摘要：恒压供水系统是在用水量发生变化时，根据用水量的变化自动启动和停止电动机，及时有效保持水压恒定来满足用水要求。在恒压供水技术问世之前人们日常生活供水需要得不到合理的满足，具有可靠性能低、成本高等缺点。

本论文从节能环保角度出发，深入剖析生产运行特点，设计了基于PLC的恒压供水系统。根据提出的设计方案，将所研究的方案应用于实际生产过程中。论文详细介绍西门子PLC编程控制器、WinccFlexible以及EPLAN制图软件，就如何实现恒压供水系统控制，给出了详细的设计图纸、PLC控制程序、相应HMI过程画面。系统主要控制目标是根据水位变化，经过检测机构反馈液位变化，自动调整电机运转，实现恒压供水。90922

毕业论文关键词：恒压供水，自动控制，PLC

Abstract: Constant pressure water supply system is in the water changes, according to the change of water automatic start and stop the motor, the timely and effective to maintain a constant water pressure, water requirements。Before the advent of constant pressure water supply technologies need not reasonable to satisfy People's Daily life water supply, low has reliable performance and high cost of shortcomings。

This paper from the perspective of energy conservation and environmental protection, the production operation characteristics, deep insight into the constant pressure water supply system based on PLC is designed。According to the design of the proposed scheme, the scheme is applied to the study by the actual production process。Paper introduces Siemens PLC programming controller, Wincc Flexible and EPLAN mapping software, how to realize the constant pressure water supply control system, gives the detailed design drawings, the PLC control program and HMI corresponding process。System is the main control objectives according to the water level change,after the examination organization feedback level change, automatically adjust the motor running, realize the constant pressure water supply。

Key words: Automatic, Constant pressure, PLC

目录

1 绪论 5

1。1 设计背景 5

1。2 课题研究内容 5

2 恒压供水方案 5

2。1 主电路的设计 6

2。1。1 空气开关 7

2。1。2 接触器 7

2。1。3 热继电器 8

2。1。4 熔断器 9

2。1。5 开关电源 9

2。2 控制回路的设计 10

2。2。1 中间继电器 10

2。2。2 按钮开关与转换开关 11

2。3 编程控制器硬件电路 11

2。3。1 S7-200 12

2。3。2 液位测量机构 13

3