耦合LNG及ORC的液态空气储能系统热力学分析

Thermodynamic analysis on the liquid air energy storage system with liquid natural gas and organic Rankine cycle

为了提高液态空气储能系统(B-LAES)的循环效率及压缩热的利用率,将液态天然气的冷能合理利用起来,提出了一种耦合液态天然气(LNG)和有机朗肯循环(ORC)实现冷热电三联供的液态空气储能系统,从导热油中压缩热的利用率、循环效率、电-电转化效率、?效率几方面对本系统进行分析。研究结果表明,通过合理综合利用导热油中的压缩热,压缩热利用率可达到96.67%,比B-LAES系统高约55%;通过耦合利用液态天然气(LNG)的冷能,系统循环效率可达93.20%,比B-LAES系统提高约16.9%;增加ORC系统可使系统电-电转化效率达81.34%,比B-LAES系统提高约42.2%。研究结果可为液态空气储能理论研究和应用提供一定的技术参考。

In order to increase circulation efficiency and utilization rate of the compressed heat of the liquid air energy storage(B-LAES) system and make wise use of the cold energy of the liquid natural gas, this study suggests a LAES system that can achieve the combined cooling, heating, and power supply by coupling the liquid natural gas and the organic Rankine cycle system. The system is examined from the utilization rate of the compressed heat in the heat transfer oil, the circulation efficiency, the electricity recurrence conversion efficiency, and the exergy efficiency. Through the thoughtful and thorough use of compression heat in the heat transfer oil, the utilization rate of the compression heat is as high as 96.67%, which is almost 55% greater than that of the B-LAES system. Using the cold energy of liquid natural gas through coupling, the circulation efficiency of the system can reach 93.20%, which is roughly 16.9% greater than that of the B-LAES system. Using the organic Rankine cycle system,the electrical conversion efficiency of the system can reach 81.34%, which is almost 42.2%greater than that of the B-LAES system.