Control And Optimization Of NO_X Concentration In Flue Gas Of Thermal Power Plant Based On APHC Control Strategy

With the national emission standards for thermal power enterprises further stringent requirements,ultra-low emission transformation has been put on the agenda of all thermal power enterprises.At present,selective catalytic reduction(SCR)is widely used in thermal power plants to reduce the concentration of nitrogen oxides in flue gas.This method is more mature,more efficient and easy to control.However,with the development of information technology and the improvement of industrial level,the load of thermal power units changes faster and faster,and the change range is larger and larger,which brings higher control requirements to the existing SCR denitration system.This paper briefly introduces the working process of thermal power plant and the principle of SCR denitration system,and analyzes the control difficulties of SCR denitration system at present.(1)According to the time-delay characteristics of the control object,the advanced prediction module based on BP neural network is designed in the control strategy.In order to realize the advanced prediction of NOx concentration at the inlet of SCR denitration system,the data prediction based on BP neural network is discussed firstly;Secondly,LM algorithm is used to optimize the BP neural network training function to achieve efficient and accurate target prediction;Finally,the real production data of SIS system in thermal power plant is used to train the algorithm to improve the prediction accuracy of the data.(2)In order to achieve better control of NOx concentration in SCR system,this paper proposes "SCR Anthropomorphic Fuzzy Algorithm",which maps the working experience and operating habits of boiler operators to the control matrix to realize anthropomorphic control of NOx concentration at SCR denitration outlet.In the control process,combined with the accurate prediction results of the advanced prediction module,the advanced control of the target is realized to avoid the phenomenon of imbalance and overshoot;Through the simulation experiment,the feasibility of the new control strategy is verified.(3)Based on the above strategies,this paper proposes an APHC control strategy(Advance Prediction Humanoid Control).The control strategy is composed of two parts: "Advanced Prediction Module" and "Anthropomorphic Control Module".The advanced prediction module is used to predict the NOx concentration at SCR inlet;On the basis of prediction,the anthropomorphic control module uses the operator’s manual control experience to formulate SCR anthropomorphic control strategy,so as to achieve more stable and efficient NOx concentration at the outlet of SCR denitration system in thermal power plant.Timely control.Finally,the paper simulates the thermal power unit in near real and lossless environment.The results show that the NOx concentration control based on APHC control strategy is better than the traditional PID control strategy.