温度分层现象的成因。研究结果表明,在电加热增压排放过程中,贮罐内部在竖直方向上存在明显的温度分层现象,大体上呈现出了平缓的递增趋势,但是由于加热壁面的扰动及冷热流体之间的换热影响,中间区域出现了比较大的梯度分布,导致了贮罐内部压力的上升。在浮升力的驱动下,贮罐内壁和加热壁面之间的液氧呈现出了近似于封闭腔内自然对流的流动状态,并且随着排放的进行,加热壁面和贮罐内壁之间的漩涡会进一步分裂成更小更复杂的漩涡,呈现出复杂的流动状态。

A numerical simulation was performed on the physical field of a liquid hydrogen horizontal tank during pressuriza- tion discharge with electrical heating. The influence of fluid flow on temperature stratification and cause of thermal stratification phenomenon were analyzed. The result shows that the thermal stratification of liquid oxygen appeares along the gravity direction during pressurization discharge process with electric heating, and it generally presents a gradual increasing trend. However, because of the thermal disturbance of the heater and the influence of heat exchanging between cold and hot liquid hydrogen, a large temperature gradient distribution appeares in the middle of liquid hydrogen tank, which may lead to the pressure up. Under the drive of buoyancy lift, the flow of liquid hydrogen between the heater and tank wall is similar to natural convection in a closed cavity. As time goes on, the swirls between the heater and tank wall will be divided into smaller and more complex swirls, and the flow becomes more complex.