PLC在变频调速恒压供水系统中的应用[精品].doc

PLC在变频调速恒压供水系统中的应用 摘 要 变频恒压供水系统是现代建筑中普遍采用的一种水处理系统，随着变频调速技术的发展和人们节能意识的不断增强，变频恒压供水系统的节能特性被广泛地应用于住宅小区、高层建筑的生活及消防供水系统。 本课题满足了变频恒压供水系统中的基本要求，是由储水系统、动力系统，回水系统和控制系统组成。它利用流量与转速成正比的关系来实现节能，即当需求的压力降低时，电动机转速降低，泵出口流量减少，电动机的消耗功率大幅度下降，从而达到节能的目的。 控制系统采用手动和自动两种控制方式，在自动控制器失效的状态下，用手动控制系统也能保证系统地可靠运行。在系统投入自动运行前，手动控制还可用于检验动力线路和动力设备的工况。在有变频和工频两种运行状态的设备间，采用机械互锁和逻辑互锁的双重保护设计，以保障设备的安全运行；该系统同时采用过载保护、漏电保护、接地保护等多重保护机制，充分保障了操作者的人身安全和设备的运行安全。 关键词: 恒压供水，变频调速，PLC，泵机切换 PLC in the frequency control water supply system ABSTRACT Constant pressure water supply system is widely used in modern construction of a water treatment system, with frequency conversion technology and the growing awareness of people to save energy, constant pressure water supply system, energy-saving features are widely used in residential quarters, the lives of high-rise buildings and fire water systems. The subject of Constant Pressure Water Supply System to meet the basic requirements, is a water storage system, power system, return water system and control system composition. It uses the relationship between flow and speed is proportional to energy saving, that is, when demand pressure is reduced, the motor speed decreased and the pump flow decreased significantly decrease the power consumption of the motor to save energy. Control system with manual or automatic control mode, in automatic failure of the state controller, with manual control system can guarantee the system to reliable operation. Frequency in a frequency and operating status of the equipment of two, the use of mechanical interlocking and interlocking logic of the dual protection designed to protect the safe operation of equipment; the system simultaneously with overload protection, leakage protection, ground fault protection of multiple protection mechanisms such as fully protect the operators personal safety and the safe operation of equipment. KEY WORDS:constant pressure water supply, frequency control, PLC 目 录 前 言 5 第一章 绪论 6 1.1 本课题设计的背景 6 1.2 本课题设计的内容 7 1.2.1