LNG冷能利用工艺技术研究

Research on LNG Cryogenic Energy Utilization Technology

近年来,在清洁能源政策的支持与推动下,LNG越来越受到欢迎,其相关的冷能利用技术也逐渐成为研究热点。以某大型LNG接收站为背景,对LNG冷能用于轻烃分离工艺进行模拟分析,得到轻烃回收率为93.43%,单位轻烃能耗为97 k J/kg;通过工艺的敏感性分析,考察对流程性能的影响,得到最优的操作条件及适应性要求,通过分析得到LNG冷的利用效率比较低,约23.82%;在此基础上,按照能量梯级利用的原则,提出了轻烃分离与橡胶低温粉碎相集成的LNG冷能利用工艺,将分离出轻烃的贫LNG冷能用于橡胶粉碎装置,每吨贫LNG可节省制冷用电196.38 k W·h,节能效果显著;分析结果表明,集成的流程中LNG冷的利用效率有了大幅提高,可以实现冷能的高效利用。

In recent years, LNG has become more and more popular under the support and promotion of clean energy policy and the LNG cryogenic energy utilization technology has also become a research issue. In this paper, simulation and analysis were carried out for the process of light hydrocarbon separation by using LNG cryogenic energy in a large LNG terminal. The recovery rate is 93.43% for light hydrocarbons and the energy consumption of unit light hydrocarbon is 97 k J/kg. Sensitivity analysis is conducted for the process, studying the influence on process performance and obtaining the operating conditions and adaptability requirement of light hydrocarbon device. LNG cryogenic exergy utilization efficiency is relatively low with exergy analysis, about 23.82%. Then a process of LNG cryogenic energy cascade utilization is proposed with integrating the light hydrocarbon separation and the rubber cryogenic comminution according to the principle of energy cascade utilization. The cryogenic energy of lean LNG separated from light hydrocarbon device is used in rubber comminution device and can save 196.38 kW h of the refrigeration power by per ton LNG. It is concluded that the energy saving effect is remarkable in this process and the results of exergy analysis show that the utilization efficiency of LNG cryogenic exergy has been greatly improved in the integration process. It can realize the efficient utilization of cryogenic energy.