Abstract: With the gradual maturity of frequency conversion technology, most of the feedwater pumps in waste incineration power plants were replaced by constant speed feedwater pumps with variable frequency feedwater pumps, but the boiler feedwater system still adopted traditional feedwater control logic, which failed to fully tap the energy saving potential of variable frequency feedwater pumps. Through the overall analysis of the boiler feed water system of waste incineration power plant, the control logic of the original feed water system was reformed. At a single boiler scale, the drum water level was directly controlled by the frequency conversion feed water pump, and the feed water control valve was fully open. The average power saving of the water supply system was 0.28 kWh/t, the power saving rate was 7.2%. The variance of monthly unit water supply energy consumption was reduced from 0.064 to 0.033, and the stability of the water supply system was greatly increased, annual power saving of 109.5 MWh, equivalent to carbon reduction of 62.45 tCO2. Under multiple boiler scales, the pressure of the main pipe of the variable frequency feed pump changed with the pressure of the drum. The average power saving of the water supply system was 0.29 kWh/t, the power saving rate was 7.2%. The average unit feedwater variance was reduced by about 36%, the stability of the water supply system was greatly improved,annual power saving was 380.8 MWh, equivalent to carbon reduction of 217.17 tCO2 .

Key words: waste incineration, variable frequency feed water pump, new logic of water supply system, energy saving