小型撬装式LNG装置的流程模拟

Simulation of small-scale natural gas liquefaction flows in skid-mounted package

为了使小型撬装式LNG(液化天然气)装置的流程研究具有普遍意义,通过对液化流程的评价,分别从混合制冷剂液化流程和膨胀机液化流程中选择了极具代表性、性能最佳的丙烷预冷混合制冷剂液化流程和N2-CH4膨胀机液化流程,并结合液化流程的发展趋势,综合多种液化流程的优点,提出了节能新型混合制冷剂液化流程,对以上液化流程进行了模拟计算,并比较了流程的关键参数.结果表明,节能新型混合制冷剂液化流程简便灵活、能耗低、液化率高,适应于小型撬装式LNG装置.

Considering the present market demand and the feasibility of technology, building small-scale LNG （liquefied natural gas） plants has been proved to be the most practical way to start LNG industry in China. A study was made to select the optimum liquefaction process to enhance the economy of the small- scale LNG equipment. In this paper, the same criteria were used to evaluate three types of liquefaction cycles. These types included propane pre-cooling mixed refrigeration cycle, nitrogen-methane expander cycle and new energy saving mixed refrigeration cycle （MRC）. The result of comparison indicated that the new energy saving MRC is suitable for the small-scale LNG equipment due to its simple process and acceptable power consumption.