储能科学与技术 ›› 2022, Vol. 11 ›› Issue (6): 1996-2006.doi: 10.19799/j.cnki.2095-4239.2021.0700

• 化工与储能专刊 • 上一篇    

耦合LNG冷能及ORC的新型液化空气储能系统分析

苏要港1(), 吴晓南2(), 廖柏睿1, 李爽1   

  1. 1.西南石油大学土木工程与测绘学院,四川 成都 610500
    2.西南石油大学工程学院,四川 南充 637000
  • 收稿日期:2021-12-23 修回日期:2022-01-19 出版日期:2022-06-05 发布日期:2022-06-13
  • 通讯作者: 吴晓南 E-mail:18839795477@163.com;wuxiaonanswpu@126.com
  • 作者简介:苏要港(1997—),男,硕士研究生,主要研究方向为LNG冷能利用及液化空气储能技术,E-mail:18839795477@163.com

Analysis of novel liquefied-air energy-storage system coupled with LNG cold energy and ORC

SU Yaogang1(), WU Xiaonan2(), LIAO Borui1, LI Shuang1   

  1. 1.School of Civil Engineering and Geomatics, Southwest Petroleum University, Chengdu 610500, Sichuan, China
    2.School of Engineering, Southwest Petroleum University, Nanchong 637000, Sichuan, China
  • Received:2021-12-23 Revised:2022-01-19 Online:2022-06-05 Published:2022-06-13
  • Contact: WU Xiaonan E-mail:18839795477@163.com;wuxiaonanswpu@126.com

摘要:

本研究提出一种耦合液化天然气(liquefied natural gas,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?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。?效率为59.71%,比常规液化空气储能系统?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。

关键词: 液化空气储能, LNG冷能, 循环效率, ?效率, 经济性评估, ORC系统

Abstract:

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.

Key words: liquefied air energy storage, LNG cold energy, round trip efficiency, exergy efficiency, economic evaluation, ORC system

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