Thermal modeling and triple objective optimization of a new compressed air energy storage system integrated with Rankine cycle, PEM fuel cell, and thermoelectric unit

Abstract

Intermittent behavior of renewable energy triggered researchers for using energy storage systems to provide continues operation of renewable-based energy systems. In the current study, an integrated energy system including compressed air energy storage, Rankine cycle, Proton Exchange Membrane (PEM) fuel cell (FC), and thermoelectric generator (TEG) modules are investigated to introduce a new system. To show effects of adding TEG units and PEM fuel cell in the new configuration, three arrangements including conventional compressed air energy storage system (CAES), CAES/TEG and CAES/TEG-FC are investigated. It is found that the proposed CAES/TEG-FC system energy efficiency is 31.85%, which is 1.6% higher than conventional CAES. The exergy efficiency of CAES/TEG-FC is 35.13%, which is 1.44% higher than the conventional one. The proposed system generates 35.6 kW hot water and charge/discharge time are 2.91 hr/4.64 hr. A parametric analysis conducted on the discharge mass flow rate, intercooler outlet temperature, compression pressure ratio, and wind velocity with charging time, exergy efficiency, and total useful products as three major outputs. The tri-objective optimization shows by the technique for order of preference by similarity to ideal solution the optimized value of exergy efficiency, total useful output, and charge time are 34%, 1078.46 kW, and 5.28 hr.