Realization Of Stochastic Distribution Control For Coal-Fired Boiler And Its Simulation Platform

Industrial boiler is not only the major coal consumption equipment in China, but also one of the major pollution sources. Among industrial boiler in China, a large proportion is layer burning coal-fired grate boilers. Grate boiler, however, has the low level of automation and its thermal efficiency is less than 70%, which of a wide gap with the developed countries.The main purpose of the thesis is applying stochastic distribution control (SDC) to the layer burning coal-fired grate boiler. For this reason, the structure and the combustion characteristics of grate boiler as well as the development of its control methods are introduced in the firstly. And then, the theories of SDC are introduced. The feasibility of applying the modeling and control methods of SDC systems to boiler combustion process control is also discussed. On this basis, the main contribution of the thesis can be summarized as follows:(1) The fast subspace modeling method based on the RBFNN and the optimal iterative learning control based on the state space of SDC systems are given. Simulation results show the feasibility of modeling and control algorithms.(2) An iterative learning based double closed-loop modeling and control algorithm of SDC system is proposed by combining the result of (1) with the modeling of SDC systems, in which the idea of iterative learning is introduced. And then, an adaptive iterative learning rate and an iteration termination threshold are presented to avoid the unnecessary or excessive iterations in the iterative learning process. The simulation results show that the effectiveness of the proposed algorithm.(3) A simulation control platform of coal-fired gate boiler is constructed and the dynamic simulation of the combustion process in layer-fired boiler is realized. The modeling and control algorithm of (2) are verified through this platform, in which, the flame shape of the combustion process and the wind distribution taken as the control output and control input, respectively.Comprehensive results of the MATLAB simulation and the simulation platform, the modeling and control methods of SDC systems in the thesis can be applied to the wind distribution optimization control of coal-fired grate boiler, and a better control effect can be expected.