多模型自适应控制在微波褐煤干燥中的应用研究

发布时间：2019-01-26 17:51

【摘要】：褐煤是我国含量较为丰富的一种低阶煤。由于褐煤具有高含水率、低发热效率的特点,导致直接使用存在热效率低、污染严重等问题。对褐煤进行干燥提质是大规模利用的一种有效手段。微波以其整体性、选择性、安全卫生无污染、即时性、能量利用率高等优势,已成为一种新型高效的清洁能源。同时,微波加热技术已成为一种新型高效的工业化加热手段。在微波干燥过程中,由于褐煤的介电常数等特性随加热环境而改变,可能会出现热失控的现象,极大地制约了微波干燥的工业应用。因此,为确保干燥过程安全进行,论文将多模型自适应控制算法引入到微波褐煤干燥过程。以微波褐煤干燥实验系统为研究对象,分别以微波系统输入功率和褐煤温度为系统的输入输出,在考虑微波加热实验系统具有非线性功率输入约束的条件下,研究多模型自适应控制对褐煤加热温度的控制,实现微波褐煤干燥系统安全高效的运行。论文主要的研究内容如下:(1)分析影响褐煤介电系数变化的因素。利用系统的输入输出数据,采用递推最小二乘法对微波褐煤干燥过程进行系统辨识,建立微波褐煤干燥过程辨识模型。(2)基于辨识模型,在分别加入扰动、参数跳变以及非线性输入约束的情况下,利用极点配置算法与极点配置自校正控制算法对微波褐煤干燥系统进行控制器的设计。并通过仿真结果分析不同情况下的控制效果。(3)针对褐煤参数存在突变或跳变的情况,采用多模型自适应控制算法对微波褐煤干燥过程进行控制。通过微波褐煤干燥实验辨识建立不同工况的48个固定模型、一个常规自适应模型、以及一个初值可变的自适应模型,共同构成系统模型集。在加入非线性输入约束的条件下,利用多模型自适应算法对系统的输出温度进行控制。最后,通过仿真与微波褐煤干燥实验,对多模型自适应控制算法在微波褐煤干燥过程中的控制效果进行验证。
[Abstract]:Lignite is a low rank coal with abundant content in China. Because lignite has the characteristics of high moisture content and low heating efficiency, there are some problems such as low thermal efficiency and serious pollution in direct use. Drying and upgrading lignite is an effective method for large-scale utilization. Microwave has become a new and efficient clean energy because of its advantages of integrity, selectivity, safety and hygiene, non-pollution, immediacy and high energy utilization. At the same time, microwave heating technology has become a new and efficient industrial heating method. In the process of microwave drying, because the permittivity and other properties of lignite change with the heating environment, the phenomenon of heat runaway may appear, which greatly restricts the industrial application of microwave drying. Therefore, in order to ensure the safety of drying process, multi-model adaptive control algorithm is introduced to microwave lignite drying process. Taking microwave lignite drying experiment system as research object, the input power of microwave system and the temperature of lignite are taken as the input and output of the system, and the nonlinear power input constraints of microwave heating experimental system are considered. The multi-model adaptive control is studied to control the heating temperature of lignite to realize the safe and efficient operation of microwave lignite drying system. The main contents of this paper are as follows: (1) the factors affecting the dielectric coefficient of lignite are analyzed. Using the input and output data of the system, the microwave lignite drying process is identified by recursive least square method, and the identification model of microwave lignite drying process is established. (2) based on the identification model, the disturbance is added respectively. The controller of microwave lignite drying system is designed by pole assignment algorithm and pole assignment self-tuning control algorithm under the condition of parameter jump and nonlinear input constraints. The simulation results are used to analyze the control effect under different conditions. (3) the multi-model adaptive control algorithm is used to control the process of microwave lignite drying in the case of sudden change or jump of lignite parameters. Through microwave lignite drying experiments, 48 fixed models, a conventional adaptive model and an initial variable adaptive model are established to form the system model set. Under the condition of nonlinear input constraints, the output temperature of the system is controlled by multi-model adaptive algorithm. Finally, through simulation and microwave lignite drying experiment, the control effect of multi-model adaptive control algorithm in microwave lignite drying process is verified.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD849.2

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