Coal-fired power plants can be coupled with the heat storage to further improve its flexible peak regulation capacity. In order to solve the problems of unclear technical path and vague performance evaluation index of the coupled coal-fired power and heat storage system

this study constructs a model of the source-storage coupling system for coal-fired power plants on the premise of ensuring the safe and efficient operation. EBSILON software is used to establish a simulation model of main steam condensation for heating molten salt (energy storage) and heating feedwater (energy release)

and the influence mechanism of the energy storage and release process on the operation characteristics of the unit is revealed through thermodynamic analysis and system efficiency evaluation. The results show that the scheme exhibits favorable economic performance across different load ranges

and the comprehensive efficiency can reach up to 116%. In specific load ranges

the comprehensive efficiency can exceed 100%

which means the peak shaving of the coupling system is better than the unit itself. During the energy storage phase

the molten salt thermal storage system has little impact on the unit’s efficiency; however

during the energy release phase

molten salt heating of the feedwater affects the unit’s heat recovery system

leading to a decrease in system efficiency. By reasonably determining the proportion of molten salt heated feedwater

the efficiency loss caused by replacing part of the heat recovery can be reduced. The results prove that the coal-fired power source-storage coupled system proposed in this paper can effectively improve the economic performance of peak shaving operation of the coal-fired power plant

providing technical and data support for the engineering application of such systems.