Study On The Energy Saving Operation And Control Optimization Of Wet Limestone-gypsum Flue Gas Desulfurization System

Limestone-gypsum wet flue gas desulfurization technology has been widely utilized in the coal-fired power at home and abroad at present.However,the process system has some problems such as complicated operation parameters and rough operation and maintenance,and thus to further optimize the system.In this thesis,the energy saving optimization and control optimization were carried out for limestone-gypsum wet flue gas desulfurization system of a 2×1000MW coal-fired unit in Henan.The optimization results are as follows:1)Collecting the historical operation data of the desulfurization system,and through correlation analysis,it was found that the unit load,SO₂ concentration of raw flue gas and raw flue gas flow were significantly correlated with the slurry circulating pump operation combination mode.Through the classification analysis,the slurry circulation pump operation combination mode is obtained,forming the guiding operation rules.Finally,through economic analysis,if the optimization operation proposal is adopted,the annual electricity cost can be saved by about 200,000 to 240,000 yuan,which reduces the operating energy consumption and improves the economic efficiency of the desulfurization system.2)By analyzing the common limestone control strategy and the reasons for its low operating rate,and according to the actual situation of the site,an optimized automatic control system for limestone slurry pump is designed.According to the special situation of the site,the optimized control system uses soft measurement technology to correct the original flue gas flow to ensure the accuracy of the input signal.The feedforward control technology is used to dynamically compensate various disturbance factors of the desulfurization system,thus to improves the stability of the desulfurization system;the dynamic optimal setpoint technology is used to further optimize the control system.Through the on-site commissioning operation,the optimized control system realizes the automatic control of the limestone slurry pump,and the various indexes such as the net flue gas SO₂ concentration and the absorption tower slurry p H value meet the control requirements,and the automation level of the desulfurization system is improved.