城市小区恒压供水系统本科毕业设计（论文）-论文.doc

毕业设计 题 目 城市小区恒压供水系统 学生姓名 学 号 专业班级 指导教师 学 院 答辩日期 摘要 我国人口众多，每年所消耗的能量巨大。近年来，能源紧张影响到工业生产及人民生活。因此，节能降耗是保证工业和生活稳定发展的一项关键措施。然而，长期以来，我国自动化程度低用水行业的技术水平相对比较落后，经常导致用水高峰期用户用水的不稳定，水压较低，供水量低于需求量。小区居民的日常用水问题，设计一套基于的变频调速恒压供水系统 此变频调速恒压供水系统由PLC、变频器、压力变送器等组成，由一台变频器实现对三台水泵电机的软启动和变频调速，三台泵电机采用变频和工频循环运行方式，运行切换采用“先启先停”的原则。使用编程软件，设计偏差进行处理，从而控制变频器的输出电压和频率，进而改变水泵电动机的转速水泵出水口流量，实现管网压力的自动调节，使管网压力稳定在设定值附近 关键词：变频调速恒压供水可编程控制器 AFor the numerous population, much energy is consumed every year in our country．In recent years have affected the industrial production and peoples life.Therefore, energy saving and reduce the consumption is a crucial measure to guarantee industry and lifes stable development.However,since automation level is low ,for a long time,our country falls behind with the technical horizon comparison with water profession, users often appears with the instability of water in using water peak-hour,such as hydraulic pressure is low and the supply of water is measured below demand. According to the problem in using water designed a variable frequency speed-regulating constant pressure water-supply system with PLC . The water supply system consists of PLC,frequency converter and pressure transmitter etc.A frequency converter to realize three phase pump generators soft start and frequency control, three pump generators to comprise the circulating run mode of frequency conversion, operation switch adopts to the principle ofstart first stop first.using STEP7 Micro/WIN program software designed a control system with PLC .The control system can compare the measured pressure with the advanced pressure , to control the real-time output Voltage and frequency.the output quality of pump is changed along with the changing of pumps speed.It makes the pressure of pipe self-regulating and steady in the scheduled value,and have designed a operation management interface using Supervision Control and Data Acquisition. Key Words：va