Under the guidance of the dual-carbon goals

to meet the safety and stability requirements of the new power system dominated by renewable energy

the Chinese government has proposed flexibility retrofits for coal-fired power units.These retrofits aim to make coal power generation more flexible

efficient

and low-carbon

thereby better supporting the integration and utilization of renewable energy.This paper explores the upgrade of static separators in older coal-fired units to dynamic-static combined rotary separators

which enhances the separation efficiency of fine coal powder and improves the adjustability of coal fineness and uniformity.This upgrade boosts boiler combustion efficiency and reduces the emission of fly ash combustibles and pollutants.A upgrade project at a power plant in Guangdong serves as a case study to validate the operational effectiveness of the dynamic-static combined rotary separators.