液化天然气冷能回收系统的设计与优化分析  

Design and optimization analysis of liquefied natural gas cold energy recovery system

作　　者：万腾 周卫红[1] WAN Teng;ZHOU Weihong(School of Civil Engineering,University of Science and Technology Liaoning,Anshan 114051,Liaoning,China)

机构地区：[1]辽宁科技大学土木工程学院,辽宁鞍山114051

出　　处：《低碳化学与化工》2024年第5期123-132,共10页Low-Carbon Chemistry and Chemical Engineering

摘　　要：液化天然气(LNG)在气化过程中释放的冷能通常未被有效利用。提出了制冷与发电相结合的LNG冷能回收系统,可以有效地回收LNG冷能。该系统的结构包括两级有机朗肯循环(ORC)、空调(AC)和直接膨胀循环(DEC)。利用HYSYS软件,对系统性能进行了模拟分析,采用遗传算法(GA)对系统中四元混合工质(甲烷、乙烷、丙烷和异丁烷)配比、蒸发压力、冷凝压力和一级膨胀压力进行了优化,随后对优化方案进行了经济性评价。结果表明,两级ORC最佳的四元混合工质配比(质量分数)前级为28.9%、57.3%、5.5%和8.3%,后级为0.4%、20.3%、56.4%和22.9%。优化方案中,系统的净输出功率可达218.28 kW,LNG冷能利用率、热效率和㶲效率分别为54.69%、20.89%和41.18%。系统具有良好的经济可行性,经济收益可达160.30×10^(4) CNY,设备的总投资成本为1215.91×10^(4) CNY,平均能源成本为0.63 CNY/(kW·h),预计7.59 a内可收回投资成本。The cold energy released during the liquefaction process of liquefied natural gas(LNG)is often underutilized.An LNG cold energy recovery system that combines refrigeration with power generation to effectively recover LNG cold energy was proposed.The system structure includes two-stage organic Rankine cycles(ORC),air conditioning(AC),and direct expansion cycle(DEC).Using HYSYS software,the system performance was simulated and analyzed.Genetic algorithm(GA)was employed to optimize the mixture ratio of the four-component working fluid(methane,ethane,propane and isobutane),evaporation pressure,condensation pressure,and primary expansion pressure in the system.Subsequently,an economic evaluation of the optimized scheme was conducted.The results show that the optimal mass fraction of the four-component working fluid for the front and rear stages of the ORC are 28.9%,57.3%,5.5%,8.3%and 0.4%,20.3%,56.4%,22.9%,respectively.In the optimized scheme,the net output power of the system can reach 218.28 kW,and the utilization rate of LNG cold energy,thermal efficiency and exergy efficiency are 54.69%,20.89%and 41.18%,respectively.The system exhibits good economic feasibility,with an economic and benefit of 160.30×10^(4) CNY.The total investment cost of the equipment is 1215.91×10^(4) CNY,and the levelized energy cost is 0.63 CNY/(kW·h),with an expected payback period of within 7.59 a.

关 键 词：LNG 混合工质 㶲分析 经济性分析 

分 类 号：TM619[电气工程—电力系统及自动化] TB69[一般工业技术—制冷工程]