模糊理论在压缩机防喘振中的应用与研究

发布时间：2019-05-29 13:22

【摘要】：在化工生产中,离心式压缩机以其结构紧凑,转速高等特点一直是气力输送环节必不可少的机械设备,随着近年来国内化工行业向大产量、高智能的方向发展,离心式压缩机的应用更是得到了推广;但是“喘振”作为离心式压缩机所固有的一种特性却束缚了离心式压缩机的发展,“喘振”是一种当压缩机在某一小流量状态下工作时在叶轮和扩压器之间产生强烈的气流分离所引起的巨量震动,会对压缩机组造成很大的危害。传统的PID控制器在对压缩机的喘振控制上具有一定的局限性,其性能取决于参数的整定情况,且快速性和超调量之间存在矛盾。本文将利用模糊控制的概念,利用输入量和设定量之间的偏差及偏差的变化率构建二维的模糊控制器,提出新的控制方式。文章通过对上海焦化厂甲醇工段丙稀压缩机的运行状况分析,基于离心式压缩机运行的安全性和可靠性考虑,根据压缩机性能曲线推导了数学模型,采用模糊控制方法设计了防喘振模糊控制器,并用Matlab中的Simulink软件包对系统进行了仿真模拟,结果证明模糊控制能更好地解决喘振问题。本方案的最终目的是通过试验的方式验证模糊控制器能使压缩机脱离喘振的危险,通过对仿真结果中入口流量和回流阀开度的比照,所设计模糊控制器符合控制要求,达到了防止喘振发生的目的。
[Abstract]:In chemical production, centrifugal compressor has always been an indispensable mechanical equipment for pneumatic conveying because of its compact structure and high speed. With the development of domestic chemical industry in the direction of large output and high intelligence in recent years, The application of centrifugal compressor has been popularized. However, as an inherent characteristic of centrifugal compressor, surge restricts the development of centrifugal compressor. Surge is a kind of huge vibration caused by strong air separation between impeller and diffuser when compressor works in a small flow state, which will cause great harm to compressor unit. The traditional PID controller has some limitations in surge control of compressor. Its performance depends on the setting of parameters, and there is a contradiction between rapidity and overshoot. In this paper, a two-dimensional fuzzy controller is constructed by using the concept of fuzzy control, the deviation between input and setting quantity and the change rate of deviation, and a new control method is proposed. Based on the analysis of the operation status of C dilute compressor in methanol section of Shanghai Coking Plant, based on the safety and reliability of centrifugal compressor operation, the mathematical model is deduced according to the performance curve of the compressor. The fuzzy controller against surge is designed by using fuzzy control method, and the system is simulated by Simulink software package in Matlab. The results show that fuzzy control can better solve the surge problem. The ultimate purpose of this scheme is to verify that the fuzzy controller can free the compressor from the danger of surge through experiments. By comparing the inlet flow rate with the opening of the backflow valve in the simulation results, the designed fuzzy controller meets the control requirements. The purpose of preventing surge is achieved.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH452

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