PLC无塔供水系统的设计.doc

目 录 中文摘要··········································Ⅰ 英文摘要··········································Ⅱ 前言 课题设计任务及要求·························1 §1.1 设计主要内容······························1 §1.2 设计要求··································1 §1.3 设计主要工作······························1 第二章 无塔供水系统的介绍·························3 §2.1 变频调速恒压供水系统简介·················3 §2.2 变频调速的节能、调速原理··················4 第三章 无塔供水系统的设计·························6 §3.1 系统的设计方案论证························6 §3.2 工艺过程分析······························6 §3.3 主电路的设计······························10 §3.4 控制柜的设计······························12 第四章 PLC控制的设计·····························14 §4.1 PLC的基本组成····························14 §4.2 可编程控制器的特点及应用··················15 §4.3 PLC的工作原理····························15 §4.4 PLC程序的设计····························16 §4.5 PLC程序的解释····························24 第五章 器件选择···································27 §5.1可编程控制器PLC的选择····················27 §5.2变频器的选择······························27 §5.3压力传感器的选择··························29 §5.4压力调节器的选择··························30 §5.4其它器件的选择····························30 结论·············································32 参考文献········································33 致谢·············································34 附录·············································35 无塔供水系统的设计 摘 要 本论文介绍了恒压供水的基本原理以及系统构成的基础，说明了可编程控制器（PLC）在恒压供水系统中所担任的角色，在分析了供水自动控制系统的发展现状和优点的基础上，结合我国中小城市楼宇供水的现状，从系统的整体设计方案和实际需求分析开始，紧密的联系实际生活的需要，力求做到使系统运行稳定，操作简便，解决实际中问题，保证供水安全、快捷、可靠。 基于上述分析设计了一套变频调速技术为基础的恒压供水系统。该系统综合运用了变频调速技术以及自动控制技术，为了提高恒压供水系统的控制精度和可靠性，所以设计中采用三台大功率电机驱动水泵在用水高峰期运行供水，在用水低谷时转化为两台小功率电机驱动水泵运行供水。供水方式为分组控制﹑轮流变频的控制策略。 变频恒压供水保证了供水质量，以PLC为主机的控制系统丰富了系统的控制功能，提高了系统的可靠性。因为此设计是基于用水量的变化，所以很可观的节省了水资源。 关键词： PLC，恒压供水系统，变频调速，节能 ABSTRACT This paper introduced the constant pressure water supply system and the basic principles constitute the basis that the programmable logic controller (PLC) in Water Supply System in the role, the analysis of water supply development of the automatic control syste