基于PLC的电厂输煤系统设计PLC300输煤系统设计

本科生毕业设计

学院：信息与电气工程学院

专业：电气工程与自动化

设计题目：基于PLC的电厂输煤系统设计专题：

任务下达日期：2012年2月20日

毕业设计日期：2012年2月20日至2012年6月15日

毕业设计题目：基于PLC的电厂输煤系统设计

摘要

输煤系统是电厂的重要组成部分，电厂输煤系统运作的性能关系到电厂生产效率以及工人的身体健康。由于早期的输煤系统设计自动化水平不高，人工作业量大，维护困难等缺点，因此与现代化工业需求不相适应。

本论文结合某电厂输煤系统来说明SIEMENS S7-300系列的PLC具有稳定性好、可靠性高、操作维护方便、抗干扰能力强、性价比高等优点。设置十六条皮带机互为备用，实现卸煤程序与给煤程序的顺煤流启动、逆煤流停车功能。系统设计八个燃料煤仓，对系统的锅炉及时加煤。通过选择多种适合的传感器，对整个系统的皮带机、煤仓以及现场进行故障信号采集并做出报警。通过将信号传送给PLC实现故障处理，使系统运行稳定、可靠。利用上位机对系统进行监控，使系统运行方便、快捷。利用PROFIBUS_DP通讯方式对系统进行通讯，设计一个主站五个从站，完成系统的通讯功能。

本文设计的基于PLC的输煤控制系统实现方案，最后通过模拟仿真实现PLC控制功能；先进的PLC技术和通讯技术，实现了系统简洁和功能完善。

关键词：输煤系统；报警；PLC

ABSTRACT

The coal transporting system is an important part of power plant. The performance of coal transporting system is closely concerned with the efficie ncy of the factory and workers’ health. As primitive coal transporting system has many disadvantages such as low level of primitive automation, large amount of work, Maintenance with a lot of difficulties and so on. It is not adaptable to the requirement of modern industry.

Coal transporting system of some certain coal factory in this paper is referred to illustrate the advantages of PLC of SIEMENS S7-300, such as good stability and reliability .convenient operation and maintenance, nice anti-interference capability and cost performance. Functions of unloading and providing coal like shunning coal flow start and inverse of coal flow parking is realized by fixing 16 alternative belt conveyors. 8 coal storehouses are established to promptly increase coal into the boiler .Alarming sound is given through opting for various appropriate sensors to this system which collect trouble signals at the point, and belt conveyors as well as coal storerooms of the whole system .All these signals are transmitted to help PLC with fault handing and make the system run stable and reliable .Transporting system is monitored by the principle computer to make the transporting system function easily and rapidly .To use PROFIBUS_DP communication style to communicate with the system .we design a primary station and five slave stations to fulfill the communication function.

The design programs in this article is based on PLC on the system of transporting coal and at last realize the controlling function ,through analogue stimulation. Advanced technology of PLC and communication fulfill concise system and function improvement.

Keywords：Coal handling system；alarm；PLC

目录

1 绪论 (1)

1.1研究基于PLC的电厂输煤系统设计的背景及意义 (1)

1.2输煤系统主要设计的内容 (2)

2 控制对象分析 (3)

2.1输煤设计系统工艺流程 (3)

2.2 控制对象分析 (3)

2.3系统设计概要 (4)

3 硬件设计 (5)

3.1传感器选型 (5)

3.3.1速度保护 (5)

3.3.2煤位保护 (5)

3.3.3跑偏保护 (6)

3.3.4烟雾保护 (7)

3.3.5温度保护 (8)

3.3.6撕带保护 (10)

3.3.7拉绳开关 (10)

3.3.8粉尘保护 (11)

3.3.9堆煤保护 (11)

3.2PLC硬件设计 (12)

3.2.1PLC选型 (12)

3.2.2PLC硬件组态以及端子接线 (15)

3.2.3符号表 (18)

3.3主回路和控制回路设计 (19)

3.3.1皮带的主回路与控制回路设计 (19)

3.3.2挡板电机设计 (21)

3.4系统结构设计 (22)

3.4.1系统工作流程图 (22)

3.4.2系统通讯功能 (24)

3.4.3系统工作方式 (25)

4 软件设计 (28)

4.1卸煤控制 (29)

4.2给煤控制 (30)

4.3挡板控制 (31)

5 监控设计 (33)

5.1监控系统概述 (33)