Abstract: 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.

Key words: 小型, 撬装式, 液化天然气, 流程, 模拟

摘要： 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.

关键词: 小型, 撬装式, 液化天然气, 流程, 模拟