环境因素对液氧泄漏扩散过程影响的数值研究

Numerical Study on the Influence of Environmental Factors on the Diffusion Process of Liquid Oxygen Leakage

针对低温液氧推进剂在运输、储存、加注过程中可能发生泄漏的问题,开展了数值模拟研究。采用Mixture多相流模型,考虑气液两相间的滑移速度和水蒸气的相变,对液氧泄漏后地面液池、氧气浓度场和温度场的变化过程,以及环境温度、大气压力、风速等因素对液氧泄漏扩散过程的影响规律进行了研究。结果表明:液氧泄漏约35 s后,流场达到准稳定状态,液池、温度场、浓度场的分布基本不变;环境温度从278 K升高到308 K时,促进了液氧吸热蒸发的过程,地面附近最大氧气体积分数从44.71%升高到47.1%;风速从0 m/s增加到10 m/s时,加快了氧气团稀释扩散的速度,低温伤害范围从175.4 m^(2)缩小到32.81 m^(2),危险浓度区域从257.0 m^(2)缩小到50.70 m^(2);大气压力从0.09 MPa升高到0.1 MPa时,低温伤害范围最远距离从26.5 m缩短到20.05 m,危险浓度区域最远距离从38.81 m缩短到30.82 m;大气相对湿度从20%提高到100%时,抑制了氧气团的稀释扩散,危险浓度区域最远距离从37.67 m增加到39.24 m。此项研究对后续液氧试验的开展提供了理论支撑,对液氧泄漏事故的应急处理具有指导意义。

A numerical simulation study is carried out to investigate the leakage problem of cryogenic liquid oxygen propellant in the process of transportation,storage and filling.The slip velocity of gas-liquid two phases and the phase transformation of water vapor is considered and the mixture multiphase flow model is used to study the change process of the ground liquid tank,oxygen concentration field and temperature field after the liquid oxygen leakage,as well as the influence of environmental temperature,atmospheric pressure,wind speed and other factors on the liquid oxygen leakage and diffusion process.After the leakage of liquid oxygen for about 35 s,the flow field reaches a quasi-stable state,and the distribution of liquid pool,temperature field and concentration field are basically unchanged.The increase of ambient temperature from 278 K to 308 K promotes the process of liquid oxygen endothermic evaporation,and the maximum oxygen concentration near the ground increases from 44.71%to 47.1%.The increase of wind speed from 0 m/s to 10 m/s accelerates the dilution and diffusion speed of oxygen masses.The damage range of low temperature decreases from 175.4 m^(2) to 32.81 m^(2),and the dangerous concentration area decrease from 257.0 m^(2) to 50.70 m^(2).When the atmospheric pressure increases from 0.09 MPa to 0.1 MPa,the maximum distance of low temperature damage range decreases from 26.5 m to 20.05 m,and the maximum distance of dangerous concentration area decreases from 38.81 m to 30.82 m.When the relative humidity of the atmosphere increases from 20%to 100%,the dilution and diffusion of oxygen clusters are inhibited,and the longest distance of the dangerous concentration area increases from 37.67 m to 39.24 m.The research results of this paper provide theoretical support for the subsequent development of liquid oxygen leakage tests,and have guiding significance for the emergency treatment of liquid oxygen leakage accidents.