摘要
随着我国社会经济的发展,住房制度改革的不断深入,人们生活水平的不断提高,城市中各类小区建设发展十分迅速,同时也对小区的基础设施建设提出了更高的要求。小区供水系统的建设是其中的一个重要方面,供水的经济性、可靠性、稳定性直接影响到小区住户的正常生活和工作,也直接体现了小区物业管理水平的高低。传统的恒速泵加压供水,水塔高位水箱供水,气压罐供水等供水方式普遍不同程度的存在效率低、可靠性差、自动化程度不高等缺点,难以满足当前经济生活的需要。
本论文针对某住宅小区的供水要求,设计了一套由PLC,变频器,多台水泵机组等主要设备构成的全自动变频恒压供水系统,具有全自动变频恒压运行,自动工频运行,系统有效地解决了传统供水方式中存在的问题,增强了系统的可靠性。并和计算机实现了有机的结合,提升了系统的总体性能.
论文论述了采用多泵并联供水方案的合理性,分析了多泵供水方式的各种供水状态及转换条件,分析了电机由变频转工频运行方式的切换过程。给出了实现有效状态循环转换控制的电气设计方案和PLC控制程序设计方案。
关键词：恒压供水;PLC;变频调速
ABSTRACT
Along with the development of the socio—economy of our country the housing system is going deep into reforms, and people's living standard is being impr0Ved.At the same time, in the city, each kind of sub—district construction is developing Very quickly, which puts f10rward higher requirement for the infrastructure construction of sub-district. And the construction of sub-district water supply system is an important aspect in which. The reality stability and economy of water supply directly affects sub—district household’s normal life and work, and also embodies the difference in the level of sub-district property management. The traditional means of water supply such as the pump pressurization water supply at constant speed, water tower of upper cistern, the jar etc .are hard to satisfy the needs of are economic life, because low efficiency, reliability and automation level all commonly existing in these means.
According to the requirement of water supply in abiding place of Lan Zhou, a set of automatic system of constant pressure water supply by using composed variable frequency and remote monitoring and controlling, which is composed of PLC, transducer pressure electro—motors ,computer and device of communication is designed to constant that end. This set of system has the functions like automatic constant pressure operation by using Variable frequency, automatic work frequency operation, and the function of long-range control by hand and the on-the—spot control by hand etc. The system has solved efficiently the problem existing in the traditional way of water supply, which has various supplementary functions to strengthen the reliability. The system has an organic combination with computer and promotes the systematic overall performance.
This paper discusses the reasonability of water supply scheme with much pump parallel connection, and analyses the conversion condition and the various states of water supply of the much pump way of water supply problem of a as well as the switch process and the problem generator from Variable frequency operation mode to work frequency .This paper has also given the electrical operation mode. design
scheme and PLC controlling program scheme that realizes electrical state circulating conversion control. By researching the communication agreement between the computer and PLC, this paper has finished setting up the communication between upper and lower computer, and also has described the method to compile computer monitoring program to realize the 10ng—range monitoring and fault reporting for water supply system through communication modular
Keywords: Constant pressure water-supply; PLC; Variable Velocity Variable frequency;
目录
摘要 .................................................................................................................................................. 1 ABSTRACT ...................................................................................................................................... 2 1 绪论 .............................................................................................................................................. 6
1.1课题背景 ............................................................................................................................. 6
1.2 变频恒压供水系统的国内外研究现状 ............................................................................ 7
1.2.1 变频恒压供水系统的国内外研究与现状 ........................................................... 7 1.2.2 变频调速技术的国内外发展与现状 ................................................................... 8 1.3 本课题的主要研究内容 .................................................................................................... 9 2 系统的理论分析及控制方案确定 ............................................................................................. 10
2.1 变频恒压供水系统的理论分析 ...................................................................................... 10
2.1.1 电动机的调速原理 ............................................................................................. 10 2.1.2 变频恒压供水系统的节能原理 ......................................................................... 10 2.2 变频恒压供水系统控制方案的确定 ............................................................................. 13
2.2.1控制方案的对比和确定 ...................................................................................... 13 2.2.3 变频恒压供水系统控制流程 ............................................................................. 16 2.2.4频恒压供水系统中加减水泵的条件分析 .......................................................... 17 3系统主电路设计 .......................................................................................................................... 19
3.1 系统主电路结构 ............................................................................................................. 19
3.2系统主电路工作原理 ...................................................................................................... 20 4 控制系统的硬件设计 ................................................................................................................. 21
4.1系统的硬件结构 ............................................................................................................... 21 4.2 PLC概述 .......................................................................................................................... 21
4.2.1 可编程控制器的定义 ........................................................................................... 21 4.2.2 PLC的发展和应用 ............................................................................................ 21 4.2.3 PLC的工作原理 .................................................................................................. 22 4.2.4欧姆龙CP1H的特点 .......................................................................................... 23 4.2.5 CP1H 的功能介绍 ............................................................................................... 24 4.3 PID控制器 ....................................................................................................................... 26 4.4变频器概述 ...................................................................................................................... 27
4.4.1 变频器的基本结构 ............................................................................................. 27 4.4.2 变频器的分类 ..................................................................................................... 28 4.4.3 变频器的接线及参数 ......................................................................................... 29 4.5 压力传感器的选择 ......................................................................................................... 29 4.6 元器件的选择 ................................................................................................................. 30 4.7 PLC的选型 ...................................................................................................................... 31 4.8 系统控制电路的设计 ..................................................................................................... 32 4.9 PLC的I/O端口分配 ...................................................................................................... 32 5控制系统的软件设计 .................................................................................................................. 35
总结与展望..................................................................................................................................... 37 致谢 ................................................................................................................................................ 38 附录 ................................................................................................................................................ 39 参考文献......................................................................................................................................... 40