纳米铁粉生产装置中蒸发器流量控制技术研究

发布时间：2018-02-09 12:20

本文关键词： 羰基铁蒸发器气体流量模糊自适应PID控制　出处：《长春工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：纳米铁粉对当代工业及日常生活有着越来越广泛的应用,其中纳米羰基铁粉即是其中的一种,其制备过程较为复杂且对设备要求苛刻,蒸发器是纳米羰基铁粉制备的一重要环节。其工作过程大致为：通过导入过热蒸汽对液态羰基铁进行加热,直至沸腾蒸发,汽化的羰基铁经蒸发器出口导出,但是羰基铁液在蒸发器内蒸发汽化的过程极易受到诸多因素的影响而变化,进而导致出口蒸汽流量的不稳定。直接影响下一环节的稳定运行和最终产品的质量。本文主要目的在于保证五羰基铁蒸发器出口蒸汽流量的稳定控制,其目标是：通过调节过热气体的流量来控制蒸发器出口工质流量维持在设定值,保证系统安全运行,并最大限度地利用能源。现阶段,针对蒸发器的模型选择与建立,学者们都已作出了丰富的总结并获得了相应的经验,经综合分析,本文所设计的基于羰基铁蒸发器的模型的建立选择用移动边界法实现。并在MATLAB/SIMULINK环境下的通过仿真结果证明了该模型的可实施性,确定其可以准确地反映出羰基铁蒸发器内运行的实际情况。通过对以往蒸发器的分析,我们知道非线性、大惯性,以及很大的控制难度是其系统中一直存在的问题,对此,本文提出一种模糊自适应PID控制器,在分析模糊理论与PID控制结构特性的基础上,给出了基于模糊思想的自适应PID控制器的设计思路。同时为了证明这种控制方法的优越性,分别给出了普通PID控制器和改进后的模糊自适应PID控制器的对比实验。仿真结果表明上述方法提高了系统的静态和动态特性。本文针对纳米羰基铁粉蒸发器的控制系统中出现的随机性、不确定性及非线性等问题,在结合了模糊控制理论与PID控制算法的基础上,尝试了新的方法并运用新的控制器,并且以集散控制系统(DCS)为基础过程控制,PCS7为核心控制系统,实现了对五羰基铁蒸发器的过程控制。实践证明,运用该控制理论及控制方法的蒸发器实现的控制效果优于过往的蒸发器。
[Abstract]:Nanocrystalline iron powder is more and more widely used in modern industry and daily life, among which nano-carbonyl iron powder is one of them, its preparation process is more complex and demanding to the equipment. The evaporator is an important part in the preparation of nanometer carbonyl iron powder. The working process is that the liquid carbonyl iron is heated by introducing superheated steam until boiling evaporation, and the vaporized carbonyl iron is exported through the evaporator outlet. However, the process of vaporizing carbonyl iron in evaporator is easily influenced by many factors. The main purpose of this paper is to ensure the steady control of the outlet steam flow of the pentacarbonyl iron evaporator, which directly affects the stable operation of the next link and the quality of the final product. The aim is to control the flow of refrigerant at the outlet of evaporator by adjusting the flow rate of superheated gas, to ensure the safe operation of the system and to make the maximum use of energy. At this stage, the model of evaporator is selected and established. Scholars have made a rich summary and gained the corresponding experience, after comprehensive analysis, The establishment of the model based on carbonyl iron evaporator is realized by moving boundary method in this paper. The simulation results under MATLAB/SIMULINK environment prove the feasibility of the model. It is determined that it can accurately reflect the actual operation of carbonyl iron evaporator. Through the analysis of the previous evaporator, we know that nonlinearity, large inertia and great difficulty of control are the problems in its system. In this paper, a fuzzy adaptive PID controller is proposed. Based on the analysis of fuzzy theory and the characteristics of PID control structure, the design idea of adaptive PID controller based on fuzzy idea is given. The comparison experiments between the ordinary PID controller and the improved fuzzy adaptive PID controller are given. The simulation results show that the proposed method improves the static and dynamic characteristics of the system. The control of the nano-carbonyl iron powder evaporator is studied in this paper. The randomness of the system, Based on the combination of fuzzy control theory and PID control algorithm, a new method and a new controller are proposed for uncertain and nonlinear problems, and the process control system based on distributed control system, PCS7, is used as the core control system. The process control of the iron pentacarbonyl evaporator is realized. The practice shows that the control effect of the evaporator using the control theory and control method is better than that of the previous evaporator.
【学位授予单位】：长春工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;TP273

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