呼图壁储气库天然气脱水工艺优化

Optimization of Natural Gas Dehydration Process in Hutubi Gas Storage

基于呼图壁储气库集注站采出天然气处理的工艺流程,针对供应西气东输二线的天然气节流后压力不足,应急工况下水露点存在一定风险的问题,对现有天然气脱水工艺流程进行改造。采用PR状态方程进行工艺模拟,用HYSYS软件分别建立三甘醇脱水和丙烷制冷脱水两种仿真模型,对主要工艺参数进行敏感性分析。结果表明,降低三甘醇循环量、重沸器温度和汽提气量能够降低三甘醇脱水工艺的能耗;降低丙烷制冷脱水工艺的天然气预冷温度和丙烷冷凝温度,提高丙烷蒸发温度,有助于压缩机节能降耗。综合两种方案技术经济特性,推荐采用丙烷制冷脱水工艺以满足外输天然气水露点控制要求和压力要求。

Based on the produced natural gas treatment process in the gas gathering and injection sta-tion of Hutubi Gas Storage,to deal with the problem that the pressure of natural gas supplied to the second line of west-east gas transmission is insufficient after throttling,and water dew point is difficult to meet the requirements in emergency working condition,the existing natural gas dehydration process is reformed.PR equation of state is used to simulate the process,and two simulation models of TEG dehydration and propane refrigeration dehydration are established in HYSYS and the sensitivity of main process parameters is analyzed.According to the calculation results,the energy consumption of TEG dehydration process can be reduced by decreasing the TEG circulation volume,reboiler temperature and stripping gas volume.Decreasing the natural gas precooling temperature and propane condensation temperature of propane refrigeration dehydration process,and increasing the propane evaporation tem-perature can reduce the consumption of compressor.Finally,considering the technical and economic advantages and disadvantages of the two schemes,the propane refrigeration dehydration process is rec-ommended to meet the requirements of both dew point control and pressure of gas transmission.