Compressed Air Energy Storage (CAES) is an effective solution to the problems of the intermittency and volatility of renewable energy. However, the process of compressing air consumes energy and converts it into low-temperature waste heat, limiting the improvement of round-trip efficiency. This paper introduces the dual-pressure evaporation organic Rankine cycle (ORC) to recover the waste heat from the CAES system compression process, which enhances the round-trip efficiency. Optimal working fluids and design schemes of parallel and series dual-pressure evaporation ORCs are analyzed. The thermodynamic performance of two cycle types is compared. The exergy loss distribution characteristics of the dual-pressure evaporation ORC are explored, and the impact on the round-trip efficiency of the CAES system is evaluated. Results show that the parallel dual-pressure evaporation ORC has better performance with an optimum working fluid of R1234yf and a maximum waste heat conversion efficiency of 9.3 %. The round-trip efficiency of the CAES system will be relatively increased by 5.2 % by introducing the parallel dual-pressure evaporation ORC. The maximum exergy efficiency of the parallel dual-pressure evaporation ORC is 52.8 %, and the condenser and low-pressure stage expander have larger exergy losses, accounting for 33.8 % and 22.0 % of the total losses, respectively.

中文翻译：

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用于回收压缩空气储能（CAES）废热的最佳双压蒸发有机朗肯循环


压缩空气储能（CAES）是解决可再生能源间歇性和波动性问题的有效解决方案。然而，压缩空气的过程会消耗能量并将其转化为低温废热，限制了往返效率的提高。本文介绍了双压蒸发有机朗肯循环（ORC）来回收CAES系统压缩过程中的废热，从而提高了往返效率。分析了并联和串联双压蒸发ORC的最佳工质和设计方案。比较了两种循环类型的热力学性能。探讨了双压蒸发ORC的火用损失分布特性，评估了其对CAES系统往返效率的影响。结果表明，并联双压蒸发ORC具有较好的性能，最佳工质为R1234yf，最大余热转换效率为9.3%。通过引入并联双压蒸发ORC，CAES系统的往返效率将相对提高5.2%。并联双压蒸发ORC的最大火用效率为52.8%，冷凝器和低压级膨胀机的火用损失较大，分别占总损失的33.8%和22.0%。