Objective Under the "dual carbon" strategy, this paper proposes a technical solution to enhance the deep peaking capability of existing coal-fired power units by externally adding a thermal energy storage device and coupling it with the thermal system.

Method Using the EBSILON software, a simulation model of the subcritical thermal power system coupled with a high-parameter thermal energy storage device was established based on a 630 MW unit, and multi-condition simulation calculations were carried out. The influence of the thermal energy storage device parameters on the power generation and heating surface were studied in this paper.

Result The results show that: after the high-parameter thermal energy storage device is coupled with the boiler system, the steam flow rates at different boiler heating surfaces are all increased, and the consumption of attempering water is reduced. When the temperature difference between the medium temperature in the thermal energy storage tank and the boiler makeup water is large (≥45 ℃), the power generation capacity of the unit can be significantly improved without causing the problem of over-temperature in the existing thermal power system.

Conclusion This study can provide guidance for the scheme design of coal-fired units coupled with high-parameter thermal energy storage devices.