摘要
本研究提出一种耦合液化天然气(liquefied naturalgas,LNG)冷能及有机朗肯循环(organic ranking cycle,ORC)系统的新型液化空气储能系统。在用电低谷期,LNG和液态丙烷的冷能共同液化压缩空气,从而存储能量。在用电高峰期,液态空气释能发电,LNG的冷能则被丙烷回收。该系统将LNG连续气化释放的冷能作为辅助能源与储能系统相结合,能够灵活释能发电。另外,该系统对LNG冷能进行梯级利用(冷能依次用于液化空气、ORC和数据中心冷却),提高了能量利用率,减少了能量损失。本工作建立了耦合系统的热力学模型和经济性评估模型,利用Aspen HYSYS软件进行过程模拟、循环效率和㶲效率分析,针对浙江宁波LNG接收站的地区电力价格,采用净现值法对系统进行经济性评估。结果表明:该系统的循环效率为110.20%,高于近期研究成果。㶲效率为59.71%,比常规液化空气储能系统㶲效率提高约10%。该储能项目具有经济可行性,且峰时电价对系统的经济效益影响最大。该研究可为LNG冷能用于能量存储和电厂调峰的工程应用提供重要参考和依据。
This paper proposes a novel liquefied-air energy-storage system that is coupled to liquefied natural gas(LNG)cold energy and organic rankine cycle(ORC)system.During off-peak period,the cold energy from LNG and liquid propane operate together to liquefy compressed air and store energy.During peak times,liquid air is released to generate electricity,and the cold energy of LNG is recovered by propane.The system combines the cold energy released by continuous gasification of LNG as auxiliary energy and the energy-storage system,which can flexibly release energy for power generation.In addition,the system employs cascade operation of the LNG cold energy(the cold energy is sequentially used for liquefied air,ORC,and data-center cooling),which improves the energy utilization rate and minimizes energy loss.By developing thermodynamic and economic-evaluation models of the coupled system,the proposed system was simulated using the Aspen HYSYS software,and the round-trip and exergy efficiency values are analyzed.By focusing on the regional power price of the Ningbo LNG receiving terminal in Zhejiang province,the net-present-value method was used to evaluate the economic feasibility of the system.The results demonstrated that the round-trip efficiency of the system was 110.20%higher than the recent related research results.The exergy efficiency was 59.71%,which was approximately 10%higher than that of conventional liquefied-air energy-storage system.The energy-storage project is economically feasible,and the peak-time electricity price exerts the largest effect on the economic benefits of the system.This research can provide important reference and basis for engineering application of LNG cold energy for energy storage and peak regulation in power plants.
作者
苏要港
吴晓南
廖柏睿
李爽
SU Yaogang;WU Xiaonan;LIAO Borui;LI Shuang(School of Civil Engineering and Geomatics,Southwest Petroleum University,Chengdu 610500,Sichuan,China;School of Engineering,Southwest Petroleum University,Nanchong 637000,Sichuan,China)
出处
《储能科学与技术》
CAS
CSCD
北大核心
2022年第6期1996-2006,共11页
Energy Storage Science and Technology
关键词
液化空气储能
LNG冷能
循环效率
㶲效率
经济性评估
ORC系统
liquefied air energy storage
LNG cold energy
round trip efficiency
exergy efficiency
economic evaluation
ORC system
