It has become the development trend of thermal power units in the future to improve the capacity of peak regulation and renewable energy consumption in China's power grid

tap the peak regulation potential of coal-fired units and enhance the flexibility of units. In this paper

a 350 MW supercritical unit is taken as the research object

and a variety of flexible peak-shaving systems for thermal power units coupled with molten salt are proposed. Through heat balance calculation

the thermal performance and peak-shaving ability of each coupling system are compared and analyzed. The results show that the molten salt energy storage system obviously improves the flexibility of unit operation

effectively relieves the contradiction between unit load and electricity price

and improves the peak shaving depth and peak capacity of the unit. The scheme of extracting main steam to condenser during heat storage has the best regulation performance

and the high-pressure feed water heated by molten salt has the best regulation performance during heat release

with the upper and lower regulation capacities reaching 23.084 MW and 31.85 MW;respectively. Reheat steam is pumped to the deaerator during the heat storage process

and molten salt heats the outlet water of the deaerator to the inlet of the low-pressure cylinder during the heat release process. The thermal efficiency and coal consumption rate are 40.06% and 307.03 g/kWh respectively;Combined with the length and proportion of peak-valley electricity price in spot trading of electricity in the whole year

the static investment of molten salt heat storage system is about 87.5 million yuan

the estimated annual net income is about 4.42 million yuan

and the static investment payback period is about 19.8 years.