新型天然气提氦工艺模拟与分析

Simulation and analysis of a novel process for extracting helium from natural gas

关键词:  天然气  氦气  HYSYS  火用分析  

Key words:  natural gas  helium  HYSYS  exergy analysis

摘要:

目的 针对中国部分地区管网发达、气质较贫的含氦天然气,在调研国内外粗氦提取工艺现状的基础上,提出了一种新的天然气提氦工艺。方法 该工艺采用低温精馏法,利用HYSYS软件对其进行模拟计算,并对提氦工艺流程进行了火用分析,同时分析了流程中关键参数提氦塔的压力、提氦塔塔顶进料温度、一级分离器进料温度、二级分离器进料温度以及侧线抽出物流的流量对流程中氦气回收率、粗氦纯度、流程能耗以及火用效率的影响规律。结果 该流程的氦气回收率为99.06%,粗氦纯度(摩尔分数)为80.39%,总能耗为994.48 kW；流程总火用损失为713.27 kW,系统的火用效率为28.28%。结论 该工艺流程可实现超高的氦气回收率和高粗氦纯度,可为国内天然气提氦工艺装置提供参考和数据指导。 

Abstract:

Objective In view of the helium-containing natural gas with developed pipeline network and poor quality in some areas of China, based on the investigation of the status quo of crude helium extraction process at home and abroad, a new helium extraction process from natural gas is proposed. Methods The process adopts low-temperature distillation method, and HYSYS software was used to simulate the process, and the thermodynamic analysis of the helium extraction process was carried out. Then, the influences of key parameters in the process on the helium recovery rate, crude helium purity, process energy consumption and exergy efficiency in the process was analyzed. The key parameters include the pressure of the helium extraction tower, the feed temperature at the top of the helium extraction tower, the feed temperature of the first-stage separator, the feed temperature of the second-stage separator, and the flow rate of the side draw stream. Results The simulation calculation results show that the recovery rate of helium in the process is 99.06%, the product purity of crude helium is 80.39%, and the total energy consumption is 994.48 kW. The total exergy loss of the process is 713.27 kW, and the exergy efficiency of the system is 28.28%. Conclusion sThis process can achieve ultra-high helium recovery rate and high crude helium purity, and can provide reference and data guidance for natural gas helium extraction process units.