液氢中空气溶解度预测及氮-氧存在模式研究

To explore dissolution limit of air in liquid hydrogen and to understand possible existing modes of nitrogen and oxygen molecule, Scartchard-Hildcbrand model (SH model) and modified Scartchard-Hildebrand model (MSH model) were utilized to conduct a theoretical analysis on the dissolution performance of air in liquid hydrogen. To solve the problem of the unreasonable solubility parameters near the critical temperature of solvent, a new formula for solving solubility parameters was proposed and the air solubility in liquid hydrogen in the temperature range of 18. 0—32. 5 K were accurately predicted. Based on the experimental data, an MSH model suitable for gas solubility prediction in liquid hydrogen was proposed. The results showed that the solubility of nitrogen, oxygen, carbon dioxide and water in liquid hydrogen were 10~8, 10~12, 10~31 and 10~89 mole fractions respectively, indicating great differences. The dissolution law and existence form of air in hydrogen is divided into three states as the air amount increases: completely dissolved nitrogen and oxygen; nitrogen solubility but oxygen partially solidification; partially solidification of nitrogen and oxygen with the ratio of nitrogen to oxygen in solid particles gradually approaching that in air. The results provide theoretical guidance for the safety design of liquid hydrogen system.