PLC太阳能热水器自动控制系统设计论文.docx

密级:公开
密级:公开
密级:公开
密级:公开
基于PLC的太阳能热水器自动控制系统设计
Design of Solar Water Heater Automatic Control System Based on PLC
摘要
现在,城市居民绝大部分都使用了太阳能热水器,农村也有相当一部分人使用。太阳能热水器在技术上比较成熟、造价比较低廉,同时由于给人民提供绝对安全的热水而受到人们的欢迎,且具有节能、环保、安全、便利、长久等优点,所以它的应用会越来越广。因此,研究和开发先进的太阳能热水器控制系统变得越来越重要。
本设计阐述了可编程控制器(PLC)在太阳能热水器控制系统中的应用,重点研究了系统的硬件构成及软件的设计过程。指出了PLC设计的关键是能满足基本的控制功能,并考虑维护的方便性、系统可扩展性等。本设计利用西门子S7-200PLC,进行了太阳能热水器自动控制系统的I/O分配和PLC选型,编写了PLC程序梯形图和接线图,实现了自动上水排水、自动循环、自动加热、PID闭环控制恒温出水、手动与自动模式切换等功能。并在此基础上,利用S7-200的仿真软件对系统进行了仿真, Flexible软件组态了人机界面,使用MPI通信协议实现了PLC与触摸屏的通信连接。把可编程控制器PLC作为太阳能热水器的控制系统,增加了系统的方便性与可靠性,减少了其它元器件的使用。它使系统接线简单,检修维护方便快捷,增进了系统的先进性。
论文分为四章:第一章介绍了太阳能热水器发展背景及设计意义;第二章介绍了太阳能热水器的工作原理;第三章介绍了硬件选型及系统流程;第四章介绍了系统程序的编写、系统的仿真、人机界面( Flexible)组态过程。
关键词:太阳能热水器;PLC;自动控制系统
Abstract
Now, vast majority of urban residents use solar water heaters, so do a considerable number of rural people. Solar water heaters are technically more mature, relatively low cost. Meanwhile, since it provide absolute security to the people of hot and people are e, and it has some advantages of energy saving, environmental protection, safety, convenience, long, etc. So it will be widely applied. Therefore, the research and development of controlling system of advanced solar water heater are ing increasingly important.
This design expounds the application of PLC in solar water heater automatic controlling system, especially the designing process of hardware and software of the system. Furthermore, the project shows that the key of PLC designing is to satisfy the basic controlling function, considering the convenience of maintenance and scalability. In this design, the address of I/O is resigned and the suitable PLC is chosen. The electrical principle diagram and the interconnection diagram are drawn, according to the requirement. Automatic water drainage, automatic cycle, automatic heating, PID loop control temperature water, manual and automatic mode switching function have been realized. And on this basis, the system was