杜笑阳 朱祚良 吴明

摘      要：BOG再冷凝工艺一直是LNG接收站的关键流程之一。现有BOG再冷凝工艺存在能耗较大的问题，为此提出了预冷法对原工艺进行优化。介绍了LNG接收站内BOG产生过程与现有处理工艺流程，对接收站内BOG再冷凝工艺的影响因素进行分析，提出了使用预冷法对BOG再冷凝工艺进行优化。运用ASPEN HYSYS流程模拟软件并结合江苏如东LNG接收站运行参数对比优化前后的再冷凝工艺流程进行实例计算、建模以及流程模拟，对比分析了优化前后的再冷凝工艺能耗。分析结果表明：影响BOG再冷凝工艺的主要因素是BOG压缩机出口压力和BOG温度;通过使用预冷法对再冷凝工艺进行优化，当优化前后物料比接近时，优化后的BOG再冷凝工艺对比原工艺节约压缩机功耗26.7%，总功耗节约6%。优化效果明显。

关  键  词：LNG接收站;BOG;再冷凝工艺;优化;能耗

中图分类号：TE 832        文献标识码： A       文章编号：1671-0460（2020）08-1762-05

Abstract： The BOG recondensing process has always been one of the key processes at the LNG receiving station. The existing BOG recondensing process has the problem of large energy consumption， and a precooling method was proposed to optimize the original process. In this paper， the BOG generation process and existing processing flow in the LNG receiving stations were introduced. The factors affecting the BOG recondensation process were analyzed. The pre-cooling method was used to optimize the BOG recondensing process. The ASPEN HYSYS was used to combine the operating parameters of Jiangsu Rudong LNG receiving station with the recondensing process before and after optimization to carry out example calculation， modeling and process simulation. The power consumptions of the recondensing process before and after optimization were compared and analyzed. The results showed that the main factors affecting the BOG recondensation process were the BOG compressor outlet pressure and BOG temperature; after the recondensation process was optimized by using pre-cooling method， when the material ratio was close before and after the optimization， the optimized BOG recondensing process saved 26.7% of compressor power consumption， and saved 6% of the total power consumption. So the optimization effect of the condensation process was obvious.

Key words： LNG terminal; BOG; Recondensation proecss; Optimization; Energy consumption

近年來我国LNG接收站的建设发展迅速[1-2]，天然气作为清洁能源也在能源结构中占据越来越大的比重。由于技术的限制，目前LNG主要通过大型LNG运输船完成国际间的贸易。低温状态下的LNG从运输船送出之后，由于在存储、运输等过程中，不可避免的会和外界进行热交换，产生蒸发气（Boil-off Gas，BOG）。BOG的直接排放不仅会造成环境污染，同时也会造成能源浪费和经济损失。因此，LNG接收站的重要工艺之一即是BOG的处理工艺。BOG处理工艺一般可分为直接压缩工艺和再冷凝工艺两种[3]。目前国内大多数LNG接收站均采用再冷凝工艺对BOG进行处理。……