氖气液化工艺参数优化分析

Analysis and optimization of neon liquefication parameters

目前适用于实验室用小型氖气液化方法主要有液氮预冷后节流液化以及制冷机提供冷量直接液化,基于Aspen HYSYS软件针对上述两种液化工艺流程进行了仿真计算,分析了进气压力和预冷温度对节流后氖的干度及进气压力和制冷量对制冷机做冷源时氖液化量的影响规律。结果表明,随着进气压力从20×105 Pa增大到200×105 Pa,节流前能够使氖气液化的最高预冷温度从43.6 K增大到68.3 K,且节流前采取气体回热可有效降低预冷温度。在使用两级G-M制冷机直接液化流程中,一级冷量预冷后的氖液化量约为未预冷时的3倍。

The temperature zone of liquid neon is similar to that of liquid hydrogen,and the liquid neon has a considerable latent heat of vaporization which is 3.3 times that of liquid hydrogen per unit volume.Besides,the liquid neon has higher security in production and application.The methods of neon liquefication available applied to the laboratory mainly include throttling liquefaction after pre-cooling by liquid nitrogen and direct cooling liquefaction by cryocooler.In this paper,the two liquefaction processes were simulated based on Aspen HYSYS software,the effect of inlet pressure and precooling on neon dryness after throttling and the effect of inlet pressure and cooling capacity of cryocooler on neon liquefaction capacity were investigated.The results show that the maximum precooling temperature before throttling increased from 43.6 K to 68.3 K as the inlet pressure increased from 20×105 Pa to 200×105 Pa.The cold recovery of throttled gas plays a positive role in decreasing pre-cooling temperature.In the direct liquefaction process using a two-stage G-M cryocooler,neon liquefaction capacity after precooling is about 3 times that before precooling.