摘 要能源工业是国家经济发展命脉的所在，结合中国国情，煤炭行业的重要性依 然如此。老式选煤厂工作环境复杂，经常还会发生大大小小的问题。近年来，可 编程逻辑控制器因为它自身的可靠，物美价廉，适应各种复杂的工业环境与可扩 展性能好，同时随着科学技术的不断进步，PLC 在小型选煤厂也得到了广泛应用。72271

近些年来，随着世界一体化的不断发展，中国选煤行业也渐渐地开始学习并 运用国外的先进技术。本设计就希望通过研究三级皮带的传输问题，将 PLC 的 应用在解决老式三级皮带传输系统里存在的各种问题。

本文就首先介绍了小型选煤厂中 PLC 集控系统，通过介绍小型选煤厂在国 内外各种情况，尤其是皮带传输机的发展状况来说明本设计的必要性。其次介绍 了选煤厂三级皮带所需要用到的电路图以及各种器件的选用。然后将 PLC 控制 纳入到三级皮带控制系统里面来。具体介绍三级皮带集控系统的组成。画出三级 皮带集控系统的系统框图，接着通过一个 PLC 扩展模块接入皮带的各种保护。 最后调试三级皮带集控系统程序，解决可能遇到的一些问题，达到小型选煤厂三 级皮带控制系统所需要实现的功能。

本论文有图 18 幅，表 6 个，参考文献 25 篇。

毕业论文关键词: 选煤厂 三级皮带 PLC 控制 集控系统

Design of PLC Centralized Control System for Three Level Belt Protect in Small Coal Preparation Plant

Abstract The energy industry is vital to the economic development of the State, according to China's national conditions, the importance of the coal industry remains the same。 Vintage coal plant complex work environment, various problems often occur。In recent years, the programmable logic controller on account of its own reliable, attractive and reasonable price, suitable for all kinds of complex industrial environments and scalable performance。 With the progress of science and technology, PLC has been widely used in small coal preparation plant。

In recent years, with the development of globalization, China's coal industry has gradually started to learn and apply advanced technologies from other countries。 I hope that by studying the three level belt transmission, application of PLC to solve the problems in three levels belt transmission system。

This thesis first introduces the PLC in central control system of coal preparation plant。 By introducing a small coal preparation plant at home and abroad situation, especially the development of the belt conveyor to illustrate the necessity of this design。 Next introduced the circuit diagram and device of three level belt system in coal preparation plant used。 And then place the PLC control into the three level belt control system。 Follow on introduced the composition of the centralized control system on three level belt。 Draw the circuit diagram of this system, then switch in a PLC extension to protect belts。 Final commissioning three level belt of centralized control system and solve problems that you may have, reach the functionality that you need to implement the three level belt control system in small coal preparation plant。

This thesis has 18 figures，6 tables and 25 references。

Key words： Coal preparation plant Three level belt PLC control Centralized control system

目录

摘要 I

Abstract II

目录 III

1 绪论