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[en] Highlights: • Four performance indexes of constant-sliding mode are the best. • Cooling capacity of constant-sliding mode is the strongest. • The exergy destruction of air storage chamber is the largest. • Three modes have similar variation tendencies of parameters of air storage chamber. - Abstract: The tri-generative system based on advanced adiabatic compressed air energy storage can simultaneously provide cooling energy, heating energy and mechanical energy. In order to study the discharge characteristics, three operation modes of expanders, which contain constant pressure, constant-sliding and sliding pressure, are proposed in this paper. By utilizing the numerical simulation method, the performance difference of three modes is compared with each other. The results show that four performance indexes of constant-sliding mode are all the biggest, which are respectively cycle efficiency 40.55%, thermal efficiency 80.06%, exergy efficiency 48.45% and exergy density 4.071 × 106 J·m−3, and cooling capacity of it is also the strongest, 8.386 × 109 J, among the three operation modes. Air storage chamber has the largest exergy destruction. Operation process of air storage chamber is similar for three operation modes. Meanwhile, the effects of heat exchanger effectiveness, ambient pressure and air storage chamber model on system performance are also investigated.
[en] Highlights: • Mode 4 has the highest exergy efficiency. • Mode 2 has the largest exergy density. • Second heat exchanger has the largest exergy destruction. - Abstract: Advanced adiabatic compressed air energy storage system plays an important role in smoothing out the fluctuated power from renewable energy. Under different operation modes of charge-discharge process, thermodynamic behavior of system will vary. In order to optimize system performance, four operation modes of charge-discharge process are proposed in this paper. The performance difference of four modes is compared with each other based on energy analysis and exergy analysis. The results show that exergy efficiency of mode 4 is the highest, 55.71%, and exergy density of mode 2 is the largest, 8.09 × 106 J m−3, when design parameters of system are identical. The second heat exchanger has the most improvement potential in elevating system performance. In addition, a parametric analysis and multi-objective optimization are also carried out to assess the effects of several key parameters on system performance.