基于KBO法的混合制冷剂级联式LNG与NGL联产工艺的优化

Process optimization of LNG and NGL co-production process based on KBO method and mixed fluid cascade liquefaction process

联产液化天然气与天然气凝析液(NGL)的工艺流程可共享一套制冷系统,能节约前期投资与运行成本。将混合制冷剂级联式(MFC)液化工艺作为液化天然气(LNG)与NGL联产工艺的制冷系统,结合KBO法和Hysys优化器两种手段,以系统最小功耗为目标函数、板翅式换热器最小换热温差3℃为约束条件,对MFC液化工艺制冷剂的配比与联产工艺的工艺参数进行优化模拟,旨在降低系统单位能耗、提高液化效率。模拟结果表明,优化后系统单位能耗为0.358(kW·h)/kg(基于LNG)、液化㶲效率为58.30%,明显优于其他联产工艺流程,为现行联产工艺的发展提供了借鉴。

Sharing a set of refrigeration system,the co-production process of liquefied natural gas(LNG)and natural gas liquid(NGL)can save the initial investment and operation cost.Therefore,KBO method and Hysys optimizer is combined to optimize the refrigerant ratio of mixed fluid cascade(MFC)liquefaction process and parameters of LNG and NGL co-production process,taking the minimum power consumption of the system as the objective function and 3℃of the minimum heat exchange temperature difference of plate fin heat exchanger as the constraint condition,so as to reduce the unit energy consumption of the system and improve the liquefaction efficiency.The simulation results show that after optimization,the unit energy consumption of the system is 0.358(kW·h)/kg(based on LNG),and the liquefaction efficiency is 58.30%,which is significantly better than other co-production processes,and provides a reference for development of current co-production process.