基于PLC程控输煤系统的设计与控制_毕业设计论文.doc

1绪论 PAGE 2 - 本科毕业设计(论文) 题目：基于PLC程控输煤系统的设计与控制 基于PLC程控输煤系统的设计与控制 摘 要 火力发电厂燃煤输送系统是保证电厂锅炉安全可靠运行的十分重要的支持系统，主要负责对发电机组燃煤的卸载、储存和上煤。如何保证设备运行的可靠性、减少操作人员与维护人员劳动强度、提高经济效益，成为一个值得研究的课题。 可编程逻辑控制器（PLC）是近年来发展极为迅速，应用面极广，以微处理器为核心，集微机技术、自动化技术、通信技术于一体的通用工业控制装置。它具有功能齐全、使用方便、维护容易、通用性强、可靠性高、性能价格比高等优点，已在工业控制的各个领域得到了极为广泛的应用，成为实现工业自动化的一种强有力工具。 本文基于西门子公司的S7-200型PLC，设计了程控输煤系统。各设备之间均实现了安全联锁保护控制功能：系统中的输煤电机启停是有着严格的控制顺序。起动时，为了避免在前段运输皮带上因煤料堆积而造成事故，系统要求逆煤料的流动方向按一定时间间隔顺序起动。停止时为了不使运输皮带上因残留煤料而造成事故，系统要求顺煤料流动方向按一定时间间隔顺序停止。PLC控制系统硬件设计布局合理，工作可靠，操作、维护方便，工作良好。用 PLC程控输煤程控系统，不但实现了设备运行的自动化管理和监控，提高了系统的可靠性和安全性，而且改善了工作环境，提高了企业经济效益和工作效率。因此PLC程控输煤系统具有一定的工程应用和推广价值。 关键词：锅炉；输煤系统；皮带运输机；可编程逻辑控制器；梯形图； Based On PLC,Program-controlled Coal Conveying System Abstract Thermal power plant coal conveying system is the guarantee of safe and reliable operation of the power plant boiler is very important support system, is mainly responsible for generating sets of coal unloading, storage and coal. How to ensure the reliability of equipment operation, reduce the operating and maintenance personnel the labor strength, improve the economic benefit, has become a topic worth studying. Programmable logic controller (PLC) is developing very rapidly in recent years, a wide application, microprocessor as the core, integrating microcomputer technology, automation technology and communication technology in the integration of general industrial control device. It has complete functions, convenient use, easy maintenance, strong commonality, high reliability, high ratio of performance to price, has been in the areas of industrial control is widely used and become a powerful tool to realize industrial automation. This article is based on Siemens S7-200 PLC, program-controlled coal conveying system is designed. Between various devices are realized safety interlock protection control function: the coal conveying system motor start-stop is fairly strict control sequence. When st