Introduction  With the gradual increase in the proportion of renewable energy generation in the power grid, the actual operating parameters of thermal power units deviate significantly from the design parameters, which will increase the amount of pollutants in the flue gas, and affect the regular operation of the flue gas treatment equipment, thus reducing the pollutant removal efficiency and the operating economy.

  Method  The analysis of typical pollutant emission characteristics and corresponding control strategies during the peak shaving process of the unit was concerned. The current research results and progress of emission characteristics of NO_x, sulfides, volatile organic compounds, heavy metals, and particulate matter were analyzed and summarized, including selective catalytic reduction technology, wet flue gas desulfurization technology, electrostatic precipitator technology, catalytic oxidation technology, gypsum absorption technology, adsorption control technology, etc.

  Result  On this basis, the control technology and control strategy used in the current flexible peak shaving process is put forward, the economics of various pollutant control technologies are compared and analyzed, and the factors influencing the pollutant control performance and costs are obtained.

  Conclusion  Under the actual demand for flexible peaking of coal-fired units, it is concluded that under the demand of flexible peak regulation, reasonable pollutant residence time, working temperature range, flow, and reaction process should be constructed based on the characteristics of various pollutants, and pollutant synergistic removal technology characterized by efficient, low-cost, adaptable and suitable for multi-pollutant removal should be developed. It is expected that this paper can provide some reference for the pollutant emission control measures in the flexible peak shaving process of thermal power units.