Study on energy-saving operation technology of environmental protection facilities of ultra-low emission coal-fired unit

Abstract The operation optimization of low nitrogen combustion, denitrification and desulfurization facility of a 335 MW coal-fired unit met ultra-low requirements has been conducted in order to lower energy and material consumption. The operation mode of low nitrogen combustion with consideration of boiler efficiency and furnace exit nitrogen oxides concentration is determined. The boiler efficiency is 0.4% higher and the power supply coal consumption is reduced by 1.4 g/(kW h). The furnace exit nitrogen oxides concentration is reduced by 16 mg/m3. The SCR outlet nitrogen oxides concentration distribution uniformity is improved by ammonia spraying optimization, and the response speed and control quality of denitrification automatic control is improved by control logic optimization, therefore the liquid ammonia consumption is decreased by 0.13 kg/(104 kW h). The combination methods of absorber slurry pumps have been improved and the total mean running current of the pumps is lowered 33 amperes. The effect of limestone slurry feed automatic control is improved. The limestone slurry flow is reduced by 18.7 kg/(104 kW h).