针对液氧/煤油火箭燃料贮箱采用的冷氦增压方案,搭建试验系统并进行地面模拟试验.探究不同增压方式,包括增压位置、扩散器形式和增压气体流量对增压排液过程的控压稳定性、贮箱气枕区温度分布、氦气消耗率、气液混合以及液体结冰状态的影响.结果表明:与气枕区增压相比,气体在液体区增压时换热充分,同等条件下气体消耗率降低33.1%,但控压稳定性较差;扩散器形式对气体消耗率和贮箱气枕区温度分布影响不大;小流量增压更加节约氦气,与40 L/s排液相比,10 L/s排液可以节约20%氦气;各工况中均未发现液体介质局部过冷结冰现象,且无气泡随液体进入排液管路.试验结果验证了煤油贮箱采用冷氦增压方案的可行性,并为箭上冷氦增压系统的结构设计和工况调节提供参考.

To verify the technical scheme of cryogenic helium pressurization in the fuel tank of liquid oxygen (LOX)-kerosene rocket, a test device was established and the ground simulation test was conducted. The influences of different pressurization methods on pressure control stability, ullage temperature distribution in tank, helium consumption, gas-liquid mixture, and liquid freezing of pressurized drainage process were investigated. The pressurization method specifically includes pressurization outlet position, diffuser form, and pressurant flow rate. The results show that when pressurized from the liquid zone, the heat exchange of pressurized gas is more sufficient, which reduced the gas consumption by 33.1% compared with that in the ullage zone. However, the stability of pressure control is less satisfying. The form of diffuser has little influence on the gas consumption and the temperature distribution of ullage. The helium consumption for pressurization at a small flow rate is less than that at a high flow rate. For example, when the drainage flow is 10 L/s, the helium consumption can be reduced by 20% compared with that at 40 L/s. Under all experimental conditions, neither ice due to local supercooling in the tank nor bubbles in the drainage pipeline are observed. The test results verify the feasibility of the proposed scheme, and provide a reference for structural design and working condition regulation of the cryogenic helium pressurization system in rocket.