液氧中水分与二氧化碳冰晶杂质特性可视化实验及分析

Visualized experiments and analysis of the icing behavior of water and carbon dioxide impurity in liquid oxygen

针对低温推进剂中高沸点杂质过冷结晶可能堵塞滤网影响输送的问题,本文设计并搭建了能够显微观察液氧中冰晶与二氧化碳杂质状态的实验系统。可视化研究了不同温度液氧中微量水、二氧化碳杂质的生成及性状变化特征。发现当水分、二氧化碳共存于液氧时,部分水分率先形成细密冰晶,并与二氧化碳一同生成松散絮状结构;当该结构内的水冰晶达到饱和态后,其形状基本不再改变,而残余的水分逐渐形成游离态冰晶;絮状结构在90K降温到65 K的过程中发生崩解,杂质的平均尺寸减小了50%以上,有利于含杂质液氧通过滤网。研究所获得的微量杂质冰晶性状变化规律,可为实际应用中火箭充注管路滤网设计和流动阻力计算提供实验参考依据。

High-boiling temperature impurities in cryogenic propellants may block filters during subcooling and af-fect propellant transportation.To address this problem,a microscopic visualized experimental system was designed and established to study the behaviors of ice crystals and carbon dioxide impurities in liquid oxygen.The formation and growth characteristics of water and carbon dioxide in liquid oxygen under small volume composition conditions and at different temperatures.With the coexistence of water and carbon dioxide in liquid oxygen,a part of water formed into fine ice crystals first,which mixed with carbon dioxide to form a loose flocculent structure.When the water crystals reached a saturated state in the flocculent structure,their shapes did not change,while the remaining water gradually turned into free ice crystals.The flocculent structure disintegrated in the cooling stage from 90 K to 65 K,which produced small pieces with an average volume decrease of 50%.This phenomenon facilitates the liq-uid oxygen-containing impurities to pass through the filters.This work on the icing behavior of water and carbon di-oxide impurities in liquid oxygen can design the filtering component and calculate fluid flow resistance for cryogenic propellant filling systems.