学士学位论文___基于plc的天然气调压站的智能监控系统设计.doc

基于PLC的天然气调压站的监控系统设计 摘 要 管道燃气供应以其方便、经济，安全等优点得到广泛应用，正逐步取代瓶装供气。燃气具有易燃、易爆的特点，为了保证燃气供应的安全并实现最佳调度，必须及时掌握系统运行状态，了解压力、流量、温度等数据。本天然气调压站智能监控正是基于以上需求的基础上研制而成的。、本文首先对调压站智能控制系统进行分析，确定系统的功能目标和性能要求，并提出调压站智能控制系统总体方案设计框架，本天然气站智能监控系统以CPU224XP控制核心，以传感器(压差传感器、温度传感器，压力传感器等)用来做检测元件，以电磁阀为执行机构．CPU不仅要分析处理判断从EM231送过来的模拟量转化数字信号，还要负责与流量计以及上位机的通信，实现对参数的控制和报警指示以及控制相关电磁阀的动作，从而实现调压站的智能监控． 关键词：天然气调压站，PLC，通信，智能监控，Modbus协议 ABSTRACT The supply of conduit gas spreads widely because of its advantages such as：convenience，economy,and safety etc,It gradually replaces the bottle packing gas．Gas is flammable and explosive．In order to ensure the safety of gas supply and realize the best adjustment，we must master the status of the system and datas such as pressure，flux，temperature in time，so the develpoment of the system is based on the need.CPU 224XP is used as controlling core of the system and the sensors as measuring component and the electromagnetic valves and the relaies as executive unit．CPU not only need to deal with analog signal from EM231，but also is responsible to communicate with flowmeter and master computer to complete the whole control mission，thus it realize the purpose of parameters controlling，warning instruction and controlling the action of related electromagnetism valve. firstly,the thesis analyse the significance of the intelligent supervision of the gas station．Confirms system function goals and performance parameters,and then putsforward the designing overall frame and dividing into functi