基于ARM的甲醇精馏塔变结构控制系统研究

发布时间：2018-04-23 22:05

本文选题：甲醇 + 温度　；参考：《华北理工大学》2017年硕士论文

【摘要】：在甲醇生产过程中,由于工艺过程中各种条件的限制,会使合成的甲醇中产生很多杂质。这就需要通过精馏方法对其进行处理,将粗甲醇精馏成高纯度甲醇产品。然而精馏系统中最重要的环节为精馏加压塔部分,其中控制精馏加压塔塔顶温度的稳定与精确对于能否生产出高质量的甲醇产品至关重要。在这种温度控制系统中,传统的控制方法主要是通过PLC结合PID控制算法来完成。但是在实际的甲醇精馏环境中,面对这种复杂的非线性系统,传统控制方法难以使温度的调节时间与超调量这两个动态性能指标同时都得到优化。为了解决这种问题,设计中选用了变结构控制算法结合ARM进行控制器的设计,从而实现多性能指标的优化。首先,利用从现场取得的数据计算并建立出甲醇精馏加压塔的数学模型,并在Simulink中搭建基于滑模变结构控制算法和传统PID算法的温度控制系统仿真模型。滑模变结构控制算法可以根据反馈值大小及变化快慢来产生不同的控制作用,这样可以根据控制作用分别在温度变化的不同阶段对控制系统有不同的操作。使温度变化过程中的调节时间与超调量这两个性能指标同时得到了良好的动态优化。其次,为了解决滑模变结构控制算法容易产生抖振的现象,通过引入模糊算法组成变结构算法,模糊算法产生调节因子,将此调节因子和系统反馈差值作为滑模变结构控制器的输入,有效地解决了单一滑模变结构算法容易产生抖振的现象。最后,搭建了精馏加压塔的硬件模拟仿真电路。在仿真过程中,通过控制器中变结构算法的处理与计算,输出控制量给步进电机,用步进电机的转动模拟阀门开度的变化,从而使塔顶温度即液晶屏显示数据得到调整。根据两种仿真平台的仿真结果比较得出,将变结构控制算法应用在甲醇精馏塔温度控制过程中,能够满足生产过程中的稳态与动态特性以及强鲁棒性的要求,对于甲醇精馏生产过程有一定的指导意义,具有非常广阔的应用前景。
[Abstract]:In the process of methanol production, a lot of impurities will be produced in the synthetic methanol due to the limitation of various conditions in the process. Therefore, it is necessary to treat the crude methanol by rectifying it and turn the crude methanol into a high purity methanol product. However, the most important link in the distillation system is the distillation pressurized column, in which the stability and accuracy of the top temperature of the distillation pressurized tower is very important for the production of high quality methanol products. In this kind of temperature control system, the traditional control method is mainly accomplished by PLC and PID control algorithm. However, in the actual methanol distillation environment, in the face of this complex nonlinear system, the traditional control method is difficult to optimize the two dynamic performance indexes of temperature adjustment time and overshoot simultaneously. In order to solve this problem, the variable structure control algorithm combined with ARM is used to design the controller. Firstly, the mathematical model of methanol distillation pressurized column is established by using the data obtained from the field, and the simulation model of temperature control system based on sliding mode variable structure control algorithm and traditional PID algorithm is built in Simulink. The sliding mode variable structure control algorithm can produce different control effects according to the feedback value and the speed and speed of change, so the control system can be operated differently according to the control action at different stages of temperature change. In the process of temperature change, the two performance indexes, the adjusting time and the overshoot, are optimized dynamically. Secondly, in order to solve the problem that sliding mode variable structure control algorithm is easy to generate buffeting, by introducing fuzzy algorithm to form variable structure algorithm, fuzzy algorithm produces adjustment factor. This adjustment factor and the feedback difference of the system are used as input of the sliding mode variable structure controller, which effectively solves the problem that the single sliding mode variable structure algorithm is easy to generate buffeting. Finally, the hardware simulation circuit of distillation pressurizer is built. In the process of simulation, through the processing and calculation of the variable structure algorithm in the controller, the output control quantity is given to the stepper motor, and the valve opening change is simulated with the rotation of the stepping motor, so that the temperature of the tower top, that is, the display data of the LCD screen, is adjusted. According to the simulation results of the two simulation platforms, the variable structure control algorithm is applied to the temperature control process of methanol distillation column, which can meet the requirements of steady and dynamic characteristics and strong robustness in the production process. It has certain guiding significance for methanol distillation production process and has a very broad application prospect.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ223.121;TP273

【参考文献】