Thermodynamic and economic performance analysis of compressed air energy storage system with a cold, heat and power tri-generation function combined with vortex tube

Abstract

Compressed air energy storage (CAES) systems offer a way to overcome the challenges of renewable energy integration and grid stabilization. Compared to other energy storage methods, CAES tends to have lower environmental impact and higher scalability to meet multiple needs. However, pressure loss at the throttle valve is one among the primary factors limiting the energy storage performance, while most studies on CAES systems haven't noticed the synergistic supply of multiple forms of energy (heat, electricity, and cold). In this study, a novel trigenerative (cooling, heating, and power) CAES system combining vortex tube and heat pump (HP-CCHP) was proposed to supply three forms of energy while fully utilizing the throttling pressure. To enhance the system's performance, the study conducted sensitivity analysis to examine the impact of vortex tube, cooling water temperature, evaporation temperature, and ambient temperature on the system's performance. The performance of this system was compared with the normal system without heat pump. It is simulated that the system power efficiency (SPE), system energy efficiency (SENE) and exergy efficiency (EXE) reach 16.99 %, 64.36 % and 26.81 %, respectively, while the levelized cost of storage of the system (LCOS) is 0.3693 $/kWh. The aggregate expense of the system is 8512 k$ while annual electricity generation reaches 3,959,000 kWh. Additionally, an exergy and economic analysis was performed, revealing that the vortex tube resulted in the greatest exergy losses. The compressors and turbines are the main parts of the total investment.