Energy analysis and economic evaluation of trigeneration system integrating compressed air energy storage system, organic Rankine cycle with different absorption refrigeration systems

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In recent years, a concerted effort has been made to reduce reliance on conventional fossil fuels by advancing the use of renewable energy. Nonetheless, the use of renewable energy presents inherent challenges, prominently including intermittency and unpredictability. These obstacles impede the seamless integration and optimal use of renewable energy. A promising solution to address the issues of intermittency and unpredictability in renewable energy is compressed air energy storage (CAES) technology. The performance of CAES can be significantly enhanced through the implementation of a trigeneration system. Some studies have been performed to develop strategies in order to improve the round-trip efficiency (RTE) of the CAES. However, no studies have evaluated the effect of integrating different types of absorption refrigeration systems (ARSs) (different effects and different working media). Steady-state models for CAES, organic Rankine cycle (ORC) and different types of ARSs were developed in Aspen Plus®. All the models were validated in Aspen Plus®. Then process study was conducted to analyse the effects of recuperator outlet temperature and ARS mass flowrate on CCHP system performance. Economic evaluation was performed using Aspen Process Economic Analyser® (APEA). The double-effect ARS is superior to single-effect ARS with the same working medium. The LiBr-H2O is more suitable than NH3-H2O as working medium. The CCHP implemented with double-effect ARS using LiBr-H2O can produce 206 MWe of electrical energy, 7.26 MWth of heating and 27.28 MWth cooling capacity with coefficient of performance (COP) 1.36. The process analysis indicates that COP and RTE increased with the ARS mass flowrate. The levelized cost of electricity (LCOE) of the CCHP-3 system is 31.01 $/MWh, the payback period of the CCHP-3 system is 12.9 years. Overall, this first systematic study comparing different types of ARS for the CCHP system will provide important guidance on the process design and analysis of CCHP.