Molten salt thermal storage technology

as a means of consuming renewable energy in the power grid

can enhance the flexibility of coal-fired units. This article proposes a dual tank heat storage system coupling scheme based on binary molten salt for a 660 MW supercritical coal-fired unit. The paper builds an operational model of the system based on EBSILON and simulates the characteristics of the heat storage and release performance of the molten salt heat storage system

as well as the stable operating characteristics of the system

including flow rate of the molten salt and the end difference of the molten salt heat exchanger. The potential for flexibility improvement of the power plant is analyzed

and the ramping rate and load lifting capacity of the plant after integrating the thermal storage system are calculated and compared. The results show that

with the boiler side kept unchanged

the maximum peak shaving capacity that the heat storage system can provide during the heat storage and release processes is −14.0%Pe and 7.8%Pe (rated power)

respectively. The climbing rate is increased from 0.76%Pe/min to 2.50%Pe/min

and the landslide rate is increased from 0.45%Pe/min to 0.50%Pe/min. Under appropriate operating strategies

adding a molten salt heat storage system to a 660 MW coal-fired unit can significantly improve its ramping rate and broaden its operating range.