预冷式混合工质循环天然气液化系统实验及组分影响分析

Experiment and composition analysis of pre-cooling mixed-refrigerant-cycle gas liquefaction system

针对中国边远离散小天然气田、油井残气、沼气等多种气源的特点,研究开发一种小型预冷式混合工质低温循环天然气液化装置,进行实验测试并分析调整混合工质组分对低温循环特性的影响。该设备以全封闭式压缩机等常规制冷器件为主,预冷采用小型常规水冷冷凝机组,系统简单,投资少,易于在各种场合灵活采用。实验测试结果表明该装置可成功制取了-186.6℃的低温,且运行稳定。通过对混合制冷工质的组分和预冷级温度的分析,揭示不同组分对整个液化系统效率的影响。

A small-scale pre-cooling mixed-refrigeratant-cycle natural gas liquefaction device was developed for the circumstance in dealing with scattered small natural gas resources in China,such as remote divergent gas fields,oil well residual gases,bio-methane gases. The experiment on this device was performed and the effects of the mixture composition variation on performance of the cryogenic cycle were studied. The tested device was composed of ordinary refrigeration parts such as a hermitic compressor and the pre-cooling was formed by a small commercial water-cooled chiller. The whole system was simple and reliable and flexible for application in various circumstances. The experiment results show that-186. 6 ℃ can be achieved and operated steadily. The effects of different composition of mixture on the system performance are revealed.