Study on the operational feasibility domain of combined heat and power generation system based on compressed carbon dioxide energy storage

Compressed carbon dioxide energy storage (CCES), as one of the compressed gas energy storage (CGES) technologies, can make the system capable of combined heat and power supply by storing and releasing electrical energy in the form of heat and potential energy, which is of positive significance for realizing efficient and comprehensive energy utilization and promoting the development of energy storage technology. A combined heat and power supply system based on compressed carbon dioxide energy storage (CCES-CHP) and its mathematical model are constructed. In order to construct a visualized operational feasibility domain, the dimensionless factors gamma 1 and gamma 2 and the ratio parameters alpha 1 and alpha 2 are defined to reflect the coupling relationship between the system storage/release energy power, mass flow rate and cooling/heat release power. A dual state of charge (SOC) model of heat and gas storage is also constructed. Further research is conducted on the shape and characteristics of the operational feasibility domain under the combined heat and power mode. The change of the ratio of themoelectric distribution ratio dispatch and wide operating conditions are analyzed. Thus provide an idea for evaluating the flexibility of the system operation combined heat and power capacity and response tracking. Finally, the analysis process and application potential of the proposed operational feasibility domain analysis method were validated for a typical integrated energy system.