PLC电厂输煤系统本科设计.doc

本科毕业论文（设计） PLC电厂输煤系统 XXX The PLC control of coal handling system in power plant 论文题目 ： PLC电厂输煤系统 摘 要 输煤系统是整个火电厂发电系统中的一个主要组成部分，通常包括堆煤、卸煤、带式输送、碎煤、除铁、除尘等过程。传统的输煤系统控制主要采用继电器、接触器控制，其有机构复杂，不易改动，抗干扰性差等缺点。随着火电厂的发展，传统的控制已不能满足要求，但PLC的出现很好的解决了这些问题。 本文主要讨论输煤系统中的皮带控制。由于整个输煤系统中包含很多个过程，必须将整个皮带系统分为好几段。这样里面对皮带最关键的一个要求就是必须要让皮带从后到前顺序启动，然后从前到后顺序停止。采用PLC能够很好的解决这个过程，我们只需将程序按照所需要求写好，然后导入PLC中便可，一旦整个系统出现问题我们只需对程序稍加修改，而不用像传统的控制那样，将整个线路推到重来。在整个过程中，PLC也具有良好的抗干扰性和准确性。 关键词：输煤系统；皮带控制；PLC；西门子S7-200 Abstract Coal handling system is a major component of the thermal power plant electricity generation system.It typically includes these process of a pile of coal, coal unloading, conveying belt, pulverized coal, iron removal and so on.The traditional control of coal handling system mainly uses the relays,contactors to control.It has many defecs such as it has a complex mechanism so it is not easy to change,and its anti-interference is bad.With the development of thermal power plant,the traditional control can not meet the requirements.But these problems hasbe well solved by the emergence of PLC. This paper mainly discusses the coal handling belt control. Because of the coal handling system includes many processes,So should take it divided into several segments.The key request for the belt is how to get the belt from the posterior to the anterior boot sequence, and then used to sequence stop.Using PLCcan solve this process easily.We will simply write the program according to the requirement,then import it intothe PLC. We only need to slightly modify theprogram when the whole system arise problems,instead of traditional control must change the whole line.In the process, PLC also has a good robustness and accuracy. Key words:Coal handling system;Belt control;PLC;Siemens S7-20 目 录 TOC \o 1-2 \h \u HYPERLINK \l _Toc23020 引 论 1 HYPERLINK \l _Toc16908 1 课题的来源与意义 1 HYPERLINK \l _Toc12515 1.1 课题的来源 1 HYPERLINK \l _Toc31525 1.2 课题研究的目的及意义 2 HYPERLINK \l _Toc29373 1.3 课题研究现状 2 HYPERLINK \