液氢贮箱热力学排气系统建模及控压特性

以低温推进剂液氢贮箱压力控制为目标，建立了热力学排气系统（TVS）和贮箱内流体流动及气液相变过程的数学模型。以18.09 m³液氢贮箱在地面工况充注率75%、漏热量0.76 W·m^-2为例，计算了贮箱自增压过程及开启TVS后对贮箱压力控制的效果。结果表明，气枕升压速率远大于液体温度对应的饱和压力的升压速率；TVS运行后可将贮箱压力有效地控制在165.5~172.4 kPa范围内。对比了混合与排气两种不同运行模式下贮箱气枕的升降压特性，发现排气模式下的气枕降压速率为混合模式的7倍，升压速率为混合模式的95%。同时还分析了贮箱内液体的温度变化规律。

Modeling and pressure control characteristics of thermodynamic venting system in liquid hydrogen storage tank

To study the pressure control of cryogenic propellant container, an analytical lumped parameter model is established to predict the behavior of pressure variation inside a liquid hydrogen tank with TVS installed.Simulations are conducted for the tank with volume of 18.09 m³ initially filled with 75% LH₂ and with a heat leak load of 0.76 W·m^-2.Calculation results are compared with literature to verify the feasibility of the proposed model.The results show that the ullage pressure rises much faster than the liquid saturation pressure, and TVS is highly effective and feasible in controlling the tank pressure within 165.5-172.4 kPa.The pressure change characteristics under mixing mode and venting mode are compared and analyzed.The pressure decreasing rate under venting mode is found to be 7 times of that under mixing mode.However, the pressure rising rate under venting mode is about 95% of that under mixing mode.The temperature profiles are also studied.