摘 要

电厂叶轮给煤机监控系统是火力发电厂的一个重要组成部分，是电厂内工作环境差，劳动强度大的一个系统。有效地提高电厂叶轮给煤机监控系统的自动控制和管理水平是国内众多电厂急待解决的问题。根据电厂的实际情况，在电厂叶轮给煤机监控系统自动化改造工程中一般采用可编程逻辑控制器 (programmable logic controller，简称PLC)实现对生产设备的自动检测与控制。再配以工业电视、模拟屏等辅助系统对输煤全线进行直接监视；采用自动广播系统实现报警及生产组织；利用上位计算机实现全面管理功能，完成对现场设备状态的显示和控制，以及智能化配煤、燃煤堆取计量、各种统计报表的生成以及与工业电视系统的联网。

本文基于S7-200系列PLC，本文在了解输煤流程和设备的基础上，通过输煤流程图和输煤皮带保护图统计出设备数目,进而统计所需I/O点的数目，进行PLC选型。介绍PLC在输煤控制系统中的应用，主要是通过输煤皮带控制、控制犁煤器抬起落下和叶轮给煤机控制来实现的，最后提出电厂叶轮给煤机监控系统的控制策略。从而改善了电厂的工作坏境，提高了电厂的工作效率。

整个系统为上下位机式结构，下位机采用PLC作主控制器，检测位置传感器和煤量传感器信号，进而控制给煤机的行走和定位，上位机采用个人电脑作为监控主机，设计组态界面，模拟给煤机在现场的工作运行状态，上下位机通过PROFIBUS现场总线完成通信。

关键词：电厂；叶轮；电厂叶轮给煤机监控系统；PLC

Abstract

Coal conveying system is an important part of thermal power plant. It is a system with poor working environment and high labor intensity.It is urgent to improve the automatic control and management level of coal conveying system in many thermal power plants in China.According to the actual situation of the power plant, the programmable logic controller (PLC) is generally used to realize the automatic detection and control of the production equipment in the automatic transformation project of coal conveying system.The auxiliary systems such as industrial television and analog screen are used to monitor the whole coal line directly. The automatic broadcasting system is adopted The system realizes alarm and production organization, uses the upper computer to realize the overall management function, accomplishes the display and control of the status of the field equipment, and intelligently compiles coal and measures the coal heaps.The generation of various statistical reports and networking with industrial television systems.

This paper is based on S7-200 series PLC, on the basis of knowing the coal transportation flow and equipment, this paper calculates the number of equipments through coal conveying flow chart and coal belt protection chart, and then counts the number of I / O points required, and makes PLC selection.This paper introduces the application of PLC in coal conveying control system, mainly through the control of coal conveyance belt, the control of coal plow lifting and falling and the control of impeller coal feeder. Finally, the control strategy of coal conveying system is put forward.Thus, the working condition of thermal power plant is improved and the working efficiency of thermal power plant is improved.

The whole system structure on the lower machine, the machine adopts PLC as the main controller, detection of position sensor and coal quantity sensor signal, then control for walking and positioning of the coal machine, PC using the personal computer as the host monitor, configuration interface design and Simulation of coal feeder in the running state of the field, the upper and lower machine communication by PROFIBUS bus.

Key words: power Plant; Impeller; Coal conveying system PLC

目   录

摘 要I

AbstractII

1绪论1

1.1 选题背景及意义1

1.2 电厂叶轮给煤机监控系统控制概述1

1.2.1电厂叶轮给煤机监控系统原理及特点1

1.2.2 电厂叶轮给煤机监控系统工艺要求2

1.3 国内外现状及发展趋势3

1.4研究主要内容4

2 电厂叶轮给煤机监控系统工艺流程5

2.1 电厂叶轮给煤机监控系统控制及主要设备6

2.1.1 卸煤控制及主要设备6

2.1.2 储煤控制及主要设备7

2.1.3 上煤控制及主要设备8

2.1.4 配煤控制及主要设备9

2.2 电厂叶轮给煤机监控系统皮带保护设备9

2.2.1 两级跑偏开关9

2.2.2 双向拉绳开关10

2.2.3 纵向撕裂检测装置11

2.2.4 溜槽堵塞检测装置11

2.2.5 打滑检测装置12

2.2.6 料流检测装置12

2.3 电厂叶轮给煤机监控系统其他保护辅助设备13

2.3.1 高低煤位检测装置13

2.3.2 电动挡板三通分料器14

2.3.3 电磁除铁器14

2.3.4 除尘设备14

2.3.5 料仓振动器14

2.3.6 碎煤机14

2.3.7 电子皮带秤15

2.4 电厂叶轮给煤机监控系统配煤、给煤设备15

2.4.1 犁煤器15

2.4.2 叶轮给煤机16

3 可编程控制器介绍18

3.1 可编程控制器概述18

3.2可编程控制器内部工作方式20

3.3 可编程控制器的应用22

3.4  西门子S7-200性能介绍23

4 电厂叶轮给煤机监控系统的软件程序设计25

4.1系统结构25

4.2 输煤工艺控制方案26

4.3 电厂叶轮给煤机监控系统的控制流程及要求27

4.4 电厂叶轮给煤机监控系统的控制方案设计27

4.4.1 控制系统的I/O点及地址分配27

4.4.2 PLC选型29

4.4.3 电厂叶轮给煤机监控系统程序及说明29

4.4.4 紫金桥组态仿真30

5 结论32

致 谢33

参考资料34

附 录35