基于PLC的锅炉三冲量给水控制系统设计毕业设计 辽宁科技大学.docVIP

基于PLC的锅炉三冲量给水控制系统设计 摘要 锅炉三冲量给水控制系统在工业控制中是一个典型的控制系统。在锅炉三冲量给水控制系统中，汽包水位是影响锅炉安全运行的一个重要参数,汽包水位过高或者过低的后果都非常严重,因此对汽包水位必须进行严格控制。PLC技术的快速发展使得PLC广泛应用于过程控制领域并极大地提高了控制系统性能,PLC已经成为当今自动控制领域不可缺少的重要设备。本文从控制方案设计、PLC简介和系统软件设计几个方面进行介绍。并且分析影响汽包水位的各种因素出发,重点分析了锅炉汽包水位的“假水位现象”,提出了锅炉汽包水位控制系统的三冲量控制方案。本系统以西门子S7-300来实现锅炉汽包水位自动控制，按照工程整定的方法进行了PID参数整定,并进行了仿真研究。根据仿真结果曲线来看，系统的性能指标都达到了要求。PLC;锅炉;三冲量;汽包水位;PID控制 Design of Three- impulse Water Supply Control System of Boiler Based on PLC Abstract The three-impulse water supply control system of boiler is a typical control system in industrial control. In the three- impulse water supply control system of boiler, the steam drum water level is a very important parameter for the boiler safe operation. Both high and low steam drum water level may lead to extremely serious consequence; therefore steam drum water level must be strictly controlled. With the rapid development of PLC technology, PLC is widely applied to the process control domain and makes the performance of control system enhance enormously. PLC has already become the essential important equipment in automatic control domain. The control design, the introduction to PLC, and system software design are introduced in the paper. Also based on the analysis of all kinds of factors which influence steam drum water level, “unreal water level phenomenon” is analyzed specially, and three impulses control scheme of steam drum water level control system is proposed. Siemens S7-300 is adopted to realize automatic control of steam drum water level in the system. PID parameters are regulated by engineering regulation method, and simulation study is done. According to the simulation results, system performance meets the requirements. Key words: PLC; Boiler; Three Impulses; Steam Drum Water Level; PID Control 目 录 摘要 I Abstract II 1.绪论 1 1.1课题背景及目的和意义 1 1.2项目研究内容 2 2.控制方案设计 4 2.1汽包水位控制系统参数选择 4 2.2控制方案设计结构选择 4 2.2.1单冲量汽包水位控制系统 4 2.2.2双冲量汽包水位控制系统 5 2.2.3三冲量汽包水位控制系统 6 2.3前馈串级控制系统 7 2.3.1串级控制系统特点 7 2.3.2串级控制系