天然气脱硫系统关键设备的优化

Optimization of key equipment in natural gas desulphurization system

为了解决天然气净化厂随着气田开发规模扩大而导致原料气酸性组分体积分数偏高、装置频繁故障这一紧迫问题,在利用DESIGNⅡ对现有气质条件下N-甲基二乙醇胺(MDEA)溶液循环量提高后的脱硫系统进行全流程模拟的基础上,重点通过FR I、HTR I等专业软件对关键设备优化前后的运行状况进行了对比分析。结果表明:胺液吸收塔和再生塔的流体力学性能满足优化后的技术要求;胺液贫富液换热器需要通过串联1台同型号换热器和更换换热管规格来达到系统指定的换热负荷并解决堵塞现象;胺液重沸器换热能力不足,可通过增加管束、表面翅化等手段提高其换热效率。该研究可为脱硫系统优化升级提供可靠的理论依据,对同类装置具有一定借鉴作用。

For the sake of solving the serious problem that excessive acid gas volume fraction contrasted to design value in raw material causes high frequency of malfunction in desulphurization system due to the expanding of exploitation scope,FRI and HTRI professional software were utilized to compare and analyze the running situation of key equipment before and after optimization on the basis of whole flow simulation after the increase of methyldiethanolamine（MDEA） solution circulation quantity on the condition of present gas composition with DESIGNⅡ.The result demonstrates that the fluid mechanics performance of amine solution contactor and regenerator was qualified for the technical requirement after optimization.It is necessary to add one piece of same size equipment in series and replace tube specification with present amine lean/rich exchangers to meet certain system demand and eliminate blocking.The heat exchange ability of amine reboiler in service is deficient and the method of increasing tube numbers or fining tube surface etc.would greatly improve the efficiency.The conclusions are reliable foundation for desulphurization system optimization or promotion and useful reference for similar device.