Abstract: The water content of the feed gas in dehydration system for a natural gas purification plant located in northern Shaanxi was too high and product gas could not meet the national standard. In order to resolve the problem ChemCAD was used to simulate the whole process and analyze the main influence factors. The best optimized operating parameters were as follows：the circulation quantity of TEG was 6.16m3/h, the temperature of feed gas was 33℃. Some professional software containing FRI, HTRI, Pipe Flow Expert and so on were used to optimize the relevant key equipment and pipelines after system transformation. The calculation result demonstrated that hydrodynamic parameters of TEG contactor would satisfy the operation requirement. The duty of jacketed pipe exchanger was deficient. The contrast analysis result showed that the selection of an efficient plate heat exchanger to replace the jacketed pipe exchanger in service was an economical and reasonable optimization method. The bundle finning ratio of feed gas precooler needed to be increased to improve heat transfer in order to be qualified for the specified heat demand. The above conclusions provided a reliable theoretical proof for dehydration system optimization and valuable reference for the same types.

Key words: natural gas, dehydration system, process simulation, equipment rating

摘要： 针对陕北某天然气净化厂脱水系统中原料气水含量偏高、产品气无法满足国标要求这一生产难题，本文利用ChemCAD对该脱水系统进行了全流程模拟，研究分析得到最佳的优化操作参数为：TEG循环量为6.16 m3/h，原料气进气温度为33 ℃。通过FRI、HTRI和Pipe Flow Expert等专业软件对系统改造后的关键设备及管线进行优化，核算结果表明，脱水塔的各个流体力学参数均可满足生产需要；套管换热器换热能力不足，通过对比分析可知选用高效板式换热器替代在役套管换热器是一种较为经济、合理的优化方案；通过提高原料气预冷器换热管束的表面翅化率可以有效改善它的换热效果，使其达到系统指定的换热要求。研究结果可为该脱水系统的升级改造提供可靠的理论依据，对同类型装置亦具有一定的借鉴作用。

关键词: 天然气, 脱水系统, 流程模拟, 设备校核