## 1 Introduction
Moreover, researches have highlighted the larger cycle efficiency of the Brayton cycles with non-ideal working fluids than that with ideal gases [22]. Moreover, plenty of CO\({}_{2}\) has to be sequestrated geologically in deep formations in order to lower the emissions of greenhouse gas [23]. Considering the above aspects, the cycle efficiency of a gas energy storage system is able to be largely enhanced by applying CO\({}_{2}\) as a working medium. Moreover, the size of storage tank can be very small, and the greenhouse effect can be well reduced. [PERSON] et al. [24] described a CO\({}_{2}\)-based energy storage technology and the performance analysis intensified its advantage of much higher energy density compared with CAES system. [PERSON] et al. [25] described a CO\({}_{2}\) energy storage system with transcritical compression and expansion processes in combination with packed bed regenerator. Results showed that the minimum pressures had a more significant influence on system performance than the maximum pressures. [PERSON] et al. [26] proposed an energy storage system by employing two saline aquifers with unequal depths, the round-trip efficiencies of which were 62.28% and 63.35% at transcritical and supercritical conditions, separately. Conventional exergy analysis is a powerful tool to present the exergy destruction distribution [27; 28]. However, on one hand, the conventional exergy analysis cannot determine the tangible promotion potential of a system component since it considers none of the technical and economic limitations; on the other hand, it cannot evaluate the reciprocal interdependencies among components. Therefore, the advanced exergy analysis was developed recently as the solution to the above issues by separating the exergy destruction of a component into different parts [29; 30; 31]. This advanced method has been utilized in many energy systems, such as refrigeration cycles [32; 33], supercritical power plant [34], underwater CAES [35], supercritical CCES [36], and trigeneration systems [37]. In accordance with the open documents, it can be concluded that the advanced exergy analysis offers much more meaningful details that cannot be acquired through resorting to the conventional one. More importantly, the advanced exergy analysis tends to clear, potentially, the misleading deductions obtained from the conventional exergy analysis. Based on the literature survey, several papers in the literature deal with the CAES-based CCHP system; only one is concerned on the CCHP system based on CCES, which is developed by authors [38]. Main investigation of the previous work is about the energy efficiency of the CCES-based CCHP system by using the first law of thermodynamics. As a further study, the focus of the present work is to pioneer the advanced exergy analysis of the CCES-based CCHP system. Splitting the component exergy destruction is clearly described. A particular focus is the sensitivity examination of the system to analyze the impacts of some key parameters on system performance. This advanced approach overcomes the most important limitations of a conventional exergetic analysis and, therefore, assists engineers in better understanding how thermodynamic inefficiencies are formed. Conventional exergy analyses only quantify the exergy destruction in different components, but cannot shed light on the interactions between components, while advanced exergy analyses overcome this weakness and uncover more of the accessible potential of the system.