Research On Predictive Control Method Of Main Steam Pressure Of Boiler Combustion System

Industrial boiler is a kind of high-pollution industrial equipment,and the optimal control of the main steam pressure is an important part of achieving energy saving and emission reduction in thermal power plant boiler.This article takes Dushanzi Petrochemical Co.,Ltd.thermal power plant 2#220t/h pulverized coal boiler as the research object.On the basis of analyzing the principles,influencing factors of the combustion process of the thermal power plant boiler and the optimal control requirements,the amount of pulverized coal fed into the furnace is used as the main control quantity,and the main steam pressure is used as the controlled quantity.Considering the combustion efficiency on the basis of ensuring safety,an optimized control scheme for the main steam pressure circuit of the boiler combustion system based on dynamic matrix control(DMC)and generalized predictive control(GPC)is proposed,and we implement the design of main steam pressure control system based on Lab VIEW.The main work of this article is summarized as follows:(1)Analyzing the control strategy of the existing power plant boiler combustion system.We use the predictive controller to control and optimize the main steam pressure control system according to the current problems of the thermal power plant.The main steam pressure control system with coal powder as its main influencing factor is designed.(2)According to the actual situation of the thermal power plant,the DMC control algorithm based on the main steam pressure control system is designed.A reasonable DMC parameter adjustment method is given to realize the simulation verification of the DMC controller,and the PID control of the main steam pressure output response is compared to verify the feasibility of DMC control procedures.(3)Analyzing the main steam pressure loop data of the thermal power plant,and we use Recursive least square method(RLS)to identify the loop data parameters.The GPC control algorithm based on the main steam pressure control system is designed,and a reasonable parameter adjustment method is given.Simulating and verifying the effectiveness and feasibility of the GPC control program.Since the large fluctuations in the response of the initial stage of GPC control,a simulated annealing scheme was designed to optimize the parameters of the control weights of the GPC controller.This scheme makes the dynamic response of the control system more stable and has a better control effect.(4)This paper implements mixed programming of C language and Lab VIEW based on predictive control of the main steam pressure control system of power plant boilers.This program including the compilation of core program dynamic link library(DLL)files of DMC,GPC and PID control algorithm,and it can adapt to different industrial control platforms on the industrial call.Moreover,the call of the control program of the Lab VIEW platform can be realized by this program,and the functions of the control interface,loop curve display and data analysis also can be realized.In order to achieve better effect of the software system,a device simulator based on the boiler combustion control system is designed.Considering the requirements of each controller for the controlled system model,the software provides a least squares system parameter identification module.