关键词: LNG接收站, 天然气, 再冷凝工艺, 预冷法, 优化, 模拟

Abstract:

Domestic and foreign scholars have proposed many optimization schemes for the recondensation process of boil-off gas (BOG) in liquefied natural gas (LNG) terminals. The pre-cooling optimization scheme has more practical significance because of less initial investment and obvious optimization effect. However, the existing pre-cooling optimization scheme has problems such as unclear optimization principles and incomplete consideration of working conditions. Therefore, this paper introduced the existing re-condensation process in LNG terminals and the process optimized by pre-cooling method. The theoretical principle of the pre-cooling optimization method was obtained and corresponding optimization principles for two typical operating conditions in LNG terminals were proposed. The existing recondensation process of Rudong LNG terminal in Jiangsu province was used as an example. The models were established and the recondensation process was simulated before and after optimization using HYSYS. A comparative analysis of the total power-consumption of the recondensation process before and after optimization was carried out using the built-in model built in HYSYS. The result showed that the improved pre-cooling optimization scheme can effectively optimize the two typical working conditions according to the corresponding optimization principle. The application of the research results at the Rudong LNG terminal in Jiangsu indicated that the improved pre-cooling optimization scheme resulted in 9.8% and 21.5% energy reduction, respectively, under the two typical operating conditions.

Key words: LNG terminal, natural gas, recondensation, pre-cooling, optimization, simulation