氧的低温吸附模型与计算

受化学氧碘激光器(COIL)高效率小型化及新型压力恢复技术发展的推动,考虑COIL中气体氧的低温吸附问题。从质量守恒观点出发考察了气体流过沸石多孔床的压力与速度的关系,建立了吸附剂吸收的物质与气流中物质关系的吸附平衡方程。由吸附物较少的特点,得出在确定的压力梯度下速度为常数的近似。由吸附平衡方程与吸附速率方程,构成低温吸附模型方程,其中,亨利等温线方程作为辅助关系。对低温吸附模型方程作数值求解,得到了气流中氧质量浓度及吸收的氧质量浓度随时间变化的规律,以及这些质量浓度分布的长时间渐近特征。

Model and computation on oxygen cryosorption

Motivated by high efficiency, tiny volume and application of new pressure recovery technique of chemical oxygen iodine laser(COIL), cryosorption of oxygen is considered. From the point of view of mass conservation, a linear relation between gaseous pressure gradient and gaseous speed at which gases flow through the zeolite porous bed is obtained, and an adsorption balance equation, describing the relation of the gaseous concentrations, is established with adsorption dynamics equation. Henry relation is employed as an isothermal equation. A set of cryosorption model equations are solved numerically and the relations of oxygen concentration changing with time, and long time character of these concentrations are described. It is found that the adsorption of oxygen in porous bed of COIL develops layer by layer, and at each fixed unit of bed layer, the concentration of absorbed oxygen will rise to the balance value that matches the concentration of oxygen contained in hybrid gases after a long time.