一种新型多联产液化空气储能系统耦合空气分离装置：热力学与经济性分析

Abstract Integrating air separation units (ASUs) with a liquid air energy storage (LAES) system offers enhanced revenue potential for LAES and a reduced payback period through shared use of compression and cooling equipment. However, the existing proposed LAES-ASU systems either fail to meet the continuous production requirements of ASU or impose limitations on the storage capacity of LAES. Therefore, this study proposes a novel multi-generation LAES-ASU system, where the LAES and ASU are coupled efficiently through stream splitting in the compression train , process modification in the liquefaction section, and exhaust reuse in the expansion train. After developing the analysis model, a parametric analysis of the coupled system is conducted to identify optimal operating parameters. Additionally, comprehensive energy, exergy, and economic analyses are performed to evaluate system performance . The results indicate a round-trip efficiency of 57.09 % for the LAES subsystem and comprehensive electricity consumption for air separation products of 0.268 kWh/Nm 3 , representing a 51.25 % decrease compared to the current ASU. The payback period of the proposed system is as short as 3.9 years, and the levelized cost of electricity is as low as 0.070 $/kWh, due to the additional revenue stream from gas products. The main exergy destruction occurs in components such as distillation columns , cryogenic heat exchangers and air compressors. This study assesses the potential and feasibility of coupling liquid air energy storage with air separation and offers insights for future optimization, ultimately contributing to the commercialization and industrial-scale application of LAES.