充注率及氦气增压对低温贮箱热分层特性影响

Effects of Filling Rate and Helium Pressurization on the Thermal Stratification Behavior of Cryogenic Tank

为了揭示低温推进剂贮箱的增压规律和热分层特性,在以液氮为贮存介质的低温流体高效贮存平台上,进行了不同充注率下的贮箱自增压及氦气增压实验。得到充注率分别为35%,50%和65%时的贮箱增压速率分别为7.54 kPa·h^(-1),13.02 kPa·h^(-1)和28.26 kPa·h^(-1).获得了达到相同压力水平时各自充注率对应的温度分布,分析了不同充注率时贮箱温度梯度的变化规律。最后使用常温氦气作为增压气体,将贮箱充注率为50%的贮箱分别增压到180 kPa,380 kPa和580kPa,分析了氦气充注过程及达到不同压力水平时贮箱内温度分布变化规律.

In order to discover the pressurization and thermal stratification behavior of cryogenic propellant tank, experimental investigation on a liquid nitrogen （LN2） tank with the volume of 1.31 m^3was conducted on the Efficient Cryogenic Fluid Storage Platform （ECFSP）, which concentrates on the effects of filling rate and gaseous helium （GHe） pressurization on the thermal stratification performance of LN2. The pressurization rates without GHe at fill rate of 35%, 50% and 65% were measured as 7.54 kPa·h^-1, 13.02 kPa·h^-1 and 28.26 kPa·h^-1, respectively. The temperature profiles were obtained at the absolute pressure of 180 kPa and the temperature gradients variation at axial and radial directions were analyzed. The LN2 tank at fill level of 50% was pressurized to 180 kPa, 380 kPa and 580 kPa, respectively, with room-temperature （293 K） GHe as the pressurant gas. The influences of helium pressurization process and pressurization level on tank temperature profile were also studied.