摘要
天然气脱水是天然气开采过程中的重要组成部分,是保证气体平稳输送的关键之一。大型气田更多采用三甘醇脱水。在实际操作中,由于进料气和甘醇循环量的变化,装置运行可能会偏离最佳工况,从而影响生产。本文采用HYSYS流程模拟软件,建立了一个100万Nm^3/天的海上天然气三甘醇脱水装置动态模型,考察了进料气流量和甘醇循环量发生阶跃变化时,整个系统的动态响应过程。研究发现:在进料气流量波动时,主要工艺参数稳定,只是再沸器负荷的响应相对滞后,因此,可以在再沸器负荷与进料气流量之间设置比例控制,加快响应速度。此外,甘醇循环量对系统脱水量影响显著,应当在甘醇泵下游设置合适的流量报警值。对两种工况的动态分析为控制系统的设计、HAZOP分析和现场人员的操作提供了依据。
Natural gas dehydration is an essential part in natural gas production, and is a key process for ensuring smooth gas transmission. Large natural gas fields typically use TEG （Tri-Ethylene Glycol） dehydration. Due to possible changes of feed gas and TEG circulation rate in operation, a TEG system may deviate from its design point, thus affecting the production. In this paper, a HYSYS dynamic model was established for a 1 MM Nm^3/day offshore TEG dehydration system. Dynamic responses of the system were obtained under step changes of the feed gas flow rate and the TEG circulation rate. In the former case, major system parameters remain stable except that the reboiler heating load responds slowly. For smoother operation, a proportional control needs to be added between the reboiler steam rate and the feed gas flow rate. In the latter case, plant dehydration quality is strongly affected by the TEG circulation rate change, so that a flow rate alarm should be added behind the TEG pump. The dynamic analyses in the two cases above provide insight for the control system design, HAZOP analysis and plant operations.
出处
《计算机与应用化学》
CAS
2015年第7期813-817,共5页
Computers and Applied Chemistry
