深冷液化空气储能系统的关键因素影响规律

(1.国网冀北电力有限公司电力科学研究院,北京 100045; 2.国网冀北电力有限公司,北京 100053; 3.西安交通大学 能源与动力工程学院,陕西 西安 710049)

深冷液化空气储能系统; Aspen Plus; 热力学分析; 系统优化

Influence of key operation parameters on cryogenic liquefied air energy storage system
HUANG Bao-hua1,GE Jun2,NI Jing-wei3,WANG Wei-meng1,LIU Ying-wen3,HE Ya-ling3

(1.Electric Power Research Institute ofState Grid Jibei Electric Power Co.,Ltd.,Beijing 100045,China; 2.State Grid Jibei Electric Power Co.,Ltd.,Beijing 100053,China; 3.School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

cryogenic liquefied air energy storage system; Aspen Plus; thermodynamic analysis; system optimization

DOI: 10.13800/j.cnki.xakjdxxb.2019.0415

备注

立足于提高深冷液化空气储能系统能量转换效率,建立了深冷液化空气储能系统的热力学模型,借助Aspen Plus商用软件建立了热力计算的稳态仿真模型。模型验证工作说明了仿真模型的计算准确性。开展了设计工况下系统热力学分析研究,结合系统性能参数,分析了系统效率较低的原因并指出了优化方向; 研究了压缩机级数、压缩机级间冷却方案和膨胀机级数等系统关键运行参数对系统及部件性能的影响规律。结果 表明:系统采用原始设计方案时,压缩热利用率仅有38.42%,导致系统效率较低,仅为31.11%,可通过改善系统压缩热利用情况显著提升系统效率; 当压缩机级数减少、采用无级间冷却方案时,膨胀机入口再热温度显著增加,使得系统效率大幅提升; 随着膨胀机级数的增多,膨胀环节压缩热利用总量越多,系统效率越高。在此基础上,进一步探究了系统内部耦合提效方法,提出了一种系统优化设计方案,相较于原始设计方案,压缩热利用率提高至64.12%,系统效率提升至41.82%.研究结果可为深冷液化空气储能系统优化及其工程应用提供理论参考。

In order to improve the energy conversion efficiency of cryogenic liquefied air energy storage system,the thermodynamic model of cryogenic liquefied air energy storage system was established,and the steady-state simulation model of thermal calculation was established by Aspen Plus commercial software.Model validation shows the accuracy of the simulation model.Thermodynamic analysis of the system under designing conditions was pointed out.The reasons for the low efficiency of the system were analyzed and the optimization direction was pointed out.The influence of three key operating parameters of the system,such as compressor stage number,compressor interstage cooling scheme and expander stage number,on the performance of the system and its components was discussed.The results show that the utilization rate of compression heat for the original system solution is only 38.42%,which leads to the low efficiency of the system,only 31.11%.The system efficiency can be significantly increased by improving the utilization of compression heat of the system.As the compressor stage number is reduced and non-interstage cooling scheme adopted,the inlet temperature of the expander increases significantly with the system efficiency greatly improved.The increase of the expander stage number results in the fact that the more the total amount of compression heat used in expansion period,the higher the system efficiency.On this basis,the method for improving efficiency by internal parameters coupling is further explored,and an optimized system solution was proposed.Compared with the original system solution,the utilization ratio of compression heat is increased to 64.12%,and the efficiency of the system is increased to 41.82%.The research results can provide a reference to the optimization of cryogenic liquefied air energy storage system and its engineering application.